Cover.

Top: Surface water entering Cripple Crawfish sinkhole as recharge to the Barton Springs segment of the Edwards


aquifer (photograph provided by Nico Hauwert, City of Austin).


Left: Well MCH (State well YD–58–50–704), one of the wells used for this report (photograph by Venezia Chavez, U.S.


Geological Survey).


Right: Main Spring, a major discharge point for the Barton Springs segment of the Edwards aquifer; Main Spring


discharges through fractured limestone.

Relation of Specific Conductance in Ground 

Water to Intersection of Flow Paths by 

Wells, and Associated Major Ion and 

Nitrate Geochemistry, Barton Springs 

Segment of the Edwards Aquifer, 

Austin, Texas, 1978–2003 

By Bradley D. Garner and Barbara J. Mahler 

In cooperation with theCity ofAustin 

Scientific Investigations Report 2007–5002 

U.S. Department of the Interior 

U.S. Geological Survey 
U.S. Department of the Interior 

DIRK KEMPTHORNE, Secretary 

U.S. Geological Survey 

Mark D. Myers, Director 

U.S. Geological Survey, Reston, Virginia: 2007 

For sale by U.S. Geological Survey, Information Services
 

Box 25286, Denver Federal Center
 

Denver, CO 80225
 

For more information about the USGS and its products:
 

Telephone: 1-888-ASK-USGS
 

World Wide Web: http://www.usgs.gov/
 

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply
 

endorsement by the U.S. Government.
 

Although this report is in the public domain, permission must be secured from the individual copyright owners to
 

reproduce any copyrighted materials contained within this report.
 

Suggested citation: 

Garner, B.D., and Mahler, B.J., 2007, Relation of specific conductance in ground water to intersection of flow paths by 

wells, and associated major ion and nitrate geochemistry, Barton Springs segment of the Edwards aquifer, Austin, 

Texas, 1978–2003: U.S. Geological Survey Scientific Investigations Report 2007–5002, 39 p., 5 appendixes. 
iii 

Contents 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
 

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
 

Purpose and Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
 

Description of the Barton Springs Segment of the Edwards Aquifer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
 

Karst Aquifer Geochemistry and Its Relation to the Barton Springs Segment . . . . . . . . . . . . . . . . . . . . . . . . . . 5
 

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
 

Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
 

Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
 

Data Sources and Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
 

Water-Quality Sample Collection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
 

AnalyticalMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
 

Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
 

Specific Conductance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
 

AnalyticalMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
 

Data Screening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
 

Specific Conductance Related to Intersection of FlowPaths byWells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
 

Specific Conductance Variability at the Event Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
 

Correlation Between Specific Conductance, Streamflow, and Spring Discharge . . . . . . . . . . . . . . . . . . . . . 11
 

Specific Conductance Negatively Correlated With Streamflow and Spring Discharge . . . . . . . . . . 11
 

Specific Conductance Negatively Correlated With Streamflow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
 

Specific Conductance Positively CorrelatedWith SpringDischarge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
 

Specific Conductance Not Correlated With Streamflow or Spring Discharge . . . . . . . . . . . . . . . . . . . 15
 

Synthesis—Intersection of Flow Paths byWells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
 

Major Ion Geochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
 

Major Ion Geochemistry of 26 Wells by Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
 

Relation Between Major Ion Geochemistry and Intersection of Flow Path by Wells . . . . . . . . . . . . . . . . . . 23
 

Mixing of Edwards Aquifer Water With Trinity Aquifer Water and Saline Zone Water . . . . . . . . . . . . . . . . 28
 

Geographic Patterns Relative to Major Ion Geochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
 

Nitrate Geochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
 

Comparison of FindingsWith Those of Other Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
 

Value of Statistical Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
 

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
 

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
 

Appendixes
 

1.	 Specific Conductance Data—Specific conductance data for samples from wells in the
 

Barton Springs segment of the Edwards aquifer and corresponding maximum 10-day 
 

streamflow for the five creeksand maximum10-day discharge for Barton Springs, Austin,
 

Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
 

2.	 Discharge Data—Daily mean streamflow for the five creeks providing recharge to the
 

Barton Springs segment of the Edwards aquifer and dailymean discharge forBarton
 

Springs,Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
 

3.	 Results of Statistical Correlation Tests—Results of Spearman’s rho correlation tests for 
 

samples fromwells in the Barton Springs segment of the Edwardsaquifer, Austin, Texas,
 

1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
 
iv 

4.	 Major Ion and Nitrate Water Analysis Data—Charge balanced major ion and nitrate water 
 

analysisdata fromwells in the Barton Springs segment of the Edwards aquifer, Austin, 
 

Texas, 1978–2003. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
 

5.	 Quality Assurance Data—Quality assurance data, Barton Springs segment of the
 

Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
 

Figures 

1.	 Map showing location of Barton Springs segment of the Edwards aquifer, Austin, Texas,


 major creeks, and data-collection sites, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
 

2.	 Schematic diagram of Barton Springs segment of the Edwards aquifer, Austin, Texas . . . . . . . . . . . . . 4
 

3.	 Graph showing specific conductance at well SVW and streamflow in Barton and 
 

Williamson Creeksduringseveral days following a rain event, Barton Springs segmentof
 

the Edwardsaquifer, Austin, Texas, October 1994 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
 

4.	 Map showing wells grouped on the basis of negative, positive, or no significant correlation
 

between ground-water specific conductance and streamflowor Barton Springs discharge,
 

or both, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . 12
 

5.	 Graphs showing specific conductance at well FMW as a function of (A) maximum 10-day 
 

streamflow of SlaughterCreek and (B) maximum10-day discharge ofBartonSprings,Barton
 

Springs segment of the Edwards aquifer,Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
 

6.	 Schematic diagram of conceptual model of the Barton Springs segment of the Edwards 
 

aquifer, Austin, Texas, showing wells and hypothesized controls on water at the wells . . . . . . . . . . . 16
 

7.	 Trilinear diagram showing relations between compositions of major ions in water sampled 
 

from Main Barton Spring (1987–96) and wells completed in the saline zone of the Edwards
 

aquifer and the underlying Trinity aquifer(1978–2003), Austin, Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
 

8.	 Trilinear diagram and graphs showing geochemistry for wells in Group C1 (specific 
 

conductance negatively correlatedwith both streamflowand spring discharge), Barton
 

Springs segment of the Edwards aquifer,Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
 

9.	 Graphs showing sulfate concentration at well SVE as a function of (A) maximum 10-day 
 

streamflow of SlaughterCreek and (B) maximum10-day discharge ofBartonSprings,Barton
 

Springs segment of the Edwards aquifer,Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
 

10.	 Trilinear diagram and graphs showing geochemistry for wells in Group C2 (specific 
 

conductance negatively correlatedwith streamflow only),Barton Springs segment of
 

the Edwardsaquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
 

11.	 Trilinear diagram and graphs showing geochemistry for wells in Group P (specific 
 

conductance positively correlatedwith spring discharge),BartonSprings segment of
 

the Edwardsaquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
 

12.	 Graph showing sulfate concentration at well FOW relative to maximum 10-day discharge of
 

Barton Springs, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . 28
 

13.	 Trilinear diagram and graphs showing geochemistry for wells in Group N (specific 
 

conductance not correlated with either streamflow or spring discharge), Barton
 

Springs segment of the Edwards aquifer,Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
 

14.	 Graphs showing nitrate nitrogen concentration relative to specific conductance for samples 
 

fromwells in (A) Group C1 (specific conductance negatively correlatedwithboth streamflow
 

and spring discharge), (B) Group C2 (specific conductance negatively correlated with
 

streamflow only), (C) Group P (specific conductance positively correlatedwith spring
 

discharge), and (D) Group N (specific conductance not correlated with either streamflow
 

or spring discharge), Barton Springs segment of the Edwards aquifer,Austin, Texas,
 

1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
 
v

15. Boxplots showing distribution of nitrate nitrogen concentrations for wells in Group C1 

(specific conductance negatively correlated with both streamflow and spring discharge), 

in Group C2 (specific conductance negatively correlated with streamflow only), in Group P 

(specific conductance positively correlated with spring discharge), and in Group N (specific 

conductance not correlated with either streamflow or spring discharge), Barton Springs 

segment of the Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

16. Graph showing relation between the number of specific conductance measurements at 

a well and the range of specific conductance at that well, Barton Springs segment of the 

Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Tables

1. Wells sampled, range of sampling dates, and number of analyses available for each 

well, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . 6

2. Coefficient of variation (Cv) for specific conductance of wells, Barton Springs segment 

of the Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3. Spearman’s rho for significant (p < .05) correlations between ground-water specific 

conductance and streamflow and between ground-water specific conductance and Barton 

Springs discharge, for wells grouped on the basis of negative, positive, or no significant 

correlation, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . 14

4. Summary of findings regarding intersection of flow paths by wells and Edwards aquifer 

water mixing with water from Trinity aquifer and saline zone, Barton Springs segment of the 

Edwards aquifer, Austin, Texas, 1978–2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Conversion Factors, Abbreviations, and Datum 

Abbreviations: 

microsiemens per centimeter at 25 degrees Celsius, μS/cm

milligram per liter, mg/L

Datum 

Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27).

Multiply By To obtain

Length

Inch/Pound to SI 

cubic foot per second 0.02832 cubic meter per second 

foot 0.3048 meter

gallon per year 0.003785 cubic meter per year

mile per day 1.609 kilometer per day

SI to Inch/Pound 

micrometer 3.937 x 10-5 inch
Blank Page 
Relation of Specific Conductance in Ground 

Water to Intersection of Flow Paths by 

Wells, and Associated Major Ion and 

Nitrate Geochemistry, Barton Springs 

Segment of the Edwards Aquifer, 

Austin, Texas, 1978–2003

By Bradley D. Garner and Barbara J. Mahler

Abstract

Understanding of karst flow systems can be complicated 

by the presence of solution-enlarged conduits, which can transmit large volumes of water through the aquifer rapidly. If the 

geochemistry at a well can be related to streamflow or spring 

discharge (springflow), or both, the relations can indicate the 

presence of recent recharge in water at the well, which in turn 

might indicate that the well intersects a conduit (and thus a 

major flow path). Increasing knowledge of the occurrence and 

distribution of conduits in the aquifer can contribute to better 

understanding of aquifer framework and function. To that end, 

26 wells in the Barton Springs segment of the Edwards aquifer, 

Austin, Texas, were investigated for potential intersection with 

conduits; 26 years of arbitrarily timed specific conductance 

measurements in the wells were compared to streamflow in five 

creeks that provide recharge to the aquifer and were compared 

to aquifer flow conditions as indicated by Barton Springs discharge. A nonparametric statistical test (Spearman’s rho) was 

used to divide the 26 wells into four groups on the basis of correlation of specific conductance of well water to streamflow or 

spring discharge, or both. Potential relations between conduit 

intersection by wells and ground-water geochemistry were 

investigated through analysis of historical major ion and nitrate 

geochemistry for wells in each of the four groups. Specific 

conductance at nine wells was negatively correlated with both 

streamflow and spring discharge, or streamflow only. These 

correlations were interpreted as evidence of an influx of surface-water recharge during periods of high streamflow and the 

influence at the wells of water from a large, upgradient part of 

the aquifer; and further interpreted as indicating that four wells 

intersect major aquifer flow paths and five wells intersect minor 

aquifer flow paths (short, tributary conduits). Specific conductance at six wells was positively correlated with spring discharge, which was interpreted as not intersecting a flow path 

(conduit). Of the 11 wells for which specific conductance did 

not correlate with either streamflow or spring discharge, no 

interpretations regarding flow-path intersection by wells 

were made. In some cases, specific conductance data might not 

have indicated intersection with a flow path because of small 

sample sets. Water in the Barton Springs segment generally is a 

calcium-magnesium-bicarbonate type, although some water 

compositions deviate from this. Multiple geochemical processes were identified that might affect geochemistry at the 

wells, but in general the geochemical composition of ground 

water, except for dilution by surface-water recharge, was not 

related to intersection of a well with a flow path. Some samples 

from wells indicate inflow of water from the saline zone to the 

east; this inflow is associated with low streamflow and spring 

discharge. Other samples indicate that the aquifer at some wells 

might be receiving water that has been in contact with rocks of 

the Trinity aquifer; this mixing is most evident when spring discharge is high. Occurrence of nitrate in ground water was unrelated to intersection of flow paths by wells and appeared to be 

the result of localized contamination. However, most of the 

wells with one or more samples contaminated by nitrate are in 

the more densely populated parts of the study area. 

Introduction

Understanding of karst aquifer flow systems can be complicated by the presence of solution-enlarged conduits. If 

present, conduits can transmit large volumes of water through 

the aquifer rapidly and likely constitute the major flow paths. 

Some water in conduits can be recent surface-water recharge, 

and this recharge can have a markedly different geochemical 

signature than longer-residence-time ground water. As such, 
2 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

ground water at wells that intersect conduits (and thus major 

flow paths) can be characterized by temporally variable 

geochemistry that is related to surface-water processes. If the 

geochemistry at a well can be related to streamflow or spring 

discharge (springflow), or both, the relations can indicate the 

presence of recent recharge in water at the well, which in turn 

might indicate that the well intersects a conduit. Increasing 

knowledge of the occurrence and distribution of conduits in the 

aquifer can contribute to better understanding of aquifer framework and function. 

In the Barton Springs segment of the Edwards aquifer at 

Austin, Tex. (fig. 1), temporal variability of geochemistry at 

wells has been documented previously (Andrews and others, 

1984; City of Austin, 1997). From 1978 through 2003, the 

U.S. Geological Survey (USGS), in cooperation with the City 

of Austin, sampled wells in the aquifer for a variety of waterquality constituents. For this report, the USGS, again in cooperation with the City of Austin, analyzed this historical waterquality dataset and contemporaneous datasets of streamflow 

and spring discharge to identify wells that intersect conduits.

Purpose and Scope

The primary purpose of this report is to identify wells that 

intersect conduits (major flow paths) in the Barton Springs segment of the Edwards aquifer by relating the geochemistry of 

water (specifically the geochemical signature of recent surfacewater recharge) at wells to streamflow and spring discharge. A 

secondary purpose is to determine whether major ion geochemistry, which can indicate geochemical processes and other 

sources of water in addition to recent recharge, is related to 

intersection of flow paths by wells; a third purpose is to determine whether nitrate nitrogen occurrence is related to intersection of flow paths by wells. The data also yield information that 

allows hypotheses about which wells might intersect minor or 

tributary flow paths. The datasets used for the analysis, collected by the USGS from 1978 through 2003, comprise specific 

conductance, major ion, and nitrate data collected from 26 

wells, streamflow from five creeks that provide recharge to the 

Barton Springs segment of the Edwards aquifer, and spring discharge from Barton Springs. The principal tool used to hypothesize recent recharge in the water, and thus the intersection of a 

well with a conduit, was correlation of specific conductance of 

water at wells with streamflow and spring discharge. Major ion 

geochemistry provided evidence to identify sources of water at 

the wells other than recent recharge, and nitrate geochemistry 

also was used to evaluate potential sources of nitrate. 

Description of the Barton Springs Segment of the 

Edwards Aquifer

The Barton Springs segment of the Edwards aquifer (hereinafter, the Barton Springs segment) is a karst aquifer that 

extends south-southwest of Austin. It is bounded on the north 

by the Colorado River (Town Lake in Austin), on the south by 

a ground-water divide, on the west by with the fault-controlled 

outcrop of the Trinity aquifer, and on the east by a zone of low 

permeability containing saline water (greater than 1,000 milligrams per liter [mg/L] dissolved solids concentration) known 

as the saline zone (fig. 1) (Abbott, 1975; Sharp and Banner, 

1997; Slade and others, 1986).

Previous studies have characterized the lithology, structure, and physical and chemical hydrogeology of the Barton 

Springs segment. The aquifer material primarily is limestone of 

Cretaceous age that has undergone multiple episodes of karstification (Maclay, 1995; Rose, 1972; Small and others, 1996). In 

the Miocene Epoch, tectonic activity caused faulting, which 

enhanced karstification and affected the aquifer structure that 

exists today (Slade and others, 1986). The aquifer generally is 

highly transmissive, with some measured straight-line transit 

times exceeding 6 miles per day (Hauwert and others, 2004). 

The Barton Springs segment comprises rocks of the Edwards 

Group and Georgetown Formation, as shown in the correlation 

chart in figure 2. In the recharge zone, which is essentially coincident with the outcrop of the aquifer, the aquifer is unconfined. 

Water in the Barton Springs segment generally is a 

calcium-bicarbonate (Ca-HCO3) to calcium-magnesiumbicarbonate (Ca-Mg-HCO3) type that contains less than 

500 mg/L dissolved solids, although appreciable variation in 

dissolved constituents and molar ratios have been observed 

(Senger and Kreitler, 1984). Studies such as Andrews and 

others (1984) have shown that some geochemical variability is 

attributable to episodic recharge of meteoric water in response 

to storms.

About 85 percent of the recharge to the aquifer is estimated 

to occur through karst features (fractures, faults, and sinkholes) 

in the beds of Barton, Williamson, Slaughter, Bear, and Onion 

Creeks (Slade and others, 1986), ephemeral creeks that cross 

the recharge zone from the west to the east (fig. 1). Additional 

potential sources of recharge include interstream infiltration 

through sinkholes and fractures, urban infrastructure, the saline 

zone, and the Trinity aquifer (Sharp and Banner, 1997). Flow in 

the aquifer generally is to the north-northeast, although direction of flow varies with changes in aquifer flow conditions and 

resulting changes in the potentiometric surface (Slade and 

others, 1986).

Discharge from the aquifer is from springs and wells. The 

primary discharge point is Barton Springs, which comprises 

several orifices. Combined long-term mean discharge from the 

three major orifices is about 50 cubic feet per second (Slade and 

others, 1986). Additional discharge is from domestic, livestock, 

and public-supply wells. In 2004 there were an estimated 970 

active wells in the Barton Springs segment, which accounted for 

withdrawals of about 2.5 billion gallons per year (Smith and 

Hunt, 2004), or a continuous average discharge of about 11 

cubic feet per second. 
Introduction 3

Figure 1. Location of Barton Springs segment of the Edwards aquifer, Austin, Texas, major creeks, and data-collection sites, 1978–2003.

Austin

TEXAS

Williamson

Creek

Slaughter

Creek

Creek

Bear

Creek

Onion

COLORADO

RIVER

Shoal

Creek

TOWN

LAKE

Creek

Barton

Little Bear

Creek

LAKE

 AUSTIN

TRAVIS COUNTY

HAYS COUNTY

TRINITY AQUIFER

97o

97 45' o

52'30"

30o

22'30"

98

o

30o07'30"

30o

15'

5 KILOMETERS

0 5 MILES

0

Saline

zone

boundary

Ground-water

divide

AUSTIN

08155200

08158920

08158840

08158810

08158700

08158922

08155240

Edwards aquifer recharge zone

Edwards aquifer confined zone

Well and identifier—

Referenced in table 1

U.S. Geological Survey gaging station

Streamflow and number

Spring discharge of Barton Springs at

Austin, Tex. (08155500)

EXPLANATION

SNL

08158840

Barton

 Springs

Base modified from Texas Natural Resources Information

System (TNRIS) digital data, 2005, 1:24,000

Albers equal area conic projection, NAD27

Barton Springs segment of the

Edwards aquifer modified from

Slagle and others, 1986

ROL

JBS

SNL

RAB

SVN

SVE

SVS

SVW

WGF

BCK

KCH

FMW

FOW HWD

HND

PLS

MCH

SLR

GHW TNR

BDW

LWK

BPS

WBG

ISD

CNE
4 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Upper confining unit

Edwards aquifer

Trinity aquifer

Solution-enlarged conduit

Flow direction

EXPLANATION

Infiltration and

recharge

Generalized

flow direction

Preferential flow

along solution-enlarged

conduits

Discharge at 

Barton Springs

Water flows across the surface exposure of Trinity aquifer rocks toward the recharge zone. Over the recharge zone, water

enters the aquifer through the beds of creeks. Water in the aquifer flows north-northeast, likely along solution-enlarged

conduits that create highly preferential flow paths. Most flow eventually discharges at the northeastern corner of the

aquifer at Barton Springs.

Losing

stream

NOT TO SCALE

Creek flows over surface exposure

of Trinity aquifer rocks upstream 

from the recharge zone

Correlation between hydrogeologic and stratigraphics units

associated with the Barton Springs segment of the Edwards

aquifer (modified from Maclay, 1995, fig. 11)

STRATIGRAPHIC 

UNIT

HYDROGEOLOGIC 

UNIT

Trinity aquifer

Del Rio Clay

Georgetown Formation

Edwards

Group

Basal nodular member

Glen Rose Limestone

Upper confining unit

Edwards aquifer,

Barton Springs

segment

Kirschberg evaporite

and dolomitic members

Grainstone member

Regional dense member

Leached and collapsed members

Cyclic and marine members

NORTH-NORTHEAST

Figure 2. Schematic diagram of Barton Springs segment of the Edwards aquifer, Austin, Texas. 
Introduction 5

Karst Aquifer Geochemistry and Its Relation to the 

Barton Springs Segment

The Barton Springs segment is a karst aquifer. In karst 

aquifers, surface water can enter the aquifer as focused recharge 

through fractures, cavities, or sinkholes and move rapidly 

through the aquifer by way of solution-enlarged fractures or 

conduits to discharge at a spring or well. Although ground water 

is stored throughout the pore spaces in the carbonate rock, most 

ground-water transport occurs through solution-enlarged 

cavities and conduits. As a result, recently recharged water 

moving through conduits has little time to equilibrate with the 

rock matrix and thus bears a geochemical signature similar to 

that of surface water.

Surface water, in general, has lower concentrations of 

dissolved solids than ground water and therefore has lower 

specific conductance. Specific conductance is a measure of the 

amount of electrical current water can transmit and a direct 

reflection of the ionic strength, or amount of dissolved solids, in 

the water (Hem, 1982). Typically, 95 percent or more of the dissolved solids in natural waters are a combination of calcium 

(Ca), magnesium (Mg), sodium (Na), potassium (K), bicarbonate (HCO3), chloride (Cl), sulfate (SO4), and nitrate (NO3) 

(Herczeg and Edmunds, 2000). Rainfall has very low specific 

conductance (Herczeg and Edmunds, 2000); surface water has 

higher specific conductance than rainfall because of chemical 

reactions with the land surface, soils, and streambed; ground 

water typically has a higher specific conductance than surface 

water because of the dissolution of the rock matrix of the 

aquifer.

The geochemical signature of ground water reflects the 

initial geochemical signature of the recharging surface water, 

over which is imprinted the interaction of the water with the 

rock through which it flows (Kehew, 2001). Rainfall and 

recharging surface water contain carbonic acid, a weak acid that 

forms from the interaction of water with carbon dioxide in the 

atmosphere and in soils. In karst terrane, the acid dissolves the 

carbonate rock matrix, releasing Ca and HCO3 ions (and Mg, if 

present in the rock) until an equilibrium concentration is 

reached, resulting in a Ca-HCO3 water or a Ca-Mg-HCO3

water. This process is not instantaneous; several days or more 

are required to approach within 90 percent of equilibrium 

(White, 1988). Therefore, water that has recharged the aquifer 

recently will have a lower dissolved solids concentration and 

specific conductance than water that has been in contact with 

the rock longer (Freeze and Cherry, 1979). In addition, water 

moving through conduits is likely to have a lower specific 

conductance than water moving through the rock matrix or 

microfractures because of the smaller surface area available, on 

a per volume basis, for water-rock interaction and shorter residence time. Other ions in karst ground water can come from 

trace elements in the limestone (for example, strontium) or from 

other minerals sometimes associated with limestone deposits, 

such as gypsum (CaSO4), pyrite (FeS2), and clay with iron or 

manganese oxide coatings. Surface recharge is an additional 

source of major ion species, as it contains ions associated with 

the soil zone through which the water has moved or with which 

the water has reacted. In agricultural or urbanized areas, an

thropogenic contaminants such as fertilizers and wastewater 

effluent also might be sources of major ion species (Freeze 

and Cherry, 1979). In the Barton Springs segment, the saline 

zone to the east and the underlying Trinity aquifer both are 

potential sources of several ion species, including Na, Cl, and 

SO4. Under some hydrologic conditions, water from the saline 

zone and Trinity aquifer has been hypothesized to flow into 

the Barton Springs segment (City of Austin, 1997; Slade and 

others, 1986; Smith and Hunt, 2004).

Because of their close connection with the surface-water 

system, karst springs can have extremely variable specific conductance (Shuster and White, 1971). In response to rain events, 

focused recharge (recharge entering into the subsurface through 

discrete openings such as fractures, sinkholes, and swallets) 

moves rapidly through fractures and conduits in the aquifer to 

springs. As a result, a rapid decrease in specific conductance 

commonly is observed at springs after a rain event, followed by 

a gradual increase to a value more representative of interaction 

with the rock matrix. Specific conductance thus can be considered as a tracer of recently infiltrated surface water; and the 

travel time of stormwater from a known recharge point to a discharge point along a flow path is reflected by the time it takes 

for specific conductance at a spring to decrease following a rain 

event (for example, Desmarais and Rojstaczer, 2002; Ryan and 

Meiman, 1996). This phenomenon is observed at Barton 

Springs after rain events, with specific conductance typically 

decreasing about 12 hours after rainfall (City of Austin, 1997; 

Mahler and others, 2006). For this report, the concept of specific conductance as a tracer is extended to wells, with the 

hypothesis that the geochemistry of water at a well intersecting 

a fracture or conduit connected to the surface should respond in 

a similar manner—that is, specific conductance should decrease 

in response to the influx of recharge.

Several approaches can be used to identify wells that intersect flow paths. Aquifer tests can identify very high transmissivity at a well, which might be related to intersection of large 

conduits. Monitoring of physical, chemical, and biological 

properties and constituents during stormflow conditions might 

also identify wells that intersect flow paths (Andrews and 

others, 1984; Mahler and others, 2000). Dye-trace studies that 

monitor the arrival or non-arrival of a dye injected at the surface 

in nearby wells provide information to map connections 

between specific recharge sites and wells (Hauwert and others, 

2004). These methods are labor and resource intensive. If longterm datasets exist, it is useful to determine if those datasets 

contain some information concerning potential intersection of 

wells with flow paths, even if the data were not collected with 

that objective. The analysis in this report uses an existing longterm historical geochemical dataset and a statistical and 

geochemical approach to identify wells that intersect flow 

paths. Historical data on major ion and nitrate concentrations 

are examined to indicate whether flow-path intersection 

influences either major ion geochemistry or susceptibility to 
6 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

nitrate contamination in ground water in the Barton Springs 

segment.

Acknowledgments

The authors thank D.A. Johns (City of Austin) for providing insight into the Barton Springs segment of the Edwards 

aquifer. Also, thanks are extended to the many scientists and 

technicians who collected, analyzed, and archived the 26 years 

of data used for this report. Thanks also are extended to the 

landowners and municipal authorities who allowed sampling of 

their wells.

Table 1. Wells sampled, range of sampling dates, and number of analyses available for each well, Barton Springs segment of the 

Edwards aquifer, Austin, Texas, 1978–2003. 

[--, not available]

Well

identifier

(fig. 1)

State well

number

USGS

identifier

Depth

(feet below

land surface)

Range of

years well

was sampled

Number of

specific

conductance

measurements

Number of

major ion

water analyses

BCK YD–58–50–101 301317097513801 217 1978–83 6 3

BDW LR–58–57–311 300646097533202 -- 1990–2003 23 14

BPS LR–58–58–403 300453097503301 390 1978–2003 53 35

CNE LR–58–58–704 300138097511501 532 1978–83 6 5

FMW YD–58–50–412 301106097520501 295 1981–94 31 19

FOW1

 YD–58–50–408 301031097515801 439 1978–2003 43 27

GHW1 LR–58–57–202 300639097571001 200 1978–89 24 14

HND YD–58–50–502 301113097485401 300 1978–87 15 9

HWD YD–58–50–401 301038097500401 404 1978–83 6 5

ISD LR–58–57–901 300148097532101 575 1978–83 6 5

JBS YD–58–42–926 301634097470001 190 1978–83 13 5

KCH YD–58–50–406 301148097503501 360 1978–99 60 38

LWK LR–58–58–105 300640097513501 477 1978–83 6 5

MCH YD–58–50–704 300813097512101 345 1978–2003 48 31

PLS YD–58–50–520 301226097480701 315 1988–2003 32 20

RAB YD–58–42–915 301526097463201 295 1993–2003 16 11

ROL YD–58–42–813 301628097474001 300 1978–94 39 23

SLR1

 LR–58–49–903 300847097545801 200 1978–89 18 11

SNL YD–58–42–809 301553097482801 340 1978–83 6 6

SVE YD–58–50–216 301356097473301 582 1978–2003 49 29

SVN YD–58–50–217 301432097480001 214 1978–2003 35 20

SVS YD–58–50–215 301339097483701 675 1978–2003 51 31

SVW YD–58–50–211 301423097495901 282 1978–2003 65 46

TNR LR–58–57–303 300646097533201 315 1978–92 26 15

WBG YD–58–50–810 300803097483801 359 1978–83 6 5

WGF YD–58–50–206 301414097483601 257 1978–83 6 6

1

Drilled partly into the Trinity aquifer.

Methods

Approach

Historical geochemical data from 26 wells in the Barton 

Springs segment (table 1) were evaluated in the context of 

contemporaneous streamflow from five creeks and spring discharge from Barton Springs, under the hypothesis that recharging water and variable aquifer flow conditions result in related 

variations in geochemistry in water at those wells that intersect 

conduits (major flow paths). Specific conductance was used 

as an overall indicator of water chemistry. Discharges from 
Methods 7

streamflow-gaging stations on Barton, Williamson, Slaughter, 

Bear, and Onion Creeks (fig. 1) were used to indicate rainfall 

events and associated recharge. The discharge of Barton 

Springs was used to indicate aquifer flow condition—that is, 

whether flow and storage in the aquifer were relatively high or 

low. Senger (1983) showed that the discharge of Barton Springs 

is controlled directly by the amount of water stored in the 

Barton Springs segment. Major ion and nitrate concentrations 

for samples from the 26 wells were interpreted in relation to 

intersection of conduits or major flow paths, other potential 

sources of water, and potential sources of nitrate.

Data Sources and Description

A large record of geochemical samples from wells, streamflow, and spring discharge (1978 through 2003) exists for 

the Barton Springs segment. These data were compiled from 

several USGS studies with various objectives and are in appendixes 1, 2, and 4.

The USGS study that produced much of the geochemical 

data used in this study began in 1978 (Slade and others, 1979). 

From 1978 through 1983, about 30 water wells were sampled 

several times a year for numerous water-quality properties and 

constituents, including specific conductance, major ions, and 

nitrate. After 1983, about 11 of the original 30 wells continued 

to be sampled periodically. Summaries of these data have been 

published (Senger, 1983; Slade and others, 1986), and most of 

the data are available from published USGS annual water-data 

reports (Barbie, 2001–04; Gandara and Barbie, 1999–2000; 

Gandara, Buckner, and Jones, 1993; Gandara and Jones, 1994–

96; Gandara, Jones, and Barbie, 1997–98; Gordon, Pate, and 

Dorsey, 1985–87; Gordon, Pate, and Slagle, 1988; Slade, 

Dorsey, Gordon, and Mitchell, 1980; Slade, Dorsey, and others, 

1981; Slade, Gaylord, and others, 1982; Slade, Gordon, and 

Mitchell, 1979; Slade, Veenhuis, Dorsey, Gardiner, and Smith, 

1983; Slade, Veenhuis, Dorsey, Stewart, and Ruiz, 1984). Data 

for 1987–91 were not previously published and are included in 

appendixes 1 and 4.

The specific conductance dataset for the 26 wells of this 

report consists of 679 values ranging from 388 to 1,530 microsiemens per centimeter at 25 degrees Celsius (μS/cm) (appendix 1). Eight wells have only six specific conductance values, 

the minimum number required for inclusion in this report, and 

four wells have more than 50 values. The largest range (445 

to 1,530 μS/cm) occurs at well SVE, and the smallest range 

(480 to 495 μS/cm) occurs at well ISD. One-half of the wells 

had less than 100 μS/cm variation. The median coefficient of 

variation (Cv), a statistic that reflects the degree of variation 

from the mean of numbers in a dataset and is defined as the standard deviation divided by the mean, for specific conductance 

for all wells is 0.035, with a range of 0.011 to 0.28 (table 2). 

Streamflow has been measured by the USGS since 1978 at 

gaging stations on five creeks (fig. 1), the flow of which 

recharges the aquifer: Barton, Williamson, Slaughter, Bear, and 

Onion Creeks. Streamflow is computed from stage-discharge 

Table 2. Coefficient of variation (Cv) for specific conductance of 

wells, Barton Springs segment of the Edwards aquifer, Austin, 

Texas, 1978–2003.

1 Group

Well identifier

(fig. 1) Cv

C1

FMW 0.033

KCH .033

SLR .074

SVE .23

Median . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .053

C2

BDW .015

HWD .015

MCH .042

SVN .13

SVW .057

Median . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .042

P

FOW .106

GHW .022

LWK .015

ROL .17

SVS .028

WGF .038

Median . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .033

N

BCK .069

BPS .029

CNE .024

HND .065

ISD .011

JBS .020

PLS .025

RAB .28

SNL .054

TNR .026

WBG .055

Median . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .029

Median, all wells . . . . . . . . . . . . . . . . . . .035

1Group classifications shown in table 3.
8 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

relations that have been developed for each of the sites and that 

are updated regularly by manual discharge measurements. 

Although occasional gaps are in the data, in most cases the flow 

of recharging creeks for the 10 days preceding the date of collection of a water sample from a well is available. The streamflow dataset consists of about 9,000 daily mean streamflow values for each of the five creeks (appendix 2). The entire 1978–

2003 period of streamflow measurements is available for Williamson Creek (two stations—08158920 Williamson Creek at 

Oak Hill, Tex., 1978–92 and 2003; 08158922 Williamson 

Creek at Brush Country Blvd., Oak Hill, Tex., 1993–2002) and 

for Slaughter Creek (station 08158840 Slaughter Creek at FM 

1826 near Austin, Tex.); 94 percent of the 1978–2003 period is 

available for Bear Creek (station 08158810 Bear Creek below 

FM 1826 near Driftwood, Tex., 1979–2003) and for Onion 

Creek (station 08158700 Onion Creek near Driftwood, Tex., 

1979–2003); and 76 percent of this period is available for Barton Creek (two stations—08155200 Barton Creek at SH 71 near 

Oak Hill, Tex., 1978–82; 08155240 Barton Creek at Lost Creek 

Blvd., Austin, Tex., 1989–2003). Streamflow for 1983–88 was 

not available for either of the two Barton Creek stations, thus 31 

percent of specific conductance measurements could not be 

tested against Barton Creek streamflow.

Discharge from Barton Springs, used as an indicator of 

aquifer flow condition, has been measured by the USGS continuously since 1978. Discharge from Barton Springs is computed 

on the basis of water levels in a nearby well, similar to use of a 

stage-discharge relation to compute streamflow. Barton Springs 

discharges from four orifices, and the discharge reported by the 

USGS reflects the sum of the discharge from all but the smallest 

orifice (Upper Barton Spring). The largest orifice, Main Spring, 

discharges into Barton Springs Pool, a public swimming pool 

formed by dams upstream and downstream from Main Spring. 

The relation between the water level in the well and spring discharge is well defined provided that the water level in Barton 

Springs Pool remains constant. When the water level in the pool 

changes—for example if it decreases when the gates to the dam 

downstream from the pool are opened or rises when the dam 

upstream from the pool is overtopped by Barton Creek—the 

established rating cannot be used. The relation is verified 

periodically and refined through the use of manual discharge 

measurements. 

The Barton Springs discharge dataset consists of about 

9,000 daily mean discharge values (appendix 2). Data are available for the entire 1978–2003 period, beginning in March 1978. 

The largest spring discharges (in particular those from 1991 and 

1992) are associated with record-setting rainfall events and 

major surface-water flooding; these discharges likely are underestimated, as flooding in Barton Creek reduces the accuracy of 

the stage-discharge relation used to compute Barton Springs 

discharge. However, because nonparametric methods (based on 

ranks) were used for interpretation of spring discharge, consistent underestimation does not affect the findings of this report.

Water-Quality Sample Collection

Sampled wells (table 1) were privately owned domestic 

and livestock wells and municipal wells. All wells except three 

were cased into and completed in the Edwards aquifer. Almost 

all of the wells were completed as open hole, and most wells do 

not penetrate the full thickness of the aquifer (Maclay, 1995). 

Three wells in the recharge zone (FOW, GHW, SLR) were 

drilled partly into the Trinity aquifer (N.A. Houston, U.S. Geological Survey, written commun., 2005). 

Samples were collected from wells at points in the plumbing upstream from pressure tanks or treatment equipment to 

obtain a sample representative of aquifer water. Before June 

2001, a bailer was used for sample collection at well sites where 

a down-hole pump was not installed. Beginning in June 2001, a 

submersible pump was used at those sites. Samples were collected after purging at least three casing volumes of water and 

after field measurements of properties (temperature, pH, and 

specific conductance) had stabilized. Before 1992, field properties were obtained by placing meter probes in a plastic bucket 

and filling the bucket from the bottom. Beginning in 1993, a 

flow-through cell was used to limit aeration and atmospheric 

exposure. Beginning in 2001, USGS National Water Quality 

Assessment Program sampling protocols and analytical schedules (Koterba and others, 1995) were incorporated into the sampling program. 

Specific conductance was measured and recorded during 

all USGS sampling at wells. The instruments used to measure 

specific conductance changed over the years, but standard procedures were followed consistently (Radtke and others, 1998). 

Instruments were calibrated using at least two standard solutions of known specific conductance and calibration was documented. Specific conductance measurements were made after at 

least three casing volumes of water were pumped or bailed from 

wells. The final reported specific conductance typically was the 

median of five readings taken over a 15-minute period.

Water samples for major ion analysis were collected and 

filtered through 0.45-micrometer cellulose filters. Anion samples were dispensed into pre-rinsed polyethylene bottles. Cation 

samples were placed in pre-rinsed, acid-cleaned polyethylene 

bottles, and samples were preserved in the field with a strong 

acid to a pH of less than 2. Samples were chilled on ice, held 

in dark conditions, and shipped to the USGS National Water 

Quality Laboratory (NWQL) for analysis.

Analytical Methods

Analytical methods at the NWQL changed over the 

period of the historical dataset. Major cations were analyzed 

by atomic absorption spectroscopy (Fishman and Friedman, 

1989), by atomic emission spectroscopy (Fishman, 1993), 

and most recently by inductively-coupled plasma mass 

spectroscopy. Before 1990, chloride concentration was measured using titrimetric or colorimetric methods (Fishman and 

Friedman, 1989), and sulfate concentration was measured using 
Quality Assurance 9

turbidimetric analysis by formation of barium sulfate. After 

1990, chloride and sulfate were measured using ion chromatography (Fishman, 1993). Nitrate was analyzed using ion chromatography or cadmium reduction-diazotization colorimetry 

(Fishman, 1993). On the basis of the findings of Andrews and 

others (1984), concentration of nitrite was assumed to be negligible, thus measured nitrite plus nitrate nitrogen was assumed to 

indicate solely nitrate concentration. Trace elements such as 

strontium were assumed to be of negligible concentration, and 

ion complexation was assumed to be negligible. Despite variations in analytical methods, the authors assume for this report 

that methods have been sufficiently consistent to allow side-byside comparison of major ion and nitrate concentrations. 

Quality Assurance

Specific Conductance Data

The quality of specific conductance data was monitored 

through the USGS National Field Quality Assurance program, 

which began in 1979. For a summary of results from 1979 

through 1997, see Stanley and others (1998). Because quality 

control is maintained across the years and across different 

instruments, long-term measurement uncertainty is estimated at 

+5 percent, and measurements made after 1999 should have 

uncertainties of +3 percent (Wagner and others, 2000).

Analytical Methods 

Field blanks and field replicates for major ion and nitrate 

analyses were collected infrequently until 2001 (M.E. Dorsey, 

U.S. Geological Survey, oral commun., 2005). However, the 

data record contains instances where multiple water samples 

were collected within several days of each other, with no intervening change in hydrologic condition. These samples, which 

can be considered sequential replicates, indicate that field techniques were carried out appropriately. From 2001 onward, 

results of quality-assurance results (appendix 5) indicate that 

analytical techniques were carried out appropriately.

Throughout the period of sample collection, the USGS 

NWQL engaged in ongoing internal quality control, including 

the use of standard reference materials, laboratory replicates, 

data review, blind samples, and performance evaluation studies 

(Pritt and Raese, 1995). The results of internal NWQL quality 

control are not part of the published USGS data record.

Data Screening

For this report, two criteria were used to screen some analytical results from the large historical record. First, water analyses with a charge balance error greater than +5 percent were 

excluded. Second, wells with fewer than six specific conductance measurements were excluded, as they did not provide a 

sufficient record for statistical analysis.

Specific Conductance Related to 

Intersection of Flow Paths by Wells 

Data for each well were tested to indicate whether there 

was a statistical relation between specific conductance and 

streamflow and a relation between specific conductance and 

aquifer flow (spring discharge) condition. The underlying 

hypothesis was that the specific conductance of water in those 

wells that intersect flow paths or conduits would decrease from 

a baseline value within 10 days following a rain event resulting 

in streamflow; thus for samples from those wells, there should 

be a relation between specific conductance and streamflow. It 

also was hypothesized that there might be a relation between 

specific conductance and spring discharge. For each specific 

conductance value, data for the previous 10 days of streamflow 

in the five creeks were inspected, and the maximum daily mean 

streamflow for each creek for the 10-day period (hereinafter, 

maximum 10-day streamflow) was recorded (appendix 1). The 

relation between the specific conductance and the corresponding maximum 10-day streamflow was tested using the nonparametric Spearman’s rho correlation coefficient (Helsel and 

Hirsch, 1995). The test measures the strength of association 

between two variables. Similarly, for the comparison of specific 

conductance and spring discharge, Spearman’s rho was used 

to test the relation between each specific conductance value 

and the maximum daily mean discharge for Barton Springs 

for the preceding 10-day period (hereinafter, maximum 10-day 

discharge) (appendix 1). A nonparametric correlation test was 

used because the streamflow and spring discharge are not normally distributed. 

The statistical analyses produced some spurious correlations resulting from autocorrelation between the flow in the different creeks. Autocorrelation occurs when a widespread rainfall produces proportional changes in flow on all five creeks; the 

geochemistry in a well might be influenced by flow in only one 

or two of the creeks, but will be correlated to flow in all five. 

For example, the specific conductance of samples from well 

MCH (near the Travis-Hays County line, fig. 1) is correlated 

with flow in Barton, Williamson, and Slaughter Creeks, but as 

MCH is far upgradient from (south of) these creeks, it is 

unlikely that flow in these creeks has an influence on the 

geochemistry of the well. Spurious correlations were identified 

on the basis of location of the wells and creeks and existing 

information on direction of flow and then removed from further 

consideration. These identifications were made conservatively 

and with caution, as direction of flow in karst terrane often is 

difficult to ascertain and can vary temporally.
10 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

OCT 7

1994

OCT 9

1994

OCT 11

1994

OCT 13

1994

OCT 15

1994

OCT 5

1994

DAILY MEAN STREAMFLOW, IN

CUBIC FEET PER SECOND

500

400

300

200

100

0

SPECIFIC CONDUCTANCE, IN

MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

700

650

600

550

500

Barton Creek streamflow

Williamson Creek streamflow

Specific conductance at well SVW

EXPLANATION

Figure 3. Specific conductance at well SVW and streamflow in Barton and Williamson Creeks during several days following a rain 

event, Barton Springs segment of the Edwards aquifer, Austin, Texas, October 1994.

Specific Conductance Variability at the Event Scale

A high sampling frequency (hours to days) is desirable for 

investigating the relation between surface water and ground 

water in a karst aquifer (for example, Dreiss, 1989; Lakey and 

Krothe 1996). However, as the dataset available for this report 

generally does not contain high-frequency sampling intervals, it 

was hypothesized that data obtained from infrequent and arbitrarily timed sampling carried out over a long period contain 

some of the same information as data obtained from highfrequency sampling. To provide a frame of reference for considering this hypothesis, a high-frequency sampling event dataset 

for this report is considered in this section.

In October 1994, well SVW was sampled at 6- to 12-hour 

intervals beginning 2 days after a rain event. The results of this 

sampling provide an opportunity to investigate how the specific 

conductance of a well changes in response to rainfall and resulting streamflow in a nearby creek at a short time scale. Flow in 

all five recharging creeks increased on October 9, 1994; the 

highest daily mean flow for that day was recorded at Barton 

Creek (476 cubic feet per second), followed by Slaughter Creek 

(99 cubic feet per second), Williamson Creek (73 cubic feet per 

second), Bear Creek (33 cubic feet per second), and Onion 

Creek (30 cubic feet per second). Sixteen samples were collected at well SVW from October 9 at 7:00 a.m. to October 15 

at 12:30 p.m.

Over the sampling period, specific conductance in samples 

from well SVW ranged from 570 to 678 μS/cm (fig. 3). The 

large variation in specific conductance over such a short time 

period in response to rainfall and streamflow indicates that this 

well intersects a conduit or conduits. The rapid (less than 2 

days) response to streamflow indicates that the 10-day criterion 

for response to streamflow for the statistical comparison of specific conductance to peak streamflow is reasonable.The lowest 

specific conductance was measured in the first sample, which 

was collected 2 days after maximum streamflow. From a comparison of flow in Barton and Williamson Creeks and specific 

conductance in well SVW (fig. 3), it appears that the well 

responded rapidly to an influx of recharge from one of the 

nearby creeks (Barton or Williamson, fig. 1). The data indicate 

that specific conductance probably had reached a minimum 

already and then had begun to rise before the first sample was 

collected. Thus, the lowest specific conductance and its timing 

in response to streamflow for this event is unknown. 

The increase in specific conductance in well SVW was 

followed by a subsequent decrease, which indicates that the 
Specific Conductance Related to Intersection of Flow Paths by Wells 11

aquifer near the well might receive recharge from more than 

one creek; the first decrease occurred less than 2 days after rainfall, and the second decrease occurred about 4 days after rainfall 

(fig. 3). Although Hauwert and others (2004) indicate that 

this well is in a small subbasin where the aquifer would not 

receive recharge from multiple creeks, it is possible that transient flow paths are activated during periods of high recharge. 

Alternatively, the aquifer could have received recharge from 

two different recharge points in the same creek.

Correlation Between Specific Conductance, 

Streamflow, and Spring Discharge

Results of Spearman’s rho correlation tests between 

Edwards aquifer specific conductance and streamflow and 

between Edwards aquifer specific conductance and spring 

discharge were used to divide the 26 wells into four groups 

(fig. 4; table 3). Group C1 comprises those wells from which 

samples showed a significant (p < .05) negative correlation 

between specific conductance and both streamflow and spring 

discharge. Group C2 comprises those wells from which samples 

showed a significant negative correlation between specific conductance and streamflow only. Group P comprises those wells 

from which samples showed a significant positive correlation 

between specific conductance and spring discharge. Group N 

comprises those wells from which samples showed no significant correlation between specific conductance and either 

streamflow or spring discharge. Complete results of the statistical tests are in appendix 3.

Specific Conductance Negatively Correlated With 

Streamflow and Spring Discharge

Four wells in Group C1 (FMW, KCH, SLR, SVE) (fig. 4; 

table 3) yielded specific conductances that are negatively correlated with streamflow in one or more of the five recharging 

creeks and also are negatively correlated with discharge from 

Barton Springs. That is, when streamflow and spring discharge 

are high, specific conductance at the four wells is more likely 

to be lower than when streamflow and spring discharge are 

low. As an example, correlations between specific conductance 

at one of the wells in Group C1 (FMW) and maximum 10-day 

streamflow of Slaughter Creek and between specific conductance at well FMW and maximum 10-day discharge of Barton 

Springs are shown in figure 5. These correlations are interpreted 

as an indication that the four Group C1 wells intersect major 

flow paths or conduits that transport recharge from the surface 

through the aquifer and that these flow paths respond to overall 

aquifer flow conditions by transporting large amounts of water. 

The major flow paths likely integrate water from a large volume 

of the aquifer. 

The Spearman’s rho correlation coefficients associated 

with wells in Group C1 are among the highest for the samples 

in any of the four groups of wells tested; 43 percent of all correlation coefficients equal to or greater than .5 are from Group 

C1 (table 3). Except for well KCH, the negative correlations 

between specific conductance at the wells in Group C1 and 

spring discharge are at least as high as the negative correlations 

between specific conductance and streamflow, which again is 

interpreted as an indication that these wells intersect major flow 

paths that integrate flow from a large part of the aquifer. Of note 

is a strong correlation (rho = -.63) between specific conductance at well SLR and streamflow in Bear Creek. Specific conductance at well SLR decreases in response to increases in 

streamflow in Bear Creek to the north of that well (fig. 1), which 

is inconsistent with dye traces that have demonstrated eastward 

ground-water flow in the area of well SLR (Hauwert and others, 

2004). One explanation for this inconsistency could be that 

north-south flow paths in the unsaturated zone transport water 

only when streamflow is high. 

Specific conductance at Group C1 wells ranges from 445 

to 1,530 μS/cm, with a median of 653 μS/cm. (Medians for 

groups of wells were computed using a two-step process. First, 

the median for each well was computed. Then, the median of 

these median values was computed, and this is the number 

reported. This two-step process was necessary to avoid sampling bias arising from variable numbers of samples taken from 

each well.) Specific conductances at wells in this group vary 

more than those at wells in the three other groups, with a median 

Cv of 0.053 (table 2). Within Group C1, well SVE yielded both 

the minimum and maximum specific conductances and the 

highest Cv (0.23) among the four wells. 

Specific Conductance Negatively Correlated With 

Streamflow

At the five wells in Group C2 (BDW, HWD, MCH, SVN, 

SVW) (fig. 4; table 3), specific conductance is negatively correlated with streamflow in one or more recharging creeks but is 

not correlated with spring discharge. This finding is interpreted 

as indicating that these wells intersect surface water recharging 

from creeks, probably by way of short, tributary conduits with 

relatively small catchment areas, but are not connected to a 

major aquifer flow path or conduit in the aquifer. 

Specific conductance at Group C2 wells ranges from 388 

to 710 μS/cm, with a median of 560 μS/cm for the five wells. 

The minimum, maximum, and median for this group of wells 

are the lowest of the four groups, indicating that water at these 

wells is less mineralized than that at wells in the other groups. 

The median Cv for Group C2 specific conductance is 0.042 

(table 2), second-highest variability after Group C1 wells. The 

minimum and maximum specific conductance was recorded at 

well SVN, and the Cv for well SVN specific conductance is the 

highest of Group C2 wells (0.13). Large changes in water level 

occur at well SVN. The well occasionally goes dry (M.E. 

Dorsey, U.S. Geological Survey, oral commun., 2005), and its 

water level changes rapidly in response to flow.
TRAVIS COUNTY

HAYS COUNTY

TRINITY AQUIFER

Williamson

Creek

Slaughter

Creek

Creek

Bear

Creek

Onion

LAKE

 TRAVIS

COLORADO

RIVER

Shoal

Creek

TOWN

LAKE

Walnut

Creek

Bull

Creek

Creek

Barton

Little Bear

Creek

LAKE

 AUSTIN

97o

97 45' o

52'30"

30o

22'30" 98o

30o07'30"

30o

15'

Saline

zone

boundary

Ground-water

divide

ROL

JBS

SNL

RAB

SVN

SVE

SVS

SVW WGF

BCK

KCH

FMW

FOW HWD

HND

PLS

MCH

SLR

GHW TNR

BDW

LWK

BPS

WBG

ISD

CNE

EXPLANATION

SNL

FMW

HWD

FOW

Edwards aquifer recharge zone

Edwards aquifer confined zone

Well identifier and group indicator

Negative correlation between specific conductance and both streamflow and spring discharge (Group C1)

Negative correlation between specific conductance and streamflow (Group C2)

Positive correlation between specific conductance and spring discharge (Group P)

No correlation between specific conductance and either streamflow or spring discharge (Group N)

Barton Springs segment of the

Edwards aquifer modified from

Slagle and others, 1986

5 KILOMETERS

0 5 MILES

0

Barton

 Springs

AUSTIN

12 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Figure 4. Wells grouped on the basis of negative, positive, or no significant correlation between ground-water specific conductance 

and streamflow or Barton Springs discharge, or both, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003.
Specific Conductance Related to Intersection of Flow Paths by Wells 13

A

B

520

530

540

550

560

570

580

590

SPECIFIC CONDUCTANCE, IN

MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

520

530

540

550

560

570

580

590

SPECIFIC CONDUCTANCE, IN

MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

600

610

MAXIMUM 10-DAY DISCHARGE, IN CUBIC FEET PER SECOND

OF BARTON SPRINGS

0 20 40 60 80 100 120

0.1 1 10 100

MAXIMUM 10-DAY STREAMFLOW, IN CUBIC FEET PER SECOND,

OF SLAUGHTER CREEK

Figure 5. Specific conductance at well FMW as a function of (A) maximum 10-day streamflow of Slaughter Creek and (B) maximum 

10-day discharge of Barton Springs, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003.

Specific Conductance Positively Correlated With 

Spring Discharge

Six wells in Group P (FOW, GHW, LWK, ROL, SVS, 

WGF) (fig. 4; table 3) yielded specific conductances that were 

positively correlated with spring discharge. When spring discharge is high, specific conductance at these wells is more 

likely to be high than when spring discharge is low. This 

response is the inverse of that seen for water at Group C1 and 

C2 wells, where high aquifer flow conditions or streamflows are 

correlated with low specific conductance of ground water, and 

is interpreted to indicate that wells in Group P do not intersect 

major flow paths or conduits. Except for wells FOW and ROL, 

specific conductance at Group P wells is not correlated with 

streamflow. Only six specific conductance measurements each 

were available at wells LWK and WGF, the minimum for inclusion in the statistical analysis. 

Specific conductance at Group P wells ranges from 480 

to 1,160 μS/cm, with a median of 603 μS/cm. The median Cv

for specific conductance at the six wells in Group P is 0.033 
14 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Table 3. Spearman’s rho for significant (p < .05) correlations between ground-water specific conductance and streamflow and 

between ground-water specific conductance and Barton Springs discharge, for wells grouped on the basis of negative, positive, or no 

significant correlation, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003.

[--, correlation not significant] 

Spearman’s rho correlation coefficient

1 Group

Well

identifier

(fig. 1)

Streamflow Barton

Springs

Barton Creek Williamson Creek Slaughter Creek Bear Creek Onion Creek discharge

C1

FMW -- -- -.55 -- -.47 -.71

KCH -- -- -.26 -- -.47 -.39

SLR -- -- -- -.63 -- -.63

SVE -.50 -- -.44 -.39 -.40 -.69

C2

BDW -- -- -- -.47 -- --

HWD -- -- -- -.90 -- --

MCH -.46 -.42 -.43 -.44 -.42 --

SVN -.50 -.63 -.54 -.35 -.41 --

SVW -.39 -.28 -.41 -.47 -.31 --

P

FOW .32 -- -- -- -- .50

GHW -- -- -- -- -- .41

LWK -- -- -- -- -- .88

ROL .53 -- .33 -- -- .46

SVS -- -- -- -- -- .29

WGF -- -- -- -- -- .94

N

BCK -- -- -- -- -- --

BPS -- -- -- -- -- --

CNE -- -- -- -- -- --

HND -- -- -- -- -- --

ISD -- -- -- -- -- --

JBS -- -- -- -- -- --

PLS -- -- -- -- -- --

RAB -- -- -- -- -- --

SNL -- -- -- -- -- --

TNR -- -- -- -- -- --

WBG -- -- -- -- -- --

1C1, negative correlation between specific conductance and both streamflow and spring discharge;

C2, negative correlation between specific conductance and streamflow;

P, positive correlation between specific conductance and spring discharge;

N, no correlation between specific conductance and either streamflow or spring discharge.
Major Ion Geochemistry 15

(table 2), the lowest among Groups C1, C2, and P. The range of 

specific conductance at four of the wells (GHW, LWK, SVS, 

WGF) was less than 100 μS/cm. The range in specific conductance at well ROL (480 to 1,160 μS/cm) was the widest of any 

well in Group P and encompassed the full range of variation 

for this group of wells. The wide range in specific conductance 

at this well indicates that the well might be connected to an 

aquifer flow path, despite its lack of a negative correlation with 

streamflow or spring discharge. Wells ROL and FOW are the 

only wells in any group for which specific conductance is positively correlated to streamflow (Barton and Slaughter Creeks) 

(table 3). Well ROL is in a subbasin thought to be hydrologically isolated from Barton Springs and most of the aquifer 

(Hauwert and others, 2004). Well FOW is upgradient from 

Barton Creek, and specific conductance at this well is not correlated with flow in either Williamson or Slaughter Creek. The 

positive correlation between specific conductance at these two 

wells and streamflow likely is the result of autocorrelation 

between streamflow, spring discharge, and interstream 

recharge. The wells that yielded specific conductances with the 

strongest positive correlation with spring discharge in Group P 

are LWK (rho = .88) and WGF (rho = .94) (table 3). Correlations for specific conductance at wells LWK and WGF are 

based on the minimum six data points and less than 60 μS/cm 

of variation in specific conductance. 

Specific Conductance Not Correlated With Streamflow 

or Spring Discharge

Specific conductance of water at the 11 wells in Group N 

(BCK, BPS, CNE, HND, ISD, JBS, PLS, RAB, SNL, TNR, and 

WBG) (fig. 4; table 3) does not show a statistically significant 

correlation with streamflow or spring discharge, so the interpretation is that none of these wells intersects a major flow path. 

However, of the 11 wells in Group N, five wells had the minimum number of specific conductance measurements for testing 

(six), and eight wells had fewer than the median number of 

specific conductance measurements for this study (23). Only 

three other wells from other groups had the minimum number 

of six conductance measurements. In effect, many of the wells 

in Group N might be in this group because the number and timing of samples was insufficient to correlate significantly with 

streamflow or spring discharge. 

Specific conductance for water at wells in Group N ranges 

from 460 to 1,190 μS/cm, with a median of 581 μS/cm. The 

median Cv for specific conductance for Group N is 0.029 (table 

2), the lowest of any group. This group also contains the well for 

which Cv was highest among all wells in this report (well RAB, 

Cv = 0.28). Cvs for specific conductance at wells BPS, PLS, and 

TNR were 0.029, 0.025, and 0.026 respectively; these low values are consistent with the hypothesis that the wells in Group N 

do not intersect flow paths.

Synthesis—Intersection of Flow Paths by Wells

This section synthesizes the evidence for the intersection 

of aquifer flow paths by wells (table 4). A conceptual model 

of the aquifer as developed here is shown schematically in 

figure 6. Some wells intersect major flow paths (Group C1). 

The specific conductance at these wells is influenced by 

recharging surface water and by water from a large upgradient 

part of the aquifer, as reflected by a negative correlation 

between specific conductance and both streamflow in one or 

more recharging streams and Barton Springs discharge. Other 

wells (Group C2) intersect short, tributary flow paths that are 

well connected to the surface. The specific conductance at these 

wells is influenced by recharging surface water and water from 

a small, localized part of the aquifer, as reflected by a negative 

correlation with streamflow but not with spring discharge. 

Water in a third set of wells (Group P) is affected by an unidentified process that results in a positive correlation between specific conductance and spring discharge; these wells likely do 

not intersect a major flow path or conduit. A fourth set of wells 

(Group N) likely do not intersect a major flow path or conduit, 

as water at these wells shows no relation between specific conductance and either streamflow or spring discharge. Some wells 

might be classified in this group, however, because of small 

sample sizes rather than lack of intersection of a flow path or 

conduit. 

Major Ion Geochemistry

Major ion geochemistry of the 26 wells was investigated to 

determine whether hydrochemical facies, major ion ratios, or 

variation in major ion concentrations were related to intersection of flow paths by wells, as classified by the specific conductance analysis. Three tools were used for this analysis: Trilinear 

diagrams, which indicate hydrogeochemical facies; graphs of 

concentration ratios of two major cations and two major anions; 

and Mg/Ca molar ratios. 

The overall geochemical character, or facies, of a water 

sample can be represented visually with a trilinear diagram, 

which is a group of two triangle-shaped diagrams (one for cations and one for anions) and a diamond-shaped diagram representing the composition of the water for both cations and anions 

(Freeze and Cherry, 1979; Piper, 1944). The triangles and diamond are subdivided into smaller areas that indicate which 

groups of ions dominate the aqueous geochemistry. The trilinear diagram allows classification through visual inspection of 

the hydrochemical facies corresponding to each water sample. 

Trilinear diagrams have the advantage of allowing comparison 

of multiple water samples on the same diagram, so that mixing 

and evolution of waters is visually evident (fig. 7). Because trilinear diagrams display only relative proportions of ions, they 

are independent of the effects of dilution.

Changes in ratios of major ions sometimes are evidence of 

water sources and geochemical processes. An ion ratio often is 
16 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Edwards aquifer

Trinity aquifer

Tributary conduit

Generalized flow direction

Fault—Arrows indicate

direction of movement

EXPLANATION

Note: Upper confining unit not shown

NORTH-NORTHEAST

Generalized

flow direction

Discharge at 

Barton Springs

Losing

stream

NOT TO SCALE

A

C B

D

E

Well A intersects a tributary conduit and represents Group C2 wells—

 negative correlation between specific conductance and streamflow

Well B intersects a tributary conduit and a major conduit and represents Group C1 wells—

 negative correlation between specific conductance and both streamflow and spring discharge

Well C intersects a zone of cross-formational flow from the Trinity aquifer

Well D intersects a zone of mixing with water from the saline zone

Well E intersects only Edwards aquifer matrix

(Controls on wells in Groups P and N are unknown. See table 3 footnote for description of groups.)

Major conduit

Tributary conduit

Saline zone

Figure 6. Schematic diagram of conceptual model of the Barton Springs segment of the Edwards aquifer, Austin, Texas, showing wells 

and hypothesized controls on water at the wells.

more useful than ion concentrations alone when identifying 

water sources and geochemical processes because ion ratios are 

independent of the effects of dilution. In the Barton Springs 

segment, temporal changes in ion ratios at a well or spring 

might indicate an influx of water from the surface, the saline 

zone, or the Trinity aquifer, or might indicate the variable 

effects of geochemical processes in the aquifer. Saline zone 

water is distinguished by a higher Cl concentration relative to 

SO4 and a higher Na concentration relative to Mg than either 

Edwards aquifer freshwater or Trinity aquifer water (Sharp and 

Clement, 1988) (fig. 7). Trinity aquifer water is characterized 

by a higher SO4 concentration relative to Cl and a higher Mg 

concentration relative to Na than freshwater from the Barton 

Springs segment (fig. 7). If major ion data for samples from 

the Barton Springs segment, Trinity aquifer, and saline zone 

are viewed on graphs of log(SO4/Cl concentration) relative to 

log(SO4 concentration) and log(Mg/Na concentration) relative 

to log(Mg concentration), saline zone data points will plot 

in the lower-right region of both graphs, Trinity aquifer data 

points will plot in the upper-right region, and Barton Springs 

segment freshwater data points will plot in the middle. If water 

from a well in the Barton Springs segment has a geochemical 
Major Ion Geochemistry 17

SULFATE (SO4

) + CHLORIDE (Cl)

CALCIUM (Ca) + MAGNESIUM (Mg)

80 80

60

40

20

20

40

60

80

60

40

20

20

40

60

80

100 100

100 100

0

0

0

0

ANIONS

60 80 100

CHLORIDE (Cl)

CARBONATE (CO3

) + BICARBONATE (HCO3

)

100

0 20 40

SULFATE (SO4

)

80

60

40

20

100

0

20

40

60

80

0

MAGNESIUM (Mg)

SODIUM (Na) + POTASSIUM (K)

CATIONS

CALCIUM (Ca)

100 80 60 40 20 0

100

80

60

40

20

100

0

20

40

60

80

0

PERCENT MILLIEQUIVALENTS

EXPLANATION

Main Barton Spring, 1987–96

Well

YD–58–50–840 (saline zone)

YD–58–50–301 (saline zone)1

YD–58–50–302 (saline zone)1

YD–58–50–304 (saline zone)1

YD–58–50–409 (Trinity aquifer)

YD–58–49–603 (Trinity aquifer)

1

 Geochemical data provided by the City of Austin

Note: Well samples are not from wells in the

group of 26 that provided the primary data

for this report.

Figure 7. Trilinear diagram showing relations between compositions of major ions in water sampled from Main Barton Spring (1987–96) 

and wells completed in the saline zone of the Edwards aquifer and the underlying Trinity aquifer (1978–2003), Austin, Texas.

composition such that data points plot toward the lower-right 

regions of both graphs, it is interpreted as evidence of mixing 

with saline zone water; if the data points plot near the upperright region of both graphs, it is interpreted as being affected by 

inflow of water from the Trinity aquifer. Multiple sources and 

geochemical processes can produce similar ion ratios. For 

example, elevated SO4/Cl concentration ratios can arise from 

the dissolution of gypsum or oxidation of pyrite, and elevated 

Mg/Na concentration ratios can be the result of longer groundwater residence times in limestone (Musgrove and Banner, 

2004).

In a karst aquifer with relatively uniform lithology, the 

Mg/Ca molar ratio can be used as an indicator of ground-water 

residence time (Musgrove and Banner, 2004). Recharging 
18 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Table 4. Summary of findings regarding intersection of flow paths by wells and Edwards aquifer water mixing with water from Trinity 

aquifer and saline zone, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003. 

Well

identifier

(fig. 1)

State well

number

Trinity

aquifer

mixing?

Saline

zone

mixing?

Comments

Wells intersecting major flow paths

FMW YD–58–50–412 No No Residence time variation is source of geochemical variability.

KCH YD–58–50–406 No Small Saline zone mixing indicated, although well KCH not near saline zone. High nitrate concentrations.

SLR LR–58–49–903 Yes No Shallow well drilled into Trinity aquifer along western edge of study area.

SVE YD–58–50–216 Small Yes Saline zone mixing at low aquifer flow conditions and streamflow.

Wells intersecting minor flow paths

BDW LR–58–57–311 No No Residence time variation is source of geochemical variability.

HWD YD–58–50–401 No No Small dataset.

MCH YD–58–50–704 Small No None.

SVN YD–58–50–217 No No Can’t be sampled under low aquifer water levels. Probably gets water directly from Barton Creek.

SVW YD–58–50–211 No Small High nitrate concentrations. Identified as a flow-path well by another study.

Unknown/no conclusions regarding flow paths

BCK YD–58–50–101 Yes No Small dataset.

BPS LR–58–58–403 No No Large, unvarying water-quality record. High residence time. No saline zone mixing despite

proximity to saline zone.

CNE LR–58–58–704 No Yes Small dataset. Pronounced mixing with nearby saline zone.

FOW YD–58–50–408 Yes No Drilled into Trinity aquifer. Mixing from Trinity aquifer during high aquifer water levels.

GHW LR–58–57–202 Yes No Shallow well, small dataset, drilled into Trinity aquifer at western edge of study area.

HND YD–58–50–502 No No Small dataset.

ISD LR–58–57–901 No No Small dataset.

JBS YD–58–42–926 No No Relatively small dataset. High bacteria and nitrate levels, indicating local contamination source.

LWK LR–58–58–105 No No Small dataset. Slight calcium and bicarbonate increases during high aquifer flow conditions.

PLS YD–58–50–520 No No Large, unvarying water-quality record.

RAB YD–58–42–915 Maybe No Unusual geochemistry controlled by unidentified processes.

ROL YD–58–42–813 No No Unusual geochemistry. Excess chloride might be anthropogenic. Well was plugged because of

bacterial contamination.

SNL YD–58–42–809 No No Small dataset.

SVS YD–58–50–215 Yes No Mixing with Trinity aquifer water during high aquifer water levels.

TNR LR–58–57–303 Yes No Located 50 feet from well BDW but different geochemistry.

WBG YD–58–50–810 No Yes Small dataset. Pronounced mixing with nearby saline zone.

WGF YD–58–50–206 No No Small dataset. Slight calcium and bicarbonate increase during high aquifer water levels.
Major Ion Geochemistry 19

water that is undersaturated with respect to calcite will dissolve 

calcite and undergo a rapid increase in Ca concentration until 

calcite saturation is reached (Palmer, 1991). Subsequently, 

incongruent dissolution of meta-stable minerals such as highmagnesium calcite and dolomite (CaMg(CO3)2) will increase 

dissolved Mg concentrations, while Ca concentrations will 

remain essentially constant owing to the simultaneous reprecipitation of more stable minerals such as low-magnesium calcite 

(James and Choquette, 1984). Thus ground waters with a longer 

residence time will have a higher Mg/Ca molar ratio than those 

with a shorter residence time, as they have undergone more 

rock-water interaction.

Major Ion Geochemistry of 26 Wells by Group

The hydrochemical facies of water at Group C1 wells 

(FMW, KCH, SLR, SVE), except for well SVE, are Ca-HCO3

to Ca-Mg-HCO3 (fig. 8A). Water at well SVE trends toward a 

mixed-SO4 or Na-mixed hydrochemical facies. Water at Group 

C1 wells, which were interpreted as intersecting major flow 

paths or conduits on the basis of specific conductance response 

to streamflow, shows some evidence of mixing with saline zone 

water and Trinity aquifer water (fig. 8B, C). Water at well SVE 

had the greatest range of SO4/Cl and Mg/Na concentration 

ratios among Group C1 wells; during periods of low streamflow 

and spring discharge, water at well SVE appears to mix with 

water from the saline zone. Although SO4 concentration at well 

SVE is not linearly correlated with streamflow, SO4 concentrations greater than 100 mg/L occur almost exclusively during 

periods of low flow (less than 4 cubic feet per second) (fig. 9A) 

in all of the creeks except Onion Creek, and SO4 concentration 

is inversely proportional to Barton Springs discharge (fig. 9B). 

These relations indicate that the source of the SO4 at well SVE 

is inflow from the saline zone, which is suppressed when spring 

discharge and streamflow are high. This hypothesis is supported 

by the relative increase in Na concentration with respect to Mg 

(fig. 8C), and it is consistent with reports by Senger (1983) and 

Slade and others (1986) that the aquifer in the area of well SVE 

might receive some water from the saline zone. The aquifer at 

well SLR appears to be receiving some water from the Trinity 

aquifer, on the basis of slight enrichment in SO4 relative to Cl 

(fig. 8B) and Mg relative to Na (fig. 8C). This likely is because 

well SLR is completed in the Trinity aquifer underlying the 

Barton Springs segment, as indicated by the driller’s logs. Samples from wells KCH and FMW show little variability in their 

SO4/Cl and Mg/Na concentration ratios, which indicates that 

variations in their geochemical composition is caused primarily 

by dilution from surface water during periods of high streamflow and spring discharge.

The Mg/Ca molar ratio for water at Group C1 wells ranges 

from about 0.3 to about 0.9 (fig. 8D). Medians of Mg/Ca generally increase from southwest to northeast, following the general 

gradient of flow in the aquifer (fig. 2). This is consistent with 

the concept of Mg/Ca increasing as a function of residence time; 

as ground water flows downgradient, its residence time, and 

thus its Mg/Ca molar ratio, increases. Water at wells SVE and, 

to a lesser extent, SLR show a correlation between Mg/Ca 

molar ratios and specific conductance when the highest 70 percent of specific conductances is considered. This correlation 

indicates that ionic strength is proportional to residence time for 

wells SVE and SLR during periods when there is little recharge 

(that is, during base-flow conditions). Wells FMW and KCH do 

not show this correlation.

The hydrochemical facies of water at Group C2 wells 

(BDW, HWD, MCH, SVN, SVW) are Ca-HCO3 to Ca-MgHCO3 (fig. 10A), which are similar to those at Group C1 wells 

(fig. 8A) but with less of a tendency toward a SO4 facies. Generally, Group C2 well geochemical variability is more tightly 

constrained than that of Group C1 (fig. 10B, compared to 

fig. 8B, C), which is interpreted as an indication that fewer processes affect the geochemical composition of water at Group C2 

wells; dilution by low-ionic-strength surface recharge appears 

to be a dominant process at most wells in Group C2. The major 

ion geochemistry of water from wells in Group C2 shows little 

or no evidence for mixing with water from the saline zone or 

Trinity aquifer (fig. 10B, C). Samples from wells BDW and 

HWD have the smallest variations in SO4/Cl concentration 

ratios in this group but some variability in Mg/Na concentration 

ratios. These relations indicate that geochemical composition is 

affected by dilution from surface water during periods of high 

streamflow, as dilution decreases residence time, resulting in a 

decrease in Mg concentration. There is a slight evolution of the 

water at wells SVN and SVW toward a more Cl-SO4 type water, 

indicating a contribution of ions from a source other than surface water. Water at well SVW is somewhat enriched in SO4

relative to Cl, but its Mg/Na concentration ratio is relatively 

constant, which indicates that the SO4 has a source other than 

the Trinity aquifer or the saline zone, possibly dissolution of 

gypsum. Thus the geochemistry of water from the Group C2 

wells is consistent with the interpretation that wells in this group 

receive water from the surrounding Edwards aquifer matrix and 

short tributary conduits but are not connected to a major aquifer 

flow path or conduit in the aquifer.

Water at the wells in Group C2 has about the same range 

of Mg/Ca molar ratio as water at wells in Group C1; maximum 

range is at well BDW (fig. 10D). There is no apparent relation 

between Mg/Ca molar ratios and location for water at Group C2 

wells, which is consistent with the hypothesis that Group C2 

wells intersect minor flow paths with relatively small catchment 

areas. Unlike water at Group C1 wells, there is no apparent relation between Mg/Ca molar ratio and specific conductance at 

any Group C2 wells.

The hydrochemical facies of water at Group P (FOW, 

GHW, LWK, ROL, SVS, WGF) wells varies from Ca-HCO3 to 

Ca-Mg-HCO3 to Ca-Mg-SO4 (fig. 11A). The specific conductance of water from Group P wells was positively correlated 

with aquifer flow condition, meaning that specific conductance 

was high when spring discharge was high. The process controlling this relation has not been identified. Four of the six 

Group P wells (GHW, LWK, SVS, WGF) contain Ca-HCO3 to 

Ca-Mg-HCO3 waters, similar to the dominant hydrochemical 
20 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

SULFATE (SO 4) + CHLORIDE (Cl)

CALCIUM (Ca) + MAGNESIUM (Mg)

80 80

60

40

20

20

40

60

80

60

40

20

20

40

60

80

100 100

100 100

0

0

0

0

ANIONS

60 80 100

CHLORIDE (Cl)

CARBONATE (CO3

) + BICARBONATE (HCO3

)

100

0 20 40

SULFATE (SO4

)

80

60

40

20

100

0

20

40

60

80

0

MAGNESIUM (Mg)

SODIUM (Na) + POTASSIUM (K)

CATIONS

CALCIUM (Ca)

100 80 60 40 20 0

100

80

60

40

20

100

0

20

40

60

80

0

PERCENT MILLIEQUIVALENTS

A

EXPLANATION

FMW

KCH

SLR

SVE

EXPLANATION

FMW

KCH

SLR

SVE

Edwards aquifer recharge zone

Edwards aquifer confined zone

Well and identifier—

Referenced in table 1

5 KILOMETERS

0 5 MILES

0

Williamson

Slaughter

Creek

COLORADO RIVER

Shoal Creek

 LAKE

AUSTIN

AUSTIN

TRAVIS COUNTY

HAYS COUNTY

Saline

zone

boundary

Ground-water divide

Creek

Creek Bear

Creek

Onion

Creek

Barton

Bear

Little

Creek

TOWN LAKE

Group C1 well locations

FMW

KCH

SLR

SVE

N

Figure 8. Trilinear diagram and graphs showing geochemistry for wells in Group C1 (specific conductance negatively correlated with 

both streamflow and spring discharge), Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003. 
Major Ion Geochemistry 21

C

B

D

FMW

KCH

SLR

SVE

EXPLANATION

LOG OF RATIO OF

SULFATE CONCENTRATION TO

CHLORIDE CONCENTRATION

2.0

1.5

1.0

0.5

0

-0.5

-1.0

LOG OF RATIO OF

MAGNESIUM CONCENTRATION TO

SODIUM CONCENTRATION

1.2

1.0

0.8

0.6

0.4

0.2

0

MOLAR RATIO OF

MAGNESIUM TO CALCIUM

-0.8

-0.4

0

0.4

0.8

1.2

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

LOG OF SULFATE CONCENTRATION

.0 1.2 1.4 1.6 1.8 2.0

LOG OF MAGNESIUM CONCENTRATION

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

200 400 600 800 1,000 1,200 1,400 1,600

1

 

Saline zone

Trinity aquifer

or increasing

residence time,

or both

Trinity aquifer

Saline zone

Figure 8. Continued. 
22 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

facies of Groups C1 and C2. Although the driller’s logs indicate 

that well GHW is completed in the Trinity aquifer, its Ca-MgHCO3 chemistry indicates Edwards aquifer water. Most of the 

variation in relative proportions of major ions is accounted for 

by Ca and Mg. In contrast, water at wells FOW and ROL trends 

toward SO4- and Cl-type facies, respectively. These two wells 

also have the largest Cv for specific conductance in Group P 

(table 2). 

The water at some wells in Group P shows evidence of 

mixing with Trinity aquifer water; at other wells, there is no 

clear explanation for the geochemical variability. The water 

at wells FOW and SVS is enriched with SO4 relative to Cl and 

Mg relative to Na under high-flow conditions, which is the 

geochemical signature of the underlying Trinity aquifer 

(fig. 11B, C). Sulfate concentrations at well FOW can increase 

to about four times the baseline maximum concentration 

(70 mg/L), but this occurs only when Barton Springs discharge 

exceeds about 85 cubic feet per second (fig. 12). Other studies 

also have indicated that sulfate-rich water from the Trinity 

aquifer enters the aquifer near well FOW when aquifer flow 

conditions are high (City of Austin, 1997; Hauwert and Vickers, 

1994), and these findings are consistent with a driller’s log 

Figure 9. Sulfate concentration at well SVE as a function of (A) maximum 10-day streamflow of Slaughter Creek and (B) maximum 

10-day discharge of Barton Springs, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003.

0 20 40 60 80 100 120

MAXIMUM 10-DAY DISCHARGE, IN CUBIC FEET PER SECOND, OF BARTON SPRINGS

MAXIMUM 10-DAY STREAMFLOW, IN CUBIC FEET PER SECOND, OF SLAUGHTER CREEK

0 5 10 15 20 25 105 110

SULFATE CONCENTRATION, IN

MILLIGRAMS PER LITER

600

500

400

300

200

100

0

SULFATE CONCENTRATION, IN

MILLIGRAMS PER LITER

600

500

400

300

200

100

0

B

A
Major Ion Geochemistry 23

indicating that well FOW is completed in the Trinity aquifer 

(N.A. Houston, U.S. Geological Survey, written commun., 

2005). Similar mixing with Trinity aquifer water is apparent at 

well SVS and is seen at well GHW to a lesser extent. Thus the 

positive correlation between specific conductance and spring 

discharge might be the result of mixing with high-sulfate Trinity aquifer water when aquifer flow conditions are high; this 

would result if, under high-flow conditions, hydraulic heads in 

the Trinity aquifer are proportionately higher than those in the 

Edwards aquifer, but the respective head differences have not 

been investigated. In contrast, water at well ROL has proportions of SO4 relative to Cl (fig. 11B) and Mg relative to Na 

(fig. 11C) that are more or less constant, with perhaps a slight 

enrichment in Cl. This geochemical signature corresponds to 

neither the Trinity aquifer nor the saline zone. One explanation 

for excess Cl and increased specific conductance with high 

aquifer flow conditions is contamination from surface water; 

the use of well ROL was discontinued several years ago because 

of defective well casing that allowed contaminated surface 

water to reach the water table (City of Austin, 1997). Only small 

datasets are available for wells LWK and WGF, and they do not 

indicate a clear source of geochemical variability.

Given the positive correlation between specific conductance in water at Group P wells and spring discharge, an inverse 

relation between specific conductance and residence time (as 

indicated by Mg/Ca molar ratio) might be expected for wells in 

this group. However, Mg/Ca molar ratios generally are independent of specific conductance for water at most wells in 

Group P (fig. 11D). Well ROL is an exception in that Mg/Ca 

molar ratios at that well decrease as specific conductance 

increases. The fact that this is only observed at well ROL indicates that some process other than mixing might be occurring. 

The aquifer at well ROL is known to have a local source of 

anthropogenic contamination (City of Austin, 1997), which 

might be responsible for the inverse relation between specific 

conductance and Mg/Ca molar ratios. Water at well FOW has a 

direct relation between Mg/Ca molar ratios and specific conductance, but this is most likely because of mixing with Trinity 

aquifer water during high aquifer flow conditions.

Ground water represented by Group N (BCK, BPS, CNE, 

HND, ISD, JBS, PLS, RAB, SNL, TNR, and WBG) has diverse 

hydrochemical facies, from Ca-HCO3 to Na-K-Cl-SO4 (mixed) 

water types (fig. 13A). The waters at this group of wells do not 

fall into any of the other three groups, rather they are in a separate group by default, and therefore are not expected necessarily 

to have similar geochemical compositions or to be controlled by 

similar geochemical processes. Water at most of the wells is a 

Ca-HCO3 to Ca-Mg-HCO3 type, similar to that at most of the 

other wells in this report; but two wells, CNE and WBG, have 

hydrochemical facies unlike those of waters from any other 

wells in this report, which might be a result of their proximity 

to the saline zone. The geochemical compositions at wells CNE 

and WBG approach the geochemical composition of saline 

zone wells (fig. 7), indicating saline zone influence. Well RAB 

has variable hydrochemical facies that are similar to those of 

well SVE (Group C1).

On the basis of ion ratios (fig. 13B, C), water at some wells 

in Group N shows evidence of mixing with water from the 

saline zone. Water at well CNE is enriched with Cl relative to 

SO4 and enriched with Na relative to Mg, indicating geochemical influence from the saline zone. Well WBG has a cation signature corresponding to saline zone influence (fig. 13C), but the 

anion signature is less conclusive (fig. 13B). The geochemistry 

of well RAB is extremely variable (fig. 13A, C, D). Although 

the concentration of SO4 is elevated relative to Cl, the Mg/Na

concentration ratio is not indicative of either a Trinity aquifer or 

saline zone source, which might indicate an alternative source 

of SO4 such as dissolution of gypsum. Well TNR is only 50 feet 

from Group C2 well BDW, yet water at each well has a different 

geochemical composition. Such spatial heterogeneity often is 

observed in karst aquifers (for example, Mahler and others, 

2000) and is a reminder that geographic patterns in karst aquifers are difficult to generalize.

Few generalizations can be made about water at the wells 

in Group N. Most of the wells in this group have fewer specific 

conductance measurements than the wells in the other groups, 

which decreases the likelihood that the samples would reflect 

periods when ground-water chemistry was influenced by 

recharge through streambeds. In other words, their sample sets 

might be too small to adequately capture the range of geochemical changes that occur. In other cases, unidentified processes 

might be affecting the geochemical composition of well water; 

for example, well RAB is thought to intersect a highly transmissive conduit system of the aquifer (Senger, 1983), but changes 

in geochemical composition of water at well RAB apparently 

are not correlated with streamflow or spring discharge.

Water at Group N wells has the largest range of Mg/Ca 

molar ratios (0.3 to 1.1) of the four groups (fig. 13D), indicating 

a wide range of residence times among the wells. Water at individual wells in Group N reflects smaller individual Mg/Ca

molar ratio ranges than water of the groups as a whole; the 

greatest range occurs in water at well TNR (0.3–0.7). Water 

with the largest mean ratios is from wells CNE and WBG, further evidence that water at these wells has a different geochemical signature. The Mg/Ca molar ratio of water at well RAB is 

almost unvarying despite its range in hydrochemical facies.

Relation Between Major Ion Geochemistry and 

Intersection of Flow Paths by Wells

The major ion geochemistry of the well waters is not 

inconsistent with the interpretations regarding flow-path 

intersection by wells based on specific conductance analysis, 

but the geochemistry alone cannot be used to make those interpretations. The wells that were interpreted as intersecting only 

minor flow paths or conduits but otherwise receiving Edwards 

matrix water (Group C2) had the most typical carbonate 

geochemistry, the least variability, and the least evidence for 

contribution from water sources other than the Edwards. Some 

of the wells interpreted as intersecting a major flow path or 

conduit (Group C1) had waters with a geochemistry indicating 
SULFATE (SO 4) + CHLORIDE (Cl)

CALCIUM (Ca) + MAGNESIUM (Mg)

80 80

60

40

20

20

40

60

80

60

40

20

20

40

60

80

100 100

100 100

0

0

0

0

ANIONS

60 80 100

CHLORIDE (Cl)

CARBONATE (CO3

) + BICARBONATE (HCO3

)

100

0 20 40

SULFATE (SO4

)

80

60

40

20

100

0

20

40

60

80

0

MAGNESIUM (Mg)

SODIUM (Na) + POTASSIUM (K)

CATIONS

CALCIUM (Ca)

100 80 40 20 60 0

100

80

60

40

20

100

0

20

40

60

80

0

PERCENT MILLIEQUIVALENTS

EXPLANATION

BDW

HWD

MCH

SVN

SVW

EXPLANATION

BDW

HWD

MCH

SVN

SVW

Edwards aquifer recharge zone

Edwards aquifer confined zone

Well and identifier—

Referenced in table 1

5 KILOMETERS

0 5 MILES

0

Williamson

Slaughter

Creek

COLORADO RIVER

Shoal

Creek

 LAKE

AUSTIN

AUSTIN

TRAVIS COUNTY

HAYS COUNTY

Saline

zone

boundary

Ground-water divide

Creek

Creek Bear

Creek

Onion

Creek

Barton

Bear

Little

Creek

TOWN LAKE

Group C2 well locations

SVN

SVW

HWD

MCH

BDW N A

24 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Figure 10. Trilinear diagram and graphs showing geochemistry for wells in Group C2 (specific conductance negatively correlated with 

streamflow only), Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003. 
Major Ion Geochemistry 25

Figure 10. Continued. 

C

B

D

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

LOG OF SULFATE CONCENTRATION

LOG OF MAGNESIUM CONCENTRATION

1.0 1.2 1.4 1.6 1.8 2.0

200 400 600 800 1,000 1,200 1,400 1,600

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

LOG OF RATIO OF 

SULFATE CONCENTRATION TO 

CHLORIDE CONCENTRATION

2.0

1.5

1.0

0.5

0

-0.5

-1.0

LOG OF RATIO OF

MAGNESIUM CONCENTRATION TO

SODIUM CONCENTRATION

-0.8

-0.4

0

0.4

0.8

1.2

1.2

1.0

0.8

0.6

0.4

0.2

0

MOLAR RATIO OF

MAGNESIUM TO CALCIUM

Saline zone

Trinity aquifer

or increasing

residence time,

or both

Trinity aquifer

Saline zone

BDW

HWD

MCH

SVN

SVW

EXPLANATION
26 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Figure 11. Trilinear diagram and graphs showing geochemistry for wells in Group P (specific conductance positively correlated with 

spring discharge), Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003.

SULFATE (SO4

) + CHLORIDE (Cl)

CALCIUM (Ca) + MAGNESIUM (Mg)

80 80

60

40

20

20

40

60

80

60

40

20

20

40

60

80

100 100

100 100

0

0

0

0

ANIONS

60 80 100

CHLORIDE (Cl)

CARBONATE (CO3

) + BICARBONATE (HCO3

)

100

0 20 40

SULFATE (SO4

)

80

60

40

20

100

0

20

40

60

80

0

MAGNESIUM (Mg)

SODIUM (Na) + POTASSIUM (K)

CATIONS

CALCIUM (Ca)

100 80 60 40 20 0

100

80

60

40

20

100

0

20

40

60

80

0

PERCENT MILLIEQUIVALENTS

A

EXPLANATION

FOW

GHW

LWK

ROL

SVS

WGF

Edwards aquifer recharge zone

Edwards aquifer confined zone

Well and identifier—

Referenced in table 1

FOW

GHW LWK

Williamson

Slaughter

COLORADO RIVER

Shoal Creek

 LAKE

AUSTIN

AUSTIN

TRAVIS COUNTY

HAYS COUNTY

zone

boundary

Ground-water divide

Creek

Creek Bear

Creek

Onion

Creek

Barton

Bear

Little

Creek

TOWN LAKE

Group P well locations

5 KILOMETERS

0 5 MILES

0

N

WGF

SVS

ROL

Creek

Saline

EXPLANATION

FOW

GHW

LWK

ROL

SVS

WGF
Major Ion Geochemistry 27

Saline zone

Trinity aquifer

or increasing

residence time,

or both

Trinity aquifer

Saline zone

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

LOG OF SULFATE CONCENTRATION

LOG OF MAGNESIUM CONCENTRATION

1.0 1.2 1.4 1.6 1.8 2.0

200 400 600 800 1,000 1,200 1,400 1,600

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

2.0

1.5

1.0

0.5

0

-0.5

-1.0

-0.8

-0.4

0

0.4

0.8

1.2

1.2

1.0

0.8

0.6

0.4

0.2

0

MOLAR RATIO OF

MAGNESIUM TO CALCIUM

LOG OF RATIO OF

MAGNESIUM CONCENTRATION TO

SODIUM CONCENTRATION

LOG OF RATIO OF 

SULFATE CONCENTRATION TO 

CHLORIDE CONCENTRATION

C

B

D

FOW

GHW

LWK

ROL

SVS

WGF

EXPLANATION

Figure 11. Continued.
28 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

contribution from the saline zone or the Trinity aquifer; major 

flow paths or conduits might be more likely to be connected to 

other water sources than minor flow paths or conduits. The positive correlation between aquifer flow condition and specific 

conductance in the Group P well waters appears in some cases 

to be associated with increased Mg and SO4 concentrations 

when aquifer flow conditions are high. On the basis of ion 

ratios, the source of the ion enrichment might be leakage from 

the Trinity aquifer under high aquifer flow conditions, but the 

controlling processes have not been identified. All but two of 

the wells that showed no relation between specific conductance 

and either recent streamflow or aquifer flow condition (Group 

N) had samples with a geochemistry representative of carbonate 

systems, as would be expected from wells that intersect the 

matrix of the Edwards aquifer.

Mixing of Edwards Aquifer Water With Trinity Aquifer 

and Saline Zone Water

Evidence in this report indicates that Trinity aquifer water 

enters the Barton Springs segment under some hydrologic conditions, although the geographic source of this water is ambiguous in most cases. Trinity aquifer water is more likely to enter 

the Barton Springs segment when spring discharge is high, on 

the basis of geochemistry at three Group P wells (FOW, GHW, 

and SVS; table 4). Trinity aquifer water mixing at wells FOW, 

GHW, and SLR likely is because of upward leakage from the 

underlying Trinity aquifer, as drillers’ logs indicate that these 

wells were completed in the upper zone of the underlying 

Trinity aquifer.

Water from the saline zone might mix with Edwards aquifer water in the Barton Springs segment, and this occurrence 

generally is associated with wells that intersect flow paths 

(wells KCH, SVE, SVW). The mixing is associated with low 

streamflow or low spring discharge, or both, which indicates 

that an absence of water recharging the aquifer or a reduction of 

the potentiometric surface associated with low aquifer flow 

conditions (Slade and others, 1986) allows influx of water from 

the saline zone. Well SVE, the second-deepest of the wells in 

this report (table 1), shows saline zone influence only under low 

aquifer flow conditions.

Geographic Patterns Relative to Major Ion 

Geochemistry

One of the most striking characteristics of karst aquifers is 

their extreme heterogeneity; wells in proximity can show very 

different hydrogeologic and geochemical characteristics (for 

example, Long and Putnam, 2004; Mahler and others, 2000; 

Malard and Chapuis, 1995). The intersection of a fracture or 

conduit by a well is likely to have a greater effect on the 

geochemistry of water at the well than the location of the well 

along the regional gradient. For example, wells BDW and TNR 

are 50 feet from one another, yet water samples from each have 

distinct geochemistries and were classified in different groups 

(Groups C2 and N, respectively). However, a few observations 

concerning geography and geochemistry can be made.

At Group C1 wells, Mg/Ca molar ratios tend to increase in 

a downgradient direction (fig. 8). This increase is interpreted as 

reflecting an increase in residence time with distance downgradient and is consistent with the hypothesis that Group C1 

wells intersect major flow paths that integrate water from large 

volumes of the aquifer. Generalized aquifer flow paths were 

delineated by Hauwert and others (2004, p. 4), and the conclusion that Group C1 wells intersect major flow paths is mostly 

supported by their findings. An increase in Mg/Ca molar ratios 

Figure 12. Sulfate concentration at well FOW relative to maximum 10-day discharge of Barton Springs, Barton Springs segment of the 

Edwards aquifer, Austin, Texas, 1978–2003. 

0 20 40 60 80 100 120

MAXIMUM 10-DAY DISCHARGE, IN CUBIC FEET PER SECOND, OF BARTON SPRINGS

SULFATE CONCENTRATION, IN

MILLIGRAMS PER LITER,

AT 

WELL FO

W

250

200

150

100

50

0

Baseline maximum concentration
Nitrate Geochemistry 29

with distance downgradient is not observed for wells in the 

other three groups, where the water apparently is subject to 

more localized influences. In karst aquifers, fractures and conduits occupy a small proportion of the total aquifer volume, and 

the likelihood of a well intersecting a major flow path is relatively small. 

Wells that intersect minor flow paths are, with one exception, in the recharge zone (fig. 10A). This is consistent with 

the conceptual model (fig. 6), in which minor flow paths are 

directly connected to and receiving recharge from the surface. 

As there is no direct connection between land surface and the 

confined zone, any confined-zone flow path must be long 

enough to have originated in the recharge zone. Longer flow 

paths are more likely to be major flow paths, in the same way 

that stream length in surface-water systems usually is proportional to the size of the catchment area.

Nitrate Geochemistry

Elevated concentrations of nitrate can result from anthropogenic contamination and also can indicate the presence of 

other anthropogenic contaminants. Nitrate is not naturally 

present in limestone and dolomite deposits, and its presence in 

ground water results from processes other than calcite/dolomite 

dissolution. Sources of nitrate include fertilizers, manure, septic 

tanks, municipal sewage treatment systems, decaying plant 

debris, and nitrogen oxide emissions. Nitrate is very soluble, 

and once present in aerated water, concentrations of nitrate generally can be lowered only by mixing with more dilute water or 

through uptake by plants or other organisms. 

Nitrate concentrations less than 1.0 to 2.0 mg/L (measured 

as nitrogen [N] in this report) are assumed to originate from natural sources such as plants and soils (Freeze and Cherry, 1979; 

Wisconsin Department of Natural Resources, 2003). Nitrate 

concentrations in Barton Springs water are suspected to be 

increasing (Turner, 2000), although no measurable increase has 

been noted in data on dissolved nitrate collected since 1984 

(Mahler and others, 2006). If such an increase were occurring, 

despite concentrations less than 2.0 mg/L, it might indicate an 

increasing contribution from an anthropogenic source. Elevated 

concentrations of nitrate at one of the Barton Springs orifices 

relative to those at the other three might be related to anthropogenic sources (Mahler and others, 2006). Excess nitrate in 

aquatic systems leads to eutrophication and has various adverse 

health effects on humans; the maximum contaminant level 

(MCL) allowed in drinking water is 10 mg/L (U.S. Environmental Protection Agency, 2005).

Nitrate concentrations and variations in those concentrations in samples from the 26 wells were investigated to determine whether there is a relation between occurrence of nitrate 

in samples from wells and intersection of flow paths by those 

wells. For example, if nitrate is elevated in surface runoff, then 

water at wells that intersect flow paths might be more likely to 

contain relatively high nitrate concentrations.

For Group C1 wells (FMW, KCH, SLR, SVE), specific 

conductance is inversely correlated with recent streamflow and 

aquifer flow condition, and the wells thus are interpreted as 

intersecting major flow paths; these wells have water with 

nitrate concentrations consistently less than 2.0 mg/L, except 

for well KCH, with nitrate concentrations ranging from 3.8 to 

8.6 mg/L (fig. 14A). Nitrate concentrations at all four wells, 

however, are independent of specific conductance, which indicates that there is no relation between nitrate concentrations and 

recent recharge. The occurrence of elevated nitrate concentrations in only one of the Group C1 wells indicates that the nitrate 

occurrence more likely is related to localized sources rather 

than connection to focused recharge. However, given that the 

highest nitrate concentrations of all 26 wells in this report 

occurred at well KCH, the likelihood that well KCH (and other 

Group C1 wells) intersects a major flow path or conduit might 

cause it to be more vulnerable to localized sources of contamination than wells in the other groups. Although the source of 

nitrate in well KCH cannot be identified from the data reported 

here, historically, a goat ranch was near this well (D.A. Johns, 

City of Austin, written commun., 2005), and agricultural runoff 

is a known source of nitrate in ground water.

For Group C2 wells (BDW, HWD, MCH, SVN, SVW), 

specific conductance is inversely correlated with recent streamflow, and these wells thus are interpreted as intersecting minor 

flow paths; nitrate concentrations in water from these wells 

were consistently less than 2.0 mg/L except for well SVW, with 

concentrations from 1.4 to 2.8 mg/L, and well MCH, with one 

concentration of 4.0 mg/L (fig. 14B). For wells BDW, HWD, 

MCH, and SVW, nitrate concentrations are positively correlated with specific conductance. If specific conductance is interpreted as a measure of the proportion of ground water in relation 

to recharge water (less recharge water results in higher specific 

conductance), then an increase in nitrate with an increase in specific conductance indicates that the ground water at these wells 

has higher ambient concentrations of nitrate than the surface 

water. Water at well SVN has relatively constant nitrate concentrations over a wide range of specific conductances.

For Group P wells (FOW, GHW, LWK, ROL, SVS, 

WGF), specific conductance is positively correlated with spring 

discharge, and these wells thus are interpreted as not intersecting a flow path or conduit; nitrate concentrations in water from 

these wells are consistently 2.0 mg/L or less except for most 

samples at well SVS and one sample at well FOW (fig. 14C). 

Nitrate concentrations in water from well SVS had a median of 

3.1 mg/L and were about two times higher than concentrations 

in water from the other Group P wells. Although the specific 

source of elevated nitrate at well SVS is not known, this well is 

in an urbanized region of the aquifer with numerous potential 

nitrate sources such as landscaping, septic systems, and wastewater infrastructure. Only well ROL shows a relation between 

nitrate concentration and specific conductance that might result 

from mixing of ground water with surface water. 

For Group N wells (BCK, BPS, CNE, HND, ISD, JBS, 

PLS, RAB, SNL, TNR, WBG), specific conductance is not correlated with either recent streamflow or spring discharge, thus 
30 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

SULFATE (SO 4) + CHLORIDE (Cl)

CALCIUM (Ca) + MAGNESIUM (Mg)

80 80

60

40

20

20

40

60

80

60

40

20

20

40

60

80

100 100

100 100

0

0

0

0

ANIONS

60 80 100

CHLORIDE (Cl)

CARBONATE (CO3

) + BICARBONATE (HCO3

)

100

0 20 40

SULFATE (SO4

)

80

60

40

20

100

0

20

40

60

80

0

MAGNESIUM (Mg)

SODIUM (Na) + POTASSIUM (K)

CATIONS

CALCIUM (Ca)

100 80 60 40 20 0

100

80

60

40

20

100

0

20

40

60

80

0

PERCENT MILLIEQUIVALENTS

EXPLANATION

BPS HND ISD JBS PLS SNL TNR

BCK

CNE

RAB

WBG

BPS HND ISD JBS PLS SNL TNR

BCK

CNE

RAB

WBG

EXPLANATION

Edwards aquifer recharge zone

Edwards aquifer confined zone

Well and identifier—

Referenced in table 1

HND

PLS

BPS

CNE

5 KILOMETERS

0 5 MILES

0

Group N well locations

Williamson

Slaughter

Creek

COLORADO RIVER

Shoal

Creek

 LAKE

AUSTIN

AUSTIN

TRAVIS COUNTY

HAYS COUNTY

boundary

Ground-water divide

Creek

Creek

Bear

Creek

Onion

Creek

Barton

Bear

Little

Creek

TOWN LAKE

N A

SNL

BCK

RAB

WBG

JBS

TNR

ISD

Saline

zone

Figure 13. Trilinear diagram and graphs showing geochemistry for wells in Group N (specific conductance not correlated with either 

streamflow or spring discharge), Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003.
Nitrate Geochemistry 31

Figure 13. Continued.

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

LOG OF SULFATE CONCENTRATION

LOG OF MAGNESIUM CONCENTRATION

1.0 1.2 1.4 1.6 1.8 2.0

200 400 600 800 1,000 1,200 1,400 1,600

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELISUS

LOG OF RATIO OF 

SULFATE CONCENTRATION TO 

CHLORIDE CONCENTRATION

2.0

1.5

1.0

0.5

0

-0.5

-1.0

LOG OF RATIO OF 

MAGNESIUM CONCENTRATION TO 

SODIUM CONCENTRATION

1.2

1.0

0.8

0.6

0.4

0.2

0

MOLAR RATIO OF

MAGNESIUM TO CALCIUM

-0.8

-0.4

0

0.4

0.8

1.2

C

B

D

Saline zone

Trinity aquifer

or increasing

residence time, 

or both

Trinity aquifer

Saline zone

BCK

BPS

CNE

HND

ISD

JBS

PLS

RAB

SNL

TNR

WBG

EXPLANATION
A

C

D

FMWKCHSLRSVE

FOWGHWLWKROLSVSWGF

350 550 750 950 1,150 1,350 1,550 350 550 750 950 1150 

350 550 750 950 1,150 1,350 1,550

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

350 550 750 950 1,150 

SPECIFIC CONDUCTANCE, IN MICROSIEMENS PER 

AT 25 DEGREES CELSIUS

8.06.04.02.0

0

8.06.04.02.0

N

0 ITRATE CONCENTRATION (AS NITROGEN),

IN MILLIGRAMS PER LITER

8.06.04.02.0

0

8.06.04.02.0

0

NITRATE CONCENTRATION (AS NITROGEN),

IN MILLIGRAMS PER LITER

Figure 14. Nitrate nitrogen concentration relative to specific conductance for samples from wells in (A) Group C1 (specific conductance negatively 

streamflow and spring discharge), (B) Group C2 (specific conductance negatively correlated with streamflow only), (C) Group P (specific conductance spring discharge), and (D) Group N (specific conductance not correlated with either streamflow or spring discharge), Barton Springs segment of the ETexas, 1978–2003.

B
Nitrate Geochemistry 33

these wells are interpreted as not intersecting a flow path or conduit; nitrate concentrations at all wells in Group N are less than 

2.0 mg/L except for one sample from well JBS and three samples from well HND (fig. 14D). Wells CNE and WBG have the 

lowest nitrate concentrations of the 26 wells in this report. 

These two wells are near the chemically reducing saline zone 

(Sharp and Clement, 1989), and the low nitrate concentrations 

might be the result of denitrification, a biological process that 

converts nitrate to nitrogen gas under reducing conditions 

(Freeze and Cherry, 1979).

Of the 26 wells from which data were analyzed for this 

study, seven had nitrate concentrations that exceeded 2.0 mg/L 

in one or more samples (wells FOW, HND, JBS, KCH, MCH, 

SVS, SVW) (fig. 15; appendix 4). Flow-path intersection by 

wells does not appear to be related to nitrate occurrence, as the 

seven wells are distributed evenly among the four groups of 

wells (C1, C2, P, and N). Geographic location and land use, 

however, might affect nitrate occurrence: If the 26 wells of this 

study are divided into two groups, 13 to the north (well HND 

and all those to the north) and 13 to the south (well FMW and 

all those to the south) (fig. 1), five of the seven wells with one 

Figure 15. Distribution of nitrate nitrogen concentrations for wells in Group C1 (specific conductance negatively correlated with both 

streamflow and spring discharge), in Group C2 (specific conductance negatively correlated with streamflow only), in Group P (specific 

conductance positively correlated with spring discharge), and in Group N (specific conductance not correlated with either streamflow or 

spring discharge), Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003. 

(11) (35) (5) (17)

(16) (26) (12) (29) (43)

(14) (20)

(25) (5) (29)

(6) (35) (9)

(3) (5) (5)

(5) (11) (15)

(17) (6) (5)

WBG

TNR

SNL

RAB

PLS

JBS

ISD

HND

CNE

BPS

BCK

WGF

SVS

ROL

LWK

GHW

SVW FOW

SVN

MCH

HWD

BDW

KCH

SVE

SLR

FMW

GROUP C1

WELLS

GROUP N

WELLS

GROUP P

WELLS

GROUP C2

WELLS

10

8

6

4

2

0

NITRATE CONCENTRATION, IN MILLIGRAMS PER LITER

Threshold for potential

anthropogenic sources

EXPLANATION

Number of samples 

Data value greater than or equal to 1.5 times

the interquartile range outside the box

Largest data value within 1.5 times the

interquartile range above the box

75th percentile

Median (50th percentile)

25th percentile

Smallest data value within 1.5 times the

interquartile range below the box

Interquartile range {

(29)
34 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

or more sample concentrations exceeding 2.0 mg/L are among 

the 13 wells to the north. The increased incidence of wells with 

nitrate concentrations greater than 2.0 mg/L to the north coincides with increased urban land use and increased population 

density to the north (Bio-West, 2001; Mahler and Massei, 

2007). Water in only two wells, KCH and SVS, had chronic 

nitrate contamination, defined as a median concentration 

exceeding 2.0 mg/L (fig. 15). 

Comparison of Findings With Those of Other 

Studies

Wells for which data were analyzed for this report have 

been sampled for other studies, the objective of which was to 

assess the relation of geochemistry to surface-water processes. 

Andrews and others (1984, p. 27) reported high counts of fecal 

streptococci bacteria in well JBS (44,000 colonies per 100 milliliters), indicating a connection to the surface or contamination 

from wastewater, or both. However, the methods of this report 

resulted in classification of well JBS in Group N, and no 

conclusions were made. One possibility is that well JBS does 

intersect a flow path, but the small specific conductance dataset 

(13 values) was not sufficient to establish a connection to a flow 

path. Another possibility is that bacterial contamination of well 

JBS is caused by a localized source such as a septic tank or leaking wastewater infrastructure. A sewage lift station in nearby 

Dry Creek historically has been responsible for accidental 

sewage releases (Hauwert and Vickers, 1994) and is a probable 

source for bacterial contamination in well JBS. Sewage contamination is consistent with the data of Andrews and others 

(1984), as specific conductance and bacteria levels do not 

co-vary in well JBS, as would be expected if it were receiving 

low-ionic-strength surface-water recharge.

Senger and Kreitler (1984) reported a hydrologic connection between wells RAB and SVE and Barton Springs Pool; 

water-level changes in the pool result in near-simultaneous 

water-level changes in these two wells. The responses indicate 

that these wells intersect transmissive conduits that connect to 

Barton Springs. Similarly, Hauwert and Vickers (1994, p. 13) 

indicated that well SVE has “good hydraulic connection to 

recharge areas” after observing a 1-foot rise in water levels following a rainfall event in August 1994. Hauwert and Vickers 

(1994) also reported that well RAB contained 2.1 mg/L total 

petroleum hydrocarbons in 1993, which indicates an anthropogenic source of contamination for this well. These findings are 

consistent with the conclusion of this report regarding major 

flow-path intersection by well SVE and are not contradicted by 

the inconclusive results of this report for well RAB. 

Hauwert and Vickers (1994) reported several instances of 

sediment filling wells or discharging with pumped well water 

and hypothesized that sediment in a well or its water might indicate that such a well intersects a flow path with rapidly moving 

water carrying sediment. Sediment might also originate from 

within the aquifer itself (autochthonous) and might be mobilized by drilling in the aquifer. Hauwert and Vickers (1994) 

reported that well SVN accumulated more than 100 feet of sediment from 1978 to 1993, which is consistent with the conclusion of this report that well SVN intersects a minor flow path. 

Well SVS was reported to contain fine, cream-colored sediment 

in its pumped water, although the findings of this report are 

inconclusive for well SVS. Similarly, well HND was reported 

to have a small amount of sediment (less than 50 mg/L total suspended solids) in its pumped water, but the findings of this 

report are inconclusive for this well.

Hauwert and others (2004) reported detection of dye from 

a dye-trace at well SVW. The dye had been injected in Williamson Creek several days earlier, indicating that well SVW intersects a flow path that connects to Williamson Creek. This finding is consistent with the conclusions of this report.

The City of Austin (1997) conducted an investigation with 

some of the same major ion data used in this study. They concluded that wells BDW, FMW, KCH, ROL, and SVW might be 

affected by urbanization, which is consistent with the findings 

of this study that these wells intersect flow paths. The City of 

Austin also identified well SVS as potentially being affected by 

urbanization. Well SVS was classified in Group P for this 

report, and the processes controlling water in the aquifer at that 

well are not well understood. Finally, wells RAB and TNR were 

noted by the City of Austin (1997) as potentially having been 

affected by urbanization, although the findings of this report are 

inconclusive.

Value of Statistical Approach

The results of this investigation demonstrate that a longterm geochemical dataset can be of value in characterizing the 

degree to which wells intersect conduits and flow paths. 

Although analysis of multiple samples collected at intervals of 

hours to days after rainfall remains the most effective way to 

evaluate the influence of surface water on geochemistry, this 

study shows that if a sufficient amount of historical data exists, 

the data can be analyzed statistically to assess surface-water/

ground-water interaction in a karst aquifer. However, there are 

some limitations on the statistical approach of this report.

In those parts of a karst aquifer where transport occurs, the 

geochemistry can vary greatly and rapidly. The effects of 

recharging surface water might be extreme but ephemeral, 

occurring during only a small part of the year. If the timing of 

sampling is random, many water samples might reflect baseflow conditions during which the geochemistry varies little. 

Thus either a large number of samples, or random chance, is 

required to collect samples that reflect the full range of 

geochemical variability that might occur at a site. Five of the 11 

wells in the group for which no statistically significant correlations were observed (Group N) had the minimum number of 

specific conductance measurements (six) (fig. 16), which indicates that six specific conductance measurements might be too 

few to capture the range of geochemical variability possible at 
Value of Statistical Approach 35

a well. Additional well sampling might have resulted in fewer 

wells placed in Group N. For example, many wells were no 

longer sampled after 1983, and continued sampling might have 

resulted in identifying them as intersecting flow paths. Thus 

wells with small sample sets and no statistically significant 

negative relation between specific conductance and either 

streamflow or aquifer flow condition cannot be definitively 

interpreted as not intersecting a flow path, but rather as having 

insufficient evidence to interpret as intersecting a flow path.

Four of the five wells in this report with the greatest 

geochemical variability (SVE [Group C1], SVN [Group C2], 

FOW [Group P], ROL [Group P], and RAB [Group N]) had 

more than 30 specific conductance measurements (fig. 16); all 

four of these wells had statistically significant correlations 

between specific conductance and streamflow or spring discharge, or both. This indicates that a large sample set might be 

necessary to capture short-term geochemical variability and 

evidence of connection to surface-water sources or flow-path 

intersection. However, another possible explanation is that 

wells with the largest sample sets were deliberately selected for 

extended sampling on the basis of variability in geochemical 

composition observed early on during the sampling program. In 

other words, large sample-set size and large geochemical variability might not be independent.

Finally, although an estimated 85 percent of aquifer 

recharge is from creeks, the authors were unable to quantitatively consider the remaining 15 percent of recharge (referred to 

as interstream recharge). There is some evidence that interstream recharge might rapidly reach the aquifer at some Groups 

C1 and C2 wells (particularly at shallow well SLR). The data 

available for this report cannot be used to determine the degree 

to which wells are affected by interstream recharge. However, 

it is likely that periods of interstream recharge and streamflow 

are correlated, and thus the statistical approach used here might 

have identified some sites as being affected by streamflow 

when in fact they are being affected by interstream recharge.

Figure 16. Relation between the number of specific conductance measurements at a well and the range of specific conductance at that 

well, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003. 

NUMBER OF SPECIFIC CONDUCTANCE MEASUREMENTS

AT A WELL

RANGE OF SPECIFIC CONDUCTANCE AT A

0 10 20 30 40 50 60 70

WELL, IN MICROSIEMENS PER CENTIMETER

AT 25 DEGREES CELSIUS

0

400

800

1,200

SVN FOW

ROL

SVE

RAB

Group C1—Negative correlation between specific conductance

and both streamflow and spring discharge

Group C2—Negative correlation between specific conductance

and streamflow

Group P—Positive correlation between specific conductance

and spring discharge

Group N—No correlation between specific conductance and

either streamflow or spring discharge

Well, by group, and identifier—The five wells with the

greatest geochemical variability are identified

EXPLANATION

ROL

SVE

RAB

SVN
36 Relation of Specific Conductance in Ground Water to Intersection of Flow Paths . . . Austin, Texas, 1978–2003

Summary

Understanding of karst flow systems is complicated by the 

presence of solution-enlarged conduits, which can transmit 

large volumes of water through the aquifer rapidly. Ground 

water at wells that intersect conduits (and thus major flow 

paths) can be characterized by temporally variable geochemistry that is related to surface-water processes. If the geochemistry at a well can be related to streamflow or spring discharge, or 

both, the relations can indicate the presence of recent recharge 

in water at the well, which in turn might indicate that the well 

intersects a conduit. Increasing knowledge of the occurrence 

and distribution of conduits in the aquifer can contribute to better understanding of aquifer framework and function.

The U.S. Geological Survey (USGS), in cooperation with 

the City of Austin, sampled 26 wells in the Barton Springs 

segment of the Edwards aquifer from 1978 through 2003 for a 

variety of water-quality constituents. In this report, this historical (1978–2003) dataset is used to identify wells that intersect 

flow paths in the aquifer. Statistical correlations between specific conductance at wells and streamflow or Barton Springs 

discharge, or both, are used to identify wells that intersect flow 

paths. Specific conductance, an overall indicator of water 

geochemistry, can act as a tracer of recently infiltrated surface 

water in a karst aquifer—recent recharge water will have a 

lower specific conductance than water that has been in the aquifer for a longer period of time. The specific conductance of 

water at a well that intersects a flow path thus should change in 

response to an inflow of recent recharge. Major ion geochemistry data also are interpreted to better understand aquifer processes; interpretive tools include summary statistics, trilinear 

diagrams, and concentration and molar ratios. Dissolved ions in 

Barton Springs segment ground water can originate from several sources including limestone, trace elements and minerals in 

limestone, surface water, the saline zone, and the Trinity aquifer. Finally, nitrate geochemistry is examined to determine 

whether there is a relation between flow-path intersection by 

wells and nitrate occurrence. 

A large dataset consisting of geochemical, streamflow, 

and spring discharge data exists for the Barton Springs segment. 

A USGS study sampled about 30 water wells several times a 

year from 1978 through 1983 for numerous water-quality 

constituents, including specific conductance, major ions, and 

nitrate. From 1983 through 2003, about 11 of these wells continued to be sampled periodically. The specific conductance 

dataset for the 26 wells of this report consists of 679 values 

ranging from 388 to 1,530 μS/cm. Streamflow and spring discharge have been measured by the USGS since 1978, and each 

dataset consists of about 9,000 daily mean values. High streamflow and spring discharge were assumed to indicate high 

recharge rates and high aquifer flow conditions, respectively.

All wells except three were cased into and completed in the 

Edwards aquifer; three wells in the recharge zone were drilled 

partly into the Trinity aquifer. Specific conductance was 

measured during all USGS well samplings. Samples for major 

ion and nitrate analysis were analyzed by the USGS National 

Water Quality Laboratory after being collected, filtered, and 

acidified in the field. Analytical methods changed through the 

years, but methods were assumed to be consistent enough to 

allow a uniform comparison of all results.

Data for each well were tested to indicate whether there 

was a statistical relation between specific conductance and 

streamflow and a relation between specific conductance and 

Barton Springs discharge. For each specific conductance value, 

the maximum daily mean streamflow for each of the five 

recharging creeks and the maximum daily mean dischare for 

Barton Springs for the 10 days preceding the specific conductance measurement were recorded. The relations between 

specific conductance and the corresponding streamflow and 

between specific conductance and the corresponding spring discharge were tested using Spearman’s rho correlation coefficient, a nonparametric test used when data are not normally distributed. Results of the Spearman’s rho test were used to divide 

the 26 wells into four groups:

• Group C1 comprises four wells whose samples showed 

a significant (p < .05) negative correlation between specific conductance and both streamflow and spring discharge. These wells are hypothesized to intersect major 

flow paths, and these flow paths likely integrate water 

from a large volume of the aquifer. The hydrochemical 

facies of Group C1 wells, with one exception, are 

Ca-HCO3 to Ca-Mg-HCO3. The one exception trends 

toward mixed-SO4 or Na-mixed facies and shows evidence of mixing with saline zone water, but only when 

streamflow and spring discharge are low. 

• Group C2 comprises five wells whose samples showed 

a significant negative correlation between specific conductance and streamflow only. These wells are hypothesized to intersect minor flow paths (short, tributary 

conduits) that connect to the surface; minor flow paths 

probably have smaller catchment areas than major flow 

paths. Water at Group C2 wells shows little evidence of 

mixing with Trinity aquifer or saline zone water. 

• Group P comprises six wells whose samples showed a 

significant positive correlation between specific conductance and spring discharge. These wells thus are 

interpreted as not intersecting a flow path (conduit). 

Water at Group P wells has a tendency to become more 

mineralized when Barton Springs discharge is high. In 

some cases, this might be caused by mixing with Trinity aquifer water. Water at four of these wells has a 

range in specific conductance of less than 100 μS/cm, 

thus the phenomenon of increased mineralization 

during high spring discharge is minor in some cases. 

• Group N comprises 11 wells whose samples showed no 

significant correlation between specific conductance 

and either streamflow or spring discharge. Most wells 

in this group had a small number of specific conductance measurements and thus might have been classified in Group N because the full range of geochemical 
References 37

variability at these wells is not reflected by the data. 

Unidentified processes unrelated to changes in streamflow or spring discharge also might affect water at 

Group N wells. 

On the basis of statistical and geochemical analysis, four 

wells appear to intersect major flow paths, five appear to intersect minor flow paths, and no conclusions are made for the 

remaining wells. Wells that intersect major flow paths (Group 

C1 wells) integrate water from a large aquifer volume, and 

might be vulnerable to both localized and distant sources of 

contamination. Wells that intersect minor flow paths (Group C2 

wells) integrate water only from a small catchment area, and are 

likely vulnerable to localized sources of contamination. Any 

well that intersects a flow path is affected by the geochemistry 

of recharging surface water. Wells in Groups P and N do not 

show evidence of flow-path intersection, but this could be the 

result of small sample sets or unknown geochemical processes, 

or both.

Water from the Trinity aquifer and the saline zone appears 

to mix with Barton Springs segment ground water under some 

hydrologic conditions. In a few areas, Trinity aquifer water 

might enter the Barton Springs segment by upward leakage 

from the underlying Trinity aquifer, and geochemical data indicate that this is more likely to occur when spring discharge is 

high. Saline zone water appears to mix with Barton Springs segment ground water; this phenomenon generally is associated 

with wells that intersect flow paths, and is associated with low 

streamflow and spring discharge. 

Despite the spatial heterogeneity inherent in karst, some 

observations were made regarding geography and geochemistry. Mg/Ca molar ratios (residence-time indicators) at Group C1 

wells increase in a downgradient direction, consistent with the 

hypothesis that Group C1 wells intersect major flow paths that 

integrate water from large volumes of the aquifer. Group C1 

wells generally are near aquifer flow paths delineated by independent dye-tracing studies, supporting the hypothesis that 

these wells intersect major flow paths. Wells that intersect 

minor flow paths mostly are in the recharge zone; this is logical, 

given that minor flow paths are short by nature, and any flow 

path in the confined zone must be longer and thus a more major 

flow path.

Concentrations and variation in nitrate concentrations 

were investigated to determine whether there was a relation 

between occurrence of nitrate in samples from wells and intersection of flow paths by those wells. For example, if nitrate is 

elevated in surface runoff, then water at wells that intersect flow 

paths might be more likely to contain high nitrate concentrations. Of the 26 wells, seven had nitrate concentrations in one or 

more samples that exceeded 2.0 mg/L, considered the upper 

limit of concentrations from natural sources. Flow-path intersection by wells does not appear to be related to nitrate occurrence, as the seven wells are distributed evenly among the four 

groups of wells (C1, C2, P, and N). However, most of the wells 

with one or more samples contaminated by nitrate are in the 

more densely populated parts of the study area.

Other studies independently analyzed water at wells used 

in this report, and the findings in this report support or do not 

contradict findings of the other studies. This report demonstrates that a statistical and geochemical analysis of a historical 

dataset can be useful for determining the degree to which wells 

intersect karst features, although high-frequency sampling 

remains the most effective tool for karst geochemical investigation. This report necessarily relied upon a large dataset, as well 

as some degree of random chance to capture the full range of 

geochemical variability at a well. Wells with large sample sets 

generally show larger geochemical variability, but this might be 

the result of deliberate choices made by sampling personnel. 

This report was unable to quantitatively consider interstream 

recharge, although it is likely that interstream recharge and 

streamflow are correlated, and thus water at some wells might 

have been identified as being affected by streamflow when it 

was being affected by interstream recharge.

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Maclay, R.W., and Land, L.F., 1988, Simulation of flow in the 

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Blank Page 
Appendix 1—Specific Conductance Data
 
Blank Page 
Specific Conductance, and Associated 

Major Ion and Nitrate Geochemistry, 

Edwards Aquifer, Austin, Texas, 

1978–2003

Appendix 1

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and

corresponding maximum 10 day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas,

1978–2003—Continued.

Appendix 1 43 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003. -

[μS/cm, microsiemens per centimeter at 25 degrees Celsius; ft

3

/s, cubic feet per second; --, no data] 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)


identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

BCK 

BCK 

BCK 

BCK 

BCK 

6/28/1978 

7/17/1979 

8/28/1980 

8/11/1981 

8/10/1982 

1000 

1230 

1000 

0830 

0920 

630 

630 

659 

538 

618 

0.7 

17.0 

0 

11.0 

1.1 

0.2 

.9 

0 

0 

0 

0.1 

2.1 

0 

.5 

.1 

--

2.5 

.1 

2.2 

.4 

--

16.0 

1.1 

19.0 

1.2 

31 

100 

41 

99 

49 

BCK 

BDW 

BDW 

BDW 

BDW 

7/19/1983 

6/14/1990 

8/22/1990 

3/19/1991 

5/7/1991 

0835 

1355 

1350 

1020 

1325 

649 

593 

603 

565 

584 

--

41.0 

.6 

87.0 

105.0 

7.7 

.5 

.5 

7.6 

10.0 

1.4 

.6 

0 

6.4 

8.0 

22.0 

1.8 

0 

11.0 

20.0 

90.0 

30.0 

2.2 

68.0 

151.0 

84 

49 

26 

85 

99 

BDW 

BDW 

BDW 

BDW 

BDW 

8/13/1991 

4/30/1992 

1/22/1993 

1/25/1993 

5/8/1993 

1220 

1120 

1220 

1342 

1145 

600 

594 

590 

589 

584 

2.5 

94.0 

262.0 

262.0 

123.0 

0 

3.5 

16.0 

16.0 

1.2 

.2 

4.7 

21.0 

21.0 

16.0 

.4 

8.5 

9.0 

9.0 

10.0 

6.5 

81.0 

231.0 

231.0 

73.0 

75 

115 

100 

100 

108 

BDW 

BDW 

BDW 

BDW 

BDW 

5/11/1993 

5/15/1993 

8/18/1993 

4/15/1994 

6/14/1995 

1500 

0835 

1200 

1000 

1055 

593 

589 

594 

591 

590 

123.0 

123.0 

.5 

6.7 

347.0 

1.2 

0 

0 

0 

12.0 

16.0 

16.0 

0 

0 

108.0 

10.0 

10.0 

.1 

.3 

32.0 

73.0 

73.0 

.5 

8.4 

294.0 

108 

108 

86 

47 

104 

BDW 

BDW 

BDW 

BDW 

BDW 

4/25/1996 

7/8/1997 

4/21/1998 

6/11/1999 

6/2/2000 

0930 

1615 

1130 

0945 

1300 

582 

585 

587 

595 

591 

.7 

322.0 

79.0 

21.0 

2.5 

0 

.9 

0 

0 

0 

0 

21.0 

8.9 

1.4 

0 

.1 

26.0 

7.5 

1.4 

.1 

.9 

510.0 

96.0 

4.9 

1.2 

25 

113 

98 

73 

22 

BDW 

BDW 

BDW 

BPS 

BPS 

6/5/2001 

6/5/2002 

5/20/2003 

7/12/1978 

7/24/1978 

1300 

1300 

1300 

1045 

1010 

595 

606 

577 

580 

572 

43.0 

7.2 

12.0 

--

--

0 

0 

0 

0 

.3 

1.7 

.1 

.3 

0 

1.1 

3.3 

.7 

1.3 

--

--

71.0 

3.8 

12.0 

--

--

103 

88 

102 

25 

21 

BPS 

BPS 

BPS 

BPS 

BPS 

8/24/1979 

8/1/1980 

8/29/1980 

7/30/1981 

8/12/1981 

1410 

1315 

0815 

1400 

0810 

588 

583 

578 

583 

568 

9.6 

.4 

0 

29.0 

11.0 

1.8 

0 

0 

1.0 

0 

1.8 

0 

0 

1.4 

.4 

4.1 

.3 

.1 

4.2 

2.1 

10.0 

1.3 

1.0 

50.0 

17.0 

94 

54 

40 

103 

98 

BPS 

BPS 

BPS 

BPS 

BPS 

7/19/1982 

7/22/1983 

6/27/1984 

9/13/1984 

2/20/1985 

1130 

1215 

1508 

1225 

1159 

586 

539 

584 

590 

586 

4.1 

--

--

--

--

0 

7.7 

0 

0 

6.3 

.5 

1.4 

0 

0 

1.6 

1.4 

22.0 

0 

0 

8.3 

10.0 

90.0 

4.6 

.2 

93.0 

60 

84 

27 

26 

72 

BPS 6/19/1985 0830 580 -- 2.4 4.0 5.6 145.0 70 

BPS 8/9/1985 1345 598 -- 0 .2 .9 15.0 64 

BPS 1/14/1986 0845 579 -- 1.5 2.6 5.2 54.0 78 

BPS 5/3/1986 0855 500 -- 59.0 3.2 6.4 38.0 62 

BPS 6/24/1986 1420 591 -- 13.0 20.0 16.0 216.0 84 
44 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

BPS 

BPS 

BPS 

BPS 

BPS 

6/25/1986 

9/3/1986 

2/11/1987 

5/20/1987 

6/1/1987 

1240 

0849 

0930 

1315 

0925 

592 

589 

588 

595 

591 

--

--

--

--

--

13.0 

0 

1.3 

12.0 

149.0 

20.0 

0 

3.2 

2.6 

93.0 

16.0 

.4 

8.9 

2.8 

41.0 

216.0 

5.8 

76.0 

38.0 

392.0 

84 

61 

80 

100 

110 

BPS 

BPS 

BPS 

BPS 

BPS 

8/19/1987 

2/29/1988 

5/3/1988 

7/19/1988 

8/17/1988 

1335 

0845 

1355 

1322 

0955 

605 

589 

575 

572 

597 

--

--

--

--

--

0 

.1 

1.4 

2.0 

1.2 

0 

.6 

.1 

0 

0 

1.6 

.9 

1.1 

.8 

0 

33.0 

8.5 

7.8 

7.5 

3.2 

110 

61 

50 

45 

45 

BPS 

BPS 

BPS 

BPS 

BPS 

2/27/1989 

5/3/1989 

7/17/1989 

8/29/1989 

1/29/1990 

1520 

0930 

1240 

1145 

1320 

596 

583 

563 

581 

585 

1.0 

15.0 

8.9 

.4 

.6 

.3 

.2 

2.0 

0 

0 

0 

0 

.2 

0 

0 

.1 

3.4 

2.9 

0 

0 

2.4 

5.4 

12.0 

2.7 

.4 

27 

33 

55 

33 

18 

BPS 

BPS 

BPS 

BPS 

BPS 

6/5/1990 

8/14/1990 

3/22/1991 

5/15/1991 

8/13/1991 

1225 

1355 

0825 

0850 

1305 

587 

566 

586 

569 

591 

41.0 

1.6 

87.0 

261.0 

2.5 

7.1 

0 

7.6 

68.0 

0 

1.0 

.1 

6.4 

38.0 

.2 

2.5 

0 

11.0 

48.0 

.4 

80.0 

2.2 

68.0 

218.0 

6.5 

50 

31 

85 

99 

75 

BPS 

BPS 

BPS 

BPS 

BPS 

4/30/1992 

8/28/1992 

5/11/1993 

8/19/1993 

8/20/1993 

1240 

1100 

1110 

1220 

0805 

589 

584 

584 

539 

579 

94.0 

4.2 

123.0 

.4 

.4 

3.5 

0 

1.2 

0 

0 

4.7 

0 

16.0 

0 

0 

8.5 

.5 

10.0 

0 

0 

81.0 

9.5 

73.0 

.3 

.3 

115 

125 

108 

86 

86 

BPS 

BPS 

BPS 

BPS 

BPS 

4/14/1994 

6/14/1995 

5/9/1996 

7/8/1997 

4/22/1998 

1215 

0930 

0900 

1435 

0830 

578 

585 

576 

575 

565 

6.9 

347.0 

.6 

322.0 

76.0 

0 

12.0 

0 

.9 

0 

0 

108.0 

0 

21.0 

8.4 

.3 

32.0 

0 

26.0 

7.2 

9.5 

294.0 

.5 

510.0 

93.0 

47 

104 

25 

113 

98 

BPS 

BPS 

BPS 

BPS 

BPS 

6/11/1999 

6/2/2000 

6/12/2001 

6/6/2002 

5/22/2003 

0800 

1500 

1100 

1100 

1100 

591 

592 

593 

596 

591 

21.0 

2.5 

21.0 

7.2 

11.0 

0 

0 

0 

0 

0 

1.4 

0 

1.0 

.1 

.3 

1.4 

.1 

2.2 

.7 

1.3 

4.9 

1.2 

41.0 

3.8 

12.0 

73 

22 

100 

88 

102 

CNE 

CNE 

CNE 

CNE 

CNE 

7/24/1978 

7/11/1979 

9/4/1980 

8/12/1981 

8/11/1982 

1015 

0950 

0900 

1230 

0930 

1,040 

1,060 

1,030 

996 

1,020 

27.0 

0 

11.0 

1.1 

.3 

5.2 

0 

0 

0 

1.1 

4.7 

0 

.4 

0 

2.6 

0 

2.1 

.3 

18.0 

.5 

17.0 

1.5 

21 

102 

38 

98 

49 

CNE 7/21/1983 1425 1,060 -- 7.7 1.4 22.0 90.0 84 

FMW 8/11/1981 0950 531 11.0 0 .5 2.2 19.0 99 

FMW 8/4/1982 1340 566 1.1 0 .1 .5 2.0 51 

FMW 7/19/1983 1245 568 -- 7.7 1.4 22.0 90.0 84 

FMW 6/19/1985 1200 547 -- 2.4 4.0 5.6 145.0 70 

FMW 8/8/1985 0930 567 -- 0 .2 1.0 15.0 64 

FMW 1/15/1986 1235 545 -- 1.5 2.6 5.2 54.0 78 

FMW 5/3/1986 1145 568 -- 59.0 3.2 6.4 38.0 62 

FMW 6/25/1986 0950 564 -- 13.0 20.0 16.0 216.0 84 

FMW 9/3/1986 1020 568 -- 0 0 .4 5.8 61 
Appendix 1 45 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

FMW 2/9/1987 1230 552 -- 1.3 3.4 9.3 81.0 83 

FMW 5/21/1987 0815 553 -- 12.0 2.6 2.8 38.0 100 

FMW 6/1/1987 1305 535 -- 149.0 93.0 41.0 392.0 110 

FMW 8/18/1987 1410 564 -- 0 0 1.6 34.0 110 

FMW 2/25/1988 0910 573 -- .1 .6 1.2 8.6 63 

FMW 

FMW 

FMW 

FMW 

FMW 

5/3/1988 

2/23/1989 

5/1/1989 

7/17/1989 

8/21/1989 

1120 

1335 

1210 

1410 

1345 

574 

560 

600 

585 

587 

--

0.9 

19.0 

8.9 

.6 

1.4 

.3 

.3 

2.0 

0 

.1 

0 

0 

.2 

0 

1.1 

.1 

3.7 

2.9 

0 

7.8 

1.4 

7.3 

12.0 

3.5 

50 

28 

36 

55 

36 

FMW 

FMW 

FMW 

FMW 

FMW 

3/5/1991 

5/7/1991 

8/19/1991 

4/28/1992 

1/21/1993 

1320 

1000 

1250 

1130 

1550 

571 

561 

561 

545 

536 

106.0 

105.0 

467.0 

115.0 

262.0 

8.5 

10.0 

107.0 

4.7 

16.0 

14.0 

8.0 

42.0 

6.2 

21.0 

15.0 

20.0 

11.0 

11.0 

9.0 

82.0 

151.0 

58.0 

98.0 

231.0 

87 

99 

71 

115 

100 

FMW 

FMW 

FMW 

FMW 

FMW 

1/24/1993 

1/28/1993 

5/8/1993 

5/11/1993 

5/15/1993 

1215 

0830 

0820 

1614 

1036 

537 

537 

535 

534 

528 

262.0 

262.0 

123.0 

123.0 

123.0 

16.0 

16.0 

1.2 

1.2 

0 

21.0 

21.0 

16.0 

16.0 

16.0 

9.0 

9.0 

10.0 

10.0 

10.0 

231.0 

231.0 

73.0 

73.0 

73.0 

100 

100 

108 

108 

108 

FMW 

FMW 

FOW 

FOW 

FOW 

8/16/1993 

4/8/1994 

6/28/1978 

7/10/1979 

8/28/1980 

1230 

0750 

1255 

1340 

1145 

537 

563 

620 

620 

686 

.5 

6.9 

.7 

27.0 

0 

0 

0 

.2 

5.2 

0 

0 

0 

.1 

4.7 

0 

.1 

.3 

2.6 

.1 

.5 

9.5 

18.0 

1.1 

87 

47 

31 

102 

41 

FOW 8/11/1981 1055 595 11.0 0 .5 2.2 19.0 99 

FOW 8/10/1982 1115 595 1.1 0 .1 .4 1.2 49 

FOW 7/19/1983 1330 597 -- 7.7 1.4 22.0 90.0 84 

FOW 8/8/1985 0915 641 -- 0 .2 1.0 15.0 64 

FOW 1/14/1986 0700 624 -- 1.5 2.6 5.2 54.0 78 

FOW 

FOW 

FOW 

FOW 

FOW 

5/1/1986 

6/25/1986 

9/3/1986 

2/10/1987 

5/20/1987 

1515 

0800 

0700 

1030 

1450 

635 

748 

610 

625 

647 

--

--

--

--

--

59.0 

13.0 

0 

1.3 

12.0 

3.2 

20.0 

0 

3.4 

2.6 

6.4 

16.0 

.4 

9.3 

2.8 

26.0 

216.0 

5.8 

81.0 

38.0 

62 

84 

61 

83 

100 

FOW 

FOW 

FOW 

FOW 

FOW 

6/1/1987 

8/26/1987 

5/6/1988 

7/18/1988 

8/17/1988 

1445 

1055 

1110 

0845 

0905 

630 

687 

670 

643 

705 

--

--

--

--

--

149.0 

0 

1.4 

2.0 

1.2 

93.0 

0 

.1 

0 

0 

41.0 

1.1 

1.1 

.8 

0 

392.0 

21.0 

7.8 

7.5 

3.2 

110 

107 

50 

45 

45 

FOW 

FOW 

FOW 

FOW 

FOW 

2/27/1989 

5/3/1989 

7/26/1989 

2/9/1990 

6/19/1990 

1045 

0840 

0935 

0930 

0840 

660 

647 

602 

658 

645 

1.0 

15.0 

2.5 

4.3 

7.0 

.3 

.2 

.3 

8.6 

0 

0 

0 

0 

0 

.4 

.1 

3.4 

1.6 

.1 

.5 

2.4 

5.4 

5.5 

1.5 

16.0 

27 

33 

48 

22 

47 

FOW 

FOW 

FOW 

FOW 

FOW 

8/14/1991 

5/1/1992 

1/21/1993 

1/24/1993 

1/28/1993 

1045 

1130 

1225 

1015 

1000 

648 

771 

863 

895 

784 

4.1 

85.0 

262.0 

262.0 

262.0 

12.0 

3.4 

16.0 

16.0 

16.0 

5.9 

4.2 

21.0 

21.0 

21.0 

1.7 

8.1 

9.0 

9.0 

9.0 

6.5 

75.0 

231.0 

231.0 

231.0 

75 

115 

100 

100 

100 
46 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

FOW 

FOW 

FOW 

FOW 

FOW 

5/7/1993 

5/14/1993 

5/27/1993 

8/17/1993 

4/18/1994 

1135 

0900 

1040 

1215 

1030 

775 

791 

758 

697 

645 

123.0 

123.0 

42.0 

.5 

4.9 

1.2 

1.2 

0 

0 

0 

16.0 

16.0 

5.0 

0 

0 

10.0 

10.0 

5.2 

.1 

.3 

73.0 

73.0 

32.0 

.5 

8.2 

108 

108 

108 

87 

46 

FOW 

FOW 

FOW 

FOW 

FOW 

6/19/1995 

5/7/1996 

7/9/1997 

4/23/1998 

6/11/1999 

1110 

0845 

1310 

0730 

1100 

760 

635 

616 

652 

654 

281.0 

.7 

273.0 

73.0 

21.0 

12.0 

0 

0 

0 

0 

108.0 

0 

17.0 

7.9 

1.4 

32.0 

0 

23.0 

6.8 

1.4 

172.0 

.5 

455.0 

90.0 

4.9 

102 

26 

113 

98 

73 

FOW 

FOW 

FOW 

FOW 

GHW 

6/1/2000 

6/19/2001 

6/5/2002 

5/21/2003 

7/12/1978 

1700 

1000 

1000 

1000 

0805 

712 

742 

660 

747 

660 

2.7 

13.0 

7.2 

12.0 

--

0 

0 

0 

0 

0 

0 

.8 

.1 

.3 

0 

.1 

1.7 

.7 

1.3 

--

1.4 

29.0 

3.8 

12.0 

--

22 

97 

88 

102 

25 

GHW 

GHW 

GHW 

GHW 

GHW 

7/9/1979 

8/29/1980 

8/12/1981 

8/16/1982 

7/21/1983 

0950 

1030 

0905 

1015 

0950 

670 

666 

650 

666 

667 

27.0 

0 

11.0 

1.1 

--

5.2 

0 

0 

0 

7.7 

4.7 

0 

.4 

0 

1.4 

2.6 

.1 

2.1 

.2 

22.0 

18.0 

1.0 

17.0 

1.9 

90.0 

103 

40 

98 

46 

84 

GHW 

GHW 

GHW 

GHW 

GHW 

6/19/1985 

8/9/1985 

1/13/1986 

5/1/1986 

6/25/1986 

0930 

1245 

1210 

1635 

1345 

659 

648 

644 

677 

676 

--

--

--

--

--

2.4 

0 

1.5 

59.0 

13.0 

4.0 

.2 

3.0 

3.2 

20.0 

5.6 

.9 

5.7 

6.4 

16.0 

145.0 

15.0 

61.0 

26.0 

216.0 

70 

64 

78 

62 

84 

GHW 

GHW 

GHW 

GHW 

GHW 

9/2/1986 

2/11/1987 

5/20/1987 

5/31/1987 

8/19/1987 

1320 

1315 

1155 

1245 

1515 

671 

672 

685 

656 

683 

--

--

--

--

--

0 

1.3 

12.0 

149.0 

0 

0 

3.2 

2.6 

93.0 

0 

.4 

8.9 

2.8 

41.0 

1.6 

5.8 

76.0 

38.0 

392.0 

33.0 

62 

80 

100 

105 

110 

GHW 2/24/1988 1245 655 -- .1 .6 1.2 8.6 63 

GHW 5/9/1988 1130 670 -- .2 .1 1.1 7.8 50 

GHW 7/14/1988 1230 670 -- 2.0 0 .8 7.5 47 

GHW 8/10/1988 1115 635 -- 0 0 0 11.0 43 

GHW 2/23/1989 0950 640 .9 .3 0 .1 1.4 28 

GHW 5/3/1989 1045 668 15.0 .2 0 3.4 5.4 33 

GHW 7/26/1989 1100 638 2.5 .3 0 1.6 5.5 48 

GHW 8/30/1989 1015 640 .4 0 0 0 2.7 32 

HND 7/5/1978 1100 560 -- 0 0 -- -- 28 

HND 7/11/1979 1400 580 27.0 5.2 4.7 2.6 18.0 102 

HND 9/8/1980 1330 559 .1 8.8 0 .2 29.0 38 

HND 8/11/1981 1440 589 11.0 0 .5 2.2 19.0 99 

HND 8/10/1982 1430 575 1.1 0 .1 .4 1.2 49 

HND 7/20/1983 1330 475 -- 7.7 1.4 22.0 90.0 84 

HND 6/18/1985 1355 516 -- 3.4 5.5 6.1 186.0 70 

HND 8/8/1985 1130 580 -- 0 .2 1.0 15.0 64 

HND 1/13/1986 1020 575 -- 1.5 3.0 5.7 61.0 78 

HND 5/2/1986 1730 559 -- 59.0 3.2 6.4 38.0 62 

HND 6/23/1986 1230 563 -- 13.0 20.0 16.0 216.0 84 

HND 9/3/1986 1140 600 -- 0 0 .4 5.8 61 
Appendix 1 47 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

HND 

HND 

HND 

HWD 

HWD 

2/11/1987 

5/20/1987 

6/1/1987 

6/28/1978 

7/9/1979 

1145 

0955 

0930 

1215 

1310 

607 

633 

564 

560 

560 

--

--

--

0.7 

27.0 

1.3 

12.0 

149.0 

.2 

5.2 

3.2 

2.6 

93.0 

.1 

4.7 

8.9 

2.8 

41.0 

2.6 

--

76.0 

38.0 

392.0 

18.0 

--

80 

100 

110 

31 

103 

HWD 

HWD 

HWD 

HWD 

ISD 

8/28/1980 

8/18/1981 

8/4/1982 

7/22/1983 

7/12/1978 

1115 

1415 

1250 

0950 

0935 

575 

551 

563 

553 

486 

0 

16.0 

1.1 

--

--

0 

.3 

0 

7.7 

0 

0 

.3 

.1 

1.4 

0 

.1 

4.3 

.5 

22.0 

--

1.1 

14.0 

2.0 

90.0 

--

41 

96 

51 

84 

25 

ISD 

ISD 

ISD 

ISD 

ISD 

7/11/1979 

9/4/1980 

8/12/1981 

8/11/1982 

7/22/1983 

0820 

1154 

1340 

1035 

1130 

480 

487 

482 

495 

489 

27.0 

0 

11.0 

1.1 

--

5.2 

0 

0 

0 

7.7 

4.7 

0 

.4 

0 

1.4 

2.6 

0 

2.1 

.3 

22.0 

18.0 

.5 

17.0 

1.5 

90.0 

102 

38 

98 

49 

84 

JBS 

JBS 

JBS 

JBS 

JBS 

7/17/1978 

7/16/1979 

8/27/1980 

8/4/1981 

4/22/1982 

1330 

1440 

1115 

0955 

0930 

550 

580 

587 

570 

570 

0 

27.0 

.1 

21.0 

20.0 

0 

.9 

0 

1.0 

30.0 

0 

2.2 

0 

1.4 

7.9 

--

2.6 

.1 

4.2 

3.2 

--

18.0 

1.1 

38.0 

8.4 

24 

100 

41 

102 

46 

JBS 

JBS 

JBS 

JBS 

JBS 

4/23/1982 

4/26/1982 

8/9/1982 

5/21/1983 

5/22/1983 

0940 

1000 

1155 

1050 

0940 

576 

576 

592 

589 

588 

31.0 

36.0 

1.1 

--

--

30.0 

30.0 

0 

39.0 

39.0 

7.9 

9.4 

.1 

23.0 

23.0 

3.2 

3.2 

.4 

27.0 

27.0 

14.0 

23.0 

1.1 

265.0 

265.0 

50 

51 

50 

77 

79 

JBS 

JBS 

JBS 

KCH 

KCH 

5/23/1983 

5/25/1983 

7/18/1983 

7/5/1978 

7/10/1979 

0830 

1115 

1205 

1215 

1300 

586 

590 

586 

640 

620 

--

--

--

--

27.0 

39.0 

39.0 

7.7 

0 

5.2 

23.0 

23.0 

1.4 

0 

4.7 

27.0 

27.0 

22.0 

2.6 

--

265.0 

265.0 

90.0 

18.0 

--

82 

84 

84 

28 

102 

KCH 8/28/1980 1045 660 0 0 0 .1 1.1 41 

KCH 8/11/1981 0925 621 11.0 0 .5 2.2 19.0 99 

KCH 8/10/1982 1015 652 1.1 0 .1 .4 1.2 49 

KCH 7/19/1983 1210 670 -- 7.7 1.4 22.0 90.0 84 

KCH 6/24/1985 1145 612 -- 33.0 28.0 8.0 300.0 72 

KCH 

KCH 

KCH 

KCH 

KCH 

8/7/1985 

5/1/1986 

6/24/1986 

8/29/1986 

2/9/1987 

1230 

1120 

1020 

1400 

1120 

635 

676 

651 

674 

641 

--

--

--

--

--

0 

59.0 

13.0 

0 

1.3 

.2 

3.2 

20.0 

0 

3.4 

1.0 

6.4 

16.0 

.4 

9.3 

16.0 

26.0 

216.0 

5.8 

81.0 

65 

62 

84 

64 

83 

KCH 

KCH 

KCH 

KCH 

KCH 

5/18/1987 

6/1/1987 

8/19/1987 

3/9/1988 

5/10/1988 

1355 

1540 

1125 

1030 

1015 

660 

644 

675 

655 

703 

--

--

--

--

--

1.0 

149.0 

0 

.2 

0 

.5 

93.0 

0 

.6 

.1 

2.3 

41.0 

1.6 

1.1 

.7 

38.0 

392.0 

33.0 

7.8 

4.7 

100 

110 

110 

58 

50 

KCH 7/11/1988 1340 672 -- 1.0 0 .1 2.2 47 

KCH 8/11/1988 1200 691 -- 1.1 0 0 11.0 43 

KCH 2/27/1989 1145 690 1.0 .3 0 .1 2.4 27 

KCH 5/2/1989 1335 693 16.0 .3 0 3.5 5.6 35 

KCH 7/21/1989 1330 676 5.8 2.0 .1 2.1 7.7 52 
48 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

KCH 8/29/1989 1400 668 0.4 0 0 0 2.7 33 

KCH 2/7/1990 1000 622 4.3 8.6 0 .1 1.5 22 

KCH 6/5/1990 1145 665 41.0 7.1 1.0 2.5 80.0 50 

KCH 8/15/1990 1400 657 1.2 0 0 0 2.2 30 

KCH 3/11/1991 1150 642 95.0 6.7 11.0 14.0 75.0 87 

KCH 5/6/1991 1400 636 105.0 10.0 8.0 20.0 151.0 99 

KCH 8/13/1991 1030 650 2.5 0 .2 .4 6.5 75 

KCH 4/29/1992 1130 623 104.0 4.0 5.2 9.8 90.0 115 

KCH 1/20/1993 1115 652 262.0 16.0 21.0 9.0 231.0 98 

KCH 1/23/1993 1000 650 262.0 16.0 21.0 9.0 231.0 100 

KCH 1/26/1993 1300 652 262.0 16.0 21.0 9.0 231.0 100 

KCH 5/6/1993 1507 641 123.0 1.2 16.0 10.0 73.0 108 

KCH 5/9/1993 1015 639 123.0 1.2 16.0 10.0 73.0 108 

KCH 5/12/1993 1349 641 123.0 1.2 16.0 10.0 73.0 108 

KCH 5/27/1993 0945 644 42.0 0 5.0 5.2 32.0 108 

KCH 8/18/1993 0745 664 .5 0 0 .1 .5 86 

KCH 4/12/1994 1220 652 6.9 0 0 .3 9.5 47 

KCH 10/10/1994 0930 652 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/10/1994 1500 660 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/10/1994 2020 651 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/11/1994 0820 657 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/11/1994 1500 654 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/11/1994 2030 652 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/12/1994 0850 653 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/12/1994 1230 653 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/12/1994 2030 653 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/13/1994 0830 655 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/13/1994 2045 655 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/14/1994 0840 657 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/14/1994 1900 657 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/15/1994 0830 658 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/15/1994 1900 658 476.0 73.0 99.0 33.0 30.0 39 

KCH 10/16/1994 1230 660 476.0 73.0 99.0 33.0 30.0 39 

KCH 6/19/1995 1300 641 281.0 12.0 108.0 32.0 172.0 102 

KCH 5/6/1996 1200 648 .7 0 0 0 .5 26 

KCH 7/8/1997 1350 568 322.0 .9 21.0 26.0 510.0 113 

KCH 4/21/1998 0920 628 79.0 0 8.9 7.5 96.0 98 

KCH 6/9/1999 1415 683 35.0 0 1.9 1.6 5.3 76 

LWK 8/8/1978 1030 480 7.6 14.0 3.5 -- -- 24 

LWK 7/11/1979 1225 499 27.0 5.2 4.7 2.6 18.0 102 

LWK 8/29/1980 0850 496 0 0 0 .1 1.0 40 

LWK 8/18/1981 1020 499 16.0 .3 .3 4.3 14.0 96 

LWK 8/17/1982 1130 493 1.1 0 0 .2 1.9 46 

LWK 7/21/1983 1330 499 -- 7.7 1.4 22.0 90.0 84 

MCH 7/5/1978 1315 540 -- 0 0 -- -- 28 

MCH 7/5/1979 0745 540 13.0 .8 2.9 -- 14.0 105 

MCH 8/28/1980 1245 570 0 0 0 .1 1.1 41 

MCH 8/11/1981 1345 537 11.0 0 .5 2.2 19.0 99 

MCH 8/11/1982 1255 528 1.1 0 0 .3 1.5 49 

MCH 7/20/1983 0930 476 -- 7.7 1.4 22.0 90.0 84 
Appendix 1 49 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

MCH 

MCH 

MCH 

MCH 

MCH 

6/19/1985 

8/9/1985 

1/13/1986 

5/1/1986 

6/24/1986 

1130 

1045 

1345 

1402 

1230 

519 

540 

537 

521 

555 

--

--

--

--

--

2.4 

0 

1.5 

59.0 

13.0 

4.0 

.2 

3.0 

3.2 

20.0 

5.6 

.9 

5.7 

6.4 

16.0 

145.0 

15.0 

61.0 

26.0 

216.0 

70 

64 

78 

62 

84 

MCH 

MCH 

MCH 

MCH 

MCH 

9/2/1986 

2/10/1987 

5/18/1987 

5/30/1987 

8/17/1987 

1020 

0930 

1230 

1550 

1505 

550 

554 

553 

512 

560 

--

--

--

--

--

0 

1.3 

1.0 

149.0 

0 

0 

3.4 

.5 

93.0 

0 

.4 

9.3 

2.3 

41.0 

1.6 

5.8 

81.0 

38.0 

208.0 

34.0 

62 

83 

100 

98 

110 

MCH 

MCH 

MCH 

MCH 

MCH 

2/22/1988 

5/3/1988 

7/11/1988 

8/10/1988 

2/21/1989 

1425 

1315 

1515 

1210 

1400 

519 

536 

557 

552 

584 

--

--

--

--

0.9 

.2 

1.4 

1.0 

0 

.2 

.6 

.1 

0 

0 

0 

1.2 

1.1 

.1 

0 

.1 

8.6 

7.8 

2.2 

11.0 

2.4 

64 

50 

47 

43 

28 

MCH 

MCH 

MCH 

MCH 

MCH 

5/2/1989 

7/24/1989 

8/29/1989 

1/31/1990 

6/12/1990 

1225 

1320 

1045 

1005 

1055 

540 

538 

547 

587 

485 

16.0 

3.7 

.4 

.7 

41.0 

.3 

0 

0 

0 

3.8 

0 

.1 

0 

0 

.7 

3.5 

1.7 

0 

0 

2.5 

5.6 

5.0 

2.7 

.4 

80.0 

35 

49 

33 

17 

49 

MCH 

MCH 

MCH 

MCH 

MCH 

8/21/1990 

3/13/1991 

5/15/1991 

8/13/1991 

4/30/1992 

1115 

1250 

1100 

1110 

0920 

542 

518 

531 

554 

564 

.9 

74.0 

261.0 

2.5 

94.0 

.5 

6.0 

68.0 

0 

3.5 

0 

8.7 

38.0 

.2 

4.7 

0 

12.0 

48.0 

.4 

8.5 

2.2 

65.0 

218.0 

6.5 

81.0 

27 

87 

99 

75 

115 

MCH 

MCH 

MCH 

MCH 

MCH 

1/22/1993 

1/25/1993 

5/8/1993 

5/11/1993 

5/15/1993 

1120 

1300 

1045 

1310 

0750 

504 

503 

521 

521 

525 

262.0 

262.0 

123.0 

123.0 

123.0 

16.0 

16.0 

1.2 

1.2 

0 

21.0 

21.0 

16.0 

16.0 

16.0 

9.0 

9.0 

10.0 

10.0 

10.0 

231.0 

231.0 

73.0 

73.0 

73.0 

100 

100 

108 

108 

108 

MCH 8/18/1993 0950 550 .5 0 0 .1 .5 86 

MCH 4/15/1994 0820 506 6.7 0 0 .3 8.4 47 

MCH 6/14/1995 1220 550 347.0 12.0 108.0 32.0 294.0 104 

MCH 5/7/1996 1045 555 .7 0 0 0 .5 26 

MCH 7/8/1997 1545 555 322.0 .9 21.0 26.0 510.0 113 

MCH 4/22/1998 1350 534 76.0 0 8.4 7.2 93.0 98 

MCH 6/6/1999 1150 545 76.0 .7 3.4 2.4 7.8 78 

MCH 6/29/2000 0900 538 49.0 0 23.0 5.4 5.2 64 

MCH 6/20/2001 1100 554 12.0 0 .8 1.6 26.0 96 

MCH 

MCH 

PLS 

PLS 

PLS 

PLS 

6/4/2002 

5/20/2003 

2/26/1988 

5/4/1988 

7/14/1988 

8/11/1988 

1100 

1200 

0830 

1340 

0913 

0845 

558 

565 

568 

574 

551 

564 

7.2 

12.0 

--

--

--

--

0 

0 

.1 

1.4 

2.0 

1.1 

.1 

.3 

.6 

.1 

0 

0 

.7 

1.3 

1.2 

1.1 

.8 

0 

3.8 

12.0 

8.6 

7.8 

7.5 

11.0 

88 

102 

62 

50 

47 

43 

PLS 

PLS 

PLS 

PLS 

PLS 

2/28/1989 

5/2/1989 

7/25/1989 

8/30/1989 

2/7/1990 

1455 

1445 

1350 

1330 

1500 

548 

582 

572 

542 

550 

1.0 

16.0 

3.1 

.4 

4.3 

.3 

.3 

0 

0 

8.6 

0 

0 

.1 

0 

0 

.1 

3.5 

1.6 

0 

.1 

2.4 

5.6 

5.5 

2.7 

1.5 

27 

35 

49 

32 

22 
50 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

PLS 

PLS 

PLS 

PLS 

PLS 

6/8/1990 

8/15/1990 

3/18/1991 

5/15/1991 

8/13/1991 

0955 

1100 

1545 

1330 

0900 

559 

543 

533 

545 

558 

41.0 

1.2 

87.0 

261.0 

2.5 

3.8 

0 

7.6 

68.0 

0 

0.8 

0 

6.4 

38.0 

.2 

2.5 

0 

11.0 

48.0 

.4 

80.0 

2.2 

68.0 

218.0 

6.5 

49 

30 

85 

99 

75 

PLS 

PLS 

PLS 

PLS 

PLS 

5/1/1992 

1/21/1993 

1/24/1993 

1/28/1993 

5/14/1993 

0950 

1130 

0850 

1146 

1313 

543 

560 

559 

559 

555 

85.0 

262.0 

262.0 

262.0 

123.0 

3.4 

16.0 

16.0 

16.0 

1.2 

4.2 

21.0 

21.0 

21.0 

16.0 

8.1 

9.0 

9.0 

9.0 

10.0 

75.0 

231.0 

231.0 

231.0 

73.0 

115 

100 

100 

100 

108 

PLS 

PLS 

PLS 

PLS 

PLS 

5/28/1993 

8/17/1993 

4/12/1994 

6/19/1995 

4/25/1996 

1100 

1030 

0900 

1640 

1200 

559 

560 

546 

561 

544 

42.0 

.5 

6.9 

281.0 

.7 

0 

0 

0 

12.0 

0 

5.0 

0 

0 

108.0 

0 

5.2 

.1 

.3 

32.0 

.1 

32.0 

.5 

9.5 

172.0 

.9 

108 

87 

47 

102 

25 

PLS 

PLS 

PLS 

PLS 

PLS 

7/8/1997 

4/21/1998 

6/11/1999 

6/1/2000 

6/8/2001 

1220 

1320 

1200 

1500 

1100 

550 

528 

564 

573 

590 

322.0 

79.0 

21.0 

2.7 

26.0 

.9 

0 

0 

0 

0 

21.0 

8.9 

1.4 

0 

1.2 

26.0 

7.5 

1.4 

.1 

2.7 

510.0 

96.0 

4.9 

1.4 

55.0 

113 

98 

73 

22 

102 

PLS 

PLS 

RAB 

RAB 

RAB 

5/23/2002 

5/21/2003 

5/6/1993 

5/9/1993 

5/12/1993 

1100 

1200 

1400 

1405 

1145 

570 

576 

596 

568 

578 

1.9 

12.0 

123.0 

123.0 

123.0 

0 

0 

1.2 

1.2 

1.2 

.1 

.3 

16.0 

16.0 

16.0 

.4 

1.3 

10.0 

10.0 

10.0 

4.2 

12.0 

73.0 

73.0 

73.0 

92 

102 

108 

108 

108 

RAB 

RAB 

RAB 

RAB 

RAB 

5/27/1993 

8/17/1993 

4/15/1994 

6/27/1995 

5/6/1996 

1140 

0745 

1215 

1015 

0945 

569 

570 

522 

507 

504 

42.0 

.5 

6.7 

99.0 

.7 

0 

0 

0 

0 

0 

5.0 

0 

0 

18.0 

0 

5.2 

.1 

.3 

12.0 

0 

32.0 

.5 

8.4 

96.0 

.5 

108 

87 

47 

98 

26 

RAB 

RAB 

RAB 

RAB 

RAB 

7/9/1997 

4/21/1998 

6/8/1999 

5/31/2000 

6/7/2001 

0740 

0757 

0900 

1300 

1600 

542 

525 

755 

555 

532 

273.0 

79.0 

51.0 

2.8 

30.0 

0 

0 

0 

0 

0 

17.0 

8.9 

2.0 

0 

1.3 

23.0 

7.5 

2.0 

.1 

2.8 

455.0 

96.0 

6.8 

1.4 

58.0 

113 

98 

77 

23 

102 

RAB 

RAB 

ROL 

ROL 

ROL 

6/3/2002 

5/30/2003 

6/26/1978 

7/10/1979 

8/27/1980 

1100 

1000 

1135 

0950 

1045 

617 

1,190 

490 

521 

559 

7.2 

14.0 

1.2 

27.0 

.1 

0 

0 

.2 

5.2 

0 

.1 

.1 

.1 

4.7 

0 

.7 

.7 

2.6 

.1 

--

3.8 

6.1 

18.0 

1.1 

--

88 

98 

32 

102 

41 

ROL 8/4/1981 0915 528 21.0 1.0 1.4 4.2 38.0 102 

ROL 8/9/1982 1110 532 1.1 0 .1 .4 1.1 50 

ROL 7/18/1983 0845 546 -- 7.7 1.4 22.0 90.0 84 

ROL 6/20/1985 0925 480 -- 1.9 3.2 5.2 116.0 71 

ROL 8/7/1985 0900 586 -- 0 .2 1.0 16.0 65 

ROL 1/15/1986 1000 610 -- 1.5 2.6 5.2 54.0 78 

ROL 5/2/1986 1420 571 -- 59.0 3.2 6.4 38.0 62 

ROL 6/23/1986 0920 585 -- 13.0 20.0 16.0 216.0 84 

ROL 9/3/1986 1300 586 -- 0 0 .4 5.8 61 

ROL 2/9/1987 0830 624 -- 1.3 3.4 9.3 81.0 83 
Appendix 1 51 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

ROL 5/18/1987 0950 608 -- 1.0 0.5 2.3 38.0 100 

ROL 6/1/1987 1230 598 -- 149.0 93.0 41.0 392.0 110 

ROL 8/17/1987 1010 642 -- 0 0 1.6 34.0 110 

ROL 2/22/1988 0910 587 -- .2 .6 1.2 8.6 64 

ROL 5/6/1988 1215 622 -- 1.4 .1 1.1 7.8 50 

ROL 

ROL 

ROL 

ROL 

ROL 

7/18/1988 

8/16/1988 

2/27/1989 

5/1/1989 

7/17/1989 

1110 

0920 

1245 

1015 

1030 

585 

596 

583 

579 

615 

--

--

1.0 

19.0 

8.9 

2.0 

1.2 

.3 

.3 

2.0 

0 

0 

0 

0 

.2 

.8 

0 

.1 

3.7 

2.9 

7.5 

3.2 

2.4 

7.3 

12.0 

45 

45 

27 

36 

55 

ROL 

ROL 

ROL 

ROL 

ROL 

8/25/1989 

1/30/1990 

6/12/1990 

8/14/1990 

3/13/1991 

1115 

1115 

0845 

1035 

0925 

607 

572 

596 

608 

612 

.5 

.6 

41.0 

1.6 

74.0 

0 

0 

3.8 

0 

6.0 

0 

0 

.7 

.1 

8.7 

0 

0 

2.5 

0 

12.0 

3.5 

.4 

80.0 

2.2 

65.0 

34 

17 

49 

31 

87 

ROL 

ROL 

ROL 

ROL 

ROL 

5/6/1991 

8/19/1991 

4/29/1992 

6/23/1992 

1/20/1993 

1200 

1037 

1315 

0755 

1300 

585 

638 

694 

1,160 

654 

105.0 

467.0 

104.0 

242.0 

262.0 

10.0 

107.0 

4.0 

7.8 

16.0 

8.0 

42.0 

5.2 

17.0 

21.0 

20.0 

11.0 

9.8 

20.0 

9.0 

151.0 

58.0 

90.0 

241.0 

231.0 

99 

71 

115 

100 

98 

ROL 

ROL 

ROL 

ROL 

ROL 

1/23/1993 

1/26/1993 

5/6/1993 

6/1/1993 

8/13/1993 

1140 

1043 

1230 

1140 

1200 

630 

625 

635 

642 

660 

262.0 

262.0 

123.0 

42.0 

.5 

16.0 

16.0 

1.2 

0 

0 

21.0 

21.0 

16.0 

5.0 

0 

9.0 

9.0 

10.0 

5.2 

.1 

231.0 

231.0 

73.0 

32.0 

.5 

100 

100 

108 

108 

88 

ROL 

SLR 

SLR 

SLR 

SLR 

4/12/1994 

7/11/1978 

7/5/1979 

9/4/1980 

8/18/1981 

1130 

1310 

0845 

1306 

0830 

597 

700 

630 

680 

583 

6.9 

13.0 

0 

16.0 

--

0 

0 

.8 

0 

.3 

0 

0 

2.9 

0 

.3 

.3 

0 

4.3 

--

--

9.5 

14.0 

.5 

14.0 

--

47 

25 

105 

38 

96 

SLR 

SLR 

SLR 

SLR 

SLR 

8/17/1982 

7/20/1983 

5/1/1986 

6/24/1986 

9/2/1986 

0920 

0830 

1330 

1250 

1130 

625 

600 

656 

640 

655 

1.1 

--

--

--

--

0 

7.7 

59.0 

13.0 

0 

0 

1.4 

3.2 

20.0 

0 

.2 

22.0 

6.4 

16.0 

.4 

1.9 

90.0 

26.0 

216.0 

5.8 

46 

84 

62 

84 

62 

SLR 

SLR 

SLR 

SLR 

SLR 

2/10/1987 

5/19/1987 

5/30/1987 

8/18/1987 

2/22/1988 

0830 

1212 

1508 

0834 

1325 

624 

642 

635 

636 

575 

--

--

--

--

--

1.3 

12.0 

149.0 

0 

.2 

3.4 

2.6 

93.0 

0 

.6 

9.3 

2.8 

41.0 

1.6 

1.2 

81.0 

38.0 

208.0 

34.0 

8.6 

83 

100 

98 

110 

64 

SLR 

SLR 

SLR 

SLR 

SNL 

5/3/1988 

7/11/1988 

8/9/1988 

2/21/1989 

6/26/1978 

1235 

1440 

1030 

1310 

1220 

707 

721 

727 

736 

460 

--

--

--

.9 

1.2 

1.4 

1.0 

0 

.2 

.2 

.1 

0 

0 

0 

.1 

1.1 

.1 

0 

.1 

7.8 

2.2 

11.0 

2.4 

50 

47 

43 

28 

32 

SNL 7/10/1979 0900 525 27.0 5.2 4.7 2.6 18.0 102 

SNL 8/27/1980 0930 503 .1 0 0 .1 1.1 41 

SNL 8/4/1981 1045 462 21.0 1.0 1.4 4.2 38.0 102 

SNL 8/9/1982 1020 468 1.1 0 .1 .4 1.1 50 

SNL 7/18/1983 1045 494 -- 7.7 1.4 22.0 90.0 84 
52 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

SVE 10/12/1978 1205 820 0.4 0 0.3 -- -- 24 

SVE 7/18/1979 1230 445 17.0 .9 2.1 2.4 14.0 100 

SVE 9/8/1980 1030 807 .1 8.8 0 .2 29.0 38 

SVE 8/19/1981 1310 638 35.0 .3 .3 4.3 39.0 96 

SVE 8/30/1982 1400 1,530 .2 0 0 .1 2.1 43 

SVE 

SVE 

SVE 

SVE 

SVE 

6/24/1985 

8/12/1985 

1/15/1986 

5/2/1986 

6/24/1986 

1040 

1000 

1430 

0830 

0805 

838 

936 

913 

897 

1,010 

--

--

--

--

--

33.0 

0 

1.5 

59.0 

13.0 

28.0 

.1 

2.6 

3.2 

20.0 

8.0 

.8 

5.2 

6.4 

16.0 

300.0 

11.0 

54.0 

38.0 

216.0 

72 

63 

78 

62 

84 

SVE 

SVE 

SVE 

SVE 

SVE 

8/29/1986 

2/10/1987 

5/19/1987 

5/31/1987 

8/19/1987 

0900 

1130 

1330 

0900 

0815 

874 

610 

614 

602 

603 

--

--

--

--

--

0 

1.3 

12.0 

149.0 

0 

0 

3.4 

2.6 

93.0 

0 

.4 

9.3 

2.8 

41.0 

1.6 

5.8 

81.0 

38.0 

392.0 

33.0 

64 

83 

100 

105 

110 

SVE 

SVE 

SVE 

SVE 

SVE 

2/24/1988 

5/3/1988 

7/11/1988 

8/9/1988 

2/21/1989 

1435 

0850 

1145 

0850 

1030 

704 

833 

910 

917 

857 

--

--

--

--

.9 

.1 

1.4 

1.0 

0 

.2 

.6 

.1 

0 

0 

0 

1.2 

1.1 

.1 

0 

.1 

8.6 

7.8 

2.2 

11.0 

2.4 

63 

50 

47 

43 

28 

SVE 

SVE 

SVE 

SVE 

SVE 

5/2/1989 

7/21/1989 

8/25/1989 

1/30/1990 

6/6/1990 

1005 

0945 

0955 

0945 

0810 

897 

975 

949 

942 

979 

16.0 

5.8 

.5 

.6 

41.0 

.3 

2.0 

0 

0 

7.1 

0 

.1 

0 

0 

.8 

3.5 

2.1 

0 

0 

2.5 

5.6 

7.7 

3.5 

.4 

80.0 

35 

52 

34 

17 

50 

SVE 

SVE 

SVE 

SVE 

SVE 

8/15/1990 

3/5/1991 

5/6/1991 

8/19/1991 

4/28/1992 

0935 

0935 

0945 

0915 

1330 

973 

916 

907 

796 

601 

1.2 

106.0 

105.0 

467.0 

115.0 

0 

8.5 

10.0 

107.0 

4.7 

0 

14.0 

8.0 

42.0 

6.2 

0 

15.0 

20.0 

11.0 

11.0 

2.2 

82.0 

151.0 

58.0 

98.0 

30 

87 

99 

71 

115 

SVE 

SVE 

SVE 

SVE 

SVE 

1/21/1993 

1/24/1993 

1/28/1993 

5/7/1993 

5/10/1993 

0900 

0700 

1300 

1430 

1345 

620 

616 

618 

616 

625 

262.0 

262.0 

262.0 

123.0 

123.0 

16.0 

16.0 

16.0 

1.2 

1.2 

21.0 

21.0 

21.0 

16.0 

16.0 

9.0 

9.0 

9.0 

10.0 

10.0 

231.0 

231.0 

231.0 

73.0 

73.0 

100 

100 

100 

108 

108 

SVE 5/14/1993 1600 623 123.0 1.2 16.0 10.0 73.0 108 

SVE 5/28/1993 0735 626 42.0 0 5.0 5.2 32.0 108 

SVE 8/16/1993 0750 652 .5 0 0 .1 .5 87 

SVE 4/12/1994 0735 1,020 6.9 0 0 .3 9.5 47 

SVE 6/14/1995 1430 867 347.0 12.0 108.0 32.0 294.0 104 

SVE 

SVE 

SVE 

SVE 

SVE 

5/9/1996 

7/9/1997 

4/22/1998 

6/9/1999 

5/31/2000 

1100 

1000 

1110 

0900 

0900 

840 

674 

596 

733 

850 

.6 

273.0 

76.0 

35.0 

2.8 

0 

0 

0 

0 

0 

0 

17.0 

8.4 

1.9 

0 

0 

23.0 

7.2 

1.6 

.1 

.5 

455.0 

93.0 

5.3 

1.4 

25 

113 

98 

76 

23 

SVE 

SVE 

SVE 

SVN 

SVN 

6/14/2001 

8/7/2002 

5/28/2003 

10/13/1978 

7/17/1979 

1200 

1200 

1200 

1300 

0715 

770 

760 

626 

500 

480 

15.0 

116.0 

14.0 

.4 

17.0 

0 

0 

0 

0 

.9 

.9 

2.1 

.1 

.3 

2.1 

2.0 

11.0 

.8 

2.5 

--

33.0 

111.0 

7.2 

16.0 

--

99 

105 

101 

24 

100 
Appendix 1 53 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

SVN 8/19/1981 1210 517 35.0 0.3 0.3 4.3 39.0 96 

SVN 5/17/1982 0835 506 1,720.0 194.0 249.0 258.0 1,960.0 72 

SVN 6/20/1985 1115 410 -- 1.9 3.2 5.2 116.0 71 

SVN 8/7/1985 1005 496 -- 0 .2 1.0 16.0 65 

SVN 1/15/1986 0900 466 -- 1.5 2.6 5.2 54.0 78 

SVN 5/2/1986 0930 389 -- 59.0 3.2 6.4 38.0 62 

SVN 6/24/1986 0845 442 -- 13.0 20.0 16.0 216.0 84 

SVN 8/29/1986 1000 514 -- 0 0 .4 5.8 64 

SVN 2/10/1987 1200 388 -- 1.3 3.4 9.3 81.0 83 

SVN 5/19/1987 1415 480 -- 12.0 2.6 2.8 38.0 100 

SVN 

SVN 

SVN 

SVN 

SVN 

5/31/1987 

8/19/1987 

2/24/1988 

3/5/1991 

5/6/1991 

1130 

0915 

1530 

1020 

1100 

409 

630 

510 

560 

547 

--

--

--

106.0 

105.0 

149.0 

0 

.1 

8.5 

10.0 

93.0 

0 

.6 

14.0 

8.0 

41.0 

1.6 

1.2 

15.0 

20.0 

392.0 

33.0 

8.6 

82.0 

151.0 

105 

110 

63 

87 

99 

SVN 

SVN 

SVN 

SVN 

SVN 

8/19/1991 

4/29/1992 

1/20/1993 

1/23/1993 

1/26/1993 

0825 

1000 

0945 

0800 

0930 

480 

469 

453 

461 

455 

467.0 

104.0 

262.0 

262.0 

262.0 

107.0 

4.0 

16.0 

16.0 

16.0 

42.0 

5.2 

21.0 

21.0 

21.0 

11.0 

9.8 

9.0 

9.0 

9.0 

58.0 

90.0 

231.0 

231.0 

231.0 

71 

115 

98 

100 

100 

SVN 

SVN 

SVN 

SVN 

SVN 

5/6/1993 

5/9/1993 

5/12/1993 

6/1/1993 

8/16/1993 

1610 

0845 

1505 

0740 

1000 

447 

471 

480 

464 

549 

123.0 

123.0 

123.0 

42.0 

.5 

1.2 

1.2 

1.2 

0 

0 

16.0 

16.0 

16.0 

5.0 

0 

10.0 

10.0 

10.0 

5.2 

.1 

73.0 

73.0 

73.0 

32.0 

.5 

108 

108 

108 

108 

87 

SVN 

SVN 

SVN 

SVN 

SVN 

6/19/1995 

7/9/1997 

4/22/1998 

6/9/1999 

6/15/2001 

0805 

1200 

1230 

1140 

1100 

460 

533 

507 

507 

710 

281.0 

273.0 

76.0 

35.0 

14.0 

12.0 

0 

0 

0 

0 

108.0 

17.0 

8.4 

1.9 

.9 

32.0 

23.0 

7.2 

1.6 

2.0 

172.0 

455.0 

93.0 

5.3 

33.0 

102 

113 

98 

76 

98 

SVN 

SVN 

SVS 

SVS 

SVS 

8/7/2002 

5/28/2003 

8/8/1978 

7/17/1979 

8/28/1980 

1000 

1000 

0750 

1200 

0930 

507 

603 

540 

580 

620 

116.0 

14.0 

7.6 

17.0 

0 

0 

0 

14.0 

.9 

0 

2.1 

.1 

3.5 

2.1 

0 

11.0 

.8 

2.5 

.1 

--

111.0 

7.2 

16.0 

1.1 

--

105 

101 

24 

100 

41 

SVS 

SVS 

SVS 

SVS 

SVS 

8/10/1981 

10/7/1981 

10/8/1981 

8/9/1982 

7/19/1983 

1407 

1420 

1130 

1355 

1000 

585 

600 

588 

584 

582 

11.0 

854.0 

854.0 

1.1 

--

.1 

12.0 

12.0 

0 

7.7 

.6 

3.2 

3.2 

.1 

1.4 

2.3 

19.0 

19.0 

.4 

22.0 

20.0 

1,150.0 

1,150.0 

1.1 

90.0 

99 

84 

86 

50 

84 

SVS 

SVS 

SVS 

SVS 

SVS 

6/19/1985 

8/7/1985 

1/13/1986 

5/2/1986 

6/23/1986 

1415 

1100 

0830 

1320 

1100 

584 

592 

589 

606 

608 

--

--

--

--

--

2.4 

0 

1.5 

59.0 

13.0 

4.0 

.2 

3.0 

3.2 

20.0 

5.6 

1.0 

5.7 

6.4 

16.0 

145.0 

16.0 

61.0 

38.0 

216.0 

70 

65 

78 

62 

84 

SVS 

SVS 

SVS 

SVS 

SVS 

8/29/1986 

2/9/1987 

5/18/1987 

6/1/1987 

8/17/1987 

1300 

1015 

1120 

1130 

1350 

596 

578 

616 

615 

603 

--

--

--

--

--

0 

1.3 

1.0 

149.0 

0 

0 

3.4 

.5 

93.0 

0 

.4 

9.3 

2.3 

41.0 

1.6 

5.8 

81.0 

38.0 

392.0 

34.0 

64 

83 

100 

110 

110 
54 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

SVS 

SVS 

SVS 

SVS 

SVS 

2/22/1988 

5/10/1988 

7/14/1988 

8/11/1988 

2/21/1989 

1120 

0900 

1500 

1100 

1140 

593 

609 

575 

607 

607 

--

--

--

--

0.9 

0.2 

0 

2.0 

1.1 

.2 

0.6 

.1 

0 

0 

0 

1.2 

.7 

.8 

0 

.1 

8.6 

4.7 

7.5 

11.0 

2.4 

64 

50 

47 

43 

28 

SVS 

SVS 

SVS 

SVS 

SVS 

5/1/1989 

7/21/1989 

8/25/1989 

1/30/1990 

6/5/1990 

1400 

1130 

1320 

1340 

1400 

586 

590 

595 

602 

590 

19.0 

5.8 

.5 

.6 

41.0 

.3 

2.0 

0 

0 

7.1 

0 

.1 

0 

0 

1.0 

3.7 

2.1 

0 

0 

2.5 

7.3 

7.7 

3.5 

.4 

80.0 

36 

52 

34 

17 

50 

SVS 

SVS 

SVS 

SVS 

SVS 

8/14/1990 

3/5/1991 

5/13/1991 

8/14/1991 

5/1/1992 

0945 

1130 

1320 

1200 

0820 

568 

560 

581 

608 

584 

1.6 

106.0 

261.0 

4.1 

85.0 

0 

8.5 

68.0 

12.0 

3.4 

.1 

14.0 

38.0 

5.9 

4.2 

0 

15.0 

48.0 

1.7 

8.1 

2.2 

82.0 

218.0 

6.5 

75.0 

31 

87 

99 

75 

115 

SVS 

SVS 

SVS 

SVS 

SVS 

1/22/1993 

1/25/1993 

5/7/1993 

5/10/1993 

5/14/1993 

0825 

1020 

0946 

0925 

1050 

603 

610 

614 

613 

614 

262.0 

262.0 

123.0 

123.0 

123.0 

16.0 

16.0 

1.2 

1.2 

1.2 

21.0 

21.0 

16.0 

16.0 

16.0 

9.0 

9.0 

10.0 

10.0 

10.0 

231.0 

231.0 

73.0 

73.0 

73.0 

100 

100 

108 

108 

108 

SVS 

SVS 

SVS 

SVS 

SVS 

5/28/1993 

8/17/1993 

4/8/1994 

6/19/1995 

5/2/1996 

0940 

0915 

0830 

1440 

1100 

615 

618 

594 

611 

592 

42.0 

.5 

6.9 

281.0 

.7 

0 

0 

0 

12.0 

0 

5.0 

0 

0 

108.0 

0 

5.2 

.1 

.3 

32.0 

.1 

32.0 

.5 

9.5 

172.0 

.6 

108 

87 

47 

102 

26 

SVS 

SVS 

SVS 

SVS 

SVS 

7/8/1997 

4/22/1998 

6/11/1999 

6/1/2000 

6/18/2001 

1045 

0931 

1340 

1400 

1200 

585 

616 

599 

610 

613 

322.0 

76.0 

21.0 

2.7 

13.0 

.9 

0 

0 

0 

0 

21.0 

8.4 

1.4 

0 

.9 

26.0 

7.2 

1.4 

.1 

1.9 

510.0 

93.0 

4.9 

1.4 

31.0 

113 

98 

73 

22 

97 

SVS 

SVS 

SVW 

SVW 

SVW 

6/6/2002 

5/19/2003 

6/27/1978 

7/12/1979 

8/28/1980 

1300 

1300 

1220 

0900 

0900 

622 

620 

560 

620 

592 

7.2 

13.0 

.9 

27.0 

0 

0 

0 

.2 

5.2 

0 

.1 

.3 

.1 

4.7 

0 

.7 

1.3 

2.6 

.1 

--

3.8 

13.0 

18.0 

1.1 

--

88 

102 

32 

101 

41 

SVW 

SVW 

SVW 

SVW 

SVW 

8/10/1981 

8/10/1982 

7/19/1983 

6/20/1985 

8/9/1985 

1340 

0815 

0805 

1200 

0830 

569 

597 

601 

611 

657 

11.0 

1.1 

--

--

--

.1 

0 

7.7 

1.9 

0 

.6 

.1 

1.4 

3.2 

.2 

2.3 

.4 

22.0 

5.2 

.9 

20.0 

1.2 

90.0 

116.0 

15.0 

99 

49 

84 

71 

64 

SVW 

SVW 

SVW 

SVW 

SVW 

1/15/1986 

5/2/1986 

6/23/1986 

8/29/1986 

2/9/1987 

1130 

1345 

1030 

1200 

0915 

622 

623 

638 

659 

591 

--

--

--

--

--

1.5 

59.0 

13.0 

0 

1.3 

2.6 

3.2 

20.0 

0 

3.4 

5.2 

6.4 

16.0 

.4 

9.3 

54.0 

38.0 

216.0 

5.8 

81.0 

78 

62 

84 

64 

83 

SVW 

SVW 

SVW 

SVW 

SVW 

5/18/1987 

6/1/1987 

8/17/1987 

2/22/1988 

5/9/1988 

1020 

1030 

1215 

1010 

0850 

661 

603 

614 

637 

690 

--

--

--

--

--

1.0 

149.0 

0 

.2 

.2 

.5 

93.0 

0 

.6 

.1 

2.3 

41.0 

1.6 

1.2 

1.1 

38.0 

392.0 

34.0 

8.6 

7.8 

100 

110 

110 

64 

50 
Appendix 1 55 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

SVW 7/18/1988 1155 569 -- 2.0 0 0.8 7.5 45 

SVW 8/11/1988 1010 658 -- 1.1 0 0 11.0 43 

SVW 2/27/1989 1350 630 1.0 .3 0 .1 2.4 27 

SVW 5/1/1989 1055 708 19.0 .3 0 3.7 7.3 36 

SVW 7/17/1989 1115 650 8.9 2.0 .2 2.9 12.0 55 

SVW 8/29/1989 0905 678 .4 0 0 0 2.7 33 

SVW 1/30/1990 1250 688 .6 0 0 0 .4 17 

SVW 6/8/1990 0715 705 41.0 3.8 .8 2.5 80.0 49 

SVW 8/15/1990 1145 694 1.2 0 0 0 2.2 30 

SVW 3/11/1991 1320 658 95.0 6.7 11.0 14.0 75.0 87 

SVW 5/7/1991 1045 646 105.0 10.0 8.0 20.0 151.0 99 

SVW 8/14/1991 1320 680 4.1 12.0 5.9 1.7 6.5 75 

SVW 4/29/1992 0830 639 104.0 4.0 5.2 9.8 90.0 115 

SVW 1/22/1993 0920 655 262.0 16.0 21.0 9.0 231.0 100 

SVW 1/25/1993 1130 621 262.0 16.0 21.0 9.0 231.0 100 

SVW 1/28/1993 1350 608 262.0 16.0 21.0 9.0 231.0 100 

SVW 5/11/1993 0910 611 123.0 1.2 16.0 10.0 73.0 108 

SVW 5/15/1993 0845 585 123.0 0 16.0 10.0 73.0 108 

SVW 6/1/1993 0935 630 42.0 0 5.0 5.2 32.0 108 

SVW 8/20/1993 1030 670 .4 0 0 0 .3 86 

SVW 4/11/1994 0730 645 6.9 0 0 .3 9.5 47 

SVW 10/9/1994 0700 570 476.0 73.0 99.0 33.0 30.0 35 

SVW 10/9/1994 1305 582 476.0 73.0 99.0 33.0 30.0 35 

SVW 10/9/1994 1855 592 476.0 73.0 99.0 33.0 30.0 35 

SVW 10/10/1994 0710 611 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/10/1994 1300 620 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/10/1994 1905 612 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/11/1994 0705 624 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/11/1994 1305 678 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/11/1994 1900 634 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/12/1994 0730 600 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/12/1994 1900 598 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/13/1994 0700 601 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/13/1994 1930 619 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/14/1994 0730 596 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/14/1994 1800 594 476.0 73.0 99.0 33.0 30.0 39 

SVW 10/15/1994 1230 645 476.0 73.0 99.0 33.0 30.0 39 

SVW 6/27/1995 0820 647 99.0 0 18.0 12.0 96.0 98 

SVW 5/2/1996 0900 643 .7 0 0 .1 .6 26 

SVW 7/9/1997 1105 580 273.0 0 17.0 23.0 455.0 113 

SVW 4/21/1998 1430 568 79.0 0 8.9 7.5 96.0 98 

SVW 6/9/1999 1245 644 35.0 0 1.9 1.6 5.3 76 

SVW 6/1/2000 1000 662 2.7 0 0 .1 1.4 22 

SVW 6/6/2001 1200 659 36.0 0 1.4 2.9 64.0 103 

SVW 6/3/2002 1400 646 7.2 0 .1 .7 3.8 88 

SVW 5/19/2003 1000 644 13.0 0 .3 1.3 13.0 102 

TNR 7/17/1978 0820 580 -- 0 0 -- -- 24 

TNR 7/9/1979 1215 580 27.0 5.2 4.7 2.6 18.0 103 

TNR 8/29/1980 0930 592 0 0 0 .1 1.0 40 

TNR 8/18/1981 0920 576 16.0 .3 .3 4.3 14.0 96 
56 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 1. Specific conductance data for samples from wells in the Barton Springs segment of the Edwards aquifer and 

corresponding maximum 10-day streamflow for the five creeks and maximum 10-day discharge for Barton Springs, Austin, Texas, 

1978–2003—Continued. 

Maximum 10-day streamflow or spring discharge
 Well Specific (ft3

/s)
 

identifier Date Time conductance 

(fig. 1) (μS/cm) Barton Williamson Slaughter Bear Onion Barton 

Creek Creek Creek Creek Creek Springs 

TNR 

TNR 

TNR 

TNR 

TNR 

8/16/1982 

7/21/1983 

6/19/1985 

8/9/1985 

1/13/1986 

0915 

1115 

1045 

1145 

1310 

584 

590 

588 

604 

576 

1.1 

--

--

--

--

0 

7.7 

2.4 

0 

1.5 

0 

1.4 

4.0 

.2 

3.0 

0.2 

22.0 

5.6 

.9 

5.7 

1.9 

90.0 

145.0 

15.0 

61.0 

46 

84 

70 

64 

78 

TNR 

TNR 

TNR 

TNR 

TNR 

5/3/1986 

6/25/1986 

9/2/1986 

2/11/1987 

5/19/1987 

1040 

1030 

1215 

1030 

1100 

592 

646 

607 

597 

605 

--

--

--

--

--

59.0 

13.0 

0 

1.3 

12.0 

3.2 

20.0 

0 

3.2 

2.6 

6.4 

16.0 

.4 

8.9 

2.8 

38.0 

216.0 

5.8 

76.0 

38.0 

62 

84 

62 

80 

100 

TNR 6/1/1987 1013 595 -- 149.0 93.0 41.0 392.0 110 

TNR 8/18/1987 1015 606 -- 0 0 1.6 34.0 110 

TNR 2/25/1988 1020 597 -- .1 .6 1.2 8.6 63 

TNR 5/9/1988 1030 598 -- .2 .1 1.1 7.8 50 

TNR 7/18/1988 1015 599 -- 2.0 0 .8 7.5 45 

TNR 

TNR 

TNR 

TNR 

TNR 

8/9/1988 

2/23/1989 

5/2/1989 

7/26/1989 

8/30/1989 

1125 

1130 

1130 

1345 

1130 

600 

579 

603 

592 

590 

--

.9 

16.0 

2.5 

.4 

0 

.3 

.3 

.3 

0 

0 

0 

0 

0 

0 

0 

.1 

3.5 

1.6 

0 

11.0 

1.4 

5.6 

5.5 

2.7 

43 

28 

35 

48 

32 

TNR 

TNR 

WBG 

WBG 

WBG 

2/7/1990 

4/30/1992 

7/10/1978 

7/5/1979 

8/28/1980 

1330 

1120 

0940 

1005 

1330 

558 

593 

700 

799 

826 

4.3 

94.0 

13.0 

0 

8.6 

3.5 

0 

.8 

0 

0 

4.7 

0 

2.9 

0 

.1 

8.5 

.1 

--

--

1.5 

81.0 

14.0 

1.1 

--

22 

115 

26 

105 

41 

WBG 8/11/1981 1305 788 11.0 0 .5 2.2 19.0 99 

WBG 8/10/1982 1330 766 1.1 0 .1 .4 1.2 49 

WBG 7/20/1983 1415 767 -- 7.7 1.4 22.0 90.0 84 

WGF 6/28/1978 1100 480 .7 .2 .1 31 

WGF 7/17/1979 1415 520 17.0 .9 2.1 2.5 16.0 100 

WGF 8/27/1980 1415 500 .1 0 0 .1 1.1 41 

WGF 8/10/1981 1315 537 11.0 .1 .6 2.3 20.0 99 

WGF 8/9/1982 1320 505 1.1 0 .1 .4 1.1 50 

WGF 7/19/1983 0918 514 -- 7.7 1.4 22.0 90.0 84 
Appendix 2—Discharge Data
 
Blank Page 
Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978 2003—Continued.

Specific Conductance, 

and Associated Major 

Ion and Nitrate

Geochemistry, Edwards 

Aquifer, Austin, Texas, 

1978–2003

Appendix 2

Appendix 2 59 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978 –2003. 

[In cubic feet per second; --, no data] 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

3/1/1978 0 0 0 -- -- 41 4/20/1978 1.2 0 0 -- -- 31 

3/2/1978 0 0 0 -- -- 41 4/21/1978 1.1 0 0 -- -- 30 

3/3/1978 0 0 0 -- -- 40 4/22/1978 .9 0 0 -- -- 30 

3/4/1978 0 0 0 -- -- 40 4/23/1978 .9 0 0 -- -- 30 

3/5/1978 0 0 0 -- -- 40 4/24/1978 .9 0 0 -- -- 30 

3/6/1978 .1 0 0 -- -- 41 4/25/1978 .8 0 0 -- -- 30 

3/7/1978 .2 0 0 -- -- 41 4/26/1978 .6 0 0 -- -- 31 

3/8/1978 .1 0 0 -- -- 40 4/27/1978 .6 0 0 -- -- 30 

3/9/1978 0 0 0 -- -- 40 4/28/1978 .5 0 0 -- -- 30 

3/10/1978 0 0 0 -- -- 42 4/29/1978 .5 0 0 -- -- 31 

3/11/1978 0 0 0 -- -- 41 4/30/1978 .4 0 0 -- -- 31 

3/12/1978 0 0 0 -- -- 42 5/1/1978 .4 0 0 -- -- 31 

3/13/1978 0 0 0 -- -- 40 5/2/1978 .4 .3 0 -- -- 30 

3/14/1978 0 0 0 -- -- 42 5/3/1978 .8 .3 0 -- -- 30 

3/15/1978 0 0 0 -- -- 41 5/4/1978 .5 0 0 -- -- 30 

3/16/1978 0 0 0 -- -- 41 5/5/1978 .4 0 0 -- -- 30 

3/17/1978 0 0 0 -- -- 39 5/6/1978 .3 0 0 -- -- 31 

3/18/1978 0 0 0 -- -- 39 5/7/1978 .4 0 0 -- -- 31 

3/19/1978 .3 0 0 -- -- 40 5/8/1978 .3 0 0 -- -- 31 

3/20/1978 .4 0 0 -- -- 39 5/9/1978 .2 0 0 -- -- 31 

3/21/1978 .4 0 0 -- -- 39 5/10/1978 .2 0 0 -- -- 31 

3/22/1978 .3 0 0 -- -- 39 5/11/1978 .1 0 0 -- -- 31 

3/23/1978 .3 0 0 -- -- 40 5/12/1978 .1 0 0 -- -- 30 

3/24/1978 .4 0 0 -- -- 33 5/13/1978 0 0 0 -- -- 31 

3/25/1978 .4 0 0 -- -- 34 5/14/1978 0 0 0 -- -- 31 

3/26/1978 .4 0 0 -- -- 34 5/15/1978 0 0 0 -- -- 31 

3/27/1978 .4 0 0 -- -- 34 5/16/1978 0 0 0 -- -- 31 

3/28/1978 .4 0 0 -- -- 34 5/17/1978 0 0 0 -- -- 31 

3/29/1978 .4 0 0 -- -- 33 5/18/1978 0 0 0 -- -- 30 

3/30/1978 .4 0 0 -- -- 33 5/19/1978 0 0 0 -- -- 31 

3/31/1978 .4 0 0 -- -- 31 5/20/1978 .1 1.7 .1 -- -- 31 

4/1/1978 .4 0 0 -- -- 32 5/21/1978 .1 .1 0 -- -- 31 

4/2/1978 .4 0 0 -- -- 32 5/22/1978 0 0 0 -- -- 32 

4/3/1978 .5 0 0 -- -- 32 5/23/1978 0 0 0 -- -- 31 

4/4/1978 .5 0 0 -- -- 32 5/24/1978 0 0 0 -- -- 31 

4/5/1978 .5 0 0 -- -- 32 5/25/1978 0 0 0 -- -- 30 

4/6/1978 .5 0 0 -- -- 32 5/26/1978 .1 0 0 -- -- 30 

4/7/1978 .5 0 0 -- -- 31 5/27/1978 .2 .2 0 -- -- 31 

4/8/1978 .5 0 0 -- -- 31 5/28/1978 .1 0 0 -- -- 31 

4/9/1978 .5 0 0 -- -- 31 5/29/1978 0 0 0 -- -- 32 

4/10/1978 9.8 3.8 .1 -- -- 31 5/30/1978 0 0 0 -- -- 32 

4/11/1978 1.5 0 0 -- -- 32 5/31/1978 0 0 0 -- -- 32 

4/12/1978 .9 0 0 -- -- 32 6/1/1978 0 0 0 -- -- 32 

4/13/1978 .9 0 0 -- -- 31 6/2/1978 0 0 0 -- -- 31 

4/14/1978 .9 0 0 -- -- 30 6/3/1978 0 0 .1 -- -- 31 

4/15/1978 .9 0 0 -- -- 31 6/4/1978 0 0 0 -- -- 31 

4/16/1978 .9 0 0 -- -- 31 6/5/1978 0 0 0 -- -- 31 

4/17/1978 .9 0 0 -- -- 31 6/6/1978 2.6 28.0 6.9 -- -- 31 

4/18/1978 1.2 0 0 -- -- 31 6/7/1978 48.0 28.0 9.3 -- -- 32 

4/19/1978 1.2 0 0 -- -- 31 6/8/1978 13.0 5.4 .4 -- -- 35 
60 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/9/1978 6.6 2.6 0.3 -- -- 34 7/29/1978 0 0 0 -- -- 19 

6/10/1978 2.8 2.1 .2 -- -- 35 7/30/1978 0 0 0 -- -- 20 

6/11/1978 2.2 1.5 .2 -- -- 35 7/31/1978 0 0 0 -- -- 20 

6/12/1978 2.1 1.7 .1 -- -- 35 8/1/1978 6.8 14.0 3.5 -- -- 19 

6/13/1978 1.9 1.7 .1 -- -- 35 8/2/1978 2.4 1.5 .4 -- -- 21 

6/14/1978 1.7 1.2 .1 -- -- 34 8/3/1978 .6 0 .2 -- -- 20 

6/15/1978 1.6 .2 .1 -- -- 33 8/4/1978 7.6 0 .2 -- -- 20 

6/16/1978 1.4 .2 .1 -- -- 32 8/5/1978 5.1 0 .2 -- -- 20 

6/17/1978 1.2 .2 .1 -- -- 32 8/6/1978 3.2 0 .1 -- -- 21 

6/18/1978 .9 .2 .1 -- -- 32 8/7/1978 2.1 0 .1 -- -- 22 

6/19/1978 .7 .2 .1 -- -- 31 8/8/1978 1.4 0 .1 -- -- 24 

6/20/1978 .5 .2 .1 -- -- 31 8/9/1978 1.1 0 0 -- -- 25 

6/21/1978 .3 .1 .1 -- -- 30 8/10/1978 1.0 0 0 -- -- 24 

6/22/1978 .1 0 0 -- -- 29 8/11/1978 .9 0 0 -- -- 24 

6/23/1978 0 0 0 -- -- 28 8/12/1978 .6 0 0 -- -- 25 

6/24/1978 0 0 0 -- -- 29 8/13/1978 .4 0 0 -- -- 24 

6/25/1978 0 0 0 -- -- 28 8/14/1978 .4 0 0 -- -- 23 

6/26/1978 0 0 0 -- -- 28 8/15/1978 .3 0 0 -- -- 22 

6/27/1978 0 0 0 -- -- 28 8/16/1978 .3 0 0 -- -- 22 

6/28/1978 0 0 0 -- -- 27 8/17/1978 .2 0 0 -- -- 21 

6/29/1978 0 0 0 -- -- 27 8/18/1978 .1 0 0 -- -- 21 

6/30/1978 0 0 0 -- -- 27 8/19/1978 .1 0 0 -- -- 22 

7/1/1978 0 0 0 -- -- 26 8/20/1978 .1 0 0 -- -- 22 

7/2/1978 0 0 0 -- -- 25 8/21/1978 .1 0 0 -- -- 22 

7/3/1978 0 0 0 -- -- 25 8/22/1978 .1 0 0 -- -- 22 

7/4/1978 0 0 0 -- -- 25 8/23/1978 0 0 0 -- -- 24 

7/5/1978 0 0 0 -- -- 24 8/24/1978 0 0 0 -- -- 23 

7/6/1978 0 0 0 -- -- 21 8/25/1978 0 0 0 -- -- 23 

7/7/1978 0 0 0 -- -- 24 8/26/1978 0 0 0 -- -- 23 

7/8/1978 0 0 0 -- -- 24 8/27/1978 0 0 0 -- -- 23 

7/9/1978 0 0 0 -- -- 23 8/28/1978 0 0 0 -- -- 23 

7/10/1978 0 0 0 -- -- 23 8/29/1978 0 0 0 -- -- 23 

7/11/1978 0 0 0 -- -- 22 8/30/1978 0 0 0 -- -- 24 

7/12/1978 0 0 0 -- -- 21 8/31/1978 0 0 0 -- -- 23 

7/13/1978 0 0 0 -- -- 20 9/1/1978 0 0 0 -- -- 22 

7/14/1978 0 0 0 -- -- 20 9/2/1978 0 0 0 -- -- 24 

7/15/1978 0 0 0 -- -- 20 9/3/1978 0 0 0 -- -- 24 

7/16/1978 0 0 0 -- -- 20 9/4/1978 .3 .1 0 -- -- 23 

7/17/1978 0 0 0 -- -- 20 9/5/1978 .4 0 0 -- -- 23 

7/18/1978 0 0 0 -- -- 20 9/6/1978 0 0 0 -- -- 23 

7/19/1978 0 0 0 -- -- 20 9/7/1978 0 0 0 -- -- 23 

7/20/1978 0 0 0 -- -- 20 9/8/1978 .2 3.2 .1 -- -- 23 

7/21/1978 0 0 0 -- -- 20 9/9/1978 .2 .2 0 -- -- 24 

7/22/1978 0 0 0 -- -- 20 9/10/1978 .8 3.7 .2 -- -- 24 

7/23/1978 0 .3 1.1 -- -- 21 9/11/1978 2.3 1.3 .1 -- -- 25 

7/24/1978 0 0 0 -- -- 20 9/12/1978 .8 .2 0 -- -- 25 

7/25/1978 0 0 0 -- -- 19 9/13/1978 1.3 3.2 .2 -- -- 25 

7/26/1978 0 0 0 -- -- 20 9/14/1978 1.7 1.0 .3 -- -- 24 

7/27/1978 0 0 0 -- -- 19 9/15/1978 1.3 .2 .3 -- -- 23 

7/28/1978 0 0 0 -- -- 19 9/16/1978 .9 .1 .3 -- -- 26 
Appendix 2 61 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/17/1978 0.2 0.2 0.3 -- -- 26 11/6/1978 1.2 4.0 1.6 -- -- 30 

9/18/1978 .2 .1 .3 -- -- 26 11/7/1978 .8 .2 .4 -- -- 28 

9/19/1978 .2 .1 .3 -- -- 26 11/8/1978 .6 .2 .4 -- -- 31 

9/20/1978 .2 0 .3 -- -- 26 11/9/1978 .5 .2 .4 -- -- 31 

9/21/1978 .2 0 .3 -- -- 25 11/10/1978 .5 0 .4 -- -- 31 

9/22/1978 .2 0 .2 -- -- 24 11/11/1978 .5 0 .4 -- -- 31 

9/23/1978 .2 0 .3 -- -- 25 11/12/1978 .6 .2 .5 -- -- 31 

9/24/1978 .2 0 .3 -- -- 26 11/13/1978 .5 0 .5 -- -- 31 

9/25/1978 .2 0 .3 -- -- 26 11/14/1978 .6 0 .5 -- -- 31 

9/26/1978 .2 0 .3 -- -- 26 11/15/1978 .6 1.5 .8 -- -- 32 

9/27/1978 .2 0 .3 -- -- 26 11/16/1978 1.1 1.9 1.1 -- -- 32 

9/28/1978 .2 .1 .3 -- -- 25 11/17/1978 1.1 1.5 1.2 -- -- 33 

9/29/1978 .2 0 .3 -- -- 24 11/18/1978 .9 1.3 1.2 -- -- 33 

9/30/1978 .2 0 .3 -- -- 25 11/19/1978 1.0 2.5 1.6 -- -- 34 

10/1/1978 .5 0 .3 -- -- 25 11/20/1978 1.2 3.0 1.8 -- -- 35 

10/2/1978 .5 0 .3 -- -- 24 11/21/1978 1.5 3.3 2.5 -- -- 35 

10/3/1978 .4 0 .3 -- -- 24 11/22/1978 2.0 3.4 2.8 -- -- 36 

10/4/1978 .4 0 .3 -- -- 24 11/23/1978 3.0 3.3 2.9 -- -- 38 

10/5/1978 .4 0 .3 -- -- 24 11/24/1978 3.3 2.7 2.9 -- -- 38 

10/6/1978 .3 0 .2 -- -- 22 11/25/1978 3.6 2.7 3.1 -- -- 39 

10/7/1978 .3 0 .2 -- -- 22 11/26/1978 4.0 2.7 3.3 -- -- 39 

10/8/1978 .3 0 .2 -- -- 23 11/27/1978 4.8 2.7 3.4 -- -- 40 

10/9/1978 .3 0 .2 -- -- 23 11/28/1978 4.7 2.4 3.4 -- -- 39 

10/10/1978 .3 0 .2 -- -- 23 11/29/1978 4.6 2.0 3.4 -- -- 38 

10/11/1978 .3 0 .2 -- -- 23 11/30/1978 4.6 2.0 3.2 -- -- 37 

10/12/1978 .3 0 .2 -- -- 23 12/1/1978 4.6 2.0 3.1 -- -- 37 

10/13/1978 .3 0 .2 -- -- 23 12/2/1978 4.6 1.7 3.1 -- -- 37 

10/14/1978 .2 0 .1 -- -- 25 12/3/1978 5.8 2.7 3.7 -- -- 37 

10/15/1978 .2 0 0 -- -- 25 12/4/1978 6.3 1.7 3.2 -- -- 37 

10/16/1978 .2 0 0 -- -- 24 12/5/1978 5.8 1.7 3.1 -- -- 37 

10/17/1978 .2 0 0 -- -- 24 12/6/1978 5.8 1.5 3.1 -- -- 38 

10/18/1978 .2 0 0 -- -- 25 12/7/1978 5.8 1.5 2.9 -- -- 37 

10/19/1978 .2 0 0 -- -- 24 12/8/1978 5.8 1.2 2.7 -- -- 37 

10/20/1978 .2 0 0 -- -- 23 12/9/1978 5.8 1.0 2.4 -- -- 37 

10/21/1978 .2 0 0 -- -- 25 12/10/1978 5.8 1.0 2.4 -- -- 37 

10/22/1978 .2 0 0 -- -- 26 12/11/1978 5.8 1.0 2.4 -- -- 37 

10/23/1978 .1 0 0 -- -- 26 12/12/1978 5.8 1.0 2.4 -- -- 37 

10/24/1978 .2 0 0 -- -- 26 12/13/1978 5.8 1.0 2.4 -- -- 36 

10/25/1978 .2 0 0 -- -- 26 12/14/1978 5.9 .7 2.4 -- -- 36 

10/26/1978 .2 0 0 -- -- 23 12/15/1978 5.8 .9 2.4 -- -- 36 

10/27/1978 .2 0 0 -- -- 25 12/16/1978 5.6 .9 2.4 -- -- 36 

10/28/1978 .2 0 0 -- -- 27 12/17/1978 5.4 .8 2.0 -- -- 36 

10/29/1978 .2 0 0 -- -- 27 12/18/1978 5.4 .8 2.1 -- -- 36 

10/30/1978 .2 0 0 -- -- 28 12/19/1978 5.4 .8 2.2 -- -- 37 

10/31/1978 .1 0 0 -- -- 29 12/20/1978 5.4 .8 2.2 -- -- 36 

11/1/1978 .1 0 0 -- -- 32 12/21/1978 5.2 .8 2.0 -- -- 35 

11/2/1978 .1 0 0 -- -- 30 12/22/1978 4.8 .8 2.0 -- -- 35 

11/3/1978 .1 0 0 -- -- 30 12/23/1978 4.8 .8 2.0 -- -- 35 

11/4/1978 .2 0 0 -- -- 28 12/24/1978 4.8 .8 2.0 -- -- 36 

11/5/1978 1.3 14.0 1.5 -- -- 30 12/25/1978 4.5 .8 2.0 -- -- 35 
62 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/26/1978 4.4 0.8 1.9 -- -- 36 2/14/1979 90.0 7.9 9.7 -- -- 80 

12/27/1978 4.3 .7 1.8 -- -- 35 2/15/1979 83.0 6.7 8.7 -- -- 80 

12/28/1978 4.3 .6 1.8 -- -- 35 2/16/1979 72.0 5.5 6.8 -- -- 80 

12/29/1978 4.3 .5 1.8 -- -- 35 2/17/1979 67.0 5.3 6.7 -- -- 80 

12/30/1978 4.3 .5 1.8 -- -- 35 2/18/1979 66.0 4.9 6.2 -- -- 79 

12/31/1978 34.0 40.0 46.0 -- -- 44 2/19/1979 63.0 4.5 5.7 -- -- 79 

1/1/1979 60.0 35.0 28.0 -- -- 50 2/20/1979 62.0 4.3 5.7 -- -- 81 

1/2/1979 48.0 12.0 12.0 -- -- 51 2/21/1979 59.0 4.4 5.3 -- -- 80 

1/3/1979 40.0 9.0 11.0 -- -- 52 2/22/1979 56.0 4.0 5.3 -- -- 79 

1/4/1979 36.0 7.7 11.0 -- -- 52 2/23/1979 86.0 56.0 90.0 -- -- 83 

1/5/1979 36.0 8.1 12.0 -- -- 52 2/24/1979 84.0 20.0 22.0 -- -- 86 

1/6/1979 37.0 11.0 14.0 -- -- 54 2/25/1979 63.0 14.0 15.0 -- -- 84 

1/7/1979 39.0 10.0 13.0 -- -- 55 2/26/1979 59.0 7.7 13.0 -- -- 84 

1/8/1979 36.0 7.4 10.0 -- -- 55 2/27/1979 59.0 6.9 11.0 -- -- 84 

1/9/1979 34.0 6.4 9.8 -- -- 53 2/28/1979 56.0 5.4 9.6 -- -- 84 

1/10/1979 67.0 52.0 69.0 -- -- 55 3/1/1979 53.0 4.0 7.9 -- -- 84 

1/11/1979 369.0 67.0 101.0 -- -- 64 3/2/1979 52.0 3.9 7.3 -- -- 84 

1/12/1979 149.0 32.0 42.0 -- -- 72 3/3/1979 54.0 3.5 7.9 -- -- 84 

1/13/1979 119.0 22.0 26.0 -- -- 71 3/4/1979 48.0 2.7 6.2 -- -- 84 

1/14/1979 108.0 15.0 17.0 -- -- 70 3/5/1979 45.0 2.6 5.7 -- -- 84 

1/15/1979 100.0 12.0 16.0 -- -- 68 3/6/1979 42.0 2.3 5.6 -- -- 85 

1/16/1979 92.0 11.0 15.0 -- -- 67 3/7/1979 42.0 2.0 5.2 -- -- 84 

1/17/1979 85.0 9.2 13.0 -- -- 70 3/8/1979 41.0 1.7 4.8 -- -- 84 

1/18/1979 74.0 8.8 13.0 -- -- 70 3/9/1979 39.0 1.7 4.7 -- -- 83 

1/19/1979 68.0 8.1 12.0 -- -- 70 3/10/1979 37.0 1.5 4.1 -- -- 82 

1/20/1979 62.0 7.1 11.0 -- -- 70 3/11/1979 37.0 1.5 4.1 -- -- 83 

1/21/1979 55.0 5.9 9.2 -- -- 69 3/12/1979 36.0 1.3 4.1 -- -- 83 

1/22/1979 50.0 5.4 8.4 -- -- 69 3/13/1979 35.0 1.2 3.7 -- -- 84 

1/23/1979 48.0 4.4 7.8 -- -- 69 3/14/1979 33.0 1.1 3.5 -- -- 83 

1/24/1979 44.0 3.8 6.8 -- -- 68 3/15/1979 31.0 1.3 3.6 -- -- 81 

1/25/1979 44.0 3.4 7.1 -- -- 70 3/16/1979 39.0 3.0 5.2 -- -- 81 

1/26/1979 45.0 3.4 7.8 -- -- 70 3/17/1979 42.0 2.7 5.7 -- -- 82 

1/27/1979 41.0 3.2 7.0 -- -- 69 3/18/1979 41.0 2.4 5.6 -- -- 82 

1/28/1979 37.0 3.0 6.3 -- -- 69 3/19/1979 88.0 2.8 8.2 -- -- 82 

1/29/1979 36.0 3.0 6.2 -- -- 69 3/20/1979 158.0 6.6 13.0 -- -- 83 

1/30/1979 37.0 3.0 6.2 -- -- 69 3/21/1979 995.0 51.0 88.0 -- -- 84 

1/31/1979 34.0 2.4 5.5 -- -- 69 3/22/1979 643.0 45.0 66.0 -- -- 84 

2/1/1979 32.0 2.3 4.8 -- -- 69 3/23/1979 327.0 20.0 33.0 -- -- 85 

2/2/1979 32.0 2.3 4.4 -- -- 69 3/24/1979 259.0 14.0 23.0 -- -- 85 

2/3/1979 34.0 2.4 5.0 -- -- 69 3/25/1979 222.0 10.0 18.0 -- -- 85 

2/4/1979 43.0 10.0 13.0 -- -- 69 3/26/1979 201.0 7.7 15.0 -- -- 86 

2/5/1979 119.0 37.0 48.0 -- -- 74 3/27/1979 181.0 6.7 13.0 -- -- 86 

2/6/1979 327.0 67.0 91.0 -- -- 84 3/28/1979 170.0 6.1 12.0 -- -- 86 

2/7/1979 209.0 32.0 37.0 -- -- 85 3/29/1979 161.0 5.5 12.0 -- -- 86 

2/8/1979 162.0 23.0 26.0 -- -- 77 3/30/1979 215.0 12.0 20.0 -- -- 92 

2/9/1979 132.0 17.0 18.0 -- -- 78 3/31/1979 197.0 14.0 21.0 -- -- 91 

2/10/1979 122.0 15.0 16.0 -- -- 78 4/1/1979 368.0 18.0 28.0 -- -- 91 

2/11/1979 114.0 12.0 14.0 -- -- 79 4/2/1979 315.0 17.0 26.0 -- -- 91 

2/12/1979 104.0 10.0 12.0 -- -- 80 4/3/1979 248.0 15.0 24.0 -- -- 92 

2/13/1979 96.0 8.2 10.0 -- -- 80 4/4/1979 221.0 12.0 19.0 -- -- 93 
Appendix 2 63 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/5/1979 201.0 10.0 16.0 -- -- 94 5/25/1979 57.0 17.0 19.0 -- -- 106 

4/6/1979 181.0 9.5 13.0 -- -- 94 5/26/1979 51.0 14.0 16.0 -- -- 106 

4/7/1979 171.0 9.1 13.0 -- -- 93 5/27/1979 50.0 12.0 14.0 -- -- 106 

4/8/1979 176.0 12.0 14.0 -- -- 93 5/28/1979 49.0 10.0 13.0 -- -- 106 

4/9/1979 150.0 12.0 11.0 -- -- 93 5/29/1979 45.0 8.9 11.0 -- -- 106 

4/10/1979 146.0 12.0 11.0 -- -- 95 5/30/1979 42.0 11.0 16.0 -- -- 106 

4/11/1979 155.0 14.0 9.7 -- -- 95 5/31/1979 38.0 9.8 14.0 -- -- 106 

4/12/1979 141.0 14.0 8.1 -- -- 94 6/1/1979 55.0 33.0 68.0 -- -- 105 

4/13/1979 155.0 15.0 7.2 -- -- 92 6/2/1979 62.0 26.0 41.0 -- -- 105 

4/14/1979 145.0 18.0 6.7 -- -- 92 6/3/1979 47.0 20.0 27.0 -- -- 106 

4/15/1979 133.0 19.0 6.5 -- -- 92 6/4/1979 41.0 18.0 23.0 -- -- 107 

4/16/1979 121.0 21.0 6.2 -- -- 92 6/5/1979 48.0 21.0 28.0 -- -- 106 

4/17/1979 143.0 26.0 7.2 -- -- 93 6/6/1979 47.0 17.0 22.0 -- -- 105 

4/18/1979 146.0 102.0 161.0 -- -- 93 6/7/1979 39.0 13.0 17.0 -- -- 105 

4/19/1979 142.0 34.0 68.0 -- -- 97 6/8/1979 42.0 11.0 15.0 -- -- 106 

4/20/1979 137.0 26.0 39.0 -- -- 98 6/9/1979 41.0 8.8 13.0 -- -- 108 

4/21/1979 530.0 81.0 98.0 -- -- 98 6/10/1979 35.0 7.1 10.0 -- -- 108 

4/22/1979 229.0 26.0 45.0 -- -- 98 6/11/1979 32.0 6.2 9.4 -- -- 108 

4/23/1979 199.0 17.0 30.0 -- -- 97 6/12/1979 29.0 5.1 8.3 -- -- 105 

4/24/1979 182.0 11.0 23.0 -- -- 98 6/13/1979 27.0 4.3 7.7 -- -- 105 

4/25/1979 166.0 7.6 18.0 -- -- 98 6/14/1979 28.0 3.7 7.1 -- -- 106 

4/26/1979 149.0 5.3 15.0 -- -- 98 6/15/1979 26.0 3.2 6.6 -- -- 107 

4/27/1979 137.0 4.1 13.0 -- -- 98 6/16/1979 24.0 2.7 6.1 -- -- 108 

4/28/1979 125.0 3.3 11.0 -- -- 99 6/17/1979 20.0 2.5 5.3 -- -- 107 

4/29/1979 354.0 24.0 45.0 -- -- 100 6/18/1979 20.0 1.9 5.2 -- -- 107 

4/30/1979 204.0 9.0 20.0 -- -- 100 6/19/1979 18.0 1.7 4.8 -- -- 107 

5/1/1979 296.0 25.0 53.0 -- -- 101 6/20/1979 17.0 1.5 4.4 -- -- 108 

5/2/1979 244.0 16.0 33.0 -- -- 102 6/21/1979 16.0 1.4 4.1 -- -- 108 

5/3/1979 222.0 13.0 29.0 -- -- 102 6/22/1979 15.0 1.2 4.0 -- -- 107 

5/4/1979 203.0 8.1 22.0 -- -- 101 6/23/1979 13.0 1.2 3.7 -- -- 107 

5/5/1979 186.0 5.6 18.0 -- -- 101 6/24/1979 13.0 .9 3.4 -- -- 107 

5/6/1979 173.0 4.2 15.0 -- -- 101 6/25/1979 12.0 .8 3.1 -- -- 106 

5/7/1979 159.0 3.2 13.0 -- -- 102 6/26/1979 13.0 .7 2.9 -- -- 105 

5/8/1979 146.0 2.7 11.0 -- -- 102 6/27/1979 13.0 .8 2.9 -- -- 105 

5/9/1979 137.0 2.7 11.0 -- -- 102 6/28/1979 12.0 .7 2.8 -- -- 104 

5/10/1979 130.0 2.2 10.0 -- -- 102 6/29/1979 12.0 .5 2.5 -- -- 103 

5/11/1979 124.0 2.1 11.0 -- -- 102 6/30/1979 11.0 .4 2.0 -- -- 103 

5/12/1979 118.0 1.7 9.4 -- -- 101 7/1/1979 10.0 .4 2.0 -- 14.0 102 

5/13/1979 99.0 1.5 8.2 -- -- 101 7/2/1979 8.1 .4 1.8 -- 14.0 102 

5/14/1979 86.0 1.4 7.2 -- -- 101 7/3/1979 7.5 .4 1.5 -- 14.0 101 

5/15/1979 77.0 2.0 6.7 -- -- 101 7/4/1979 6.7 .4 1.5 -- 14.0 101 

5/16/1979 73.0 2.8 6.6 -- -- 101 7/5/1979 5.7 .3 1.6 -- 13.0 101 

5/17/1979 62.0 4.0 6.2 -- -- 101 7/6/1979 16.0 5.2 4.7 -- 14.0 100 

5/18/1979 59.0 5.8 6.1 -- -- 101 7/7/1979 27.0 .5 2.2 2.6 18.0 100 

5/19/1979 57.0 7.3 5.7 -- -- 101 7/8/1979 17.0 .4 1.9 2.5 16.0 100 

5/20/1979 53.0 8.3 5.6 -- -- 101 7/9/1979 13.0 .4 1.8 2.4 13.0 100 

5/21/1979 64.0 238.0 250.0 -- -- 101 7/10/1979 17.0 .9 1.9 2.3 13.0 99 

5/22/1979 767.0 140.0 196.0 -- -- 103 7/11/1979 12.0 .4 2.1 2.2 14.0 99 

5/23/1979 91.0 33.0 43.0 -- -- 105 7/12/1979 10.0 .3 1.4 2.1 13.0 99 

5/24/1979 61.0 23.0 27.0 -- -- 107 7/13/1979 8.7 .2 1.3 2.0 13.0 98 
64 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

7/14/1979 6.8 0.2 1.1 1.9 12.0 98 9/2/1979 2.0 0.1 .5 1.3 5.2 88 

7/15/1979 6.5 .2 1.1 1.9 12.0 98 9/3/1979 1.8 0 .5 1.3 5.6 88 

7/16/1979 6.5 .2 1.0 1.7 12.0 97 9/4/1979 1.9 .6 .5 1.3 5.2 87 

7/17/1979 6.1 .1 1.0 1.6 12.0 97 9/5/1979 2.8 1.2 .6 2.9 5.2 87 

7/18/1979 5.8 .2 1.1 1.7 11.0 97 9/6/1979 3.8 1.0 .5 1.9 5.2 87 

7/19/1979 12.0 .2 1.1 1.7 11.0 97 9/7/1979 2.9 .6 .5 1.6 5.2 87 

7/20/1979 37.0 6.9 11.0 1.7 12.0 96 9/8/1979 2.7 .2 .5 1.4 5.2 86 

7/21/1979 35.0 1.6 2.6 1.7 13.0 96 9/9/1979 2.2 0 .4 1.3 4.8 86 

7/22/1979 16.0 .4 1.4 1.7 12.0 96 9/10/1979 1.8 0 .4 1.2 4.3 85 

7/23/1979 10.0 .3 1.3 1.6 11.0 95 9/11/1979 1.7 0 .4 1.2 3.8 85 

7/24/1979 7.6 .2 1.1 1.6 11.0 95 9/12/1979 1.7 0 .4 1.2 3.8 85 

7/25/1979 6.3 .2 1.1 1.6 11.0 95 9/13/1979 1.6 0 .3 1.0 3.7 85 

7/26/1979 5.7 .2 1.1 1.4 11.0 94 9/14/1979 1.4 0 .3 1.0 3.2 85 

7/27/1979 26.0 44.0 83.0 156.0 216.0 96 9/15/1979 1.3 0 .3 .9 2.3 85 

7/28/1979 47.0 12.0 13.0 14.0 42.0 98 9/16/1979 1.3 0 .3 .9 2.5 84 

7/29/1979 15.0 5.9 7.0 10.0 7.8 99 9/17/1979 1.2 0 .3 .9 4.3 84 

7/30/1979 12.0 3.7 5.5 9.3 9.3 99 9/18/1979 1.8 1.7 .4 1.9 4.3 84 

7/31/1979 11.0 2.9 4.4 8.7 3.7 97 9/19/1979 2.2 .7 .4 1.4 4.0 83 

8/1/1979 9.9 2.3 3.7 7.5 4.4 96 9/20/1979 2.4 .1 .4 1.2 3.5 83 

8/2/1979 8.9 2.3 3.1 7.2 5.4 96 9/21/1979 2.2 0 .4 1.0 3.2 82 

8/3/1979 8.0 2.2 2.8 6.6 6.1 96 9/22/1979 1.8 0 .3 .9 3.8 82 

8/4/1979 7.4 1.5 2.6 5.7 9.0 96 9/23/1979 1.6 .1 .3 .8 3.8 82 

8/5/1979 6.6 1.2 2.3 5.2 8.6 96 9/24/1979 1.4 0 .3 .8 3.8 80 

8/6/1979 5.9 1.2 2.0 4.6 8.2 96 9/25/1979 1.3 0 .3 .7 3.8 80 

8/7/1979 5.5 1.0 1.9 4.3 8.2 95 9/26/1979 1.2 0 .3 .9 3.8 79 

8/8/1979 5.2 .7 1.8 4.1 8.6 95 9/27/1979 1.1 0 .3 .8 3.8 79 

8/9/1979 5.1 .3 1.8 4.1 8.6 95 9/28/1979 1.0 0 .3 .7 3.2 78 

8/10/1979 4.7 .3 1.8 3.6 8.6 94 9/29/1979 .9 0 .3 .7 3.2 78 

8/11/1979 26.0 3.9 6.1 7.2 9.4 94 9/30/1979 .9 0 .3 .7 2.7 77 

8/12/1979 34.0 1.0 2.9 5.2 12.0 94 10/1/1979 .9 0 .3 .7 2.7 77 

8/13/1979 18.0 .5 2.3 4.3 11.0 94 10/2/1979 .9 0 .2 .6 2.7 77 

8/14/1979 11.0 .5 1.9 4.9 11.0 94 10/3/1979 .8 0 .2 .7 2.7 76 

8/15/1979 9.6 .5 1.8 4.1 10.0 94 10/4/1979 .7 0 .2 .5 2.2 75 

8/16/1979 7.8 .4 1.8 3.6 9.8 94 10/5/1979 .6 0 .2 .5 1.8 74 

8/17/1979 6.3 .5 1.5 3.6 9.0 93 10/6/1979 .6 0 .2 .6 1.8 73 

8/18/1979 5.4 .6 1.4 3.1 9.0 93 10/7/1979 .6 0 .2 .7 2.0 72 

8/19/1979 4.6 .2 1.2 2.5 8.6 93 10/8/1979 .6 0 .2 .7 2.3 72 

8/20/1979 4.5 .1 1.1 2.3 7.9 93 10/9/1979 .6 0 .1 .8 3.1 71 

8/21/1979 3.9 .1 1.0 2.3 7.5 92 10/10/1979 .6 0 .1 .8 1.6 71 

8/22/1979 3.6 .1 1.0 2.1 7.5 92 10/11/1979 .6 0 .1 .8 2.2 71 

8/23/1979 3.4 1.8 1.0 1.9 6.5 91 10/12/1979 .5 0 .1 .8 2.9 71 

8/24/1979 3.0 .3 .9 1.6 6.5 91 10/13/1979 .5 0 .1 .9 4.1 71 

8/25/1979 2.8 .4 .8 1.9 6.5 91 10/14/1979 .5 0 .1 .9 3.9 71 

8/26/1979 2.9 .1 .8 1.4 6.1 91 10/15/1979 .5 0 .1 .9 3.2 71 

8/27/1979 2.9 .1 .7 1.3 5.2 91 10/16/1979 .4 0 .1 .9 3.2 70 

8/28/1979 2.8 .1 .7 1.2 5.2 90 10/17/1979 .4 0 .1 .9 3.8 70 

8/29/1979 2.4 .1 .7 1.2 5.2 90 10/18/1979 .4 0 .1 1.0 3.8 69 

8/30/1979 2.3 .1 .7 1.3 5.2 90 10/19/1979 .4 0 .1 1.0 3.8 68 

8/31/1979 2.2 .1 .6 1.4 5.2 89 10/20/1979 .4 0 0 1.0 3.8 66 

9/1/1979 2.1 .1 .5 1.4 5.2 88 10/21/1979 .4 0 0 .9 3.8 66 
Appendix 2 65 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/22/1979 0.4 0 0 0.9 3.5 65 12/11/1979 0.2 0 0 0.5 1.3 46 

10/23/1979 .3 0 0 .9 2.2 65 12/12/1979 .3 2.2 0 .6 2.4 46 

10/24/1979 .3 0 0 .8 2.2 64 12/13/1979 .3 .1 0 1.0 3.7 46 

10/25/1979 .3 0 0 .7 2.2 64 12/14/1979 .3 0 0 .7 1.7 46 

10/26/1979 .3 0 0 .6 2.2 63 12/15/1979 .3 0 0 .6 1.6 46 

10/27/1979 .3 0 0 .6 2.2 62 12/16/1979 .2 0 0 .6 1.6 45 

10/28/1979 .3 0 0 .5 2.2 62 12/17/1979 .2 0 0 .6 1.6 45 

10/29/1979 .3 0 0 .5 2.2 61 12/18/1979 .2 0 0 .6 1.6 45 

10/30/1979 .3 0 0 .4 3.8 61 12/19/1979 .2 0 0 .6 1.6 44 

10/31/1979 .3 0 0 .4 2.9 61 12/20/1979 .2 0 0 .6 1.6 44 

11/1/1979 .3 0 0 .4 1.4 60 12/21/1979 .2 0 0 .6 1.6 44 

11/2/1979 .3 0 0 .4 1.1 59 12/22/1979 .3 0 0 .6 1.6 44 

11/3/1979 .3 0 0 .4 1.1 59 12/23/1979 .3 2.6 0 .6 1.8 44 

11/4/1979 .3 0 0 .4 1.1 59 12/24/1979 .3 0 0 .6 2.2 44 

11/5/1979 .3 0 0 .5 1.1 59 12/25/1979 .3 0 0 .5 2.1 44 

11/6/1979 .3 0 0 .5 1.1 58 12/26/1979 .2 0 0 .5 1.8 43 

11/7/1979 .3 0 0 .5 1.1 58 12/27/1979 .2 0 0 .5 1.8 43 

11/8/1979 .3 0 0 .5 1.2 58 12/28/1979 .5 5.5 0 .9 2.6 43 

11/9/1979 .3 0 0 .5 1.3 57 12/29/1979 1.4 .8 0 .7 4.0 44 

11/10/1979 .3 0 0 .5 1.3 57 12/30/1979 1.0 0 0 .6 1.8 44 

11/11/1979 .3 0 0 .5 1.3 56 12/31/1979 .9 0 0 .5 1.8 43 

11/12/1979 .3 0 0 .4 1.3 56 1/1/1980 1.0 0 0 .5 1.6 43 

11/13/1979 .3 0 0 .4 1.3 55 1/2/1980 1.1 0 0 .5 1.6 42 

11/14/1979 .3 0 0 .4 1.3 54 1/3/1980 1.1 0 0 .4 1.6 42 

11/15/1979 .3 0 0 .4 1.3 54 1/4/1980 1.1 0 0 .4 1.6 41 

11/16/1979 .3 0 0 .4 1.5 54 1/5/1980 1.1 0 0 .4 1.6 40 

11/17/1979 .3 0 0 .4 1.6 54 1/6/1980 1.0 0 0 .4 1.6 40 

11/18/1979 .3 0 0 .4 2.2 53 1/7/1980 1.0 0 0 .4 1.6 39 

11/19/1979 .3 0 0 .5 2.4 53 1/8/1980 .9 0 0 .4 1.6 39 

11/20/1979 .3 0 0 .5 2.7 53 1/9/1980 .9 0 0 .4 1.6 38 

11/21/1979 .3 0 0 .5 2.7 53 1/10/1980 1.0 0 0 .4 1.6 38 

11/22/1979 .3 0 0 .5 2.7 52 1/11/1980 1.0 0 0 .4 1.6 38 

11/23/1979 .3 0 0 .5 2.7 52 1/12/1980 1.0 0 0 .4 1.6 38 

11/24/1979 .3 0 0 .5 2.3 52 1/13/1980 .9 0 0 .4 1.6 38 

11/25/1979 .3 0 0 .5 3.2 52 1/14/1980 .9 0 0 .4 1.6 38 

11/26/1979 .3 0 0 .5 2.6 51 1/15/1980 .9 0 0 .3 1.6 37 

11/27/1979 .3 0 0 .5 2.2 51 1/16/1980 .9 0 0 .3 1.6 37 

11/28/1979 .3 0 0 .5 1.5 51 1/17/1980 .9 0 0 .4 2.2 37 

11/29/1979 .3 0 0 .5 1.3 50 1/18/1980 .9 0 0 .4 2.6 37 

11/30/1979 .3 0 0 .5 1.3 50 1/19/1980 .9 0 0 .4 2.2 38 

12/1/1979 .3 0 0 .5 1.3 50 1/20/1980 .9 .7 0 .4 2.2 38 

12/2/1979 .3 0 0 .5 1.3 49 1/21/1980 1.1 1.8 0 .9 3.0 37 

12/3/1979 .3 0 0 .5 1.3 49 1/22/1980 1.4 .8 0 .8 3.2 37 

12/4/1979 .3 0 0 .5 1.3 49 1/23/1980 1.5 0 0 .6 3.2 37 

12/5/1979 .3 0 0 .5 1.3 48 1/24/1980 1.3 0 0 .5 2.9 37 

12/6/1979 .3 0 0 .5 1.3 48 1/25/1980 1.2 0 0 .4 2.7 37 

12/7/1979 .3 0 0 .5 1.6 47 1/26/1980 1.1 0 0 .3 2.7 38 

12/8/1979 .2 0 0 .5 1.3 47 1/27/1980 1.0 0 0 .3 2.4 39 

12/9/1979 .2 0 0 .5 1.3 46 1/28/1980 1.0 0 0 .3 2.2 39 

12/10/1979 .2 0 0 .5 1.3 46 1/29/1980 .9 0 0 .3 2.2 38 
66 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/30/1980 0.9 0 0 0.3 2.2 38 3/20/1980 1.4 0.4 0.2 0.8 3.2 34 

1/31/1980 .9 0 0 .3 2.2 38 3/21/1980 1.3 .3 .2 .8 2.8 34 

2/1/1980 .9 0 0 .3 2.2 38 3/22/1980 1.3 .3 .2 .8 2.7 34 

2/2/1980 .9 0 0 .3 2.2 38 3/23/1980 1.3 .4 .2 .8 3.0 34 

2/3/1980 .9 0 0 .3 2.2 38 3/24/1980 1.3 .4 .2 .8 2.8 34 

2/4/1980 1.0 0 0 .3 2.2 38 3/25/1980 1.4 .8 .2 .8 2.7 34 

2/5/1980 1.0 0 0 .3 2.2 37 3/26/1980 1.5 .9 .2 .8 2.7 34 

2/6/1980 1.0 0 0 .3 2.2 36 3/27/1980 42.0 36.0 12.0 9.0 7.0 34 

2/7/1980 1.0 1.0 0 .3 2.3 36 3/28/1980 52.0 9.3 1.4 6.9 8.3 36 

2/8/1980 1.3 .5 0 .4 2.7 37 3/29/1980 27.0 4.8 1.0 6.3 7.5 39 

2/9/1980 1.9 5.9 0 .8 3.1 38 3/30/1980 20.0 3.2 .9 5.8 7.0 43 

2/10/1980 2.5 1.2 0 .5 3.2 38 3/31/1980 19.0 2.7 .8 5.2 7.0 43 

2/11/1980 1.7 1.0 0 .6 3.2 37 4/1/1980 18.0 4.3 1.5 4.9 7.7 43 

2/12/1980 1.5 .7 0 .6 3.2 37 4/2/1980 18.0 6.1 2.0 4.9 8.2 43 

2/13/1980 1.2 .5 0 .6 3.2 37 4/3/1980 17.0 3.6 1.2 4.3 8.3 42 

2/14/1980 1.3 .5 0 .6 3.2 36 4/4/1980 16.0 2.6 1.1 3.9 8.3 42 

2/15/1980 1.2 .3 0 .6 3.2 36 4/5/1980 15.0 2.3 1.1 3.5 8.3 42 

2/16/1980 1.8 3.5 .1 1.1 4.4 37 4/6/1980 15.0 2.1 1.1 3.3 8.3 42 

2/17/1980 1.8 1.2 .1 .8 3.2 37 4/7/1980 15.0 2.0 1.1 3.2 8.1 41 

2/18/1980 1.8 1.2 .1 .8 3.2 37 4/8/1980 13.0 1.4 1.0 2.9 7.7 41 

2/19/1980 1.7 1.1 .1 .8 2.7 37 4/9/1980 13.0 1.2 1.0 2.6 6.5 41 

2/20/1980 1.5 1.0 .1 .9 2.7 37 4/10/1980 13.0 1.2 1.0 2.7 6.5 41 

2/21/1980 1.5 1.0 .1 .9 2.7 37 4/11/1980 12.0 1.2 1.0 2.7 6.5 40 

2/22/1980 1.4 .8 .1 .9 2.7 37 4/12/1980 33.0 1.7 1.0 2.7 6.5 40 

2/23/1980 1.4 .7 .1 .9 2.7 36 4/13/1980 71.0 3.1 1.7 2.7 32.0 40 

2/24/1980 1.4 .6 .1 .9 2.7 36 4/14/1980 39.0 1.7 1.6 2.4 10.0 42 

2/25/1980 1.4 .5 .1 .9 2.7 35 4/15/1980 30.0 1.5 1.5 2.3 10.0 43 

2/26/1980 1.5 .4 .1 1.0 2.7 35 4/16/1980 27.0 1.5 1.1 2.1 10.0 43 

2/27/1980 1.4 .3 .1 1.0 2.7 35 4/17/1980 24.0 1.5 1.0 1.7 10.0 43 

2/28/1980 1.4 .3 .2 1.2 2.7 35 4/18/1980 24.0 1.2 1.0 1.7 9.0 42 

2/29/1980 1.4 3.2 .6 1.6 2.7 35 4/19/1980 22.0 1.2 .9 1.7 9.0 42 

3/1/1980 2.8 1.8 .2 2.2 2.7 36 4/20/1980 22.0 1.2 .9 1.7 9.0 41 

3/2/1980 2.6 .7 .1 1.3 2.7 36 4/21/1980 20.0 1.2 .9 1.6 9.0 41 

3/3/1980 2.1 .7 .2 1.0 2.7 36 4/22/1980 20.0 1.2 .9 1.8 9.4 41 

3/4/1980 1.7 .7 .2 1.0 2.7 36 4/23/1980 19.0 1.1 .9 1.7 9.8 41 

3/5/1980 1.6 .7 .2 1.0 2.7 35 4/24/1980 18.0 1.0 .7 1.6 9.8 40 

3/6/1980 1.5 .7 .2 1.0 2.7 35 4/25/1980 51.0 10.0 3.9 4.0 13.0 41 

3/7/1980 1.5 .7 .2 1.0 2.7 35 4/26/1980 35.0 .2 1.3 1.7 14.0 43 

3/8/1980 1.5 .7 .2 .9 2.7 35 4/27/1980 26.0 .2 1.1 1.5 13.0 44 

3/9/1980 1.5 .7 .2 .9 2.7 35 4/28/1980 24.0 .2 1.0 1.5 12.0 44 

3/10/1980 1.5 .6 .2 .9 2.7 35 4/29/1980 22.0 .2 1.0 1.4 11.0 44 

3/11/1980 1.5 .5 .2 .9 2.7 35 4/30/1980 22.0 .2 .9 1.3 11.0 43 

3/12/1980 1.5 .4 .2 1.0 3.4 35 5/1/1980 35.0 .2 .9 1.3 11.0 42 

3/13/1980 1.4 .3 .2 1.0 3.3 35 5/2/1980 24.0 .1 .9 1.3 11.0 42 

3/14/1980 1.4 .3 .2 1.0 3.2 34 5/3/1980 22.0 .2 .9 1.3 11.0 42 

3/15/1980 1.3 .3 .2 1.0 3.2 34 5/4/1980 20.0 .2 .7 1.3 11.0 42 

3/16/1980 1.4 .5 .2 1.0 3.2 34 5/5/1980 20.0 .2 .7 1.2 11.0 42 

3/17/1980 1.5 .5 .2 1.0 3.2 34 5/6/1980 19.0 .2 .7 1.1 11.0 42 

3/18/1980 1.5 .3 .2 .9 3.2 34 5/7/1980 24.0 2.7 1.1 1.6 11.0 42 

3/19/1980 1.5 .3 .2 .8 3.2 34 5/8/1980 79.0 23.0 76.0 11.0 12.0 44 
Appendix 2 67 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

5/9/1980 62.0 1.8 7.7 4.1 13.0 48 6/28/1980 2.1 0 0.3 1.2 10.0 67 

5/10/1980 41.0 1.3 4.7 3.1 13.0 51 6/29/1980 2.1 0 .3 1.1 9.0 66 

5/11/1980 38.0 1.2 4.4 2.9 13.0 51 6/30/1980 2.1 0 .3 1.1 7.9 65 

5/12/1980 186.0 63.0 104.0 41.0 91.0 54 7/1/1980 2.0 0 .3 1.0 7.5 64 

5/13/1980 205.0 56.0 99.0 73.0 88.0 58 7/2/1980 1.8 0 .2 1.0 6.1 64 

5/14/1980 333.0 51.0 134.0 51.0 225.0 61 7/3/1980 1.6 0 .2 .9 5.6 64 

5/15/1980 267.0 44.0 108.0 43.0 115.0 65 7/4/1980 1.4 0 .2 .8 4.8 62 

5/16/1980 257.0 42.0 94.0 43.0 101.0 68 7/5/1980 1.2 0 .2 .7 4.3 62 

5/17/1980 220.0 26.0 48.0 34.0 87.0 73 7/6/1980 1.0 0 .2 .7 3.8 62 

5/18/1980 183.0 17.0 28.0 29.0 77.0 74 7/7/1980 1.0 0 .2 .7 2.7 61 

5/19/1980 177.0 16.0 27.0 28.0 82.0 75 7/8/1980 .9 0 .2 .6 3.2 61 

5/20/1980 146.0 11.0 19.0 23.0 74.0 75 7/9/1980 .8 0 .2 .6 2.2 60 

5/21/1980 129.0 9.7 16.0 55.0 255.0 77 7/10/1980 .6 0 .1 .6 2.2 59 

5/22/1980 115.0 8.8 12.0 18.0 145.0 77 7/11/1980 .6 0 .1 .6 2.2 58 

5/23/1980 104.0 8.4 11.0 15.0 124.0 77 7/12/1980 .5 0 .1 .5 2.7 59 

5/24/1980 91.0 8.8 9.1 14.0 114.0 77 7/13/1980 .5 0 .1 .5 2.2 58 

5/25/1980 86.0 9.5 7.2 13.0 107.0 77 7/14/1980 .4 0 0 .4 2.7 58 

5/26/1980 81.0 11.0 6.7 12.0 101.0 77 7/15/1980 .4 0 0 .4 2.7 57 

5/27/1980 73.0 11.0 5.7 12.0 97.0 77 7/16/1980 .4 0 0 .4 1.5 57 

5/28/1980 67.0 12.0 4.8 11.0 90.0 77 7/17/1980 .4 0 0 .3 1.3 56 

5/29/1980 60.0 14.0 4.8 11.0 83.0 77 7/18/1980 .4 0 0 .3 1.1 55 

5/30/1980 54.0 13.0 4.1 11.0 72.0 78 7/19/1980 .3 0 0 .3 1.1 55 

5/31/1980 48.0 12.0 3.7 9.9 94.0 77 7/20/1980 .3 0 0 .3 1.1 55 

6/1/1980 42.0 12.0 3.1 9.7 91.0 77 7/21/1980 .3 0 0 .3 1.1 54 

6/2/1980 36.0 10.0 3.1 9.7 72.0 77 7/22/1980 .4 0 0 .3 1.3 54 

6/3/1980 30.0 10.0 2.9 9.7 69.0 77 7/23/1980 .4 0 0 .3 1.3 54 

6/4/1980 27.0 8.5 2.4 9.1 61.0 77 7/24/1980 .3 0 0 .3 1.0 53 

6/5/1980 26.0 7.8 2.2 8.5 53.0 77 7/25/1980 .3 0 0 .3 .9 52 

6/6/1980 24.0 6.9 2.0 8.0 44.0 74 7/26/1980 .3 0 0 .3 .9 51 

6/7/1980 21.0 6.2 2.0 7.3 42.0 73 7/27/1980 .3 0 0 .2 .9 51 

6/8/1980 19.0 5.8 1.6 6.8 39.0 73 7/28/1980 .3 0 0 .2 .8 51 

6/9/1980 19.0 6.0 1.6 6.3 37.0 73 7/29/1980 .3 0 0 .2 .8 51 

6/10/1980 19.0 5.9 1.6 6.1 35.0 73 7/30/1980 .2 0 0 .2 .8 51 

6/11/1980 16.0 5.4 1.6 5.5 32.0 73 7/31/1980 .2 0 0 .2 .8 51 

6/12/1980 15.0 4.7 1.3 5.0 29.0 72 8/1/1980 .2 0 0 .2 .8 51 

6/13/1980 15.0 4.2 1.2 4.6 28.0 71 8/2/1980 .2 0 0 .1 .8 46 

6/14/1980 13.0 3.4 1.1 4.0 26.0 71 8/3/1980 .2 0 0 .1 .9 45 

6/15/1980 11.0 2.6 1.1 3.7 26.0 70 8/4/1980 .2 0 0 .1 1.1 45 

6/16/1980 9.0 2.2 1.0 3.5 26.0 69 8/5/1980 .2 0 0 .1 1.1 44 

6/17/1980 8.1 1.7 .9 3.3 24.0 70 8/6/1980 .2 0 0 .1 1.0 44 

6/18/1980 7.8 1.1 .7 3.0 23.0 70 8/7/1980 .2 0 0 .1 1.0 44 

6/19/1980 5.8 .8 .7 2.8 23.0 70 8/8/1980 .2 0 0 .1 1.1 43 

6/20/1980 5.0 .5 .7 2.5 22.0 70 8/9/1980 .1 0 0 0 1.1 43 

6/21/1980 3.9 .5 .6 2.2 21.0 71 8/10/1980 .2 0 0 .1 1.8 42 

6/22/1980 3.2 .5 .5 2.1 20.0 70 8/11/1980 .2 0 0 .2 2.5 42 

6/23/1980 2.4 .2 .5 1.9 18.0 69 8/12/1980 .2 0 0 .1 1.5 42 

6/24/1980 2.2 .1 .5 1.7 17.0 68 8/13/1980 .2 0 0 .1 1.3 42 

6/25/1980 2.1 0 .5 1.6 15.0 68 8/14/1980 .2 0 0 .1 1.2 42 

6/26/1980 2.1 0 .4 1.5 14.0 67 8/15/1980 .1 0 0 .1 1.1 42 

6/27/1980 2.1 0 .4 1.4 12.0 66 8/16/1980 .1 0 0 .1 1.3 42 
68 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

8/17/1980 0.1 0 0 0.1 .9 41 10/6/1980 11.0 0.2 0.3 8.6 14.0 48 

8/18/1980 .1 0 0 .1 1.0 41 10/7/1980 9.5 .2 .3 7.6 18.0 48 

8/19/1980 0 0 0 .1 1.1 41 10/8/1980 8.8 .2 .3 7.0 18.0 48 

8/20/1980 0 0 0 .1 1.0 40 10/9/1980 8.6 .1 .3 6.4 17.0 47 

8/21/1980 0 0 0 .1 .9 40 10/10/1980 8.0 .1 .2 5.5 15.0 47 

8/22/1980 0 0 0 .1 .9 40 10/11/1980 7.3 .1 .2 5.0 15.0 47 

8/23/1980 0 0 0 0 .8 40 10/12/1980 7.0 0 .2 4.5 13.0 46 

8/24/1980 0 0 0 0 .7 40 10/13/1980 6.3 0 .2 4.3 12.0 46 

8/25/1980 0 0 0 0 .6 40 10/14/1980 6.0 .1 .2 4.3 12.0 46 

8/26/1980 0 0 0 0 .5 38 10/15/1980 5.8 0 .2 4.3 12.0 46 

8/27/1980 0 0 0 0 .5 38 10/16/1980 785.0 .6 .4 4.6 198.0 48 

8/28/1980 0 0 0 0 .4 37 10/17/1980 59.0 .1 .3 4.0 38.0 48 

8/29/1980 0 0 0 0 .4 38 10/18/1980 40.0 .1 .3 3.5 27.0 47 

8/30/1980 0 0 0 0 .4 38 10/19/1980 43.0 .1 .3 3.8 28.0 47 

8/31/1980 0 0 0 0 .4 38 10/20/1980 28.0 .1 .3 3.9 24.0 47 

9/1/1980 0 0 0 0 .4 37 10/21/1980 25.0 .1 .3 3.0 22.0 47 

9/2/1980 0 0 0 0 .4 37 10/22/1980 23.0 .1 .3 2.7 21.0 47 

9/3/1980 0 0 0 0 .3 37 10/23/1980 21.0 .1 .3 2.4 19.0 47 

9/4/1980 0 0 0 0 .3 37 10/24/1980 20.0 .1 .3 1.9 16.0 46 

9/5/1980 0 0 0 0 .3 36 10/25/1980 18.0 .1 .3 1.8 14.0 46 

9/6/1980 0 .3 0 0 .5 37 10/26/1980 18.0 .1 .3 1.7 14.0 46 

9/7/1980 0 8.8 0 .2 9.0 37 10/27/1980 18.0 0 .3 1.7 15.0 46 

9/8/1980 .1 .5 0 .2 29.0 38 10/28/1980 17.0 0 .3 1.7 15.0 45 

9/9/1980 7.0 0 0 .3 16.0 38 10/29/1980 16.0 0 .3 1.6 15.0 45 

9/10/1980 4.2 0 0 .2 10.0 38 10/30/1980 16.0 0 .3 1.5 16.0 45 

9/11/1980 2.3 0 0 .2 8.6 38 10/31/1980 15.0 0 .3 1.4 16.0 45 

9/12/1980 1.4 0 0 .2 7.5 36 11/1/1980 14.0 0 .3 1.3 15.0 45 

9/13/1980 .8 0 0 .2 5.2 37 11/2/1980 14.0 0 .3 1.2 15.0 44 

9/14/1980 .7 0 0 .1 4.8 37 11/3/1980 13.0 0 .3 1.1 15.0 44 

9/15/1980 .6 0 0 .1 4.3 36 11/4/1980 13.0 0 .3 1.0 14.0 44 

9/16/1980 .5 0 0 .1 3.8 35 11/5/1980 12.0 0 .3 .9 13.0 43 

9/17/1980 .4 0 0 .1 2.7 35 11/6/1980 12.0 0 .3 .9 13.0 43 

9/18/1980 .4 0 0 .1 2.2 35 11/7/1980 11.0 0 .3 .9 12.0 43 

9/19/1980 .4 22.0 0 11.0 41.0 37 11/8/1980 11.0 0 .3 .8 13.0 43 

9/20/1980 1.1 0 0 .3 15.0 38 11/9/1980 11.0 0 .3 .8 11.0 42 

9/21/1980 3.3 0 0 .2 8.6 38 11/10/1980 11.0 0 .3 .8 11.0 42 

9/22/1980 2.3 0 0 .2 7.0 38 11/11/1980 10.0 0 .3 .9 12.0 42 

9/23/1980 1.5 0 0 .2 5.6 38 11/12/1980 9.9 0 .3 .9 13.0 42 

9/24/1980 1.2 0 0 .2 5.2 37 11/13/1980 9.5 0 .3 .9 9.8 42 

9/25/1980 .9 4.8 0 .3 5.2 37 11/14/1980 9.6 0 .3 .9 9.8 42 

9/26/1980 3.0 13.0 3.3 .6 4.3 37 11/15/1980 9.6 0 .3 .8 9.0 41 

9/27/1980 6.2 5.8 .2 1.0 6.5 37 11/16/1980 15.0 3.2 1.0 2.3 13.0 43 

9/28/1980 7.1 8.0 .4 1.9 9.8 37 11/17/1980 30.0 .3 .6 3.3 22.0 43 

9/29/1980 11.0 1.5 .1 2.1 14.0 37 11/18/1980 19.0 0 .5 2.1 17.0 43 

9/30/1980 54.0 2.2 4.7 51.0 116.0 37 11/19/1980 15.0 0 .4 1.8 14.0 43 

10/1/1980 31.0 .6 .7 15.0 51.0 39 11/20/1980 14.0 0 .4 1.7 11.0 42 

10/2/1980 18.0 .5 .5 13.0 37.0 42 11/21/1980 13.0 0 .4 1.6 11.0 42 

10/3/1980 14.0 .4 .3 11.0 30.0 45 11/22/1980 14.0 0 .4 1.7 13.0 42 

10/4/1980 13.0 .2 .3 10.0 26.0 46 11/23/1980 15.0 0 .4 1.9 17.0 42 

10/5/1980 11.0 .2 .3 9.5 22.0 47 11/24/1980 17.0 0 .4 1.7 15.0 42 
Appendix 2 69 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

11/25/1980 19.0 2.1 0.8 2.9 14.0 43 1/14/1981 19.0 0.4 1.2 2.1 27.0 47 

11/26/1980 44.0 1.0 1.2 5.5 37.0 44 1/15/1981 18.0 .4 1.2 2.0 27.0 46 

11/27/1980 44.0 .2 1.5 5.3 40.0 45 1/16/1981 18.0 .4 1.1 1.9 26.0 46 

11/28/1980 39.0 .2 1.6 4.7 38.0 46 1/17/1981 17.0 .4 1.0 1.8 26.0 46 

11/29/1980 37.0 .2 1.6 4.6 36.0 46 1/18/1981 16.0 .4 .9 1.7 26.0 46 

11/30/1980 36.0 .2 1.6 4.6 35.0 51 1/19/1981 21.0 4.9 2.4 4.2 26.0 46 

12/1/1980 35.0 .2 1.6 4.6 37.0 47 1/20/1981 33.0 .6 3.2 6.1 26.0 48 

12/2/1980 32.0 .2 1.4 4.3 37.0 47 1/21/1981 27.0 .2 2.7 4.6 26.0 48 

12/3/1980 30.0 .2 1.2 4.1 37.0 47 1/22/1981 23.0 .2 2.4 4.1 26.0 48 

12/4/1980 30.0 .2 1.3 4.2 37.0 48 1/23/1981 22.0 .2 2.4 4.1 25.0 49 

12/5/1980 31.0 .2 1.6 4.6 39.0 48 1/24/1981 22.0 .2 2.6 3.9 26.0 49 

12/6/1980 31.0 .2 1.6 4.3 38.0 48 1/25/1981 21.0 .2 2.6 3.7 25.0 49 

12/7/1980 30.0 .2 1.6 4.1 37.0 48 1/26/1981 21.0 .2 2.6 3.5 25.0 49 

12/8/1980 39.0 2.4 2.6 5.4 39.0 48 1/27/1981 20.0 .2 2.4 3.5 24.0 49 

12/9/1980 61.0 1.3 3.3 6.3 45.0 49 1/28/1981 19.0 .2 2.0 3.3 23.0 49 

12/10/1980 48.0 .8 3.1 6.3 41.0 49 1/29/1981 19.0 .4 2.0 3.3 24.0 49 

12/11/1980 45.0 .7 3.1 6.3 39.0 49 1/30/1981 19.0 .4 1.7 3.3 23.0 49 

12/12/1980 45.0 .7 3.1 6.3 39.0 50 1/31/1981 19.0 .3 1.6 3.4 21.0 49 

12/13/1980 44.0 .6 3.1 6.2 39.0 50 2/1/1981 20.0 1.2 2.5 3.8 23.0 49 

12/14/1980 44.0 .6 3.1 6.0 38.0 50 2/2/1981 21.0 .3 1.7 3.1 23.0 49 

12/15/1980 51.0 3.5 4.4 5.9 38.0 51 2/3/1981 19.0 .2 1.6 3.1 22.0 49 

12/16/1980 51.0 1.5 3.8 5.9 37.0 52 2/4/1981 19.0 1.3 2.1 3.9 22.0 49 

12/17/1980 45.0 1.2 3.1 5.4 35.0 52 2/5/1981 24.0 3.1 2.5 5.4 22.0 49 

12/18/1980 44.0 1.1 3.1 5.4 34.0 51 2/6/1981 26.0 2.1 2.6 5.7 23.0 50 

12/19/1980 40.0 .9 2.7 5.1 31.0 51 2/7/1981 25.0 2.0 2.6 5.7 23.0 51 

12/20/1980 37.0 .8 2.4 4.8 29.0 51 2/8/1981 25.0 1.9 2.6 5.7 24.0 51 

12/21/1980 37.0 .7 2.4 4.6 28.0 51 2/9/1981 24.0 1.7 2.6 5.7 24.0 52 

12/22/1980 37.0 .7 2.4 4.6 27.0 51 2/10/1981 28.0 3.7 3.1 7.1 39.0 52 

12/23/1980 37.0 .7 2.4 4.6 27.0 51 2/11/1981 29.0 1.5 2.5 6.1 38.0 53 

12/24/1980 35.0 .6 2.2 4.4 27.0 51 2/12/1981 26.0 1.5 2.4 6.1 37.0 53 

12/25/1980 32.0 .6 1.7 4.1 27.0 51 2/13/1981 26.0 1.5 2.4 6.3 38.0 53 

12/26/1980 32.0 .6 1.6 4.1 27.0 50 2/14/1981 27.0 1.5 2.4 6.4 38.0 54 

12/27/1980 31.0 .6 1.6 3.8 25.0 50 2/15/1981 27.0 1.5 2.5 6.6 38.0 54 

12/28/1980 30.0 .6 1.6 3.8 24.0 50 2/16/1981 27.0 1.5 2.6 6.6 39.0 54 

12/29/1980 29.0 .6 1.6 3.7 24.0 50 2/17/1981 28.0 1.5 2.6 6.5 39.0 55 

12/30/1980 27.0 .6 1.5 3.3 23.0 51 2/18/1981 28.0 1.7 2.6 6.5 38.0 55 

12/31/1980 27.0 .6 1.6 3.3 23.0 51 2/19/1981 26.0 2.0 2.5 6.4 37.0 55 

1/1/1981 26.0 .6 1.6 3.1 23.0 51 2/20/1981 26.0 2.0 2.4 6.0 37.0 55 

1/2/1981 25.0 .6 1.6 2.7 23.0 50 2/21/1981 26.0 1.9 2.4 6.1 37.0 55 

1/3/1981 24.0 .6 1.6 2.8 23.0 50 2/22/1981 25.0 1.4 2.0 5.7 36.0 54 

1/4/1981 24.0 .5 1.6 2.7 24.0 50 2/23/1981 24.0 1.2 2.0 5.5 34.0 54 

1/5/1981 23.0 .5 1.6 2.7 25.0 50 2/24/1981 24.0 1.3 2.0 5.4 34.0 54 

1/6/1981 23.0 .5 1.6 2.7 25.0 50 2/25/1981 24.0 1.7 2.0 5.4 34.0 54 

1/7/1981 23.0 .5 1.6 2.5 26.0 49 2/26/1981 24.0 1.6 2.0 5.3 34.0 54 

1/8/1981 22.0 .6 1.7 2.5 26.0 49 2/27/1981 24.0 1.5 2.0 5.4 34.0 54 

1/9/1981 22.0 .5 2.0 2.7 27.0 49 2/28/1981 24.0 1.3 1.8 5.2 34.0 55 

1/10/1981 22.0 .4 1.6 2.4 27.0 49 3/1/1981 24.0 2.9 2.3 6.3 38.0 55 

1/11/1981 21.0 .4 1.5 2.3 26.0 48 3/2/1981 26.0 1.1 2.0 5.7 38.0 55 

1/12/1981 19.0 .4 1.2 2.1 26.0 48 3/3/1981 87.0 80.0 79.0 30.0 57.0 55 

1/13/1981 19.0 .4 1.2 2.1 26.0 47 3/4/1981 913.0 67.0 57.0 66.0 765.0 59 
70 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

3/5/1981 228.0 21.0 13.0 19.0 139.0 63 4/24/1981 25.0 0.3 1.6 5.2 43.0 62 

3/6/1981 187.0 14.0 10.0 18.0 117.0 67 4/25/1981 21.0 .3 1.5 4.8 38.0 62 

3/7/1981 192.0 17.0 11.0 19.0 116.0 69 4/26/1981 20.0 .4 1.5 4.5 35.0 62 

3/8/1981 171.0 11.0 9.0 18.0 112.0 70 4/27/1981 19.0 .4 1.3 3.9 32.0 61 

3/9/1981 148.0 8.3 8.3 17.0 103.0 71 4/28/1981 17.0 .4 1.3 3.8 32.0 61 

3/10/1981 138.0 6.3 7.9 16.0 100.0 70 4/29/1981 17.0 .6 1.2 3.8 30.0 61 

3/11/1981 141.0 8.0 8.9 17.0 102.0 70 4/30/1981 16.0 .7 1.1 3.5 29.0 61 

3/12/1981 166.0 14.0 15.0 19.0 114.0 71 5/1/1981 16.0 1.3 1.1 3.4 28.0 61 

3/13/1981 214.0 17.0 20.0 23.0 142.0 70 5/2/1981 16.0 2.5 1.1 3.5 27.0 61 

3/14/1981 177.0 12.0 16.0 21.0 122.0 70 5/3/1981 16.0 5.2 1.1 3.5 28.0 61 

3/15/1981 163.0 9.8 14.0 20.0 120.0 69 5/4/1981 17.0 2.5 1.2 3.5 28.0 61 

3/16/1981 146.0 7.9 12.0 19.0 113.0 69 5/5/1981 16.0 2.0 1.1 3.3 27.0 60 

3/17/1981 140.0 6.7 12.0 18.0 111.0 68 5/6/1981 14.0 2.1 .9 2.8 25.0 60 

3/18/1981 126.0 5.1 11.0 17.0 106.0 67 5/7/1981 12.0 2.2 .8 2.6 23.0 59 

3/19/1981 115.0 4.3 9.1 15.0 99.0 67 5/8/1981 12.0 2.1 .8 2.5 22.0 59 

3/20/1981 111.0 3.9 9.1 15.0 98.0 66 5/9/1981 11.0 2.2 .8 2.5 21.0 58 

3/21/1981 106.0 3.3 9.1 14.0 96.0 66 5/10/1981 10.0 2.0 .7 2.2 20.0 57 

3/22/1981 94.0 2.4 7.2 13.0 91.0 66 5/11/1981 9.3 1.3 .7 2.1 20.0 56 

3/23/1981 89.0 2.3 5.7 13.0 87.0 66 5/12/1981 8.4 1.3 .7 2.1 20.0 56 

3/24/1981 86.0 2.1 5.7 12.0 85.0 66 5/13/1981 8.4 1.1 .7 2.1 19.0 56 

3/25/1981 81.0 2.0 5.7 11.0 84.0 66 5/14/1981 7.8 .6 .7 1.9 18.0 56 

3/26/1981 77.0 1.8 4.8 11.0 83.0 67 5/15/1981 7.3 .5 .6 1.8 17.0 56 

3/27/1981 75.0 1.7 4.8 11.0 81.0 67 5/16/1981 13.0 10.0 1.0 3.1 21.0 56 

3/28/1981 72.0 1.6 4.8 10.0 80.0 67 5/17/1981 12.0 .1 .8 2.2 21.0 55 

3/29/1981 103.0 2.2 4.8 10.0 97.0 67 5/18/1981 7.5 .1 .7 1.8 19.0 55 

3/30/1981 78.0 1.5 4.1 9.4 85.0 67 5/19/1981 6.3 .1 .6 1.5 17.0 54 

3/31/1981 65.0 1.2 3.7 9.0 79.0 67 5/20/1981 5.6 0 .6 1.4 16.0 53 

4/1/1981 61.0 1.2 3.1 8.7 77.0 67 5/21/1981 5.0 0 .6 1.2 14.0 53 

4/2/1981 56.0 1.2 2.9 8.4 74.0 66 5/22/1981 5.0 0 .6 1.3 15.0 53 

4/3/1981 56.0 1.0 2.9 8.4 73.0 66 5/23/1981 5.2 0 .6 1.3 15.0 53 

4/4/1981 49.0 1.0 2.9 8.0 69.0 66 5/24/1981 90.0 175.0 12.0 6.8 139.0 53 

4/5/1981 34.0 .9 2.6 7.4 63.0 65 5/25/1981 296.0 130.0 57.0 24.0 124.0 55 

4/6/1981 35.0 1.1 2.4 7.2 61.0 65 5/26/1981 36.0 6.5 2.4 5.4 46.0 57 

4/7/1981 34.0 1.6 2.4 7.1 61.0 65 5/27/1981 24.0 3.7 1.6 4.1 34.0 59 

4/8/1981 33.0 2.0 2.4 6.9 60.0 65 5/28/1981 20.0 2.7 1.3 3.4 31.0 61 

4/9/1981 33.0 2.3 2.4 6.5 58.0 65 5/29/1981 18.0 2.1 1.1 3.4 30.0 62 

4/10/1981 31.0 2.3 2.4 6.3 57.0 65 5/30/1981 36.0 33.0 4.4 8.7 34.0 63 

4/11/1981 29.0 2.3 2.2 6.2 50.0 65 5/31/1981 51.0 13.0 5.1 8.5 45.0 65 

4/12/1981 28.0 2.7 2.2 6.0 53.0 64 6/1/1981 37.0 5.8 3.4 7.4 42.0 66 

4/13/1981 26.0 2.5 2.0 5.6 50.0 63 6/2/1981 38.0 4.1 3.3 6.8 46.0 67 

4/14/1981 25.0 2.1 2.0 5.4 49.0 63 6/3/1981 51.0 4.0 3.7 12.0 52.0 67 

4/15/1981 23.0 2.0 1.8 5.2 48.0 63 6/4/1981 154.0 40.0 52.0 43.0 93.0 68 

4/16/1981 23.0 2.3 1.8 5.1 47.0 63 6/5/1981 243.0 65.0 75.0 41.0 101.0 69 

4/17/1981 23.0 2.3 1.8 4.8 46.0 63 6/6/1981 162.0 18.0 23.0 27.0 72.0 70 

4/18/1981 23.0 2.4 2.0 6.0 44.0 63 6/7/1981 114.0 9.2 13.0 24.0 63.0 71 

4/19/1981 22.0 2.4 2.0 5.4 41.0 63 6/8/1981 93.0 5.7 9.8 21.0 59.0 72 

4/20/1981 21.0 1.7 1.6 4.9 38.0 63 6/9/1981 76.0 4.0 7.5 18.0 55.0 73 

4/21/1981 21.0 2.1 1.6 4.8 37.0 63 6/10/1981 170.0 71.0 27.0 55.0 53.0 73 

4/22/1981 21.0 2.3 1.5 4.4 36.0 62 6/11/1981 3,000.0 977.0 901.0 915.0 1,990.0 74 

4/23/1981 23.0 7.4 2.6 6.8 43.0 62 6/12/1981 2,310.0 299.0 423.0 586.0 1,840.0 76 
Appendix 2 71 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/13/1981 1,920.0 489.0 681.0 684.0 1,730.0 77 8/2/1981 11.0 0 0.5 2.2 19.0 99 

6/14/1981 2,930.0 233.0 336.0 696.0 1,390.0 78 8/3/1981 11.0 0 .4 2.1 17.0 98 

6/15/1981 1,100.0 63.0 61.0 172.0 225.0 80 8/4/1981 10.0 0 .3 2.0 15.0 98 

6/16/1981 1,950.0 156.0 191.0 350.0 1,810.0 81 8/5/1981 10.0 0 .3 1.9 13.0 98 

6/17/1981 941.0 54.0 54.0 131.0 238.0 83 8/6/1981 9.6 0 .3 1.7 11.0 97 

6/18/1981 607.0 35.0 32.0 98.0 551.0 84 8/7/1981 9.0 0 .3 1.7 8.4 96 

6/19/1981 446.0 26.0 25.0 78.0 486.0 86 8/8/1981 8.7 0 .3 1.5 7.0 97 

6/20/1981 356.0 19.0 18.0 64.0 352.0 87 8/9/1981 8.0 0 .2 1.4 6.2 96 

6/21/1981 288.0 15.0 11.0 50.0 307.0 88 8/10/1981 7.3 0 .2 1.4 6.1 96 

6/22/1981 247.0 12.0 12.0 41.0 276.0 90 8/11/1981 7.3 0 .2 1.4 6.2 95 

6/23/1981 204.0 9.4 11.0 35.0 238.0 91 8/12/1981 7.3 0 .2 1.6 6.7 95 

6/24/1981 176.0 8.1 9.5 30.0 204.0 92 8/13/1981 6.8 0 .2 1.4 8.0 94 

6/25/1981 182.0 8.6 8.4 27.0 203.0 94 8/14/1981 5.8 0 .2 1.4 6.5 94 

6/26/1981 163.0 7.1 7.8 25.0 198.0 94 8/15/1981 5.4 0 .2 1.3 6.5 93 

6/27/1981 121.0 8.0 7.8 22.0 193.0 95 8/16/1981 4.8 0 .2 1.3 6.1 93 

6/28/1981 117.0 6.5 7.5 20.0 176.0 95 8/17/1981 5.4 0 .1 1.2 7.9 92 

6/29/1981 106.0 5.3 6.5 19.0 164.0 96 8/18/1981 16.0 .3 .3 4.3 14.0 92 

6/30/1981 88.0 4.4 6.1 18.0 171.0 98 8/19/1981 35.0 0 .2 2.8 39.0 92 

7/1/1981 79.0 4.2 5.5 16.0 173.0 99 8/20/1981 21.0 0 .2 1.6 23.0 92 

7/2/1981 66.0 3.8 4.8 14.0 163.0 100 8/21/1981 11.0 0 .2 1.4 16.0 92 

7/3/1981 59.0 3.4 4.6 13.0 154.0 101 8/22/1981 8.7 0 .2 1.3 13.0 92 

7/4/1981 56.0 3.3 4.1 12.0 148.0 101 8/23/1981 5.4 0 .2 1.3 12.0 92 

7/5/1981 205.0 61.0 17.0 18.0 154.0 101 8/24/1981 2.6 0 .1 1.3 9.8 91 

7/6/1981 115.0 16.0 7.8 13.0 139.0 102 8/25/1981 2.2 0 .1 1.3 8.6 91 

7/7/1981 72.0 11.0 5.8 11.0 123.0 102 8/26/1981 2.1 0 .1 1.3 8.6 91 

7/8/1981 68.0 7.7 5.4 11.0 119.0 102 8/27/1981 1.8 0 .1 1.1 8.3 91 

7/9/1981 62.0 9.3 4.8 10.0 114.0 102 8/28/1981 1.5 0 .1 1.1 7.9 91 

7/10/1981 56.0 5.4 4.3 9.3 105.0 102 8/29/1981 1.4 0 .2 1.3 8.6 91 

7/11/1981 48.0 4.0 3.6 8.8 97.0 104 8/30/1981 2.0 0 .1 1.7 9.8 91 

7/12/1981 46.0 3.7 3.1 8.3 91.0 105 8/31/1981 4.7 0 .1 1.9 13.0 90 

7/13/1981 44.0 2.6 2.8 7.5 87.0 104 9/1/1981 6.5 0 .1 1.2 12.0 90 

7/14/1981 42.0 2.4 2.6 7.0 81.0 104 9/2/1981 4.8 0 .1 1.2 12.0 90 

7/15/1981 40.0 2.0 2.3 6.5 76.0 104 9/3/1981 13.0 5.8 .4 2.6 14.0 90 

7/16/1981 38.0 1.7 2.1 5.9 71.0 103 9/4/1981 8.3 .2 .2 1.3 15.0 90 

7/17/1981 36.0 1.5 1.8 5.6 65.0 103 9/5/1981 5.2 0 .2 1.2 13.0 89 

7/18/1981 34.0 1.4 1.6 5.2 62.0 103 9/6/1981 3.8 0 .2 1.1 10.0 89 

7/19/1981 32.0 .9 1.6 4.7 58.0 103 9/7/1981 2.9 0 .2 1.1 9.8 88 

7/20/1981 30.0 .8 1.4 4.0 54.0 102 9/8/1981 2.2 0 .2 1.8 12.0 88 

7/21/1981 28.0 .6 1.3 3.8 50.0 102 9/9/1981 1.8 0 .2 1.1 12.0 88 

7/22/1981 26.0 .4 1.2 3.7 47.0 103 9/10/1981 1.4 0 .2 1.0 12.0 87 

7/23/1981 29.0 .3 1.1 3.3 42.0 103 9/11/1981 1.3 0 .1 .9 10.0 87 

7/24/1981 23.0 .2 1.0 3.0 39.0 102 9/12/1981 1.3 0 .1 .9 8.7 86 

7/25/1981 22.0 .2 .9 2.9 37.0 102 9/13/1981 1.2 0 .1 .8 7.6 86 

7/26/1981 21.0 1.0 1.0 3.9 38.0 102 9/14/1981 1.3 4.6 .4 6.3 6.5 86 

7/27/1981 20.0 .5 1.4 4.2 35.0 101 9/15/1981 3.8 1.6 .2 4.0 31.0 86 

7/28/1981 16.0 .2 1.1 3.3 33.0 100 9/16/1981 4.4 0 .2 2.2 19.0 86 

7/29/1981 13.0 .2 .8 2.8 29.0 100 9/17/1981 2.9 0 .1 1.6 14.0 86 

7/30/1981 13.0 .1 .7 2.6 25.0 99 9/18/1981 2.1 0 .1 1.4 11.0 85 

7/31/1981 12.0 .1 .6 2.4 22.0 99 9/19/1981 1.5 0 .1 1.3 10.0 85 

8/1/1981 11.0 .1 .6 2.3 20.0 99 9/20/1981 1.3 0 .1 1.3 9.0 85 
72 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/21/1981 1.1 0 0.1 1.3 8.3 84 11/10/1981 23.0 0.1 2.5 2.3 28.0 85 

9/22/1981 .9 0 .1 1.3 7.8 84 11/11/1981 22.0 .1 2.4 2.3 27.0 85 

9/23/1981 .8 0 .1 1.2 8.0 84 11/12/1981 21.0 .1 2.4 2.3 26.0 85 

9/24/1981 .8 0 .1 1.2 6.0 84 11/13/1981 19.0 .1 2.4 2.1 26.0 84 

9/25/1981 .8 0 .1 1.1 5.2 83 11/14/1981 18.0 .1 2.0 2.1 27.0 84 

9/26/1981 .7 0 .1 1.1 4.4 83 11/15/1981 17.0 .1 2.0 2.1 25.0 84 

9/27/1981 .7 0 .1 1.1 3.6 83 11/16/1981 16.0 .1 1.8 2.1 25.0 84 

9/28/1981 .7 0 .1 1.0 3.1 82 11/17/1981 17.0 .1 1.8 2.1 24.0 84 

9/29/1981 .7 0 .1 1.0 1.8 82 11/18/1981 17.0 .2 1.8 2.1 24.0 84 

9/30/1981 .6 0 .1 1.0 1.6 82 11/19/1981 17.0 .1 1.7 2.1 23.0 83 

10/1/1981 .5 0 .1 1.0 1.8 81 11/20/1981 17.0 .1 1.5 1.9 22.0 82 

10/2/1981 .4 0 0 .9 1.8 81 11/21/1981 16.0 .1 1.5 1.9 21.0 82 

10/3/1981 .5 0 0 .9 1.8 81 11/22/1981 16.0 .1 1.5 1.7 21.0 81 

10/4/1981 .5 0 0 .9 1.8 81 11/23/1981 16.0 .1 1.5 1.7 21.0 81 

10/5/1981 .4 0 0 .9 1.8 81 11/24/1981 16.0 .1 1.4 1.7 20.0 81 

10/6/1981 854.0 12.0 3.2 19.0 1,150.0 82 11/25/1981 16.0 .1 1.3 1.7 20.0 81 

10/7/1981 176.0 3.6 2.5 8.1 139.0 84 11/26/1981 16.0 0 1.2 1.7 20.0 81 

10/8/1981 96.0 .1 2.0 6.1 93.0 86 11/27/1981 16.0 0 1.1 1.7 20.0 80 

10/9/1981 61.0 .1 .8 5.7 65.0 88 11/28/1981 15.0 0 1.1 1.7 19.0 80 

10/10/1981 47.0 0 .5 4.9 53.0 90 11/29/1981 15.0 0 1.1 1.7 19.0 80 

10/11/1981 43.0 2.3 1.8 4.7 45.0 91 11/30/1981 15.0 0 1.2 1.7 19.0 80 

10/12/1981 38.0 .1 .9 4.7 40.0 91 12/1/1981 15.0 0 1.1 1.6 18.0 80 

10/13/1981 37.0 .1 1.6 4.6 40.0 90 12/2/1981 14.0 0 1.0 1.4 17.0 79 

10/14/1981 34.0 0 2.1 4.5 43.0 90 12/3/1981 14.0 0 .9 1.4 16.0 79 

10/15/1981 30.0 0 1.4 4.1 36.0 89 12/4/1981 13.0 0 .9 1.4 15.0 79 

10/16/1981 28.0 0 1.2 4.0 30.0 88 12/5/1981 12.0 0 .8 1.4 15.0 79 

10/17/1981 26.0 0 1.1 3.8 27.0 88 12/6/1981 11.0 0 .9 1.4 16.0 79 

10/18/1981 25.0 0 .9 3.5 23.0 87 12/7/1981 11.0 0 .9 1.4 15.0 78 

10/19/1981 23.0 0 .8 3.3 20.0 87 12/8/1981 11.0 0 .9 1.4 15.0 78 

10/20/1981 22.0 0 .8 3.3 21.0 87 12/9/1981 11.0 0 .9 1.4 15.0 78 

10/21/1981 22.0 0 .9 3.2 21.0 86 12/10/1981 11.0 0 .9 1.5 15.0 77 

10/22/1981 24.0 .4 1.6 3.9 22.0 86 12/11/1981 11.0 0 .9 1.3 15.0 77 

10/23/1981 27.0 .1 1.5 3.7 26.0 85 12/12/1981 10.0 0 .8 1.3 15.0 75 

10/24/1981 24.0 0 1.2 3.3 26.0 84 12/13/1981 9.6 0 .8 1.4 14.0 76 

10/25/1981 23.0 0 1.2 3.3 22.0 84 12/14/1981 8.7 0 .7 1.4 14.0 76 

10/26/1981 21.0 0 1.0 3.1 20.0 85 12/15/1981 9.0 0 .7 1.1 13.0 76 

10/27/1981 20.0 0 .9 2.9 18.0 85 12/16/1981 9.5 0 .7 1.2 14.0 75 

10/28/1981 19.0 0 .9 2.8 17.0 85 12/17/1981 9.6 0 .7 1.2 13.0 75 

10/29/1981 19.0 0 .9 2.8 16.0 85 12/18/1981 8.6 0 .6 1.0 13.0 75 

10/30/1981 19.0 .1 1.0 2.7 18.0 85 12/19/1981 7.8 0 .6 1.0 12.0 75 

10/31/1981 24.0 1.6 4.8 3.3 27.0 85 12/20/1981 8.4 0 .6 1.2 12.0 74 

11/1/1981 33.0 .2 4.5 2.9 51.0 85 12/21/1981 9.0 0 .8 1.1 12.0 72 

11/2/1981 27.0 .1 3.1 2.5 32.0 86 12/22/1981 9.0 0 .7 1.0 12.0 72 

11/3/1981 24.0 .1 2.6 2.5 28.0 86 12/23/1981 7.8 0 .6 1.0 12.0 71 

11/4/1981 23.0 0 2.4 2.3 27.0 86 12/24/1981 7.6 0 .6 1.1 12.0 70 

11/5/1981 22.0 0 2.2 2.2 26.0 85 12/25/1981 7.1 0 .6 1.0 11.0 70 

11/6/1981 22.0 0 2.0 2.1 25.0 85 12/26/1981 7.3 0 .6 1.0 11.0 70 

11/7/1981 21.0 0 1.8 2.1 24.0 85 12/27/1981 7.0 0 .6 1.0 11.0 69 

11/8/1981 26.0 .9 4.2 2.7 26.0 85 12/28/1981 7.0 0 .6 1.2 11.0 69 

11/9/1981 30.0 .2 3.4 2.3 38.0 85 12/29/1981 6.8 0 .6 1.0 11.0 68 
Appendix 2 73 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

12/30/1981 6.8 0 0.6 1.0 11.0 68 2/18/1982 2.8 0 0.2 0.5 7.0 52 

12/31/1981 6.9 0 .6 1.2 11.0 68 2/19/1982 2.7 0 .2 .5 6.5 52 

1/1/1982 7.0 0 .5 1.2 11.0 67 2/20/1982 2.7 0 .2 .5 6.5 52 

1/2/1982 7.0 0 .5 1.0 11.0 67 2/21/1982 2.7 0 .2 .5 6.6 52 

1/3/1982 6.7 0 .5 1.0 11.0 67 2/22/1982 2.7 0 .2 .5 6.5 52 

1/4/1982 5.8 0 .5 1.0 9.8 67 2/23/1982 2.8 0 .2 .5 6.5 52 

1/5/1982 5.6 0 .5 .9 9.8 66 2/24/1982 2.8 0 .2 .4 6.3 51 

1/6/1982 6.0 0 .5 .8 10.0 64 2/25/1982 2.8 0 .2 .5 6.1 50 

1/7/1982 6.1 0 .5 .9 9.7 63 2/26/1982 3.7 0 .4 .6 7.2 51 

1/8/1982 5.6 0 .4 .9 9.1 63 2/27/1982 3.2 0 .3 .5 6.5 52 

1/9/1982 5.6 0 .4 .8 8.6 62 2/28/1982 2.8 0 .2 .5 6.5 51 

1/10/1982 5.6 0 .4 .8 8.2 62 3/1/1982 3.1 0 .2 .5 6.5 51 

1/11/1982 5.6 0 .4 .9 7.8 62 3/2/1982 3.0 0 .2 .5 6.5 51 

1/12/1982 6.3 0 .6 1.2 9.8 62 3/3/1982 2.9 0 .2 .5 6.1 51 

1/13/1982 6.8 0 .5 .9 9.8 62 3/4/1982 2.9 0 .2 .5 6.1 51 

1/14/1982 7.0 0 .5 .9 9.8 62 3/5/1982 2.8 0 .2 .5 6.1 51 

1/15/1982 7.0 0 .5 .9 9.8 61 3/6/1982 2.8 0 .2 .5 6.1 50 

1/16/1982 6.3 0 .4 .9 9.8 61 3/7/1982 2.8 0 .2 .4 6.2 49 

1/17/1982 6.1 0 .4 .7 9.4 60 3/8/1982 2.8 0 .2 .4 4.8 48 

1/18/1982 5.8 0 .4 .7 9.4 59 3/9/1982 2.8 0 .2 .4 4.8 48 

1/19/1982 5.8 0 .4 .8 9.4 58 3/10/1982 2.8 0 .2 .4 4.8 48 

1/20/1982 5.8 0 .4 .8 9.4 58 3/11/1982 2.9 0 .2 .4 4.8 47 

1/21/1982 5.8 0 .4 .7 9.4 57 3/12/1982 2.9 0 .2 .4 4.8 47 

1/22/1982 5.8 0 .4 .7 9.4 57 3/13/1982 2.9 0 .2 .5 4.8 46 

1/23/1982 5.6 0 .4 .7 9.3 56 3/14/1982 2.9 0 .2 .5 4.8 45 

1/24/1982 5.4 0 .4 .7 9.0 56 3/15/1982 2.9 0 .2 .5 4.8 45 

1/25/1982 5.2 0 .4 .7 9.0 56 3/16/1982 2.9 0 .2 .5 4.8 44 

1/26/1982 4.8 0 .3 .6 9.0 55 3/17/1982 2.9 0 .2 .5 3.8 44 

1/27/1982 4.8 0 .3 .6 9.0 55 3/18/1982 2.9 0 .2 .4 3.8 43 

1/28/1982 4.8 0 .3 .6 8.6 55 3/19/1982 2.9 0 .2 .4 3.8 42 

1/29/1982 4.8 0 .3 .6 8.6 54 3/20/1982 2.8 0 .2 .4 3.8 42 

1/30/1982 5.2 0 .5 .8 8.6 55 3/21/1982 2.8 0 .2 .4 3.8 42 

1/31/1982 4.6 0 .4 .6 8.3 55 3/22/1982 2.8 .2 .2 .4 3.2 46 

2/1/1982 4.1 0 .3 .6 8.3 56 3/23/1982 3.4 4.3 .7 .5 3.2 46 

2/2/1982 4.0 0 .3 .6 8.5 57 3/24/1982 3.5 .2 .3 .4 3.2 47 

2/3/1982 3.5 0 .3 .6 8.6 56 3/25/1982 3.4 0 .2 .4 3.2 46 

2/4/1982 3.3 0 .3 .6 8.6 55 3/26/1982 3.2 0 .2 .4 3.2 44 

2/5/1982 3.2 0 .3 .6 8.6 55 3/27/1982 3.3 .2 .3 .4 5.4 42 

2/6/1982 3.2 0 .3 .5 8.0 54 3/28/1982 3.3 .1 .3 .4 6.1 43 

2/7/1982 3.1 0 .3 .6 7.9 54 3/29/1982 3.4 .1 .3 .4 5.6 42 

2/8/1982 3.1 0 .3 .5 7.5 51 3/30/1982 3.5 .1 .3 .4 5.6 42 

2/9/1982 3.1 0 .3 .5 7.4 50 3/31/1982 3.4 0 .3 .4 5.2 42 

2/10/1982 3.1 0 .3 .5 7.0 50 4/1/1982 3.3 0 .3 .4 5.2 42 

2/11/1982 3.1 0 .3 .5 7.0 49 4/2/1982 3.2 .1 .3 .4 5.2 41 

2/12/1982 3.0 0 .3 .5 7.0 49 4/3/1982 3.1 0 .2 .3 5.2 41 

2/13/1982 2.9 0 .3 .5 7.0 50 4/4/1982 2.8 0 .2 .3 4.8 41 

2/14/1982 2.9 0 .3 .5 7.0 53 4/5/1982 2.8 0 .2 .3 4.8 41 

2/15/1982 2.9 0 .3 .5 7.0 53 4/6/1982 2.6 0 .2 .3 3.8 40 

2/16/1982 2.9 0 .3 .5 7.0 53 4/7/1982 2.6 0 .2 .3 3.4 40 

2/17/1982 2.9 0 .3 .5 7.0 53 4/8/1982 2.7 0 .2 .3 4.0 40 
74 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/9/1982 2.7 0.3 0.3 0.3 3.4 41 5/29/1982 39.0 0.9 5.3 9.6 51.0 71 

4/10/1982 2.7 .1 .3 .3 3.3 41 5/30/1982 35.0 .6 4.8 8.7 46.0 71 

4/11/1982 2.7 0 .3 .3 2.6 40 5/31/1982 31.0 .4 4.1 8.1 42.0 70 

4/12/1982 2.8 0 .3 .3 2.2 40 6/1/1982 27.0 .3 4.1 7.5 38.0 70 

4/13/1982 2.5 0 .2 .3 2.2 40 6/2/1982 26.0 .2 3.7 6.9 36.0 70 

4/14/1982 2.7 0 .2 .3 1.7 40 6/3/1982 24.0 .2 3.7 6.9 34.0 69 

4/15/1982 2.7 0 .2 .3 2.0 38 6/4/1982 30.0 .2 3.4 6.6 32.0 69 

4/16/1982 2.6 0 .2 .3 2.2 37 6/5/1982 39.0 .2 3.1 6.0 30.0 70 

4/17/1982 2.5 0 .2 .3 2.0 38 6/6/1982 30.0 .2 2.6 5.7 27.0 70 

4/18/1982 2.5 0 .2 .3 1.4 38 6/7/1982 25.0 .2 2.6 5.4 26.0 70 

4/19/1982 2.9 0 .2 .3 2.0 38 6/8/1982 22.0 .3 2.2 4.9 24.0 69 

4/20/1982 3.4 2.4 .5 .9 6.2 41 6/9/1982 20.0 .3 2.0 4.3 23.0 69 

4/21/1982 3.9 .2 .1 .4 4.3 41 6/10/1982 21.0 .3 1.6 3.8 20.0 68 

4/22/1982 20.0 30.0 7.9 3.2 8.4 46 6/11/1982 18.0 .3 1.5 3.3 18.0 68 

4/23/1982 31.0 14.0 6.7 2.6 14.0 50 6/12/1982 25.0 .8 2.0 4.9 22.0 70 

4/24/1982 31.0 15.0 9.4 2.8 20.0 51 6/13/1982 29.0 .3 1.6 3.6 25.0 70 

4/25/1982 36.0 8.8 8.6 3.2 23.0 51 6/14/1982 22.0 .2 1.3 3.1 21.0 70 

4/26/1982 29.0 6.7 5.9 3.0 19.0 51 6/15/1982 19.0 .2 1.2 2.9 19.0 69 

4/27/1982 27.0 4.9 5.1 2.7 17.0 51 6/16/1982 21.0 2.3 1.8 3.6 21.0 69 

4/28/1982 25.0 4.4 4.7 2.6 16.0 51 6/17/1982 19.0 .2 1.2 2.9 21.0 68 

4/29/1982 24.0 3.4 4.0 2.4 15.0 50 6/18/1982 15.0 .1 1.0 2.7 17.0 67 

4/30/1982 23.0 3.0 3.7 2.3 15.0 50 6/19/1982 13.0 0 .8 2.5 15.0 66 

5/1/1982 23.0 2.6 3.6 2.2 14.0 50 6/20/1982 12.0 0 .7 2.3 14.0 65 

5/2/1982 22.0 2.4 3.1 2.0 13.0 49 6/21/1982 12.0 0 .7 2.1 13.0 64 

5/3/1982 22.0 2.0 2.8 1.9 13.0 49 6/22/1982 68.0 7.9 37.0 17.0 16.0 65 

5/4/1982 20.0 1.7 2.6 1.7 12.0 48 6/23/1982 83.0 .6 6.5 7.8 19.0 67 

5/5/1982 19.0 1.5 2.4 1.7 11.0 48 6/24/1982 22.0 0 1.9 4.1 18.0 67 

5/6/1982 29.0 14.0 7.7 3.4 16.0 48 6/25/1982 17.0 0 1.5 3.1 15.0 67 

5/7/1982 28.0 2.7 3.6 2.2 17.0 48 6/26/1982 16.0 0 1.4 2.7 15.0 67 

5/8/1982 23.0 2.0 3.1 1.8 15.0 48 6/27/1982 15.0 .7 2.1 5.2 16.0 67 

5/9/1982 21.0 1.7 2.8 1.7 13.0 49 6/28/1982 12.0 0 1.3 3.6 14.0 67 

5/10/1982 21.0 1.7 2.6 1.7 13.0 49 6/29/1982 11.0 0 1.1 2.9 12.0 67 

5/11/1982 21.0 1.7 2.6 1.8 13.0 48 6/30/1982 10.0 0 1.1 3.9 13.0 67 

5/12/1982 22.0 4.9 3.4 2.0 14.0 48 7/1/1982 9.9 0 1.2 3.4 12.0 66 

5/13/1982 1,720.0 194.0 249.0 258.0 1,960.0 54 7/2/1982 9.4 0 1.0 2.9 12.0 65 

5/14/1982 298.0 27.0 31.0 22.0 201.0 60 7/3/1982 8.7 0 .7 2.6 12.0 65 

5/15/1982 172.0 14.0 25.0 19.0 133.0 66 7/4/1982 8.2 0 .7 2.4 12.0 64 

5/16/1982 145.0 12.0 44.0 21.0 115.0 71 7/5/1982 8.1 0 .6 2.3 11.0 64 

5/17/1982 215.0 14.0 42.0 22.0 117.0 72 7/6/1982 7.8 0 .6 2.1 11.0 63 

5/18/1982 150.0 7.4 23.0 19.0 109.0 72 7/7/1982 7.0 0 .5 1.9 11.0 62 

5/19/1982 118.0 4.8 16.0 18.0 102.0 73 7/8/1982 5.6 0 .4 1.7 10.0 61 

5/20/1982 98.0 3.2 12.0 16.0 96.0 73 7/9/1982 4.3 0 .4 1.3 10.0 60 

5/21/1982 84.0 2.5 11.0 15.0 85.0 73 7/10/1982 4.1 0 .4 1.3 10.0 60 

5/22/1982 75.0 2.0 9.1 14.0 78.0 73 7/11/1982 3.6 0 .4 1.1 9.7 59 

5/23/1982 65.0 1.6 7.8 12.0 72.0 72 7/12/1982 3.6 0 .4 1.1 8.9 59 

5/24/1982 78.0 9.5 16.0 14.0 74.0 72 7/13/1982 3.6 0 .4 1.2 8.3 59 

5/25/1982 67.0 2.7 9.8 12.0 71.0 72 7/14/1982 3.5 0 .5 1.4 7.8 57 

5/26/1982 54.0 2.0 7.8 11.0 62.0 72 7/15/1982 3.1 0 .4 1.2 7.2 56 

5/27/1982 48.0 1.5 7.2 11.0 58.0 71 7/16/1982 2.9 0 .4 1.1 6.4 56 

5/28/1982 44.0 1.2 6.2 10.0 55.0 71 7/17/1982 2.7 0 .4 1.0 5.6 55 
Appendix 2 75 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

7/18/1982 2.2 0 0.3 1.0 5.0 55 9/6/1982 0.1 0 0 0 1.9 38 

7/19/1982 1.9 0 .2 1.0 4.5 54 9/7/1982 .1 0 0 .1 1.5 38 

7/20/1982 1.8 0 .2 .9 4.3 54 9/8/1982 .1 0 0 0 1.6 37 

7/21/1982 1.5 0 .2 .7 3.4 53 9/9/1982 .1 0 0 0 1.6 37 

7/22/1982 1.5 0 .2 .7 2.8 53 9/10/1982 .1 0 0 0 1.5 37 

7/23/1982 1.4 0 .2 .7 2.1 52 9/11/1982 .1 0 0 0 1.3 36 

7/24/1982 1.3 0 .2 .6 3.6 52 9/12/1982 .1 0 0 0 1.3 37 

7/25/1982 1.2 0 .2 .6 2.1 51 9/13/1982 .1 0 0 0 1.0 36 

7/26/1982 1.1 0 .1 .5 2.0 51 9/14/1982 .1 0 0 0 1.2 36 

7/27/1982 1.0 0 .1 .5 1.8 50 9/15/1982 .1 0 0 0 1.4 35 

7/28/1982 .9 0 .1 .4 1.2 50 9/16/1982 .1 0 0 0 1.6 35 

7/29/1982 .8 0 .1 .4 1.3 50 9/17/1982 .1 0 0 0 1.5 35 

7/30/1982 .8 0 .1 .4 1.0 50 9/18/1982 .1 0 0 0 1.2 35 

7/31/1982 .7 0 .1 .4 1.0 50 9/19/1982 .2 0 0 0 1.2 35 

8/1/1982 .6 0 .1 .4 1.0 49 9/20/1982 .2 .3 0 .1 3.2 35 

8/2/1982 .6 0 0 .3 1.1 49 9/21/1982 .1 0 0 .1 2.8 34 

8/3/1982 .6 0 0 .3 .9 47 9/22/1982 .1 0 0 0 1.1 34 

8/4/1982 .5 0 0 .3 1.0 47 9/23/1982 0 0 0 0 1.1 34 

8/5/1982 .5 0 0 .3 .8 47 9/24/1982 0 0 0 0 1.1 34 

8/6/1982 .4 0 0 .3 .8 47 9/25/1982 0 0 0 0 1.0 34 

8/7/1982 .7 0 0 .2 .8 46 9/26/1982 0 0 0 0 .7 34 

8/8/1982 1.1 0 0 .2 1.0 46 9/27/1982 0 0 0 0 .6 34 

8/9/1982 .4 0 0 .2 .9 46 9/28/1982 0 0 0 0 .5 35 

8/10/1982 .3 0 0 .2 1.2 45 9/29/1982 0 0 0 0 .5 36 

8/11/1982 .3 0 0 .2 1.5 45 9/30/1982 0 0 0 0 .5 36 

8/12/1982 .3 0 0 .2 1.8 45 10/1/1982 0 0 0 0 .6 35 

8/13/1982 .2 0 0 .2 1.9 44 10/2/1982 0 0 0 0 .6 33 

8/14/1982 .2 0 0 .2 1.6 44 10/3/1982 0 0 0 0 .6 33 

8/15/1982 .2 0 0 .1 1.6 44 10/4/1982 0 0 0 0 .6 34 

8/16/1982 .2 0 0 .1 1.5 44 10/5/1982 0 0 0 0 .6 33 

8/17/1982 .2 0 0 .1 1.0 43 10/6/1982 0 0 0 .1 .8 34 

8/18/1982 5.6 31.0 0 .1 .8 43 10/7/1982 .1 0 0 .4 1.7 34 

8/19/1982 1.1 .1 0 .1 .7 43 10/8/1982 0 0 0 .3 3.9 35 

8/20/1982 .2 0 0 .1 .7 43 10/9/1982 0 0 0 .2 2.0 34 

8/21/1982 .2 0 0 .1 .7 43 10/10/1982 0 0 0 .2 1.6 33 

8/22/1982 .2 0 0 .1 1.1 42 10/11/1982 0 0 0 .2 1.3 33 

8/23/1982 .2 0 0 .1 1.6 42 10/12/1982 0 0 0 .2 1.7 33 

8/24/1982 .2 0 0 .1 1.3 41 10/13/1982 0 0 0 .2 1.7 34 

8/25/1982 .2 0 0 .1 1.2 41 10/14/1982 0 0 0 .2 1.2 34 

8/26/1982 .2 0 0 .1 1.7 40 10/15/1982 0 0 0 .2 .9 33 

8/27/1982 .2 0 0 .1 1.6 40 10/16/1982 -- 0 0 .1 .8 32 

8/28/1982 .1 0 0 .1 1.6 40 10/17/1982 -- 0 0 .1 .8 32 

8/29/1982 .1 0 0 .1 1.7 40 10/18/1982 -- 0 0 .1 .8 33 

8/30/1982 .1 0 0 0 2.1 40 10/19/1982 -- 0 0 .1 .8 32 

8/31/1982 .1 0 0 0 2.2 39 10/20/1982 -- 0 0 .1 .7 32 

9/1/1982 .1 0 0 0 2.2 38 10/21/1982 -- 0 0 .1 .6 32 

9/2/1982 .1 0 0 0 2.1 38 10/22/1982 -- 0 0 .1 .7 31 

9/3/1982 .1 0 0 0 4.1 38 10/23/1982 -- 0 0 .1 .9 31 

9/4/1982 .1 0 0 0 4.1 38 10/24/1982 -- 0 0 .1 .8 31 

9/5/1982 .1 0 0 0 2.4 38 10/25/1982 -- 0 0 .1 .7 32 
76 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/26/1982 -- 0 0 0.1 0.6 32 12/15/1982 -- 0 0.1 4.0 2.7 42 

10/27/1982 -- 0 0 .1 .6 32 12/16/1982 -- 0 .1 3.8 2.7 41 

10/28/1982 -- 0 0 .1 .6 33 12/17/1982 -- 0 .1 3.8 2.7 41 

10/29/1982 -- 0 0 .1 .7 34 12/18/1982 -- 0 .1 3.8 3.0 42 

10/30/1982 -- 0 0 .1 .6 32 12/19/1982 -- 0 .1 3.6 2.9 42 

10/31/1982 -- 0 0 .1 .6 32 12/20/1982 -- 0 .1 3.5 2.2 42 

11/1/1982 -- 0 0 .1 .6 32 12/21/1982 -- 0 .1 3.5 2.2 42 

11/2/1982 -- 0 0 .2 .9 32 12/22/1982 -- 0 .1 3.4 2.2 42 

11/3/1982 -- 0 0 .6 3.2 32 12/23/1982 -- 0 .1 3.3 2.4 42 

11/4/1982 -- 0 0 .2 .8 32 12/24/1982 -- 0 .1 3.2 2.7 42 

11/5/1982 -- 0 0 .2 .6 32 12/25/1982 -- 0 .1 2.9 2.7 42 

11/6/1982 -- 0 0 .3 .6 32 12/26/1982 -- 0 .1 3.1 2.2 41 

11/7/1982 -- 0 0 .3 .8 32 12/27/1982 -- .8 .3 4.3 4.7 43 

11/8/1982 -- 0 0 .3 .9 34 12/28/1982 -- .2 .2 3.1 3.3 43 

11/9/1982 -- 0 0 .3 .8 39 12/29/1982 -- .3 .2 2.4 2.7 42 

11/10/1982 -- 0 0 .3 1.3 36 12/30/1982 -- .1 .1 2.5 2.7 42 

11/11/1982 -- 0 0 .4 2.8 32 12/31/1982 -- 1.5 .1 2.4 2.9 42 

11/12/1982 -- 0 0 .4 1.2 32 1/1/1983 -- 4.0 .7 4.4 5.2 44 

11/13/1982 -- 0 0 .3 .6 32 1/2/1983 -- 3.0 .4 3.6 5.2 45 

11/14/1982 -- 0 0 .3 .6 32 1/3/1983 -- 2.7 .4 3.5 5.6 45 

11/15/1982 -- 0 0 .3 .7 32 1/4/1983 -- 2.7 .4 3.7 6.1 45 

11/16/1982 -- 0 0 .3 .8 32 1/5/1983 -- 2.7 .4 3.9 7.3 45 

11/17/1982 -- 0 0 .3 .8 32 1/6/1983 -- 2.7 .4 4.0 8.0 45 

11/18/1982 -- 0 0 .3 .9 32 1/7/1983 -- 2.4 .4 4.0 8.4 45 

11/19/1982 -- 0 0 .4 1.5 32 1/8/1983 -- 2.3 .4 4.0 8.6 43 

11/20/1982 -- 0 0 .4 1.3 31 1/9/1983 -- 2.2 .4 4.1 8.6 42 

11/21/1982 -- 0 0 .4 1.0 31 1/10/1983 -- 2.0 .4 3.9 8.6 40 

11/22/1982 -- 0 0 .4 .9 32 1/11/1983 -- 2.0 .3 3.7 8.3 38 

11/23/1982 -- 0 0 .4 1.0 32 1/12/1983 -- 2.0 .3 3.5 8.2 38 

11/24/1982 -- .1 0 .4 2.0 33 1/13/1983 -- 1.6 .3 3.5 7.9 38 

11/25/1982 -- 0 0 .4 1.4 33 1/14/1983 -- 1.7 .3 3.5 7.9 38 

11/26/1982 -- 9.5 .1 3.1 4.7 34 1/15/1983 -- 1.7 .3 3.1 7.6 38 

11/27/1982 -- 1.1 0 5.0 6.8 38 1/16/1983 -- 1.7 .3 3.3 7.5 38 

11/28/1982 -- 0 0 4.6 5.5 42 1/17/1983 -- 1.5 .3 3.3 7.5 38 

11/29/1982 -- 0 0 4.0 4.3 45 1/18/1983 -- 2.0 .3 4.0 8.4 39 

11/30/1982 -- 0 0 3.5 3.8 49 1/19/1983 -- 1.9 .3 3.9 8.4 41 

12/1/1982 -- 0 0 3.2 3.3 42 1/20/1983 -- 1.7 .3 4.1 8.3 42 

12/2/1982 -- .4 0 3.3 3.1 36 1/21/1983 -- 2.2 .6 4.4 8.9 42 

12/3/1982 -- 6.9 .5 4.4 3.0 37 1/22/1983 -- 2.0 .5 4.3 9.0 43 

12/4/1982 -- 0 .1 3.6 2.3 38 1/23/1983 -- 1.7 .5 4.3 9.0 43 

12/5/1982 -- 0 .1 3.5 2.1 37 1/24/1983 -- 1.7 .5 4.6 9.2 42 

12/6/1982 -- 0 0 3.3 1.6 36 1/25/1983 -- 1.5 .5 4.7 9.4 42 

12/7/1982 -- 0 0 3.3 1.6 36 1/26/1983 -- 1.5 .5 4.6 9.7 42 

12/8/1982 -- 0 0 3.3 1.6 36 1/27/1983 -- 1.5 .5 4.6 10.0 42 

12/9/1982 -- 0 0 3.1 1.6 35 1/28/1983 -- 1.5 .5 4.7 10.0 42 

12/10/1982 -- .2 0 3.9 2.9 36 1/29/1983 -- 1.5 .5 4.7 10.0 42 

12/11/1982 -- .9 .1 4.2 2.5 37 1/30/1983 -- 1.2 .5 4.5 10.0 42 

12/12/1982 -- 0 .1 3.8 2.0 38 1/31/1983 -- 1.2 .5 4.7 11.0 42 

12/13/1982 -- 0 .1 3.8 1.8 39 2/1/1983 -- 1.2 .5 4.5 11.0 42 

12/14/1982 -- 0 .1 4.0 2.4 42 2/2/1983 -- 1.2 .5 4.3 10.0 42 
Appendix 2 77 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

2/3/1983 -- 1.2 0.5 4.1 9.9 42 3/25/1983 -- 4.8 17.0 18.0 110.0 75 

2/4/1983 -- 1.1 .5 4.1 9.8 42 3/26/1983 -- 32.0 93.0 31.0 223.0 77 

2/5/1983 -- 1.8 .7 5.0 10.0 42 3/27/1983 -- 5.9 27.0 19.0 156.0 79 

2/6/1983 -- 1.1 .7 4.5 11.0 42 3/28/1983 -- 4.8 18.0 18.0 129.0 80 

2/7/1983 -- 1.0 .7 4.3 11.0 42 3/29/1983 -- 4.4 16.0 17.0 137.0 80 

2/8/1983 -- 1.0 .7 4.3 11.0 42 3/30/1983 -- 4.1 15.0 17.0 206.0 81 

2/9/1983 -- 5.1 2.7 7.1 13.0 42 3/31/1983 -- 3.5 14.0 16.0 135.0 81 

2/10/1983 -- 2.1 1.1 7.4 22.0 43 4/1/1983 -- 3.4 12.0 15.0 114.0 80 

2/11/1983 -- 1.8 1.1 7.2 21.0 43 4/2/1983 -- 3.0 9.0 14.0 101.0 80 

2/12/1983 -- 1.7 1.1 7.2 20.0 43 4/3/1983 -- 2.8 8.4 13.0 99.0 80 

2/13/1983 -- 1.5 1.1 6.9 19.0 44 4/4/1983 -- 3.0 8.3 13.0 96.0 80 

2/14/1983 -- 1.5 1.0 7.2 19.0 45 4/5/1983 -- 2.8 6.6 12.0 90.0 80 

2/15/1983 -- 3.9 4.0 13.0 48.0 45 4/6/1983 -- 3.0 5.7 12.0 85.0 80 

2/16/1983 -- 2.9 4.6 10.0 53.0 45 4/7/1983 -- 2.9 5.3 11.0 81.0 80 

2/17/1983 -- 2.7 3.8 10.0 49.0 46 4/8/1983 -- 2.7 4.9 11.0 78.0 79 

2/18/1983 -- 2.3 3.7 10.0 47.0 46 4/9/1983 -- 2.4 4.4 10.0 74.0 79 

2/19/1983 -- 2.3 3.7 10.0 45.0 47 4/10/1983 -- 2.3 4.2 10.0 72.0 79 

2/20/1983 -- 2.3 4.1 10.0 44.0 47 4/11/1983 -- 2.3 4.0 9.8 68.0 79 

2/21/1983 -- 2.0 4.1 10.0 43.0 47 4/12/1983 -- 2.3 3.7 9.5 67.0 79 

2/22/1983 -- 2.0 4.1 10.0 42.0 47 4/13/1983 -- 2.8 3.7 9.3 65.0 79 

2/23/1983 -- 1.8 4.1 9.9 41.0 48 4/14/1983 -- 3.1 3.1 8.8 60.0 79 

2/24/1983 -- 1.7 4.1 9.6 40.0 48 4/15/1983 -- 3.0 3.1 8.4 59.0 78 

2/25/1983 -- 1.7 3.7 9.6 39.0 48 4/16/1983 -- 3.0 2.9 8.0 56.0 78 

2/26/1983 -- 1.7 3.4 9.3 38.0 48 4/17/1983 -- 3.1 2.9 7.6 54.0 78 

2/27/1983 -- 1.7 3.4 9.3 37.0 48 4/18/1983 -- 3.2 2.9 7.3 53.0 78 

2/28/1983 -- 1.6 3.1 9.0 36.0 47 4/19/1983 -- 2.8 2.9 7.0 51.0 78 

3/1/1983 -- 1.5 3.1 9.0 36.0 47 4/20/1983 -- 2.7 2.9 6.5 50.0 77 

3/2/1983 -- 1.5 2.9 8.9 35.0 46 4/21/1983 -- 2.7 2.9 6.0 49.0 76 

3/3/1983 -- 1.5 2.9 8.7 34.0 46 4/22/1983 -- 2.1 2.9 5.6 49.0 75 

3/4/1983 -- 3.5 7.2 18.0 163.0 48 4/23/1983 -- 1.7 2.8 5.1 45.0 74 

3/5/1983 -- 1.8 6.2 14.0 136.0 50 4/24/1983 -- 1.5 2.6 4.6 43.0 74 

3/6/1983 -- 1.7 4.4 12.0 104.0 49 4/25/1983 -- 1.5 2.6 4.5 42.0 73 

3/7/1983 -- 1.6 3.7 12.0 90.0 49 4/26/1983 -- 1.5 2.4 4.3 40.0 73 

3/8/1983 -- 1.5 3.4 11.0 83.0 50 4/27/1983 -- 1.7 2.4 4.3 40.0 73 

3/9/1983 -- 1.8 3.1 11.0 81.0 51 4/28/1983 -- 1.7 2.1 4.0 38.0 72 

3/10/1983 -- 1.5 3.1 11.0 76.0 52 4/29/1983 -- 1.5 2.0 3.8 38.0 71 

3/11/1983 -- 1.5 2.9 10.0 75.0 54 4/30/1983 -- 1.4 2.0 3.8 38.0 71 

3/12/1983 -- 1.5 2.9 10.0 75.0 56 5/1/1983 -- 1.0 1.9 3.7 37.0 71 

3/13/1983 -- 1.7 2.9 10.0 75.0 57 5/2/1983 -- .9 1.6 3.5 34.0 71 

3/14/1983 -- 1.7 3.1 10.0 74.0 59 5/3/1983 -- .6 1.4 3.2 32.0 71 

3/15/1983 -- 2.8 3.4 10.0 76.0 61 5/4/1983 -- .6 1.1 2.9 30.0 70 

3/16/1983 -- 6.2 11.0 15.0 89.0 63 5/5/1983 -- .3 1.0 2.7 28.0 70 

3/17/1983 -- 3.1 7.2 14.0 93.0 65 5/6/1983 -- .2 .8 2.7 28.0 69 

3/18/1983 -- 2.9 5.7 12.0 85.0 66 5/7/1983 -- .2 .8 2.5 26.0 69 

3/19/1983 -- 2.7 5.7 12.0 82.0 68 5/8/1983 -- .1 .6 2.3 24.0 69 

3/20/1983 -- 2.7 5.7 12.0 81.0 69 5/9/1983 -- .2 .6 2.3 23.0 68 

3/21/1983 -- 2.4 4.6 12.0 79.0 69 5/10/1983 -- .9 .8 2.6 23.0 67 

3/22/1983 -- 2.4 4.4 11.0 76.0 69 5/11/1983 -- 7.0 3.0 4.4 45.0 66 

3/23/1983 -- 20.0 35.0 23.0 114.0 72 5/12/1983 -- 0 .9 3.1 34.0 68 

3/24/1983 -- 5.5 19.0 19.0 116.0 74 5/13/1983 -- 0 .7 2.7 28.0 70 
78 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

5/14/1983 -- 0 0.7 2.5 24.0 71 7/3/1983 -- 0.9 0.5 3.3 27.0 81 

5/15/1983 -- 0 .9 3.3 27.0 71 7/4/1983 -- .8 .5 3.1 26.0 81 

5/16/1983 -- 0 .8 2.5 24.0 71 7/5/1983 -- 1.4 .5 3.2 29.0 80 

5/17/1983 -- 0 .6 2.3 24.0 70 7/6/1983 -- 1.0 .5 3.0 51.0 80 

5/18/1983 -- 1.9 1.1 3.2 24.0 70 7/7/1983 -- .7 .5 2.6 41.0 79 

5/19/1983 -- 0 .7 2.4 22.0 72 7/8/1983 -- .7 .4 2.4 27.0 79 

5/20/1983 -- 35.0 14.0 14.0 94.0 74 7/9/1983 -- .7 .4 2.2 25.0 79 

5/21/1983 -- 39.0 23.0 27.0 265.0 77 7/10/1983 -- .6 .4 2.1 23.0 78 

5/22/1983 -- 3.9 2.0 12.0 118.0 79 7/11/1983 -- .6 .3 2.0 23.0 78 

5/23/1983 -- 2.7 1.0 11.0 79.0 82 7/12/1983 -- .9 .3 2.2 23.0 78 

5/24/1983 -- 2.2 .9 9.9 66.0 83 7/13/1983 -- .9 .5 2.7 23.0 78 

5/25/1983 -- 2.1 .7 9.0 59.0 84 7/14/1983 -- 1.7 .7 3.1 30.0 78 

5/26/1983 -- 2.0 .6 8.7 54.0 83 7/15/1983 -- 1.7 .6 2.8 34.0 78 

5/27/1983 -- 1.9 .7 7.8 49.0 83 7/16/1983 -- 7.7 1.3 3.5 42.0 80 

5/28/1983 -- 2.0 .6 7.2 47.0 83 7/17/1983 -- 2.4 1.4 22.0 90.0 82 

5/29/1983 -- 2.2 .6 6.9 44.0 83 7/18/1983 -- 1.2 .7 8.3 64.0 84 

5/30/1983 -- 2.8 .5 6.6 41.0 82 7/19/1983 -- .9 .6 7.7 52.0 83 

5/31/1983 -- 2.9 .5 6.3 39.0 82 7/20/1983 -- .6 .5 7.1 45.0 82 

6/1/1983 -- 3.6 .5 6.3 39.0 81 7/21/1983 -- .6 .5 6.8 40.0 82 

6/2/1983 -- 3.9 .5 6.0 38.0 81 7/22/1983 -- .5 .5 6.5 36.0 81 

6/3/1983 -- 3.9 .5 5.4 37.0 81 7/23/1983 -- .5 .5 6.2 33.0 81 

6/4/1983 -- 4.4 .5 5.2 36.0 82 7/24/1983 -- .7 .4 5.8 28.0 81 

6/5/1983 -- 18.0 5.6 7.5 45.0 83 7/25/1983 -- .7 .4 5.5 25.0 80 

6/6/1983 -- 4.6 1.7 7.5 50.0 84 7/26/1983 -- .5 .4 5.1 24.0 79 

6/7/1983 -- 2.8 1.6 6.9 49.0 86 7/27/1983 -- .4 .4 4.8 22.0 79 

6/8/1983 -- 2.5 1.2 6.3 42.0 85 7/28/1983 -- .2 .4 4.6 20.0 78 

6/9/1983 -- 2.5 1.1 5.4 38.0 84 7/29/1983 -- .1 .3 4.3 20.0 78 

6/10/1983 -- 2.4 1.1 5.2 36.0 83 7/30/1983 -- 0 .3 4.0 18.0 77 

6/11/1983 -- 2.6 1.0 4.3 34.0 83 7/31/1983 -- 0 .3 3.7 17.0 77 

6/12/1983 -- 2.6 .9 4.1 33.0 83 8/1/1983 -- 0 .3 3.4 16.0 77 

6/13/1983 -- 2.4 .8 3.3 31.0 83 8/2/1983 -- 0 .2 3.0 16.0 76 

6/14/1983 -- 8.6 3.9 17.0 71.0 84 8/3/1983 -- 0 .2 2.9 15.0 76 

6/15/1983 -- 2.9 2.0 11.0 124.0 87 8/4/1983 -- 0 .2 2.9 15.0 76 

6/16/1983 -- 4.4 4.8 8.4 85.0 86 8/5/1983 -- 0 .2 2.6 15.0 77 

6/17/1983 -- 2.6 2.7 8.4 86.0 85 8/6/1983 -- 0 .2 2.7 14.0 77 

6/18/1983 -- 2.3 2.3 7.8 62.0 85 8/7/1983 -- 1.8 .3 2.5 16.0 76 

6/19/1983 -- 2.3 2.0 7.5 56.0 85 8/8/1983 -- 35.0 51.0 15.0 17.0 77 

6/20/1983 -- 2.0 1.9 7.2 52.0 85 8/9/1983 -- .3 1.4 5.5 16.0 79 

6/21/1983 -- 2.0 1.8 7.2 49.0 84 8/10/1983 -- .2 1.0 4.2 19.0 78 

6/22/1983 -- 1.7 1.6 6.6 46.0 84 8/11/1983 -- .1 .9 3.6 16.0 77 

6/23/1983 -- 1.7 1.6 6.2 45.0 84 8/12/1983 -- .1 .8 3.3 14.0 76 

6/24/1983 -- 1.7 1.5 5.8 42.0 84 8/13/1983 -- .1 .8 3.2 14.0 76 

6/25/1983 -- 2.1 1.7 6.0 64.0 84 8/14/1983 -- 0 .8 3.0 13.0 75 

6/26/1983 -- 1.5 1.4 5.4 60.0 84 8/15/1983 -- 0 .8 2.8 14.0 74 

6/27/1983 -- 1.5 1.2 5.3 49.0 84 8/16/1983 -- 0 .8 2.7 12.0 74 

6/28/1983 -- 1.4 1.0 4.8 42.0 83 8/17/1983 -- 0 .8 2.5 11.0 73 

6/29/1983 -- 1.2 1.0 4.5 38.0 83 8/18/1983 -- 0 .8 2.4 11.0 72 

6/30/1983 -- 1.0 .8 4.0 35.0 82 8/19/1983 -- 0 .8 2.6 11.0 71 

7/1/1983 -- 1.2 .8 3.7 34.0 82 8/20/1983 -- 0 .8 2.5 10.0 70 

7/2/1983 -- 1.0 .6 3.5 31.0 82 8/21/1983 -- 0 .8 2.2 11.0 70 
Appendix 2 79 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

8/22/1983 -- 0 0.8 2.1 11.0 70 10/11/1983 -- 4.1 3.3 2.5 14.0 66 

8/23/1983 -- 0 .7 1.9 9.6 70 10/12/1983 -- 6.8 4.0 2.3 14.0 67 

8/24/1983 -- 0 .6 1.9 9.5 69 10/13/1983 -- 2.7 3.2 1.9 13.0 67 

8/25/1983 -- 0 .6 2.1 9.8 69 10/14/1983 -- 2.0 2.8 1.9 12.0 66 

8/26/1983 -- 0 .6 1.8 9.4 69 10/15/1983 -- 1.2 2.6 1.9 11.0 66 

8/27/1983 -- 0 .6 1.7 8.6 68 10/16/1983 -- 1.2 2.6 1.7 11.0 66 

8/28/1983 -- 4.0 .7 1.8 7.9 68 10/17/1983 -- 1.2 2.6 1.7 10.0 66 

8/29/1983 -- .1 .7 1.8 8.5 67 10/18/1983 -- 1.2 2.5 1.9 9.8 66 

8/30/1983 -- 0 .6 1.6 7.3 67 10/19/1983 -- 1.2 2.5 1.9 9.0 65 

8/31/1983 -- 0 .6 1.6 6.4 66 10/20/1983 -- 20.0 11.0 3.5 13.0 67 

9/1/1983 -- 0 .5 1.5 5.9 66 10/21/1983 -- 2.3 7.1 2.9 12.0 67 

9/2/1983 -- 0 .5 1.5 5.5 66 10/22/1983 -- 1.5 4.8 2.5 10.0 67 

9/3/1983 -- 0 .5 1.4 4.3 65 10/23/1983 -- 1.2 4.1 2.5 10.0 67 

9/4/1983 -- 0 .5 1.4 4.1 65 10/24/1983 -- 1.2 4.0 2.3 10.0 67 

9/5/1983 -- 0 .4 1.3 3.8 65 10/25/1983 -- 1.1 3.3 2.3 9.1 66 

9/6/1983 -- 0 .4 1.2 3.2 65 10/26/1983 -- 1.0 3.1 2.3 9.0 65 

9/7/1983 -- 13.0 .4 1.1 2.6 64 10/27/1983 -- .9 2.6 2.3 9.0 64 

9/8/1983 -- 0 .2 1.0 4.1 64 10/28/1983 -- 1.0 2.6 2.3 8.6 63 

9/9/1983 -- 11.0 .5 1.4 6.2 63 10/29/1983 -- 1.1 2.4 2.1 8.6 62 

9/10/1983 -- .1 .3 1.1 5.2 63 10/30/1983 -- 1.0 2.4 2.1 8.3 62 

9/11/1983 -- 0 .2 .9 4.2 62 10/31/1983 -- 1.8 2.4 2.1 8.2 61 

9/12/1983 -- 0 .2 .8 3.1 62 11/1/1983 -- 2.2 2.3 2.1 7.9 61 

9/13/1983 -- 0 .2 .5 1.8 62 11/2/1983 -- 2.2 2.2 1.9 7.6 61 

9/14/1983 -- 0 .2 .2 1.6 61 11/3/1983 -- 2.5 2.2 2.3 7.5 62 

9/15/1983 -- 0 .2 .2 1.6 60 11/4/1983 -- 3.3 2.1 2.3 7.5 63 

9/16/1983 -- 0 .2 .2 1.6 60 11/5/1983 -- 16.0 9.7 2.5 8.0 61 

9/17/1983 -- 0 .2 .1 1.6 59 11/6/1983 -- 30.0 9.3 2.3 7.9 61 

9/18/1983 -- 49.0 25.0 3.8 6.8 60 11/7/1983 -- 9.9 7.6 2.1 7.9 61 

9/19/1983 -- 48.0 27.0 4.0 86.0 63 11/8/1983 -- 5.1 5.6 2.1 7.6 62 

9/20/1983 -- 32.0 8.7 2.7 41.0 66 11/9/1983 -- 4.0 4.7 1.9 7.4 63 

9/21/1983 -- 9.6 5.0 2.1 22.0 69 11/10/1983 -- 2.9 3.7 1.7 6.9 62 

9/22/1983 -- 3.9 3.2 1.9 20.0 72 11/11/1983 -- 2.5 3.2 1.7 6.5 61 

9/23/1983 -- 1.7 2.8 1.7 18.0 71 11/12/1983 -- 2.2 3.1 1.7 7.0 61 

9/24/1983 -- 1.2 2.6 1.6 17.0 71 11/13/1983 -- 2.1 2.8 1.6 6.7 61 

9/25/1983 -- 1.0 2.2 1.6 15.0 70 11/14/1983 -- 2.0 2.6 1.6 6.9 60 

9/26/1983 -- .7 2.2 1.6 14.0 69 11/15/1983 -- 1.6 2.0 1.4 5.6 60 

9/27/1983 -- .6 2.0 1.6 13.0 68 11/16/1983 -- 1.8 2.0 1.4 5.2 59 

9/28/1983 -- .4 1.9 1.6 12.0 66 11/17/1983 -- 2.0 2.0 1.4 5.2 59 

9/29/1983 -- .3 1.6 1.7 11.0 66 11/18/1983 -- 1.7 2.0 1.4 5.2 59 

9/30/1983 -- .2 1.5 1.6 9.8 64 11/19/1983 -- 1.7 1.9 1.4 4.9 59 

10/1/1983 -- .2 1.5 1.6 9.2 63 11/20/1983 -- 1.5 1.6 1.4 4.3 59 

10/2/1983 -- .1 1.4 1.5 8.7 63 11/21/1983 -- 1.5 1.6 1.4 4.3 58 

10/3/1983 -- .1 1.2 1.4 8.6 62 11/22/1983 -- 1.5 1.8 1.4 4.6 58 

10/4/1983 -- .1 1.1 1.4 8.2 62 11/23/1983 -- 2.2 2.0 1.4 5.2 57 

10/5/1983 -- .1 1.1 1.4 7.8 61 11/24/1983 -- 1.2 1.6 1.2 3.8 56 

10/6/1983 -- 0 1.0 1.3 7.5 62 11/25/1983 -- 1.4 1.6 1.0 3.8 55 

10/7/1983 -- 0 1.0 1.3 7.5 60 11/26/1983 -- 1.5 1.6 1.0 4.1 55 

10/8/1983 -- .1 1.0 1.3 7.8 59 11/27/1983 -- 2.2 1.9 1.3 5.0 55 

10/9/1983 -- 33.0 11.0 4.2 26.0 62 11/28/1983 -- 1.7 1.3 1.0 4.2 54 

10/10/1983 -- 2.0 3.7 2.5 21.0 64 11/29/1983 -- 1.5 1.3 1.0 3.8 54 
80 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

11/30/1983 -- 1.6 1.3 1.0 4.7 54 1/19/1984 -- 0.6 1.5 1.0 4.8 43 

12/1/1983 -- 1.5 1.2 .9 4.3 53 1/20/1984 -- .6 1.5 1.0 4.8 43 

12/2/1983 -- 1.5 1.4 .9 4.6 53 1/21/1984 -- .6 1.5 1.0 4.8 43 

12/3/1983 -- 12.0 12.0 1.9 8.4 54 1/22/1984 -- .8 1.6 1.1 5.3 43 

12/4/1983 -- 1.5 3.6 1.2 7.9 55 1/23/1984 -- 1.0 2.0 1.2 6.2 43 

12/5/1983 -- 1.4 3.2 1.2 7.6 54 1/24/1984 -- .8 1.8 1.2 5.6 43 

12/6/1983 -- 1.2 2.2 1.1 6.5 54 1/25/1984 -- .8 1.7 1.2 5.2 43 

12/7/1983 -- 1.0 2.0 1.0 6.1 53 1/26/1984 -- .7 1.6 1.1 5.1 43 

12/8/1983 -- 1.0 2.0 1.0 5.6 53 1/27/1984 -- .7 1.5 1.1 4.8 42 

12/9/1983 -- .9 2.0 1.0 5.9 52 1/28/1984 -- .6 1.5 1.1 5.0 42 

12/10/1983 -- .9 2.2 1.0 6.1 52 1/29/1984 -- .6 1.5 1.1 4.8 42 

12/11/1983 -- .9 1.9 1.0 5.9 51 1/30/1984 -- .6 1.2 1.0 4.8 42 

12/12/1983 -- .9 1.8 1.0 5.1 51 1/31/1984 -- .6 1.1 1.0 4.8 41 

12/13/1983 -- .9 1.7 1.1 5.5 51 2/1/1984 -- .7 1.1 1.0 4.8 41 

12/14/1983 -- .8 1.6 1.0 5.2 50 2/2/1984 -- .7 1.2 1.1 5.1 41 

12/15/1983 -- .8 1.6 1.0 5.2 50 2/3/1984 -- .8 1.2 1.1 4.9 40 

12/16/1983 -- .8 1.5 1.0 5.2 50 2/4/1984 -- .9 1.2 1.0 4.8 40 

12/17/1983 -- .7 1.5 1.0 5.2 49 2/5/1984 -- .7 1.2 1.0 4.6 40 

12/18/1983 -- .7 1.4 1.0 5.2 49 2/6/1984 -- .6 1.1 1.0 4.3 39 

12/19/1983 -- .8 1.3 .9 5.2 48 2/7/1984 -- .6 1.0 1.0 4.3 39 

12/20/1983 -- .9 1.3 .9 5.2 48 2/8/1984 -- .5 .9 1.0 4.4 39 

12/21/1983 -- .9 1.3 .9 5.2 48 2/9/1984 -- 1.2 1.1 1.2 5.2 38 

12/22/1983 -- .6 1.1 .9 5.0 47 2/10/1984 -- 1.0 1.1 1.2 4.9 38 

12/23/1983 -- .6 1.2 .9 4.8 47 2/11/1984 -- 1.0 1.0 1.1 5.0 38 

12/24/1983 -- .6 1.0 .9 4.5 47 2/12/1984 -- .9 1.0 1.1 4.8 37 

12/25/1983 -- .5 1.0 1.0 4.3 46 2/13/1984 -- .9 .9 1.0 4.1 37 

12/26/1983 -- .6 1.0 1.0 4.3 46 2/14/1984 -- .8 .9 .9 3.8 36 

12/27/1983 -- .5 1.0 1.0 4.8 46 2/15/1984 -- .8 .9 .9 4.2 36 

12/28/1983 -- .5 1.1 1.0 5.1 45 2/16/1984 -- .7 .8 .9 4.2 36 

12/29/1983 -- .4 .9 .9 4.2 45 2/17/1984 -- .7 .8 1.0 4.0 35 

12/30/1983 -- .5 .9 .9 3.8 44 2/18/1984 -- 1.0 .9 1.0 4.5 35 

12/31/1983 -- .5 .9 .9 4.1 44 2/19/1984 -- .9 .6 .9 4.2 33 

1/1/1984 -- .5 .9 .9 4.4 44 2/20/1984 -- .8 .6 1.0 3.8 34 

1/2/1984 -- .5 1.0 .9 4.6 43 2/21/1984 -- .7 .6 1.0 3.8 34 

1/3/1984 -- .6 1.0 .9 4.3 43 2/22/1984 -- .7 .6 .9 3.8 33 

1/4/1984 -- .7 1.0 .9 4.3 43 2/23/1984 -- .6 .6 .9 4.3 33 

1/5/1984 -- .8 .9 .8 4.9 43 2/24/1984 -- .6 .5 .8 3.8 33 

1/6/1984 -- .9 .9 .8 4.8 43 2/25/1984 -- .4 .5 .9 3.2 33 

1/7/1984 -- .9 .8 .7 4.3 43 2/26/1984 -- .6 .8 2.1 6.1 34 

1/8/1984 -- 4.8 1.8 .9 4.7 43 2/27/1984 -- .2 .4 1.2 3.2 34 

1/9/1984 -- 5.9 6.3 2.0 7.8 47 2/28/1984 -- .2 .4 1.2 2.7 34 

1/10/1984 -- .7 1.8 1.1 4.8 46 2/29/1984 -- .3 .4 1.2 3.2 34 

1/11/1984 -- .7 1.6 1.0 4.3 46 3/1/1984 -- .3 .4 1.2 4.3 34 

1/12/1984 -- .8 1.6 1.0 5.2 45 3/2/1984 -- .3 .4 1.2 4.3 34 

1/13/1984 -- .8 1.6 1.0 4.9 45 3/3/1984 -- .3 .4 1.2 4.3 34 

1/14/1984 -- .9 1.6 1.0 4.8 44 3/4/1984 -- 1.0 .6 2.9 4.3 34 

1/15/1984 -- .7 1.6 1.0 4.8 44 3/5/1984 -- .3 .6 3.4 14.0 34 

1/16/1984 -- .8 1.6 1.0 5.2 44 3/6/1984 -- .2 .5 1.9 9.8 34 

1/17/1984 -- .8 1.6 1.0 5.2 44 3/7/1984 -- .2 .4 1.6 8.2 34 

1/18/1984 -- .7 1.6 1.0 5.2 43 3/8/1984 -- .2 .4 1.4 7.9 34 
Appendix 2 81 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

3/9/1984 -- 0.2 0.4 1.3 6.5 34 4/28/1984 -- 0 0.1 0.4 1.7 30 

3/10/1984 -- .2 .4 1.3 6.5 34 4/29/1984 -- .1 .1 .4 2.0 30 

3/11/1984 -- .3 .4 1.3 6.1 34 4/30/1984 -- 0 .1 .3 1.0 30 

3/12/1984 -- 1.7 .8 1.6 6.1 34 5/1/1984 -- .1 .1 .3 1.5 30 

3/13/1984 -- .3 .4 1.3 5.6 34 5/2/1984 -- .1 .1 .3 2.7 30 

3/14/1984 -- .3 .5 1.3 5.6 34 5/3/1984 -- .1 .1 .3 2.9 30 

3/15/1984 -- .3 .5 1.3 5.2 34 5/4/1984 -- 0 .1 .3 1.8 30 

3/16/1984 -- .5 .5 1.3 5.2 34 5/5/1984 -- 0 .1 .3 1.8 30 

3/17/1984 -- .4 .5 1.2 5.2 34 5/6/1984 -- 0 .1 .3 2.3 30 

3/18/1984 -- .6 .5 1.2 5.2 34 5/7/1984 -- 0 0 .2 3.0 30 

3/19/1984 -- .4 .5 1.3 6.1 34 5/8/1984 -- 0 0 .2 1.8 29 

3/20/1984 -- .3 .4 1.2 5.2 34 5/9/1984 -- 0 0 .2 1.3 29 

3/21/1984 -- .2 .4 1.2 4.8 34 5/10/1984 -- 0 0 .2 1.5 29 

3/22/1984 -- .3 .4 1.2 5.2 34 5/11/1984 -- 0 0 .2 1.5 29 

3/23/1984 -- .4 .5 1.3 5.6 34 5/12/1984 -- 0 0 .2 1.6 29 

3/24/1984 -- .3 .5 1.2 4.8 34 5/13/1984 -- 0 0 .2 1.6 29 

3/25/1984 -- .3 .5 1.0 4.8 34 5/14/1984 -- 0 0 .3 1.6 28 

3/26/1984 -- .4 .5 1.0 4.8 34 5/15/1984 -- 0 0 .2 2.0 27 

3/27/1984 -- .4 .5 1.0 4.8 34 5/16/1984 -- 0 0 .2 2.6 28 

3/28/1984 -- .5 .3 1.0 4.8 34 5/17/1984 -- 0 0 .2 3.7 28 

3/29/1984 -- .5 .3 .9 4.3 34 5/18/1984 -- .1 0 .2 4.1 29 

3/30/1984 -- .4 .3 .9 4.3 33 5/19/1984 -- .1 0 .1 5.8 29 

3/31/1984 -- .5 .3 1.0 4.8 33 5/20/1984 -- 0 0 .1 4.1 29 

4/1/1984 -- .4 .3 .9 4.8 33 5/21/1984 -- 0 0 .1 3.2 29 

4/2/1984 -- .4 .4 1.0 4.8 33 5/22/1984 -- 0 0 .1 3.4 28 

4/3/1984 -- .5 .4 .9 4.3 33 5/23/1984 -- 0 0 0 3.2 27 

4/4/1984 -- .4 .3 .8 3.2 32 5/24/1984 -- 0 0 0 2.3 27 

4/5/1984 -- .6 .3 .8 3.2 32 5/25/1984 -- 0 0 0 2.2 27 

4/6/1984 -- .5 .3 .8 3.8 33 5/26/1984 -- 0 0 0 2.7 28 

4/7/1984 -- .6 .3 .8 4.7 33 5/27/1984 -- 0 0 0 2.5 28 

4/8/1984 -- .5 .3 .8 4.7 33 5/28/1984 -- 0 0 0 5.0 28 

4/9/1984 -- .4 .3 .7 3.8 32 5/29/1984 -- 0 0 0 3.7 28 

4/10/1984 -- .4 .3 .7 4.3 32 5/30/1984 -- 0 0 0 3.0 28 

4/11/1984 -- .3 .2 .7 3.8 32 5/31/1984 -- 0 0 0 2.3 28 

4/12/1984 -- .3 .2 .6 3.2 32 6/1/1984 -- 0 0 0 2.6 27 

4/13/1984 -- .3 .2 .6 2.7 32 6/2/1984 -- 0 0 0 2.2 27 

4/14/1984 -- .3 .2 .6 2.6 32 6/3/1984 -- 0 0 0 2.8 28 

4/15/1984 -- .3 .2 .6 2.7 31 6/4/1984 -- 0 0 0 3.8 28 

4/16/1984 -- .3 .2 .5 2.2 31 6/5/1984 -- 7.3 .1 0 7.5 28 

4/17/1984 -- .3 .1 .5 2.2 31 6/6/1984 -- 0 0 0 5.9 29 

4/18/1984 -- .3 .1 .6 2.8 31 6/7/1984 -- 0 0 0 7.8 29 

4/19/1984 -- .3 .1 .6 3.8 31 6/8/1984 -- 0 0 0 11.0 28 

4/20/1984 -- .2 .1 .6 4.0 31 6/9/1984 -- 0 0 0 10.0 28 

4/21/1984 -- .2 .1 .5 3.7 31 6/10/1984 -- 0 0 0 9.2 28 

4/22/1984 -- .2 .1 .4 2.7 31 6/11/1984 -- 0 0 0 7.9 28 

4/23/1984 -- .1 .1 .4 2.2 31 6/12/1984 -- 0 0 0 8.2 28 

4/24/1984 -- .1 .1 .4 2.6 31 6/13/1984 -- 0 0 0 7.4 28 

4/25/1984 -- .1 .1 .4 2.7 31 6/14/1984 -- 0 0 0 6.0 28 

4/26/1984 -- .2 .1 .4 1.7 31 6/15/1984 -- 0 0 0 5.6 27 

4/27/1984 -- .1 .1 .4 1.8 30 6/16/1984 -- 0 0 0 5.0 27 
82 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/17/1984 -- 0 0 0 4.5 27 8/6/1984 -- 0 0 0 0.1 25 

6/18/1984 -- 0 0 0 4.6 27 8/7/1984 -- 0 0 0 .1 26 

6/19/1984 -- 0 0 0 3.7 27 8/8/1984 -- 0 0 0 .1 26 

6/20/1984 -- 0 0 0 3.1 27 8/9/1984 -- 0 0 0 .1 26 

6/21/1984 -- 0 0 0 2.4 27 8/10/1984 -- 0 0 0 .1 25 

6/22/1984 -- 0 0 0 2.5 27 8/11/1984 -- 0 0 0 .1 25 

6/23/1984 -- 0 0 0 2.2 27 8/12/1984 -- 0 0 0 .1 25 

6/24/1984 -- 0 0 0 2.3 27 8/13/1984 -- 0 0 0 .1 25 

6/25/1984 -- 0 0 0 1.5 27 8/14/1984 -- .1 0 0 .1 25 

6/26/1984 -- 0 0 0 1.3 27 8/15/1984 -- 0 0 0 .2 27 

6/27/1984 -- 0 0 0 1.6 27 8/16/1984 -- 0 0 0 .1 26 

6/28/1984 -- 0 .1 0 1.7 27 8/17/1984 -- 0 0 0 .1 26 

6/29/1984 -- 0 0 0 2.1 27 8/18/1984 -- 0 0 0 .1 26 

6/30/1984 -- 0 0 0 2.7 27 8/19/1984 -- 0 0 0 .1 26 

7/1/1984 -- 0 0 0 2.3 27 8/20/1984 -- 0 0 0 0 26 

7/2/1984 -- 0 0 0 1.5 27 8/21/1984 -- 0 0 0 0 26 

7/3/1984 -- 0 0 0 1.5 27 8/22/1984 -- 0 0 0 0 25 

7/4/1984 -- 0 0 0 1.5 27 8/23/1984 -- 0 0 0 0 25 

7/5/1984 -- 0 0 0 1.6 27 8/24/1984 -- 0 0 0 0 25 

7/6/1984 -- 0 0 0 1.6 26 8/25/1984 -- 0 0 0 .1 25 

7/7/1984 -- 0 0 0 1.6 26 8/26/1984 -- 0 0 0 .1 25 

7/8/1984 -- 0 0 0 1.8 26 8/27/1984 -- 0 0 0 .1 25 

7/9/1984 -- 0 0 0 1.6 26 8/28/1984 -- 0 0 0 .2 25 

7/10/1984 -- 0 0 0 1.6 26 8/29/1984 -- 0 0 0 .2 25 

7/11/1984 -- 0 0 0 1.3 26 8/30/1984 -- 0 0 0 .2 25 

7/12/1984 -- 0 0 0 1.1 26 8/31/1984 -- 0 0 0 .2 25 

7/13/1984 -- 0 0 0 1.2 26 9/1/1984 -- 0 0 0 .2 25 

7/14/1984 -- 0 0 0 .9 26 9/2/1984 -- 0 0 0 .2 25 

7/15/1984 -- 0 0 0 .9 26 9/3/1984 -- 0 0 0 .2 25 

7/16/1984 -- 0 0 0 .6 26 9/4/1984 -- 0 0 0 .2 26 

7/17/1984 -- 0 0 0 .4 26 9/5/1984 -- 0 0 0 .1 26 

7/18/1984 -- 0 0 0 .4 26 9/6/1984 -- 0 0 0 .1 26 

7/19/1984 -- 0 0 0 .3 26 9/7/1984 -- 0 0 0 .1 25 

7/20/1984 -- 0 0 0 .2 26 9/8/1984 -- 0 0 0 .1 25 

7/21/1984 -- 0 0 0 .1 26 9/9/1984 -- 0 0 0 .1 25 

7/22/1984 -- 0 0 0 .2 26 9/10/1984 -- 0 0 0 .1 25 

7/23/1984 -- 0 0 0 .1 26 9/11/1984 -- 0 0 0 .1 25 

7/24/1984 -- .1 0 0 .2 26 9/12/1984 -- 0 0 0 .1 25 

7/25/1984 -- 0 0 0 .7 26 9/13/1984 -- 0 0 0 .1 25 

7/26/1984 -- 0 0 0 .8 26 9/14/1984 -- 0 0 0 0 24 

7/27/1984 -- 0 0 0 2.1 26 9/15/1984 -- 0 0 0 0 24 

7/28/1984 -- 0 0 0 .8 26 9/16/1984 -- 0 0 0 0 24 

7/29/1984 -- 0 0 0 .4 26 9/17/1984 -- 0 0 0 0 24 

7/30/1984 -- 0 0 0 .4 26 9/18/1984 -- 0 0 0 0 24 

7/31/1984 -- 0 0 0 .3 26 9/19/1984 -- 0 0 0 0 24 

8/1/1984 -- 0 0 0 .2 26 9/20/1984 -- 0 0 0 0 24 

8/2/1984 -- 0 0 0 .2 26 9/21/1984 -- 0 0 0 0 24 

8/3/1984 -- 0 0 0 .1 26 9/22/1984 -- 0 0 0 0 24 

8/4/1984 -- 0 0 0 .2 25 9/23/1984 -- 0 0 0 0 24 

8/5/1984 -- 0 0 0 .2 25 9/24/1984 -- 0 0 0 0 25 
Appendix 2 83 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/25/1984 -- 0 0 0 0 25 11/14/1984 -- 1.2 1.1 1.2 15.0 45 

9/26/1984 -- 0 0 0 0 25 11/15/1984 -- 1.2 1.2 1.2 15.0 45 

9/27/1984 -- 0 0 0 0 25 11/16/1984 -- 1.0 1.2 1.1 14.0 45 

9/28/1984 -- 0 0 0 0 24 11/17/1984 -- .7 1.2 .9 14.0 45 

9/29/1984 -- 0 0 0 0 24 11/18/1984 -- 2.3 1.8 1.4 17.0 45 

9/30/1984 -- 0 0 0 0 24 11/19/1984 -- 1.2 1.2 .8 15.0 45 

10/1/1984 -- 0 0 0 0 24 11/20/1984 -- 1.0 1.0 .8 13.0 45 

10/2/1984 -- 0 0 0 0 24 11/21/1984 -- 1.0 1.0 .8 13.0 44 

10/3/1984 -- 0 0 0 0 24 11/22/1984 -- .7 1.0 .6 12.0 44 

10/4/1984 -- 0 0 0 0 24 11/23/1984 -- .9 1.0 .6 10.0 44 

10/5/1984 -- 0 0 0 0 24 11/24/1984 -- 9.5 13.0 2.1 14.0 44 

10/6/1984 -- 0 0 0 0 24 11/25/1984 -- 5.8 15.0 5.1 35.0 44 

10/7/1984 -- 16.0 .1 0 0 26 11/26/1984 -- 1.9 5.2 2.7 28.0 45 

10/8/1984 -- 0 0 0 0 28 11/27/1984 -- 1.4 3.1 2.3 20.0 45 

10/9/1984 -- 0 0 0 0 30 11/28/1984 -- 1.2 2.6 2.2 18.0 46 

10/10/1984 -- 87.0 .1 0 0 32 11/29/1984 -- 1.1 2.8 2.4 18.0 47 

10/11/1984 -- 5.8 0 0 75.0 34 11/30/1984 -- .9 2.9 2.4 19.0 48 

10/12/1984 -- .2 0 0 27.0 34 12/1/1984 -- .9 2.6 2.3 19.0 48 

10/13/1984 -- 53.0 .7 0 18.0 36 12/2/1984 -- .9 2.5 2.2 18.0 48 

10/14/1984 -- 31.0 1.0 .2 26.0 36 12/3/1984 -- .9 2.0 2.1 18.0 48 

10/15/1984 -- 3.7 0 .2 30.0 38 12/4/1984 -- 1.1 2.2 2.3 18.0 48 

10/16/1984 -- 1.3 0 .1 15.0 38 12/5/1984 -- 1.9 3.3 2.3 19.0 48 

10/17/1984 -- .6 0 0 9.4 40 12/6/1984 -- 1.0 2.7 2.1 20.0 49 

10/18/1984 -- .4 0 0 8.3 40 12/7/1984 -- 1.0 2.6 1.9 19.0 49 

10/19/1984 -- .4 0 0 4.1 42 12/8/1984 -- 1.2 2.6 2.0 19.0 50 

10/20/1984 -- 5.8 0 0 3.4 42 12/9/1984 -- 1.2 2.6 2.2 19.0 50 

10/21/1984 -- 98.0 27.0 8.1 169.0 44 12/10/1984 -- 1.0 2.4 2.1 19.0 51 

10/22/1984 -- 36.0 50.0 1.8 55.0 44 12/11/1984 -- 1.2 2.2 2.1 20.0 51 

10/23/1984 -- 29.0 26.0 2.0 56.0 48 12/12/1984 -- 1.6 2.2 2.1 20.0 52 

10/24/1984 -- 23.0 18.0 2.0 57.0 48 12/13/1984 -- 4.0 3.5 2.4 31.0 53 

10/25/1984 -- 18.0 15.0 2.1 78.0 48 12/14/1984 -- 2.1 2.5 2.1 42.0 54 

10/26/1984 -- 16.0 19.0 2.8 46.0 50 12/15/1984 -- 6.5 21.0 2.5 30.0 55 

10/27/1984 -- 13.0 21.0 3.4 43.0 50 12/16/1984 -- 9.2 32.0 9.4 209.0 55 

10/28/1984 -- 9.6 16.0 4.2 82.0 50 12/17/1984 -- 9.2 29.0 7.5 148.0 55 

10/29/1984 -- 7.8 11.0 4.5 206.0 51 12/18/1984 -- 8.5 39.0 9.9 149.0 55 

10/30/1984 -- 5.5 8.5 4.0 58.0 51 12/19/1984 -- 6.7 33.0 10.0 134.0 56 

10/31/1984 -- 5.7 6.9 3.5 44.0 51 12/20/1984 -- 5.9 31.0 10.0 123.0 56 

11/1/1984 -- 4.5 5.9 3.2 38.0 51 12/21/1984 -- 4.6 26.0 9.9 112.0 56 

11/2/1984 -- 4.1 4.7 2.6 35.0 50 12/22/1984 -- 3.3 20.0 9.4 101.0 56 

11/3/1984 -- 3.8 4.4 2.3 32.0 50 12/23/1984 -- 3.0 19.0 9.3 97.0 57 

11/4/1984 -- 3.2 4.1 2.2 30.0 49 12/24/1984 -- 3.2 19.0 8.9 94.0 57 

11/5/1984 -- 2.4 3.0 1.8 26.0 49 12/25/1984 -- 2.7 14.0 7.9 83.0 57 

11/6/1984 -- 2.3 2.6 1.7 23.0 48 12/26/1984 -- 2.7 14.0 7.8 78.0 57 

11/7/1984 -- 2.0 2.6 1.7 22.0 48 12/27/1984 -- 3.4 14.0 8.2 81.0 57 

11/8/1984 -- 2.0 2.6 1.7 21.0 47 12/28/1984 -- 3.3 15.0 8.9 86.0 58 

11/9/1984 -- 1.7 2.4 1.7 20.0 47 12/29/1984 -- 3.2 14.0 8.5 78.0 58 

11/10/1984 -- 1.4 1.7 1.4 18.0 46 12/30/1984 -- 8.6 52.0 19.0 79.0 58 

11/11/1984 -- 1.2 .9 1.2 16.0 46 12/31/1984 -- 27.0 143.0 28.0 440.0 58 

11/12/1984 -- 1.2 .9 1.3 16.0 46 1/1/1985 -- 10.0 44.0 18.0 220.0 60 

11/13/1984 -- 1.1 .9 1.2 16.0 45 1/2/1985 -- 8.7 31.0 18.0 198.0 62 
84 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/3/1985 -- 13.0 41.0 18.0 193.0 64 2/22/1985 -- 4.7 0.9 7.2 67.0 80 

1/4/1985 -- 10.0 45.0 19.0 197.0 68 2/23/1985 -- 71.0 241.0 360.0 1,710.0 85 

1/5/1985 -- 7.1 34.0 18.0 187.0 70 2/24/1985 -- 11.0 47.0 100.0 304.0 89 

1/6/1985 -- 5.3 21.0 17.0 177.0 70 2/25/1985 -- 7.8 27.0 43.0 253.0 90 

1/7/1985 -- 4.4 17.0 16.0 162.0 70 2/26/1985 -- 6.2 18.0 30.0 230.0 90 

1/8/1985 -- 2.4 15.0 15.0 149.0 70 2/27/1985 -- 5.5 15.0 20.0 212.0 88 

1/9/1985 -- 2.0 13.0 14.0 146.0 71 2/28/1985 -- 11.0 39.0 16.0 224.0 88 

1/10/1985 -- 1.5 10.0 13.0 142.0 71 3/1/1985 -- 8.0 34.0 40.0 250.0 87 

1/11/1985 -- 2.1 8.9 13.0 138.0 71 3/2/1985 -- 6.1 21.0 35.0 218.0 86 

1/12/1985 -- 3.0 8.4 13.0 140.0 71 3/3/1985 -- 6.4 17.0 20.0 212.0 85 

1/13/1985 -- 4.5 8.4 13.0 145.0 71 3/4/1985 -- 6.5 15.0 18.0 200.0 84 

1/14/1985 -- 6.5 12.0 14.0 147.0 71 3/5/1985 -- 5.9 11.0 16.0 185.0 83 

1/15/1985 -- 7.4 17.0 16.0 177.0 71 3/6/1985 -- 5.0 11.0 15.0 181.0 82 

1/16/1985 -- 18.0 53.0 20.0 208.0 71 3/7/1985 -- 5.8 10.0 14.0 180.0 81 

1/17/1985 -- 14.0 38.0 19.0 225.0 72 3/8/1985 -- 5.6 9.0 13.0 174.0 80 

1/18/1985 -- 11.0 25.0 18.0 209.0 74 3/9/1985 -- 5.5 8.3 13.0 168.0 80 

1/19/1985 -- 8.6 19.0 17.0 198.0 74 3/10/1985 -- 4.9 7.8 12.0 162.0 80 

1/20/1985 -- 6.0 11.0 15.0 183.0 74 3/11/1985 -- 4.9 7.0 12.0 165.0 80 

1/21/1985 -- 6.4 10.0 15.0 173.0 74 3/12/1985 -- 5.2 5.9 12.0 157.0 80 

1/22/1985 -- 6.3 9.8 15.0 173.0 74 3/13/1985 -- 5.2 5.7 12.0 153.0 80 

1/23/1985 -- 5.7 9.8 15.0 169.0 74 3/14/1985 -- 16.0 36.0 26.0 198.0 80 

1/24/1985 -- 8.1 8.1 14.0 161.0 74 3/15/1985 -- 9.2 15.0 18.0 198.0 80 

1/25/1985 -- 7.1 7.0 14.0 148.0 74 3/16/1985 -- 8.8 15.0 17.0 195.0 80 

1/26/1985 -- 7.0 5.7 13.0 143.0 74 3/17/1985 -- 7.7 13.0 16.0 185.0 80 

1/27/1985 -- 8.7 5.7 13.0 144.0 74 3/18/1985 -- 7.8 11.0 15.0 180.0 80 

1/28/1985 -- 7.3 4.8 12.0 140.0 74 3/19/1985 -- 7.9 11.0 15.0 177.0 80 

1/29/1985 -- 5.3 4.8 12.0 137.0 73 3/20/1985 -- 30.0 83.0 25.0 211.0 80 

1/30/1985 -- 6.5 4.7 12.0 137.0 73 3/21/1985 -- 11.0 32.0 17.0 189.0 80 

1/31/1985 -- 5.2 3.6 11.0 127.0 73 3/22/1985 -- 9.3 27.0 16.0 182.0 80 

2/1/1985 -- 4.3 2.9 11.0 121.0 72 3/23/1985 -- 7.6 23.0 16.0 175.0 80 

2/2/1985 -- 5.8 2.6 11.0 120.0 72 3/24/1985 -- 7.0 21.0 15.0 167.0 80 

2/3/1985 -- 5.0 2.6 11.0 115.0 72 3/25/1985 -- 7.1 18.0 14.0 160.0 80 

2/4/1985 -- 4.5 2.6 11.0 115.0 72 3/26/1985 -- 7.0 17.0 13.0 153.0 80 

2/5/1985 -- 5.4 2.6 11.0 120.0 72 3/27/1985 -- 8.9 20.0 15.0 185.0 80 

2/6/1985 -- 5.3 2.6 10.0 112.0 72 3/28/1985 -- 7.8 17.0 13.0 166.0 81 

2/7/1985 -- 5.5 2.3 9.6 104.0 72 3/29/1985 -- 7.5 16.0 12.0 155.0 81 

2/8/1985 -- 5.4 2.2 9.0 99.0 72 3/30/1985 -- 7.4 15.0 12.0 151.0 81 

2/9/1985 -- 5.9 2.2 9.0 97.0 72 3/31/1985 -- 7.2 13.0 11.0 141.0 81 

2/10/1985 -- 7.4 2.2 9.0 98.0 72 4/1/1985 -- 7.0 12.0 9.9 139.0 81 

2/11/1985 -- 6.3 1.6 8.3 93.0 72 4/2/1985 -- 7.3 11.0 9.6 136.0 81 

2/12/1985 -- 5.8 1.3 8.0 85.0 71 4/3/1985 -- 7.5 10.0 9.2 128.0 81 

2/13/1985 -- 6.0 1.3 8.1 83.0 71 4/4/1985 -- 7.8 9.6 9.0 123.0 81 

2/14/1985 -- 6.0 1.3 7.7 79.0 71 4/5/1985 -- 8.1 8.5 8.7 105.0 80 

2/15/1985 -- 6.1 1.2 7.5 75.0 71 4/6/1985 -- 7.3 7.7 8.1 104.0 80 

2/16/1985 -- 6.2 1.2 7.2 74.0 71 4/7/1985 -- 6.7 7.2 8.0 102.0 80 

2/17/1985 -- 5.9 1.0 7.2 70.0 71 4/8/1985 -- 5.9 6.5 7.5 91.0 80 

2/18/1985 -- 5.1 1.0 7.2 69.0 71 4/9/1985 -- 5.9 6.2 7.3 85.0 80 

2/19/1985 -- 5.0 1.0 7.2 67.0 71 4/10/1985 -- 6.7 7.2 7.0 98.0 80 

2/20/1985 -- 4.9 .9 7.0 66.0 71 4/11/1985 -- 7.1 8.4 7.5 104.0 80 

2/21/1985 -- 4.2 .9 6.9 67.0 75 4/12/1985 -- 3.3 7.3 7.1 96.0 80 
Appendix 2 85 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/13/1985 -- 3.5 6.7 10.0 99.0 80 6/2/1985 -- 0.1 0.3 1.2 10.0 66 

4/14/1985 -- 2.6 8.0 10.0 123.0 80 6/3/1985 -- .1 .3 1.1 9.3 66 

4/15/1985 -- 2.0 5.6 7.2 95.0 80 6/4/1985 -- .1 .3 1.1 9.2 67 

4/16/1985 -- 1.7 3.9 6.6 79.0 80 6/5/1985 -- 13.0 3.2 5.0 14.0 67 

4/17/1985 -- 1.8 3.0 6.3 70.0 80 6/6/1985 -- 123.0 209.0 129.0 2,850.0 68 

4/18/1985 -- 2.0 2.7 5.9 65.0 80 6/7/1985 -- 9.1 17.0 9.1 264.0 68 

4/19/1985 -- 1.7 2.0 5.8 70.0 79 6/8/1985 -- 4.4 8.5 6.8 207.0 69 

4/20/1985 -- 1.5 2.1 5.9 61.0 79 6/9/1985 -- 3.4 5.5 6.1 186.0 69 

4/21/1985 -- 1.5 2.5 6.0 57.0 79 6/10/1985 -- 2.4 4.0 5.6 145.0 70 

4/22/1985 -- 1.2 2.6 5.9 54.0 78 6/11/1985 -- 1.7 3.2 5.2 116.0 70 

4/23/1985 -- 1.0 2.4 5.3 51.0 78 6/12/1985 -- 1.7 2.6 4.8 93.0 70 

4/24/1985 -- .9 2.1 4.9 43.0 78 6/13/1985 -- 1.5 2.4 4.5 83.0 69 

4/25/1985 -- 1.4 2.1 4.7 41.0 78 6/14/1985 -- 1.5 2.2 4.3 74.0 69 

4/26/1985 -- 2.9 3.0 5.7 45.0 77 6/15/1985 -- 1.0 1.9 4.1 59.0 69 

4/27/1985 -- 1.0 2.2 5.0 42.0 77 6/16/1985 -- .7 1.6 4.0 44.0 69 

4/28/1985 -- 3.3 2.5 4.6 40.0 77 6/17/1985 -- 1.0 1.5 3.3 38.0 69 

4/29/1985 -- 1.2 2.2 4.8 41.0 76 6/18/1985 -- 1.4 1.4 3.5 43.0 70 

4/30/1985 -- .8 2.1 4.9 39.0 76 6/19/1985 -- 1.2 1.6 3.8 82.0 70 

5/1/1985 -- .6 1.8 5.0 40.0 76 6/20/1985 -- 1.9 1.4 3.4 42.0 71 

5/2/1985 -- .6 1.6 4.2 37.0 75 6/21/1985 -- 1.6 1.2 3.3 38.0 71 

5/3/1985 -- .5 1.4 3.8 31.0 75 6/22/1985 -- 14.0 28.0 8.0 38.0 72 

5/4/1985 -- .4 1.2 3.5 28.0 75 6/23/1985 -- 33.0 9.1 6.6 300.0 72 

5/5/1985 -- .4 1.2 3.4 27.0 75 6/24/1985 -- 10.0 5.6 5.4 200.0 72 

5/6/1985 -- .4 1.1 3.3 27.0 75 6/25/1985 -- 3.2 4.3 8.5 150.0 72 

5/7/1985 -- .4 1.0 3.1 25.0 74 6/26/1985 -- 2.0 3.6 8.7 120.0 72 

5/8/1985 -- .5 .9 3.0 25.0 74 6/27/1985 -- 1.7 3.1 7.1 100.0 72 

5/9/1985 -- .5 .8 2.9 25.0 74 6/28/1985 -- 1.7 2.7 6.5 90.0 72 

5/10/1985 -- .4 .8 2.9 25.0 73 6/29/1985 -- 1.3 2.2 6.1 85.0 72 

5/11/1985 -- .4 .7 2.7 24.0 73 6/30/1985 -- 1.0 2.0 5.6 80.0 72 

5/12/1985 -- .3 .7 2.7 25.0 72 7/1/1985 -- .9 1.8 5.2 70.0 72 

5/13/1985 -- 5.5 1.0 2.8 26.0 72 7/2/1985 -- .8 1.5 4.8 65.0 71 

5/14/1985 -- 1.4 1.9 3.4 32.0 73 7/3/1985 -- 3.1 1.9 5.6 60.0 71 

5/15/1985 -- .7 1.0 2.7 26.0 73 7/4/1985 -- 4.3 2.9 6.6 100.0 72 

5/16/1985 -- .6 .7 2.7 22.0 73 7/5/1985 -- 1.2 2.2 5.5 90.0 72 

5/17/1985 -- .8 .7 3.1 24.0 72 7/6/1985 -- 1.5 1.6 5.2 80.0 72 

5/18/1985 -- .4 .7 2.7 22.0 72 7/7/1985 -- 1.1 1.3 4.9 75.0 72 

5/19/1985 -- .4 .7 2.5 19.0 71 7/8/1985 -- 1.1 1.2 4.3 70.0 72 

5/20/1985 -- .3 .6 2.5 19.0 71 7/9/1985 -- 1.0 1.2 4.0 65.0 71 

5/21/1985 -- 1.0 .7 2.7 20.0 71 7/10/1985 -- .7 1.1 3.8 60.0 70 

5/22/1985 -- .5 .6 2.5 21.0 70 7/11/1985 -- .5 1.0 3.6 75.0 70 

5/23/1985 -- .4 .6 2.5 22.0 70 7/12/1985 -- .7 1.1 4.3 89.0 70 

5/24/1985 -- .3 .5 2.3 18.0 69 7/13/1985 -- .4 .8 3.4 75.0 70 

5/25/1985 -- .3 .5 2.1 16.0 68 7/14/1985 -- .3 .7 3.2 64.0 69 

5/26/1985 -- .3 .5 1.9 15.0 68 7/15/1985 -- .2 .7 3.0 53.0 69 

5/27/1985 -- .3 .5 1.7 14.0 68 7/16/1985 -- .2 .6 2.7 46.0 68 

5/28/1985 -- .3 .5 1.7 14.0 68 7/17/1985 -- .1 .5 2.5 41.0 68 

5/29/1985 -- .3 .5 1.7 12.0 67 7/18/1985 -- .1 .5 2.3 36.0 68 

5/30/1985 -- .2 .4 1.4 12.0 67 7/19/1985 -- .1 .4 2.1 35.0 68 

5/31/1985 -- .1 .4 1.3 11.0 66 7/20/1985 -- .1 .4 2.1 33.0 67 

6/1/1985 -- .1 .4 1.3 10.0 66 7/21/1985 -- 0 .4 1.8 33.0 67 
86 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

7/22/1985 -- 0 0.4 1.6 31.0 67 9/10/1985 -- 0 0 0.4 3.2 50 

7/23/1985 -- 0 .3 1.4 29.0 66 9/11/1985 -- 0 0 .7 4.0 50 

7/24/1985 -- 0 .3 1.4 26.0 66 9/12/1985 -- 0 .1 1.1 4.2 50 

7/25/1985 -- 0 .3 1.3 24.0 66 9/13/1985 -- 0 0 1.5 8.8 50 

7/26/1985 -- 0 .3 1.3 21.0 65 9/14/1985 -- 3.4 .1 .8 10.0 51 

7/27/1985 -- 0 .3 1.2 19.0 65 9/15/1985 -- 0 0 .6 6.3 51 

7/28/1985 -- 0 .3 1.0 17.0 65 9/16/1985 -- 0 0 .5 4.0 51 

7/29/1985 -- 0 .2 1.0 16.0 65 9/17/1985 -- 0 0 .4 3.4 51 

7/30/1985 -- 0 .2 1.0 15.0 64 9/18/1985 -- 0 0 .4 3.0 50 

7/31/1985 -- 0 .2 .9 15.0 64 9/19/1985 -- 0 0 .4 3.2 50 

8/1/1985 -- 0 .2 .9 13.0 64 9/20/1985 -- 0 0 .3 2.4 49 

8/2/1985 -- 0 .1 .8 12.0 63 9/21/1985 -- 0 0 .3 2.0 48 

8/3/1985 -- 0 .1 .8 11.0 63 9/22/1985 -- 0 0 .3 1.9 48 

8/4/1985 -- 0 .1 .7 10.0 63 9/23/1985 -- 0 0 .3 2.0 47 

8/5/1985 -- 0 .1 .7 11.0 63 9/24/1985 -- 0 0 .2 1.3 47 

8/6/1985 -- 0 .1 .6 11.0 62 9/25/1985 -- 0 0 .2 2.1 46 

8/7/1985 -- 0 .1 .6 10.0 62 9/26/1985 -- 0 0 .2 1.3 46 

8/8/1985 -- 0 .1 .6 9.6 62 9/27/1985 -- 0 0 .2 1.2 45 

8/9/1985 -- 0 .1 .5 9.8 61 9/28/1985 -- 0 0 .3 2.5 45 

8/10/1985 -- 0 .1 .5 8.7 61 9/29/1985 -- 22.0 .5 1.9 8.9 45 

8/11/1985 -- 0 .1 .4 8.2 61 9/30/1985 -- 0 .1 1.0 4.6 45 

8/12/1985 -- 0 0 .4 7.6 61 10/1/1985 -- 0 .1 1.0 3.6 47 

8/13/1985 -- 0 0 .3 8.6 60 10/2/1985 -- 0 .1 .8 3.7 47 

8/14/1985 -- 0 0 .3 11.0 60 10/3/1985 -- 0 0 .6 3.6 46 

8/15/1985 -- 0 0 .3 9.2 60 10/4/1985 -- 0 0 .6 3.3 46 

8/16/1985 -- 0 0 .3 8.0 59 10/5/1985 -- 0 0 .5 3.0 45 

8/17/1985 -- 0 0 .3 5.7 59 10/6/1985 -- 0 0 .5 3.3 45 

8/18/1985 -- 0 0 .3 4.5 59 10/7/1985 -- 0 0 .5 3.5 44 

8/19/1985 -- 0 0 .2 3.5 58 10/8/1985 -- 0 0 .5 3.4 44 

8/20/1985 -- 0 0 .2 3.0 58 10/9/1985 -- 0 0 .5 3.5 43 

8/21/1985 -- 0 0 .2 3.6 57 10/10/1985 -- 0 0 .5 3.7 43 

8/22/1985 -- 0 0 .2 4.1 57 10/11/1985 -- 0 0 .5 3.5 43 

8/23/1985 -- 0 0 .2 3.7 56 10/12/1985 -- 0 0 .5 3.2 42 

8/24/1985 -- 0 0 .2 3.7 56 10/13/1985 -- 0 0 .5 2.9 42 

8/25/1985 -- 0 0 .2 3.3 55 10/14/1985 -- 16.0 .1 .6 3.2 45 

8/26/1985 -- 0 0 .2 3.1 55 10/15/1985 -- 14.0 .5 1.3 21.0 50 

8/27/1985 -- 0 0 .2 3.1 55 10/16/1985 -- .1 .2 1.0 31.0 60 

8/28/1985 -- 0 0 .2 2.9 55 10/17/1985 -- .1 .2 .9 20.0 68 

8/29/1985 -- 0 0 .2 3.2 54 10/18/1985 -- .3 .2 1.1 18.0 72 

8/30/1985 -- 0 0 .2 3.4 54 10/19/1985 -- 46.0 14.0 9.9 123.0 71 

8/31/1985 -- 0 0 .2 3.5 53 10/20/1985 -- 2.4 1.6 6.2 120.0 70 

9/1/1985 -- 0 0 .1 2.2 53 10/21/1985 -- .9 1.2 4.4 49.0 67 

9/2/1985 -- 0 0 .1 3.4 53 10/22/1985 -- .3 1.2 4.1 41.0 65 

9/3/1985 -- 0 0 .1 3.4 52 10/23/1985 -- .2 1.1 3.6 39.0 61 

9/4/1985 -- 0 0 .1 2.8 52 10/24/1985 -- .1 .9 3.3 35.0 60 

9/5/1985 -- 0 0 .2 3.1 52 10/25/1985 -- .1 .9 3.0 30.0 58 

9/6/1985 -- 2.6 0 .4 4.7 51 10/26/1985 -- .1 .8 2.9 29.0 57 

9/7/1985 -- 0 0 .2 2.9 51 10/27/1985 -- 0 .7 2.6 30.0 57 

9/8/1985 -- 0 0 .2 2.0 51 10/28/1985 -- 0 .7 2.5 26.0 56 

9/9/1985 -- 0 0 .1 3.4 51 10/29/1985 -- .1 .6 2.5 25.0 55 
Appendix 2 87 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/30/1985 -- 0.1 0.6 2.5 34.0 55 12/19/1985 -- 4.4 7.8 9.6 145.0 79 

10/31/1985 -- 0 .5 2.3 30.0 55 12/20/1985 -- 4.0 7.3 9.4 141.0 79 

11/1/1985 -- 1.6 .7 2.5 25.0 55 12/21/1985 -- 3.4 6.7 9.0 135.0 79 

11/2/1985 -- 4.5 1.5 3.8 29.0 55 12/22/1985 -- 3.0 6.6 9.0 137.0 79 

11/3/1985 -- .2 .9 2.8 28.0 56 12/23/1985 -- 2.8 6.2 8.7 132.0 79 

11/4/1985 -- .1 .8 2.5 25.0 55 12/24/1985 -- 2.6 5.5 8.2 124.0 79 

11/5/1985 -- .2 .8 2.5 24.0 54 12/25/1985 -- 2.3 4.8 7.6 116.0 79 

11/6/1985 -- .1 .8 2.5 25.0 54 12/26/1985 -- 2.3 4.6 7.5 102.0 79 

11/7/1985 -- .1 .7 2.3 26.0 53 12/27/1985 -- 2.2 4.6 7.5 99.0 79 

11/8/1985 -- .1 .7 2.3 26.0 53 12/28/1985 -- 1.6 4.5 7.2 95.0 79 

11/9/1985 -- .1 .7 2.3 26.0 52 12/29/1985 -- 1.5 4.1 6.9 89.0 78 

11/10/1985 -- 0 .7 2.3 26.0 52 12/30/1985 -- 1.5 4.1 6.9 81.0 78 

11/11/1985 -- 6.5 5.4 4.8 27.0 54 12/31/1985 -- 1.5 3.8 6.7 77.0 78 

11/12/1985 -- .4 1.3 3.3 25.0 57 1/1/1986 -- 1.6 3.4 6.3 71.0 78 

11/13/1985 -- .3 1.2 3.3 20.0 57 1/2/1986 -- 1.6 3.4 6.3 72.0 78 

11/14/1985 -- .1 1.2 3.3 21.0 57 1/3/1986 -- 1.2 3.2 6.1 66.0 78 

11/15/1985 -- .7 1.3 3.6 25.0 57 1/4/1986 -- 1.2 3.0 5.7 61.0 78 

11/16/1985 -- 1.2 1.7 3.5 25.0 57 1/5/1986 -- .9 2.6 5.2 54.0 78 

11/17/1985 -- .6 1.6 3.5 31.0 58 1/6/1986 -- .9 2.6 5.2 53.0 78 

11/18/1985 -- .6 1.6 3.7 30.0 58 1/7/1986 -- .9 2.6 5.2 52.0 78 

11/19/1985 -- 47.0 12.0 5.0 30.0 58 1/8/1986 -- 1.5 2.6 5.2 53.0 78 

11/20/1985 -- 15.0 4.9 4.8 40.0 60 1/9/1986 -- 1.3 2.6 5.2 54.0 78 

11/21/1985 -- 8.0 4.3 4.3 27.0 61 1/10/1986 -- .9 2.6 5.2 49.0 78 

11/22/1985 -- 5.5 3.8 4.3 25.0 62 1/11/1986 -- .9 2.3 4.9 44.0 78 

11/23/1985 -- 4.6 3.7 4.3 24.0 63 1/12/1986 -- .8 2.1 4.6 41.0 78 

11/24/1985 -- 60.0 55.0 7.2 107.0 64 1/13/1986 -- .7 2.0 4.3 37.0 77 

11/25/1985 -- 25.0 38.0 11.0 133.0 67 1/14/1986 -- .5 2.0 4.3 36.0 78 

11/26/1985 -- 20.0 26.0 9.9 112.0 70 1/15/1986 -- .5 1.9 4.1 35.0 78 

11/27/1985 -- 450.0 219.0 68.0 787.0 63 1/16/1986 -- .4 1.9 4.1 33.0 78 

11/28/1985 -- 200.0 76.0 23.0 326.0 54 1/17/1986 -- .4 1.8 4.1 34.0 78 

11/29/1985 -- 80.0 49.0 20.0 263.0 69 1/18/1986 -- .4 1.7 4.1 32.0 77 

11/30/1985 -- 40.0 39.0 19.0 238.0 77 1/19/1986 -- .4 1.6 3.9 29.0 77 

12/1/1985 -- 27.0 28.0 17.0 212.0 82 1/20/1986 -- .4 1.5 3.8 26.0 77 

12/2/1985 -- 20.0 22.0 15.0 190.0 83 1/21/1986 -- .4 1.4 3.8 26.0 77 

12/3/1985 -- 16.0 21.0 15.0 173.0 80 1/22/1986 -- .3 1.2 3.5 24.0 77 

12/4/1985 -- 12.0 19.0 15.0 161.0 77 1/23/1986 -- .3 1.2 3.3 21.0 77 

12/5/1985 -- 10.0 15.0 13.0 187.0 77 1/24/1986 -- .4 1.2 3.3 22.0 77 

12/6/1985 -- 9.0 13.0 13.0 143.0 78 1/25/1986 -- .4 1.2 3.4 21.0 76 

12/7/1985 -- 8.0 12.0 12.0 140.0 78 1/26/1986 -- .4 1.2 3.2 18.0 76 

12/8/1985 -- 7.2 11.0 11.0 132.0 78 1/27/1986 -- .4 1.1 3.1 16.0 76 

12/9/1985 -- 6.5 9.9 11.0 128.0 78 1/28/1986 -- .5 1.1 3.1 16.0 76 

12/10/1985 -- 12.0 11.0 12.0 211.0 77 1/29/1986 -- .5 1.0 3.2 16.0 76 

12/11/1985 -- 18.0 24.0 15.0 409.0 76 1/30/1986 -- .5 1.0 3.1 14.0 75 

12/12/1985 -- 11.0 16.0 13.0 244.0 80 1/31/1986 -- .5 1.0 3.1 15.0 76 

12/13/1985 -- 9.3 13.0 12.0 218.0 79 2/1/1986 -- .6 1.0 3.1 15.0 75 

12/14/1985 -- 8.0 11.0 11.0 196.0 79 2/2/1986 -- .7 1.0 3.1 15.0 75 

12/15/1985 -- 6.9 11.0 11.0 186.0 79 2/3/1986 -- 23.0 4.7 7.4 223.0 77 

12/16/1985 -- 6.5 9.9 11.0 172.0 79 2/4/1986 -- 5.1 4.4 8.2 213.0 79 

12/17/1985 -- 5.4 9.2 11.0 167.0 79 2/5/1986 -- 2.9 2.4 5.8 121.0 80 

12/18/1985 -- 4.7 8.4 9.9 157.0 79 2/6/1986 -- 2.3 2.0 5.4 104.0 78 
88 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

2/7/1986 -- 2.0 2.0 5.2 94.0 78 3/29/1986 -- 0 0.5 1.7 20.0 67 

2/8/1986 -- 1.6 1.8 4.7 89.0 78 3/30/1986 -- 0 .5 1.6 19.0 67 

2/9/1986 -- 1.7 1.7 4.6 87.0 78 3/31/1986 -- 0 .5 1.6 18.0 67 

2/10/1986 -- 1.7 1.7 4.6 87.0 78 4/1/1986 -- 0 .5 1.6 15.0 67 

2/11/1986 -- 1.6 1.7 4.6 82.0 78 4/2/1986 -- 0 .5 1.5 14.0 67 

2/12/1986 -- 1.1 1.6 4.3 80.0 77 4/3/1986 -- 0 .5 1.5 13.0 67 

2/13/1986 -- .9 1.5 4.3 77.0 77 4/4/1986 -- 0 .5 1.6 14.0 66 

2/14/1986 -- .9 1.5 4.4 79.0 76 4/5/1986 -- 0 .5 1.4 12.0 66 

2/15/1986 -- .8 1.4 4.2 77.0 76 4/6/1986 -- .1 .5 1.4 12.0 65 

2/16/1986 -- .8 1.4 4.3 75.0 77 4/7/1986 -- 0 .5 1.4 10.0 65 

2/17/1986 -- .8 1.3 4.3 73.0 75 4/8/1986 -- 0 .5 1.4 9.4 65 

2/18/1986 -- .7 1.2 4.1 70.0 73 4/9/1986 -- .2 .5 1.2 11.0 65 

2/19/1986 -- .7 1.2 3.8 65.0 72 4/10/1986 -- .1 .5 1.2 11.0 64 

2/20/1986 -- .7 1.2 3.5 62.0 71 4/11/1986 -- 0 .5 1.2 11.0 64 

2/21/1986 -- .7 1.1 3.3 58.0 69 4/12/1986 -- 0 .5 1.2 12.0 64 

2/22/1986 -- .8 1.0 3.1 56.0 68 4/13/1986 -- 0 .5 1.1 12.0 64 

2/23/1986 -- .8 1.0 3.1 55.0 73 4/14/1986 -- 0 .4 .9 10.0 64 

2/24/1986 -- .9 1.0 3.1 54.0 74 4/15/1986 -- 0 .4 .7 10.0 64 

2/25/1986 -- 1.0 1.0 3.2 53.0 74 4/16/1986 -- 0 .4 .7 11.0 64 

2/26/1986 -- 1.0 1.0 3.1 51.0 75 4/17/1986 -- 0 .4 .7 10.0 63 

2/27/1986 -- 1.0 .9 3.1 50.0 75 4/18/1986 -- 0 .4 .7 9.6 63 

2/28/1986 -- .9 .9 3.1 46.0 75 4/19/1986 -- 0 .4 .8 9.4 63 

3/1/1986 -- .9 .9 2.9 45.0 74 4/20/1986 -- 0 .3 .7 11.0 62 

3/2/1986 -- .7 .9 3.0 45.0 74 4/21/1986 -- 0 .3 .6 10.0 62 

3/3/1986 -- .7 .9 3.3 48.0 74 4/22/1986 -- 0 .3 .6 12.0 62 

3/4/1986 -- .5 .9 2.9 44.0 74 4/23/1986 -- 0 .3 .6 12.0 62 

3/5/1986 -- .5 .9 2.9 42.0 74 4/24/1986 -- 0 .3 .6 15.0 61 

3/6/1986 -- .5 .9 2.9 42.0 73 4/25/1986 -- 0 .3 .6 11.0 61 

3/7/1986 -- .5 .8 2.7 41.0 73 4/26/1986 -- 0 .3 .5 11.0 60 

3/8/1986 -- .5 .8 2.7 41.0 73 4/27/1986 -- 0 .3 .5 10.0 60 

3/9/1986 -- .4 .8 2.7 39.0 73 4/28/1986 -- 0 .3 .5 11.0 60 

3/10/1986 -- .4 .8 2.7 38.0 73 4/29/1986 -- 0 .2 .6 11.0 60 

3/11/1986 -- .4 .8 2.5 36.0 73 4/30/1986 -- 5.3 .3 .6 11.0 59 

3/12/1986 -- .6 .8 2.5 39.0 73 5/1/1986 -- 59.0 3.2 6.4 26.0 60 

3/13/1986 -- .3 .8 2.3 36.0 72 5/2/1986 -- .1 .7 1.8 38.0 61 

3/14/1986 -- .3 .8 2.3 35.0 72 5/3/1986 -- 0 .6 1.3 21.0 62 

3/15/1986 -- .3 .7 2.1 34.0 72 5/4/1986 -- 0 .5 1.2 17.0 62 

3/16/1986 -- .3 .8 1.9 32.0 72 5/5/1986 -- 0 .5 1.2 16.0 62 

3/17/1986 -- .2 .8 2.0 31.0 72 5/6/1986 -- 0 .5 1.1 15.0 61 

3/18/1986 -- .3 .8 2.0 32.0 71 5/7/1986 -- 0 .5 1.2 15.0 61 

3/19/1986 -- .1 .6 1.7 29.0 71 5/8/1986 -- 0 .5 1.2 14.0 60 

3/20/1986 -- .1 .6 1.7 27.0 71 5/9/1986 -- 202.0 147.0 47.0 242.0 60 

3/21/1986 -- .1 .6 1.7 26.0 70 5/10/1986 -- 41.0 43.0 16.0 1,500.0 62 

3/22/1986 -- .1 .6 1.7 29.0 70 5/11/1986 -- 16.0 10.0 8.0 143.0 64 

3/23/1986 -- .1 .6 1.7 26.0 70 5/12/1986 -- 7.9 7.1 7.0 105.0 67 

3/24/1986 -- .1 .6 1.7 26.0 69 5/13/1986 -- 4.5 5.8 6.5 76.0 69 

3/25/1986 -- .1 .6 1.7 26.0 69 5/14/1986 -- 3.0 5.0 6.3 68.0 71 

3/26/1986 -- .1 .6 1.7 24.0 69 5/15/1986 -- 119.0 117.0 9.0 84.0 73 

3/27/1986 -- .1 .6 1.8 23.0 68 5/16/1986 -- 31.0 36.0 7.3 78.0 76 

3/28/1986 -- .1 .6 1.7 21.0 68 5/17/1986 -- 137.0 186.0 44.0 546.0 78 
Appendix 2 89 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

5/18/1986 -- 46.0 89.0 18.0 263.0 79 7/7/1986 -- 0.4 1.2 3.8 36.0 80 

5/19/1986 -- 29.0 44.0 16.0 160.0 79 7/8/1986 -- .3 1.3 3.5 35.0 79 

5/20/1986 -- 21.0 28.0 15.0 141.0 79 7/9/1986 -- .2 .9 3.4 33.0 78 

5/21/1986 -- 16.0 21.0 14.0 132.0 79 7/10/1986 -- .2 .8 3.2 31.0 78 

5/22/1986 -- 13.0 17.0 13.0 116.0 79 7/11/1986 -- .2 .7 2.9 29.0 78 

5/23/1986 -- 9.9 13.0 12.0 112.0 79 7/12/1986 -- .1 .6 2.8 27.0 78 

5/24/1986 -- 8.7 11.0 12.0 102.0 79 7/13/1986 -- .1 .6 2.5 26.0 78 

5/25/1986 -- 7.6 9.0 11.0 95.0 79 7/14/1986 -- .1 .5 2.5 25.0 78 

5/26/1986 -- 8.3 8.9 11.0 121.0 79 7/15/1986 -- .1 .5 2.3 24.0 76 

5/27/1986 -- 6.5 8.9 11.0 119.0 79 7/16/1986 -- .1 .4 2.3 23.0 74 

5/28/1986 -- 5.3 7.5 9.9 102.0 79 7/17/1986 -- 0 .4 2.1 21.0 73 

5/29/1986 -- 4.7 6.4 9.4 101.0 79 7/18/1986 -- 0 .4 2.1 22.0 71 

5/30/1986 -- 5.1 9.1 9.1 115.0 79 7/19/1986 -- 0 .3 2.1 22.0 70 

5/31/1986 -- 9.8 12.0 10.0 103.0 79 7/20/1986 -- 0 .4 2.0 20.0 69 

6/1/1986 -- 18.0 37.0 11.0 109.0 82 7/21/1986 -- 0 .3 1.7 19.0 67 

6/2/1986 -- 11.0 20.0 9.8 112.0 82 7/22/1986 -- 0 .3 1.7 18.0 65 

6/3/1986 -- 8.3 15.0 9.1 101.0 82 7/23/1986 -- 0 .3 1.7 17.0 64 

6/4/1986 -- 10.0 15.0 9.5 104.0 82 7/24/1986 -- 0 .2 1.7 16.0 63 

6/5/1986 -- 7.1 14.0 9.1 103.0 81 7/25/1986 -- 0 .2 1.7 15.0 62 

6/6/1986 -- 5.4 11.0 8.6 89.0 81 7/26/1986 -- 0 .2 1.6 14.0 60 

6/7/1986 -- 15.0 57.0 12.0 133.0 80 7/27/1986 -- 0 .2 1.6 13.0 59 

6/8/1986 -- 13.0 43.0 12.0 137.0 81 7/28/1986 -- 0 .2 1.4 12.0 58 

6/9/1986 -- 18.0 34.0 11.0 138.0 80 7/29/1986 -- 0 .1 1.4 12.0 57 

6/10/1986 -- 9.8 23.0 9.9 114.0 79 7/30/1986 -- 0 .1 1.3 12.0 55 

6/11/1986 -- 8.5 18.0 9.9 122.0 83 7/31/1986 -- 0 .1 1.3 11.0 54 

6/12/1986 -- 15.0 16.0 10.0 350.0 82 8/1/1986 -- 0 .1 1.3 10.0 53 

6/13/1986 -- 9.6 14.0 9.8 200.0 82 8/2/1986 -- 0 .1 1.2 9.5 52 

6/14/1986 -- 7.4 11.0 9.1 143.0 83 8/3/1986 -- 0 .1 1.0 9.5 51 

6/15/1986 -- 6.1 9.2 8.6 139.0 83 8/4/1986 -- 0 0 1.0 8.8 50 

6/16/1986 -- 4.9 7.9 8.3 129.0 75 8/5/1986 -- 0 0 1.0 8.6 50 

6/17/1986 -- 13.0 20.0 14.0 216.0 64 8/6/1986 -- 0 0 1.0 8.5 50 

6/18/1986 -- 6.5 11.0 16.0 153.0 58 8/7/1986 -- 0 0 1.0 7.8 52 

6/19/1986 -- 5.5 10.0 13.0 142.0 53 8/8/1986 -- 0 0 .9 8.2 53 

6/20/1986 -- 3.7 8.4 12.0 127.0 65 8/9/1986 -- 0 0 .9 8.4 55 

6/21/1986 -- 3.0 7.1 11.0 116.0 84 8/10/1986 -- 0 0 .8 6.9 57 

6/22/1986 -- 2.5 6.3 11.0 106.0 84 8/11/1986 -- 0 0 .8 7.9 58 

6/23/1986 -- 2.3 5.7 11.0 94.0 74 8/12/1986 -- 0 0 .8 8.8 59 

6/24/1986 -- 2.7 4.9 11.0 84.0 78 8/13/1986 -- 0 0 .7 7.5 60 

6/25/1986 -- 1.7 4.8 9.9 78.0 84 8/14/1986 -- 0 0 .7 6.8 61 

6/26/1986 -- 1.4 4.0 9.5 73.0 85 8/15/1986 -- 0 0 .6 6.2 62 

6/27/1986 -- 1.0 3.6 8.7 70.0 84 8/16/1986 -- 0 0 .6 5.6 63 

6/28/1986 -- .9 3.2 8.0 64.0 83 8/17/1986 -- 0 0 .6 5.6 63 

6/29/1986 -- .7 2.9 7.4 61.0 84 8/18/1986 -- 0 0 .5 4.9 64 

6/30/1986 -- .7 2.5 6.7 56.0 84 8/19/1986 -- 0 0 .4 4.2 64 

7/1/1986 -- .8 2.3 5.9 53.0 83 8/20/1986 -- 0 0 .4 3.9 64 

7/2/1986 -- .6 2.2 5.6 48.0 83 8/21/1986 -- 0 0 .4 4.4 63 

7/3/1986 -- .5 1.9 5.5 44.0 82 8/22/1986 -- 0 0 .4 4.4 63 

7/4/1986 -- .4 1.7 5.1 41.0 82 8/23/1986 -- 0 0 .4 4.7 62 

7/5/1986 -- .4 1.5 4.7 39.0 81 8/24/1986 -- 0 0 .4 5.2 62 

7/6/1986 -- .4 1.3 4.1 37.0 81 8/25/1986 -- 0 0 .4 5.8 61 
90 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

8/26/1986 -- 0 0 0.4 4.3 61 10/15/1986 -- 5.7 7.0 5.9 57.0 46 

8/27/1986 -- 0 0 .4 3.6 61 10/16/1986 -- 4.4 5.3 5.6 45.0 43 

8/28/1986 -- 0 0 .3 3.4 60 10/17/1986 -- 3.6 4.9 5.1 38.0 64 

8/29/1986 -- 0 0 .3 3.4 60 10/18/1986 -- 3.1 4.2 4.6 34.0 63 

8/30/1986 -- 0 0 .3 2.8 60 10/19/1986 -- 2.6 4.1 4.5 31.0 63 

8/31/1986 -- 0 0 .3 2.7 59 10/20/1986 -- 2.3 3.9 4.3 28.0 62 

9/1/1986 -- 0 0 .3 2.9 58 10/21/1986 -- 4.2 4.3 4.6 28.0 61 

9/2/1986 -- 0 0 .4 3.6 58 10/22/1986 -- 10.0 7.7 5.9 35.0 75 

9/3/1986 -- 0 0 .3 2.6 57 10/23/1986 -- 310.0 516.0 321.0 1,060.0 89 

9/4/1986 -- 0 0 .3 2.2 57 10/24/1986 -- 51.0 110.0 53.0 291.0 95 

9/5/1986 -- 0 0 .4 2.3 57 10/25/1986 -- 27.0 56.0 40.0 218.0 100 

9/6/1986 -- 94.0 9.0 2.8 21.0 58 10/26/1986 -- 22.0 39.0 34.0 182.0 86 

9/7/1986 -- .4 .3 1.2 5.8 58 10/27/1986 -- 15.0 29.0 29.0 156.0 79 

9/8/1986 -- .1 .2 .8 7.4 58 10/28/1986 -- 10.0 22.0 26.0 142.0 76 

9/9/1986 -- 0 .1 .7 8.0 58 10/29/1986 -- 7.4 17.0 23.0 133.0 76 

9/10/1986 -- 0 .1 .6 7.1 59 10/30/1986 -- 5.9 15.0 22.0 121.0 76 

9/11/1986 -- 0 .1 .6 13.0 58 10/31/1986 -- 4.7 13.0 20.0 111.0 76 

9/12/1986 -- 0 .1 .5 8.5 57 11/1/1986 -- 4.1 11.0 18.0 104.0 76 

9/13/1986 -- 0 .1 .6 6.4 57 11/2/1986 -- 4.0 9.4 16.0 98.0 73 

9/14/1986 -- 0 .1 .5 5.4 56 11/3/1986 -- 3.9 9.1 15.0 92.0 72 

9/15/1986 -- 0 .1 .5 4.6 56 11/4/1986 -- 11.0 17.0 21.0 104.0 70 

9/16/1986 -- 0 .1 .5 4.6 55 11/5/1986 -- 4.4 12.0 17.0 106.0 69 

9/17/1986 -- 0 .1 .5 4.6 55 11/6/1986 -- 3.9 9.8 15.0 90.0 67 

9/18/1986 -- 0 .1 .5 4.3 55 11/7/1986 -- 3.5 9.6 15.0 89.0 66 

9/19/1986 -- 9.0 1.0 .5 4.3 54 11/8/1986 -- 3.5 9.5 14.0 84.0 65 

9/20/1986 -- .4 .5 .5 4.4 54 11/9/1986 -- 3.2 8.4 14.0 76.0 63 

9/21/1986 -- 0 .3 .5 4.4 53 11/10/1986 -- 2.7 7.8 13.0 70.0 62 

9/22/1986 -- 0 .3 .5 4.2 53 11/11/1986 -- 2.2 6.9 13.0 66.0 60 

9/23/1986 -- 0 .3 .5 4.0 52 11/12/1986 -- 2.9 6.5 12.0 64.0 77 

9/24/1986 -- 0 .3 .5 3.6 51 11/13/1986 -- 2.5 6.0 12.0 61.0 77 

9/25/1986 -- 0 .2 .5 3.4 51 11/14/1986 -- 2.2 5.9 12.0 59.0 78 

9/26/1986 -- 0 .2 .5 3.4 51 11/15/1986 -- 2.2 5.8 11.0 58.0 78 

9/27/1986 -- 0 .2 .4 3.4 51 11/16/1986 -- 2.1 5.5 11.0 56.0 78 

9/28/1986 -- 0 .1 .4 3.5 51 11/17/1986 -- 1.9 5.0 10.0 54.0 72 

9/29/1986 -- 0 .1 .4 3.6 50 11/18/1986 -- 1.8 4.6 8.9 51.0 72 

9/30/1986 -- 0 .1 .4 3.4 50 11/19/1986 -- 1.6 4.3 8.1 47.0 72 

10/1/1986 -- 0 .1 .4 3.4 49 11/20/1986 -- 1.6 3.9 7.7 45.0 71 

10/2/1986 -- 0 .1 .4 4.1 49 11/21/1986 -- 1.6 3.7 7.2 43.0 71 

10/3/1986 -- 0 .1 .4 3.5 48 11/22/1986 -- 1.5 3.7 7.4 44.0 72 

10/4/1986 -- 0 .1 .4 3.4 48 11/23/1986 -- 3.1 3.8 7.3 43.0 76 

10/5/1986 -- 0 .1 .4 3.6 48 11/24/1986 -- 7.3 5.1 7.6 46.0 77 

10/6/1986 -- 5.7 .4 .6 4.3 48 11/25/1986 -- 9.2 13.0 14.0 98.0 79 

10/7/1986 -- .2 .3 .5 4.5 48 11/26/1986 -- 2.8 6.3 9.0 72.0 78 

10/8/1986 -- 0 .3 .5 4.1 48 11/27/1986 -- 2.1 5.3 8.5 60.0 78 

10/9/1986 -- 0 .3 .4 3.4 48 11/28/1986 -- 2.2 5.0 8.1 57.0 77 

10/10/1986 -- 0 .3 .4 3.4 47 11/29/1986 -- 2.0 4.6 7.7 54.0 77 

10/11/1986 -- 6.2 .6 .7 7.7 47 11/30/1986 -- 1.9 4.4 7.7 53.0 76 

10/12/1986 -- 149.0 201.0 68.0 394.0 47 12/1/1986 -- 1.8 3.9 7.5 50.0 76 

10/13/1986 -- 20.0 28.0 9.3 156.0 48 12/2/1986 -- 1.6 3.6 7.3 47.0 75 

10/14/1986 -- 8.5 11.0 7.2 83.0 52 12/3/1986 -- 1.7 3.3 7.0 46.0 74 
Appendix 2 91 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/4/1986 -- 1.7 3.1 7.0 45.0 73 1/23/1987 -- 1.1 5.9 12.0 114.0 78 

12/5/1986 -- 1.7 2.8 7.0 43.0 73 1/24/1987 -- 1.1 5.8 12.0 111.0 79 

12/6/1986 -- 1.8 2.6 6.7 44.0 72 1/25/1987 -- .9 4.7 12.0 104.0 79 

12/7/1986 -- 2.0 2.6 7.0 47.0 72 1/26/1987 -- .9 4.6 11.0 99.0 80 

12/8/1986 -- 2.2 2.7 7.0 47.0 72 1/27/1987 -- 1.0 4.4 10.0 96.0 80 

12/9/1986 -- 3.2 3.6 8.3 49.0 72 1/28/1987 -- 1.1 4.3 10.0 94.0 81 

12/10/1986 -- 19.0 14.0 14.0 81.0 72 1/29/1987 -- 1.2 4.0 10.0 91.0 81 

12/11/1986 -- 12.0 13.0 16.0 167.0 73 1/30/1987 -- 1.2 3.6 9.2 84.0 82 

12/12/1986 -- 8.6 10.0 14.0 138.0 73 1/31/1987 -- 1.2 3.4 9.2 80.0 82 

12/13/1986 -- 6.6 9.1 14.0 131.0 72 2/1/1987 -- 1.2 3.4 9.3 81.0 83 

12/14/1986 -- 37.0 32.0 23.0 155.0 73 2/2/1987 -- 1.2 3.2 8.9 76.0 80 

12/15/1986 -- 57.0 85.0 40.0 261.0 76 2/3/1987 -- 1.1 3.1 8.9 73.0 80 

12/16/1986 -- 31.0 49.0 34.0 238.0 78 2/4/1987 -- 1.3 3.0 8.5 71.0 80 

12/17/1986 -- 22.0 37.0 32.0 231.0 75 2/5/1987 -- 1.0 2.8 8.5 68.0 80 

12/18/1986 -- 42.0 57.0 36.0 252.0 74 2/6/1987 -- .8 2.7 8.0 70.0 79 

12/19/1986 -- 26.0 41.0 33.0 246.0 74 2/7/1987 -- .8 2.4 7.7 66.0 79 

12/20/1986 -- 18.0 31.0 31.0 234.0 74 2/8/1987 -- .6 2.3 7.3 62.0 79 

12/21/1986 -- 15.0 25.0 29.0 224.0 71 2/9/1987 -- .5 2.1 6.8 58.0 78 

12/22/1986 -- 336.0 361.0 231.0 1,860.0 70 2/10/1987 -- .4 2.1 6.7 56.0 78 

12/23/1986 -- 110.0 142.0 111.0 1,480.0 111 2/11/1987 -- .5 2.1 6.6 56.0 78 

12/24/1986 -- 50.0 78.0 75.0 806.0 111 2/12/1987 -- .4 2.0 6.5 54.0 77 

12/25/1986 -- 30.0 52.0 60.0 615.0 97 2/13/1987 -- .3 1.9 6.7 52.0 77 

12/26/1986 -- 18.0 40.0 50.0 505.0 78 2/14/1987 -- .3 1.9 6.2 51.0 77 

12/27/1986 -- 11.0 31.0 43.0 410.0 78 2/15/1987 -- .7 2.1 6.5 53.0 76 

12/28/1986 -- 7.4 25.0 38.0 338.0 78 2/16/1987 -- .1 1.6 5.7 47.0 76 

12/29/1986 -- 5.6 24.0 35.0 311.0 80 2/17/1987 -- .1 1.5 5.4 44.0 76 

12/30/1986 -- 4.1 19.0 32.0 285.0 80 2/18/1987 -- .1 1.5 5.3 43.0 75 

12/31/1986 -- 3.0 17.0 29.0 273.0 79 2/19/1987 -- .2 1.6 5.4 43.0 75 

1/1/1987 -- 2.2 14.0 26.0 260.0 79 2/20/1987 -- .6 2.6 6.8 64.0 74 

1/2/1987 -- 1.8 12.0 24.0 250.0 79 2/21/1987 -- .1 2.2 6.0 63.0 74 

1/3/1987 -- 1.5 11.0 23.0 236.0 79 2/22/1987 -- .1 1.8 5.4 52.0 73 

1/4/1987 -- 1.2 10.0 21.0 217.0 78 2/23/1987 -- .1 1.6 4.9 47.0 73 

1/5/1987 -- 1.2 9.4 20.0 206.0 78 2/24/1987 -- 1.9 4.7 8.3 76.0 74 

1/6/1987 -- 1.1 8.9 19.0 198.0 78 2/25/1987 -- 8.8 16.0 14.0 92.0 78 

1/7/1987 -- 1.0 8.1 18.0 189.0 77 2/26/1987 -- 39.0 60.0 39.0 350.0 85 

1/8/1987 -- .8 7.5 17.0 181.0 77 2/27/1987 -- 22.0 40.0 28.0 268.0 94 

1/9/1987 -- 3.5 9.2 18.0 179.0 77 2/28/1987 -- 25.0 45.0 28.0 259.0 100 

1/10/1987 -- .9 7.5 15.0 164.0 76 3/1/1987 -- 13.0 24.0 24.0 233.0 99 

1/11/1987 -- .8 6.6 14.0 152.0 75 3/2/1987 -- 11.0 19.0 23.0 219.0 98 

1/12/1987 -- .9 6.2 14.0 147.0 75 3/3/1987 -- 9.0 15.0 21.0 204.0 99 

1/13/1987 -- .9 5.7 13.0 144.0 74 3/4/1987 -- 7.5 13.0 20.0 188.0 103 

1/14/1987 -- 1.0 5.6 13.0 143.0 74 3/5/1987 -- 6.6 11.0 18.0 173.0 109 

1/15/1987 -- 1.1 5.4 12.0 140.0 74 3/6/1987 -- 6.2 11.0 17.0 164.0 110 

1/16/1987 -- .9 5.2 12.0 137.0 74 3/7/1987 -- 5.6 9.7 16.0 155.0 109 

1/17/1987 -- 7.3 13.0 19.0 144.0 75 3/8/1987 -- 5.4 9.1 15.0 148.0 109 

1/18/1987 -- 2.6 9.9 16.0 142.0 76 3/9/1987 -- 5.0 8.4 15.0 145.0 109 

1/19/1987 -- 1.8 8.2 14.0 135.0 76 3/10/1987 -- 5.2 7.7 14.0 143.0 109 

1/20/1987 -- 1.4 7.5 14.0 127.0 77 3/11/1987 -- 6.9 9.7 15.0 155.0 109 

1/21/1987 -- 1.3 7.0 14.0 125.0 77 3/12/1987 -- 5.0 8.1 13.0 144.0 108 

1/22/1987 -- 1.1 6.3 13.0 121.0 78 3/13/1987 -- 4.6 7.8 12.0 140.0 108 
92 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

3/14/1987 -- 4.7 7.4 12.0 138.0 108 5/3/1987 -- 0 0.7 2.2 28.0 98 

3/15/1987 -- 4.5 7.1 11.0 135.0 108 5/4/1987 -- .6 .8 2.4 30.0 98 

3/16/1987 -- 4.3 6.6 11.0 132.0 108 5/5/1987 -- .3 .6 2.3 30.0 98 

3/17/1987 -- 7.2 9.9 16.0 247.0 107 5/6/1987 -- .2 .6 2.0 28.0 97 

3/18/1987 -- 3.3 7.1 12.0 187.0 107 5/7/1987 -- .1 .5 2.0 26.0 97 

3/19/1987 -- 3.2 6.5 11.0 165.0 107 5/8/1987 -- .3 .5 2.0 28.0 97 

3/20/1987 -- 3.2 6.2 11.0 158.0 107 5/9/1987 -- .2 .5 1.9 29.0 96 

3/21/1987 -- 3.0 5.9 10.0 152.0 107 5/10/1987 -- .1 .5 1.7 25.0 96 

3/22/1987 -- 3.3 5.8 10.0 148.0 106 5/11/1987 -- .1 .5 1.7 25.0 96 

3/23/1987 -- 3.5 5.1 9.7 146.0 106 5/12/1987 -- .2 .5 1.7 24.0 95 

3/24/1987 -- 3.1 4.7 8.9 142.0 106 5/13/1987 -- .1 .4 1.7 21.0 95 

3/25/1987 -- 2.9 4.8 8.5 140.0 106 5/14/1987 -- .1 .4 1.6 20.0 95 

3/26/1987 -- 2.8 4.6 8.1 138.0 106 5/15/1987 -- .2 .4 1.5 21.0 94 

3/27/1987 -- 2.9 4.6 7.4 133.0 105 5/16/1987 -- 1.0 .5 2.3 22.0 96 

3/28/1987 -- 4.4 4.6 7.4 129.0 105 5/17/1987 -- .5 .5 1.9 38.0 100 

3/29/1987 -- 1.6 4.1 7.0 119.0 105 5/18/1987 -- .3 .5 1.5 30.0 100 

3/30/1987 -- 1.5 3.9 6.6 114.0 105 5/19/1987 -- 12.0 2.6 2.8 32.0 100 

3/31/1987 -- 1.5 3.9 6.3 110.0 105 5/20/1987 -- 1.3 1.0 2.5 35.0 99 

4/1/1987 -- 1.6 3.7 6.2 106.0 105 5/21/1987 -- .6 .8 1.8 30.0 98 

4/2/1987 -- 1.5 3.5 6.0 101.0 105 5/22/1987 -- .6 .8 1.7 28.0 94 

4/3/1987 -- 1.3 3.2 5.6 95.0 104 5/23/1987 -- .5 .8 1.5 23.0 92 

4/4/1987 -- 1.4 3.2 5.4 91.0 104 5/24/1987 -- 3.6 .9 1.5 20.0 92 

4/5/1987 -- 1.5 3.1 5.2 88.0 104 5/25/1987 -- .3 .8 1.5 19.0 92 

4/6/1987 -- 1.4 3.3 5.1 92.0 104 5/26/1987 -- .3 .7 1.3 18.0 92 

4/7/1987 -- 1.3 3.2 4.8 85.0 103 5/27/1987 -- .3 .6 1.2 17.0 91 

4/8/1987 -- 1.4 3.0 4.4 78.0 103 5/28/1987 -- .3 .6 1.3 16.0 90 

4/9/1987 -- 1.3 3.0 4.2 73.0 102 5/29/1987 -- 149.0 93.0 41.0 208.0 90 

4/10/1987 -- 1.4 2.8 4.2 71.0 102 5/30/1987 -- 9.3 6.4 17.0 200.0 90 

4/11/1987 -- 1.4 2.7 4.1 70.0 102 5/31/1987 -- 5.0 5.2 32.0 392.0 105 

4/12/1987 -- 1.3 2.7 3.9 65.0 102 6/1/1987 -- 10.0 12.0 34.0 386.0 110 

4/13/1987 -- 1.8 2.6 4.0 62.0 102 6/2/1987 -- 65.0 87.0 65.0 1,430.0 108 

4/14/1987 -- .8 2.2 3.5 55.0 101 6/3/1987 -- 50.0 67.0 61.0 1,380.0 106 

4/15/1987 -- .6 1.8 3.4 52.0 101 6/4/1987 -- 285.0 651.0 419.0 2,510.0 101 

4/16/1987 -- .6 1.8 3.2 50.0 101 6/5/1987 -- 47.0 86.0 96.0 1,100.0 96 

4/17/1987 -- .4 1.6 3.4 48.0 101 6/6/1987 -- 24.0 33.0 71.0 740.0 109 

4/18/1987 -- .4 1.5 3.4 48.0 100 6/7/1987 -- 14.0 18.0 55.0 568.0 114 

4/19/1987 -- .3 1.5 3.2 46.0 100 6/8/1987 -- 14.0 15.0 47.0 506.0 106 

4/20/1987 -- .3 1.4 3.2 43.0 100 6/9/1987 -- 90.0 121.0 70.0 849.0 111 

4/21/1987 -- .3 1.3 3.0 41.0 100 6/10/1987 -- 94.0 170.0 89.0 1,170.0 100 

4/22/1987 -- .3 1.1 3.0 40.0 100 6/11/1987 -- 98.0 136.0 115.0 2,140.0 95 

4/23/1987 -- .2 1.0 2.9 40.0 100 6/12/1987 -- 121.0 212.0 191.0 1,580.0 94 

4/24/1987 -- .1 1.0 2.8 39.0 100 6/13/1987 -- 176.0 423.0 165.0 2,610.0 90 

4/25/1987 -- .1 .9 2.8 37.0 100 6/14/1987 -- 58.0 90.0 96.0 1,320.0 88 

4/26/1987 -- .1 .8 2.6 35.0 100 6/15/1987 -- 30.0 53.0 74.0 866.0 98 

4/27/1987 -- .1 .8 2.4 33.0 100 6/16/1987 -- 20.0 31.0 59.0 661.0 105 

4/28/1987 -- 0 .7 2.4 31.0 100 6/17/1987 -- 14.0 21.0 49.0 524.0 109 

4/29/1987 -- 0 .7 2.3 30.0 100 6/18/1987 -- 84.0 55.0 49.0 530.0 113 

4/30/1987 -- 0 .6 2.2 29.0 100 6/19/1987 -- 22.0 24.0 39.0 376.0 110 

5/1/1987 -- 0 .6 2.2 28.0 99 6/20/1987 -- 14.0 15.0 33.0 317.0 109 

5/2/1987 -- 0 .7 2.2 28.0 98 6/21/1987 -- 9.8 11.0 29.0 286.0 109 
Appendix 2 93 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/22/1987 -- 6.7 8.8 26.0 273.0 108 8/11/1987 -- 0 0 1.5 30.0 109 

6/23/1987 -- 5.5 7.8 23.0 259.0 109 8/12/1987 -- 0 0 1.4 29.0 109 

6/24/1987 -- 4.9 7.0 20.0 245.0 111 8/13/1987 -- 0 0 1.3 28.0 109 

6/25/1987 -- 4.7 5.9 19.0 228.0 110 8/14/1987 -- 0 0 1.3 26.0 108 

6/26/1987 -- 3.9 4.9 17.0 212.0 113 8/15/1987 -- 0 0 1.2 24.0 107 

6/27/1987 -- 3.1 4.0 15.0 195.0 113 8/16/1987 -- 0 0 1.2 23.0 107 

6/28/1987 -- 2.8 3.6 14.0 181.0 114 8/17/1987 -- 0 0 1.1 21.0 107 

6/29/1987 -- 2.5 3.4 13.0 168.0 115 8/18/1987 -- 0 0 1.1 20.0 106 

6/30/1987 -- 2.3 3.1 12.0 155.0 112 8/19/1987 -- 0 0 1.0 18.0 106 

7/1/1987 -- 2.8 2.6 11.0 148.0 110 8/20/1987 -- 0 0 1.0 14.0 106 

7/2/1987 -- 2.8 2.6 11.0 220.0 110 8/21/1987 -- 0 0 1.0 11.0 106 

7/3/1987 -- 1.8 1.9 9.4 145.0 109 8/22/1987 -- 0 0 .9 9.1 106 

7/4/1987 -- 1.4 1.7 8.2 135.0 108 8/23/1987 -- 0 0 .9 8.3 106 

7/5/1987 -- 1.3 1.5 7.3 122.0 106 8/24/1987 -- 0 0 .9 7.8 106 

7/6/1987 -- 1.1 1.3 6.8 111.0 104 8/25/1987 -- 0 0 .8 7.4 105 

7/7/1987 -- 1.0 1.3 6.1 102.0 102 8/26/1987 -- 0 0 .8 7.2 105 

7/8/1987 -- .9 1.4 5.8 96.0 100 8/27/1987 -- 1.1 0 .8 6.2 105 

7/9/1987 -- 2.3 2.4 6.9 101.0 99 8/28/1987 -- .2 0 .7 7.6 104 

7/10/1987 -- 1.2 4.1 6.3 128.0 98 8/29/1987 -- 0 0 .7 7.5 104 

7/11/1987 -- .9 2.3 5.4 93.0 97 8/30/1987 -- .1 .9 1.6 12.0 104 

7/12/1987 -- .8 1.6 4.9 83.0 96 8/31/1987 -- 0 .3 1.0 19.0 103 

7/13/1987 -- .7 1.3 4.6 73.0 95 9/1/1987 -- 0 .2 .7 19.0 102 

7/14/1987 -- .7 1.2 4.4 70.0 94 9/2/1987 -- 0 .1 .7 15.0 102 

7/15/1987 -- .7 1.4 4.0 71.0 93 9/3/1987 -- 0 .1 .6 13.0 102 

7/16/1987 -- .6 1.2 4.0 67.0 92 9/4/1987 -- 0 .1 .6 10.0 101 

7/17/1987 -- 22.0 41.0 11.0 336.0 100 9/5/1987 -- 0 .1 .5 7.3 101 

7/18/1987 -- 1.3 2.5 6.2 153.0 114 9/6/1987 -- 0 .1 .3 5.2 101 

7/19/1987 -- .9 1.5 5.0 96.0 114 9/7/1987 -- 0 .1 .4 6.2 101 

7/20/1987 -- .8 1.4 4.2 73.0 96 9/8/1987 -- 0 .4 .4 6.0 100 

7/21/1987 -- .7 2.0 4.0 67.0 100 9/9/1987 -- 0 .2 .3 6.7 100 

7/22/1987 -- .7 2.3 3.8 70.0 114 9/10/1987 -- 14.0 .7 .5 7.2 100 

7/23/1987 -- .6 1.7 3.5 56.0 100 9/11/1987 -- .5 .5 .6 18.0 100 

7/24/1987 -- .7 1.9 3.3 50.0 97 9/12/1987 -- 0 .4 .3 12.0 100 

7/25/1987 -- .7 2.4 3.3 67.0 114 9/13/1987 -- 0 .3 .3 10.0 100 

7/26/1987 -- .6 1.9 3.3 60.0 114 9/14/1987 -- 0 .3 .3 8.6 99 

7/27/1987 -- .6 1.8 3.1 53.0 103 9/15/1987 -- 0 .3 .2 8.3 99 

7/28/1987 -- .5 1.4 2.8 49.0 108 9/16/1987 -- 0 .2 .1 9.0 99 

7/29/1987 -- .4 1.2 2.5 45.0 113 9/17/1987 -- 0 .1 .1 7.0 98 

7/30/1987 -- .4 .9 2.5 43.0 102 9/18/1987 -- .7 .3 .2 5.0 97 

7/31/1987 -- .3 .6 2.3 41.0 100 9/19/1987 -- 0 .1 .1 3.7 97 

8/1/1987 -- .3 .5 2.2 40.0 113 9/20/1987 -- 0 .1 .1 3.0 97 

8/2/1987 -- .3 .3 2.1 43.0 112 9/21/1987 -- 0 .1 .1 2.6 97 

8/3/1987 -- .2 .2 2.0 35.0 102 9/22/1987 -- 0 .1 .1 2.7 97 

8/4/1987 -- .1 .1 1.9 32.0 106 9/23/1987 -- 0 .1 .1 2.7 97 

8/5/1987 -- .1 0 1.8 30.0 111 9/24/1987 -- 0 .1 .1 2.9 96 

8/6/1987 -- 0 0 1.7 30.0 101 9/25/1987 -- 0 .1 .1 2.0 95 

8/7/1987 -- 0 0 1.7 36.0 105 9/26/1987 -- 0 .1 .1 1.0 95 

8/8/1987 -- 0 0 1.6 34.0 110 9/27/1987 -- 0 .1 .2 1.5 95 

8/9/1987 -- 0 0 1.6 34.0 110 9/28/1987 -- 0 .1 .2 1.7 95 

8/10/1987 -- 0 0 1.6 33.0 110 9/29/1987 -- 0 .1 .1 .8 95 
94 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/30/1987 -- 0 0.1 0.1 0.5 95 11/19/1987 -- 0 0.1 0.6 11.0 79 

10/1/1987 -- 0 .1 .1 .4 95 11/20/1987 -- 0 .1 .4 10.0 78 

10/2/1987 -- 0 .1 .1 .5 94 11/21/1987 -- 0 .1 .3 13.0 78 

10/3/1987 -- 0 .1 .1 .4 94 11/22/1987 -- 0 .1 .2 5.6 79 

10/4/1987 -- 0 .1 .1 .5 94 11/23/1987 -- 0 .1 .3 8.9 79 

10/5/1987 -- 0 .1 0 .5 93 11/24/1987 -- 0 .1 .3 9.0 79 

10/6/1987 -- 0 .1 0 .5 93 11/25/1987 -- 21.0 22.0 8.3 316.0 80 

10/7/1987 -- 0 .1 0 .4 93 11/26/1987 -- .2 .2 2.3 28.0 81 

10/8/1987 -- 0 .1 0 .4 92 11/27/1987 -- 2.7 .4 2.3 20.0 82 

10/9/1987 -- 0 .1 0 .6 92 11/28/1987 -- .3 .2 2.0 17.0 82 

10/10/1987 -- 0 .1 0 .4 91 11/29/1987 -- .2 .2 1.8 15.0 82 

10/11/1987 -- 0 .1 0 .1 91 11/30/1987 -- .2 .2 1.6 12.0 82 

10/12/1987 -- 0 .1 0 .1 91 12/1/1987 -- .1 .2 1.5 9.6 82 

10/13/1987 -- 0 .1 .1 .2 91 12/2/1987 -- .1 .2 1.5 8.2 82 

10/14/1987 -- 0 .1 0 .2 91 12/3/1987 -- .1 .2 1.3 6.4 81 

10/15/1987 -- 0 .1 0 .2 92 12/4/1987 -- .1 .2 1.2 5.6 81 

10/16/1987 -- 0 .1 0 .2 92 12/5/1987 -- 0 .2 1.1 5.3 81 

10/17/1987 -- 0 .1 0 .3 93 12/6/1987 -- 0 .2 1.1 5.1 80 

10/18/1987 -- 0 .1 0 .3 93 12/7/1987 -- 0 .2 .9 4.5 78 

10/19/1987 -- 0 .1 0 .5 93 12/8/1987 -- 0 .2 .9 4.1 75 

10/20/1987 -- 0 .1 0 .4 93 12/9/1987 -- 0 .2 .8 3.1 73 

10/21/1987 -- 0 .1 0 .2 93 12/10/1987 -- 0 .2 .8 2.9 73 

10/22/1987 -- 0 .1 0 .8 93 12/11/1987 -- 0 .2 .7 2.9 73 

10/23/1987 -- 0 .1 0 .9 91 12/12/1987 -- 0 .2 .7 2.2 73 

10/24/1987 -- 0 .1 .1 1.0 89 12/13/1987 -- 0 .2 .7 2.3 74 

10/25/1987 -- 0 .1 0 1.1 89 12/14/1987 -- 0 .3 .9 2.5 74 

10/26/1987 -- 0 .1 0 1.0 89 12/15/1987 -- 0 .1 1.1 1.3 74 

10/27/1987 -- 0 .1 0 .7 89 12/16/1987 -- 0 .2 1.1 1.0 74 

10/28/1987 -- 0 .1 0 1.0 89 12/17/1987 -- 0 .2 1.1 1.2 74 

10/29/1987 -- 0 .1 .1 1.9 89 12/18/1987 -- .1 .2 1.1 1.9 74 

10/30/1987 -- 0 .1 .1 2.3 87 12/19/1987 -- 6.3 .7 2.8 9.4 75 

10/31/1987 -- 0 .1 .1 3.1 85 12/20/1987 -- .5 .4 1.5 11.0 75 

11/1/1987 -- 0 .1 0 3.2 86 12/21/1987 -- .4 .3 1.5 14.0 76 

11/2/1987 -- 0 .1 .1 3.3 86 12/22/1987 -- .2 .3 1.5 13.0 76 

11/3/1987 -- 0 .1 .1 3.3 85 12/23/1987 -- .2 .3 1.4 13.0 76 

11/4/1987 -- 0 .1 0 3.3 85 12/24/1987 -- .6 .4 1.4 13.0 75 

11/5/1987 -- 0 .1 0 2.7 84 12/25/1987 -- .8 .5 1.4 12.0 75 

11/6/1987 -- 0 .1 0 2.5 82 12/26/1987 -- 1.2 .6 1.3 11.0 75 

11/7/1987 -- 0 .1 0 3.3 83 12/27/1987 -- .6 .5 1.4 11.0 75 

11/8/1987 -- 18.0 .3 .3 18.0 83 12/28/1987 -- .5 .6 1.4 11.0 75 

11/9/1987 -- .5 .1 .4 9.2 83 12/29/1987 -- .5 .6 1.2 11.0 74 

11/10/1987 -- 0 .1 .3 6.3 83 12/30/1987 -- .5 .6 1.2 11.0 74 

11/11/1987 -- 0 .1 .2 9.0 82 12/31/1987 -- .5 .7 1.2 11.0 74 

11/12/1987 -- 0 .1 .2 10.0 82 1/1/1988 -- .4 .6 1.2 10.0 74 

11/13/1987 -- 0 .1 .2 9.7 82 1/2/1988 -- .3 .6 1.2 10.0 74 

11/14/1987 -- 0 .1 .2 9.1 81 1/3/1988 -- .4 .6 1.2 11.0 74 

11/15/1987 -- .6 .2 .8 12.0 81 1/4/1988 -- .4 .6 1.2 10.0 74 

11/16/1987 -- 6.0 .2 1.2 7.6 80 1/5/1988 -- .4 .6 1.1 9.6 73 

11/17/1987 -- .1 .1 .7 9.0 80 1/6/1988 -- .8 .7 1.4 11.0 73 

11/18/1987 -- 0 .1 .6 11.0 79 1/7/1988 -- .5 .7 1.4 11.0 73 
Appendix 2 95 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/8/1988 -- 0.4 0.7 1.2 9.5 73 2/27/1988 -- 0 0.5 0.8 6.0 59 

1/9/1988 -- .4 .7 1.2 9.5 73 2/28/1988 -- 0 .5 .8 6.0 58 

1/10/1988 -- .4 .7 1.1 9.7 73 2/29/1988 -- 0 .5 .8 6.3 58 

1/11/1988 -- .4 .7 1.1 10.0 72 3/1/1988 -- 0 .5 .8 6.2 58 

1/12/1988 -- .4 .7 1.1 10.0 72 3/2/1988 -- .2 .6 1.1 7.8 57 

1/13/1988 -- .4 .6 1.1 9.1 72 3/3/1988 -- 0 .5 .9 6.7 57 

1/14/1988 -- .4 .6 .9 9.6 72 3/4/1988 -- 0 .5 .8 6.2 56 

1/15/1988 -- .4 .6 .9 9.8 71 3/5/1988 -- 0 .6 .8 5.9 57 

1/16/1988 -- .4 .6 1.1 9.8 71 3/6/1988 -- 0 .6 .7 5.3 56 

1/17/1988 -- .4 .6 1.1 9.4 71 3/7/1988 -- 0 .6 .7 5.4 56 

1/18/1988 -- .4 .7 1.1 9.2 70 3/8/1988 -- 0 .6 .7 6.5 55 

1/19/1988 -- .4 .6 1.1 8.8 70 3/9/1988 -- 0 .5 .7 4.6 55 

1/20/1988 -- .3 .5 1.1 8.0 69 3/10/1988 -- 0 .6 .7 4.5 54 

1/21/1988 -- .3 .5 1.1 7.9 68 3/11/1988 -- 0 .6 .7 5.0 54 

1/22/1988 -- .3 .5 1.1 7.9 68 3/12/1988 -- 0 .5 .7 4.6 54 

1/23/1988 -- .4 .5 1.1 6.8 67 3/13/1988 -- 0 .5 .6 4.1 53 

1/24/1988 -- .3 .5 .9 6.7 67 3/14/1988 -- 0 .5 .6 4.5 53 

1/25/1988 -- .3 .5 .9 6.5 67 3/15/1988 -- 0 .5 .6 4.2 53 

1/26/1988 -- .3 .5 1.0 6.8 66 3/16/1988 -- 0 .5 .6 4.2 52 

1/27/1988 -- .3 .4 1.1 6.8 66 3/17/1988 -- 8.3 .6 1.5 8.1 52 

1/28/1988 -- .3 .4 1.1 7.1 66 3/18/1988 -- .3 .5 .9 13.0 60 

1/29/1988 -- .2 .4 1.1 7.5 66 3/19/1988 -- .2 .5 .7 16.0 58 

1/30/1988 -- .3 .4 1.1 7.5 66 3/20/1988 -- .1 .4 .7 13.0 57 

1/31/1988 -- .2 .4 1.1 7.5 66 3/21/1988 -- .1 .4 .7 11.0 57 

2/1/1988 -- .2 .4 1.1 8.1 65 3/22/1988 -- .1 .4 .7 10.0 57 

2/2/1988 -- .2 .4 1.1 7.6 65 3/23/1988 -- .1 .4 .7 9.6 57 

2/3/1988 -- .1 .5 .9 6.8 64 3/24/1988 -- .1 .4 .7 9.0 56 

2/4/1988 -- .2 .5 .9 6.3 63 3/25/1988 -- 0 .4 .7 8.4 56 

2/5/1988 -- .2 .5 1.0 7.1 62 3/26/1988 -- 0 .4 .7 8.0 55 

2/6/1988 -- .1 .5 1.1 7.3 62 3/27/1988 -- 0 .3 .7 7.8 55 

2/7/1988 -- .2 .5 1.1 6.8 62 3/28/1988 -- 0 .3 .7 7.6 55 

2/8/1988 -- .1 .5 1.1 7.1 62 3/29/1988 -- .1 .3 .7 7.4 55 

2/9/1988 -- .1 .5 1.1 7.5 61 3/30/1988 -- 0 .3 .6 6.1 54 

2/10/1988 -- .1 .6 .9 7.5 61 3/31/1988 -- 0 .3 .7 6.2 54 

2/11/1988 -- .1 .5 .9 7.1 63 4/1/1988 -- .1 .3 .7 5.9 54 

2/12/1988 -- .1 .5 .8 6.5 64 4/2/1988 -- .1 .3 .7 5.7 54 

2/13/1988 -- .1 .5 .8 6.8 64 4/3/1988 -- 0 .3 .7 7.6 54 

2/14/1988 -- .2 .5 .8 6.8 63 4/4/1988 -- 0 .3 .7 7.7 54 

2/15/1988 -- .1 .5 .8 6.0 63 4/5/1988 -- 0 .3 .7 7.1 54 

2/16/1988 -- .1 .5 .8 6.3 63 4/6/1988 -- .1 .3 .7 6.2 54 

2/17/1988 -- .1 .5 .8 7.7 62 4/7/1988 -- 0 .3 .7 5.6 54 

2/18/1988 -- .1 .6 1.2 8.6 62 4/8/1988 -- 0 .2 .7 5.2 54 

2/19/1988 -- .1 .6 1.0 7.8 62 4/9/1988 -- 1.6 .3 1.0 5.7 53 

2/20/1988 -- .1 .6 .9 7.9 61 4/10/1988 -- .3 .2 .8 7.4 54 

2/21/1988 -- 0 .6 .8 8.5 61 4/11/1988 -- .2 .2 .7 5.5 53 

2/22/1988 -- 0 .6 .8 8.4 60 4/12/1988 -- .2 .1 .7 6.2 53 

2/23/1988 -- 0 .5 .8 7.7 60 4/13/1988 -- .1 .1 .7 5.6 53 

2/24/1988 -- 0 .5 .8 5.8 60 4/14/1988 -- .1 .1 .7 5.9 53 

2/25/1988 -- 0 .5 .8 5.1 59 4/15/1988 -- 0 .1 .7 6.2 52 

2/26/1988 -- 0 .5 .8 5.1 59 4/16/1988 -- 0 .1 .7 6.2 52 
96 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/17/1988 -- 0 0.1 0.7 6.2 52 6/6/1988 -- 0 0.1 0.2 3.7 48 

4/18/1988 -- 0 .1 .7 5.1 51 6/7/1988 -- 0 .1 .2 3.4 48 

4/19/1988 -- 0 .1 .6 3.9 51 6/8/1988 -- 0 .1 .2 3.4 48 

4/20/1988 -- 0 .1 .6 4.2 51 6/9/1988 -- 0 0 .1 3.2 48 

4/21/1988 -- 0 .1 .5 4.3 51 6/10/1988 -- 0 0 .1 3.0 47 

4/22/1988 -- 0 .1 .5 4.6 50 6/11/1988 -- 0 0 .1 3.1 47 

4/23/1988 -- 0 .1 .5 4.6 50 6/12/1988 -- 0 0 .1 2.5 47 

4/24/1988 -- 0 .1 .3 3.8 50 6/13/1988 -- 0 0 .1 2.6 47 

4/25/1988 -- 0 .1 .3 4.1 50 6/14/1988 -- 0 0 .1 2.7 46 

4/26/1988 -- 0 .1 .2 3.6 50 6/15/1988 -- 0 0 .1 2.7 46 

4/27/1988 -- 0 .1 .1 3.5 50 6/16/1988 -- 0 0 .1 2.7 46 

4/28/1988 -- 0 .1 .1 3.6 50 6/17/1988 -- 0 0 .1 2.2 46 

4/29/1988 -- 1.4 .1 1.0 5.4 50 6/18/1988 -- 0 0 .1 2.2 45 

4/30/1988 -- .2 .1 1.1 7.8 50 6/19/1988 -- 0 0 0 2.7 45 

5/1/1988 -- 0 .1 .7 4.7 50 6/20/1988 -- 0 0 0 2.7 45 

5/2/1988 -- 0 .1 .7 3.8 49 6/21/1988 -- 0 0 0 1.7 45 

5/3/1988 -- 0 .1 .6 4.0 49 6/22/1988 -- 0 .1 0 1.1 45 

5/4/1988 -- 0 .1 .5 3.4 48 6/23/1988 -- 0 0 0 1.1 45 

5/5/1988 -- 0 .1 .5 3.3 48 6/24/1988 -- 0 0 0 1.1 45 

5/6/1988 -- 0 .1 .4 3.8 48 6/25/1988 -- 0 0 0 1.0 45 

5/7/1988 -- 0 .1 .3 4.2 48 6/26/1988 -- 1.2 0 .1 6.7 46 

5/8/1988 -- 0 .1 .3 4.4 48 6/27/1988 -- 0 0 .1 5.3 46 

5/9/1988 -- 0 .1 .3 3.9 48 6/28/1988 -- 0 0 .1 3.6 46 

5/10/1988 -- 0 .1 .3 3.9 48 6/29/1988 -- 0 0 .1 3.0 45 

5/11/1988 -- 1.6 .1 .6 5.5 48 6/30/1988 -- 0 0 0 2.7 45 

5/12/1988 -- .3 .1 .6 6.1 48 7/1/1988 -- 0 0 0 2.6 45 

5/13/1988 -- 0 .1 .4 3.2 48 7/2/1988 -- 0 0 0 2.2 45 

5/14/1988 -- 0 .1 .3 3.1 48 7/3/1988 -- 0 0 0 2.2 45 

5/15/1988 -- 0 .1 .1 3.2 48 7/4/1988 -- .4 0 0 2.2 45 

5/16/1988 -- 0 .1 .3 6.4 48 7/5/1988 -- 0 0 0 2.2 45 

5/17/1988 -- 0 .1 .1 4.4 48 7/6/1988 -- 0 0 .1 2.2 47 

5/18/1988 -- 0 .1 .1 3.7 48 7/7/1988 -- 0 0 .1 2.2 46 

5/19/1988 -- 0 .1 .1 3.3 48 7/8/1988 -- 0 0 0 2.2 44 

5/20/1988 -- 4.6 .1 .5 3.5 50 7/9/1988 -- 0 0 .1 2.0 45 

5/21/1988 -- 8.8 .2 1.5 18.0 54 7/10/1988 -- 1.0 0 0 1.8 45 

5/22/1988 -- 0 .1 .7 7.1 52 7/11/1988 -- .2 0 0 1.8 45 

5/23/1988 -- 0 .1 .5 5.6 51 7/12/1988 -- 2.0 0 .8 7.5 45 

5/24/1988 -- 0 .1 .5 5.1 50 7/13/1988 -- .1 0 .2 2.4 45 

5/25/1988 -- 0 .1 .5 5.1 49 7/14/1988 -- 0 0 .1 1.1 45 

5/26/1988 -- 0 .1 .5 3.9 49 7/15/1988 -- 0 0 .1 1.0 45 

5/27/1988 -- 0 .1 .4 1.2 49 7/16/1988 -- 0 0 .1 .8 45 

5/28/1988 -- 0 .1 .4 3.5 48 7/17/1988 -- 0 0 0 .9 45 

5/29/1988 -- 0 .1 .3 4.0 48 7/18/1988 -- 0 0 0 .6 45 

5/30/1988 -- 0 .1 .4 6.9 48 7/19/1988 -- 0 0 0 .5 44 

5/31/1988 -- .6 .1 .4 3.4 48 7/20/1988 -- 0 0 0 .6 44 

6/1/1988 -- .5 .1 .5 4.5 48 7/21/1988 -- 0 0 0 .9 44 

6/2/1988 -- 1.2 .1 .4 3.8 50 7/22/1988 -- 0 0 0 .7 44 

6/3/1988 -- 3.3 .2 .7 3.7 50 7/23/1988 -- 0 0 0 .4 44 

6/4/1988 -- 0 .2 .4 3.7 49 7/24/1988 -- 0 0 0 .4 44 

6/5/1988 -- 0 .2 .4 3.7 49 7/25/1988 -- 0 0 0 .4 43 
Appendix 2 97 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

7/26/1988 -- 0 0 0 0.4 41 9/14/1988 -- 0 0 0 0.2 40 

7/27/1988 -- 0 0 0 1.6 43 9/15/1988 -- 0 0 0 .2 40 

7/28/1988 -- 0 0 0 5.2 42 9/16/1988 -- 0 0 0 .2 40 

7/29/1988 -- 0 0 0 .9 41 9/17/1988 -- 4.0 0 0 1.2 41 

7/30/1988 -- 0 0 0 1.2 43 9/18/1988 -- 0 0 0 2.0 41 

7/31/1988 -- 0 0 0 1.2 43 9/19/1988 -- 0 0 0 .8 41 

8/1/1988 -- 0 0 0 .9 42 9/20/1988 -- 0 0 0 .6 41 

8/2/1988 -- 0 0 0 4.6 41 9/21/1988 -- 0 0 0 .4 40 

8/3/1988 -- 0 0 0 11.0 43 9/22/1988 -- 0 0 0 .3 40 

8/4/1988 -- 0 0 0 2.4 43 9/23/1988 -- 0 0 0 .2 39 

8/5/1988 -- 0 0 0 2.0 42 9/24/1988 -- 0 0 0 .2 40 

8/6/1988 -- 0 0 0 2.1 43 9/25/1988 -- 0 0 0 .2 40 

8/7/1988 -- 0 0 0 1.8 43 9/26/1988 -- 0 0 0 .2 40 

8/8/1988 -- 0 0 0 1.6 42 9/27/1988 -- 0 0 0 .2 40 

8/9/1988 -- 0 0 0 1.4 41 9/28/1988 -- 0 0 0 .2 40 

8/10/1988 -- 0 0 0 1.4 42 9/29/1988 -- 0 0 0 .2 39 

8/11/1988 -- 1.1 0 0 1.3 43 9/30/1988 -- 0 0 0 .3 38 

8/12/1988 -- 0 0 0 3.2 44 10/1/1988 -- 0 0 0 .3 31 

8/13/1988 -- 0 0 0 1.6 45 10/2/1988 -- 0 0 0 .3 31 

8/14/1988 -- 0 0 0 1.1 45 10/3/1988 -- 0 0 0 .3 31 

8/15/1988 -- 0 0 0 .9 44 10/4/1988 -- 0 0 0 .3 30 

8/16/1988 -- 1.2 0 0 .9 43 10/5/1988 -- 0 0 0 .3 29 

8/17/1988 -- 0 0 0 .9 43 10/6/1988 -- 0 0 0 .3 28 

8/18/1988 -- 0 0 0 .9 43 10/7/1988 -- 0 0 0 .3 28 

8/19/1988 -- 0 0 0 1.1 43 10/8/1988 -- 0 0 0 .3 28 

8/20/1988 -- 0 0 0 1.1 43 10/9/1988 -- 0 0 0 .3 28 

8/21/1988 -- 0 0 0 1.1 43 10/10/1988 -- 0 0 0 .3 28 

8/22/1988 -- 0 0 0 .9 42 10/11/1988 -- 0 0 0 .3 28 

8/23/1988 -- 0 0 0 .7 41 10/12/1988 -- 0 0 0 .3 28 

8/24/1988 -- 0 0 0 .6 42 10/13/1988 -- 0 0 0 .3 28 

8/25/1988 -- 0 0 0 .6 41 10/14/1988 -- 0 0 0 .3 27 

8/26/1988 -- 0 0 0 .6 41 10/15/1988 -- 0 0 0 .3 27 

8/27/1988 -- 0 0 0 .6 42 10/16/1988 -- 0 0 0 .3 27 

8/28/1988 -- 0 0 0 .5 42 10/17/1988 -- 0 0 0 .2 27 

8/29/1988 -- 0 0 0 .5 42 10/18/1988 -- 0 0 0 .2 27 

8/30/1988 -- 0 0 0 .5 41 10/19/1988 -- 0 0 0 .2 27 

8/31/1988 -- 0 0 0 .5 41 10/20/1988 -- 0 0 0 .2 27 

9/1/1988 -- 0 0 0 .4 41 10/21/1988 -- 0 0 0 .2 26 

9/2/1988 -- 0 0 0 .5 40 10/22/1988 -- 0 0 0 .2 26 

9/3/1988 -- 0 0 0 .4 40 10/23/1988 -- 0 0 0 .2 27 

9/4/1988 -- 0 0 0 .3 40 10/24/1988 -- 0 0 0 .2 27 

9/5/1988 -- 0 0 0 .2 40 10/25/1988 -- 0 0 0 .1 27 

9/6/1988 -- 0 0 0 .2 40 10/26/1988 -- 0 0 0 .1 28 

9/7/1988 -- 0 0 0 .2 40 10/27/1988 -- 0 0 0 .1 28 

9/8/1988 -- 0 0 0 .2 39 10/28/1988 -- 0 0 0 .1 27 

9/9/1988 -- 0 0 0 .2 39 10/29/1988 -- 0 0 0 .1 27 

9/10/1988 -- 0 0 0 .2 40 10/30/1988 -- 0 0 0 .1 27 

9/11/1988 -- 0 0 0 .2 40 10/31/1988 -- 2.0 0 0 .2 27 

9/12/1988 -- 0 0 0 .2 40 11/1/1988 -- 0 0 0 .2 26 

9/13/1988 -- 0 0 0 .2 40 11/2/1988 -- 0 0 0 .2 26 
98 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

11/3/1988 -- 0 0 0 0.2 25 12/23/1988 -- 0 0 0 0.1 24 

11/4/1988 -- 0 0 0 .1 25 12/24/1988 -- 0 0 0 .1 24 

11/5/1988 -- 0 0 0 .1 26 12/25/1988 -- 0 0 0 .1 24 

11/6/1988 -- 0 0 0 .1 27 12/26/1988 -- 0 0 0 .1 24 

11/7/1988 -- 0 0 0 .1 25 12/27/1988 -- 0 0 0 .1 24 

11/8/1988 -- 0 0 0 .1 24 12/28/1988 .3 0 0 0 .1 24 

11/9/1988 -- 0 0 0 .1 23 12/29/1988 .3 0 0 0 .1 24 

11/10/1988 -- 0 0 0 .1 23 12/30/1988 .3 0 0 0 .1 24 

11/11/1988 -- 0 0 0 .1 23 12/31/1988 .3 0 0 0 .1 24 

11/12/1988 -- 0 0 0 .1 24 1/1/1989 .4 0 0 0 .1 24 

11/13/1988 -- 0 0 0 .1 24 1/2/1989 .4 0 0 0 .1 24 

11/14/1988 -- 0 0 0 .1 24 1/3/1989 .4 0 0 0 .1 24 

11/15/1988 -- 0 0 0 .1 24 1/4/1989 .3 0 0 0 .1 24 

11/16/1988 -- 0 0 0 .1 25 1/5/1989 .3 0 0 0 .1 24 

11/17/1988 -- 0 0 0 .1 25 1/6/1989 .3 0 0 0 .1 24 

11/18/1988 -- 0 0 0 .1 25 1/7/1989 .3 .1 0 0 .1 24 

11/19/1988 -- 0 0 0 .1 25 1/8/1989 .3 0 0 0 .1 24 

11/20/1988 -- 0 0 0 .1 26 1/9/1989 .3 0 0 0 .1 24 

11/21/1988 -- 0 0 0 .1 26 1/10/1989 .3 0 0 0 .2 24 

11/22/1988 -- 0 0 0 .1 27 1/11/1989 .3 0 0 0 .2 24 

11/23/1988 -- 0 0 0 .1 26 1/12/1989 .4 0 0 0 .2 24 

11/24/1988 -- 0 0 0 .1 26 1/13/1989 .4 .7 0 0 .2 24 

11/25/1988 -- 0 0 0 .1 26 1/14/1989 .4 .1 0 0 .2 25 

11/26/1988 -- 0 0 0 .1 26 1/15/1989 .3 0 0 0 .2 24 

11/27/1988 -- 0 0 0 .1 26 1/16/1989 .3 0 0 0 .2 24 

11/28/1988 -- 0 0 0 .1 26 1/17/1989 .3 0 0 0 .2 24 

11/29/1988 -- 0 0 0 .1 26 1/18/1989 .4 0 0 0 .2 24 

11/30/1988 -- 0 0 0 .1 26 1/19/1989 .5 1.9 .1 0 .2 25 

12/1/1988 -- 0 0 0 .1 26 1/20/1989 .4 .5 0 0 .2 27 

12/2/1988 -- 0 0 0 .1 26 1/21/1989 .4 0 0 0 .2 26 

12/3/1988 -- 0 0 0 .1 26 1/22/1989 .4 0 0 0 .2 26 

12/4/1988 -- 0 0 0 .1 26 1/23/1989 .4 0 0 0 .2 25 

12/5/1988 -- 0 0 0 .1 26 1/24/1989 .5 .4 0 0 .2 25 

12/6/1988 -- 0 0 0 .1 26 1/25/1989 .5 .5 0 0 .2 26 

12/7/1988 -- 0 0 0 .1 25 1/26/1989 3.2 22.0 .3 0 1.6 28 

12/8/1988 -- 0 0 0 .1 23 1/27/1989 1.2 .2 0 0 2.5 30 

12/9/1988 -- 0 0 0 .1 25 1/28/1989 2.2 2.8 .1 0 1.2 32 

12/10/1988 -- 0 0 0 .1 25 1/29/1989 7.5 9.4 .2 0 8.0 34 

12/11/1988 -- 0 0 0 .1 26 1/30/1989 3.0 .7 0 0 7.4 36 

12/12/1988 -- 0 0 0 .1 25 1/31/1989 1.6 .3 0 0 3.8 34 

12/13/1988 -- 0 0 0 .1 25 2/1/1989 1.3 .2 0 0 2.7 32 

12/14/1988 -- 0 0 0 .1 25 2/2/1989 1.3 .7 .1 0 2.7 31 

12/15/1988 -- 0 0 0 .1 24 2/3/1989 1.5 .5 0 0 6.3 30 

12/16/1988 -- 0 0 0 .1 24 2/4/1989 1.1 .1 0 0 5.4 29 

12/17/1988 -- 0 0 0 .1 24 2/5/1989 1.0 .2 0 0 5.0 29 

12/18/1988 -- 0 0 0 .1 24 2/6/1989 1.0 .2 0 0 4.3 29 

12/19/1988 -- 0 0 0 .1 24 2/7/1989 1.0 .1 0 0 3.6 29 

12/20/1988 -- 0 0 0 .1 24 2/8/1989 .9 .1 0 0 3.1 29 

12/21/1988 -- 0 0 0 .1 24 2/9/1989 1.0 .1 0 0 2.6 29 

12/22/1988 -- 0 0 0 .1 24 2/10/1989 .9 .1 0 0 2.2 29 
Appendix 2 99 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

2/11/1989 0.9 0.1 0 0 1.8 28 4/2/1989 11.0 0.1 0 1.4 4.8 27 

2/12/1989 .9 .1 0 0 1.6 28 4/3/1989 11.0 .1 0 1.4 4.5 27 

2/13/1989 .9 .1 0 0 2.4 28 4/4/1989 11.0 0 0 1.3 4.3 26 

2/14/1989 .9 0 0 0 1.2 28 4/5/1989 9.9 0 0 1.3 4.1 26 

2/15/1989 .8 0 0 0 .9 28 4/6/1989 9.4 0 0 1.1 3.8 26 

2/16/1989 .8 0 0 0 .9 27 4/7/1989 9.1 0 0 1.1 3.7 25 

2/17/1989 .9 .2 0 .1 1.1 27 4/8/1989 8.8 0 0 1.1 3.7 25 

2/18/1989 .9 .1 0 .1 1.4 26 4/9/1989 8.0 0 0 1.1 3.7 26 

2/19/1989 .9 .1 0 .1 1.4 27 4/10/1989 7.4 0 0 1.0 3.6 26 

2/20/1989 .9 0 0 .1 1.3 27 4/11/1989 7.5 0 0 .9 3.4 26 

2/21/1989 .9 .2 0 .1 1.1 27 4/12/1989 7.7 0 0 .9 3.4 26 

2/22/1989 .9 .3 0 .1 1.1 26 4/13/1989 9.0 .1 0 .9 3.4 26 

2/23/1989 .9 0 0 .1 1.1 26 4/14/1989 15.0 3.2 0 2.2 4.4 26 

2/24/1989 .9 0 0 .1 1.3 26 4/15/1989 16.0 .1 0 1.3 3.8 27 

2/25/1989 1.0 0 0 .1 1.9 25 4/16/1989 14.0 0 0 1.1 3.7 27 

2/26/1989 1.0 0 0 .1 2.4 26 4/17/1989 11.0 0 0 .9 3.7 27 

2/27/1989 1.0 0 0 .1 2.2 26 4/18/1989 10.0 0 0 .9 3.7 27 

2/28/1989 1.0 0 0 .1 1.6 26 4/19/1989 26.0 20.0 .9 40.0 11.0 28 

3/1/1989 1.4 .1 0 .1 1.8 26 4/20/1989 33.0 .7 0 5.0 8.7 37 

3/2/1989 6.9 .1 0 .2 2.2 27 4/21/1989 23.0 .4 0 4.3 8.4 38 

3/3/1989 6.9 0 0 .3 2.3 26 4/22/1989 19.0 .3 0 3.7 7.3 36 

3/4/1989 7.1 .5 0 .4 2.7 25 4/23/1989 16.0 .3 0 3.5 5.6 35 

3/5/1989 6.6 0 0 .2 2.3 26 4/24/1989 15.0 .2 0 3.4 4.6 33 

3/6/1989 6.1 0 0 .2 1.4 26 4/25/1989 14.0 .1 0 3.2 4.9 32 

3/7/1989 5.6 0 0 .3 1.9 26 4/26/1989 14.0 .1 0 3.2 5.4 32 

3/8/1989 5.1 0 0 .3 1.1 25 4/27/1989 14.0 .1 0 3.0 5.1 31 

3/9/1989 4.0 0 0 .3 1.2 25 4/28/1989 13.0 0 0 3.0 4.6 30 

3/10/1989 3.9 0 0 .3 1.4 25 4/29/1989 12.0 .1 0 3.0 4.6 29 

3/11/1989 4.5 0 0 .3 1.4 25 4/30/1989 11.0 .2 0 3.0 4.2 30 

3/12/1989 4.5 0 0 .3 1.2 24 5/1/1989 11.0 0 0 2.8 3.6 30 

3/13/1989 4.3 0 0 .4 1.2 24 5/2/1989 9.9 0 0 2.6 4.2 30 

3/14/1989 4.4 0 0 .3 1.5 24 5/3/1989 9.1 0 0 2.4 3.0 30 

3/15/1989 4.7 0 0 .3 1.8 24 5/4/1989 8.6 0 0 2.4 3.0 29 

3/16/1989 4.5 0 0 .2 1.5 23 5/5/1989 27.0 15.0 .3 4.1 8.5 33 

3/17/1989 4.3 0 0 .3 1.4 23 5/6/1989 21.0 .3 0 2.9 4.7 32 

3/18/1989 4.3 0 0 .3 1.4 23 5/7/1989 15.0 .1 0 2.6 4.1 31 

3/19/1989 4.3 0 0 .3 1.4 24 5/8/1989 12.0 .1 0 2.5 2.9 30 

3/20/1989 6.1 .2 0 .4 2.7 25 5/9/1989 9.9 .1 0 2.4 3.0 30 

3/21/1989 6.9 1.0 0 .2 2.0 27 5/10/1989 814.0 87.0 23.0 137.0 480.0 46 

3/22/1989 7.3 .1 0 .2 1.4 27 5/11/1989 200.0 12.0 4.3 18.0 85.0 45 

3/23/1989 6.9 0 0 .2 1.1 26 5/12/1989 120.0 7.5 3.9 16.0 47.0 43 

3/24/1989 6.4 0 0 .2 1.3 25 5/13/1989 180.0 72.0 19.0 17.0 37.0 41 

3/25/1989 6.2 0 0 .4 1.8 24 5/14/1989 349.0 40.0 13.0 16.0 36.0 43 

3/26/1989 6.3 0 0 .5 2.2 25 5/15/1989 278.0 34.0 11.0 17.0 102.0 41 

3/27/1989 7.5 0 0 .5 2.2 25 5/16/1989 184.0 20.0 9.7 16.0 83.0 39 

3/28/1989 14.0 9.1 0 1.3 6.7 27 5/17/1989 1,790.0 134.0 76.0 48.0 1,430.0 88 

3/29/1989 24.0 .4 0 1.5 6.1 27 5/18/1989 699.0 44.0 24.0 27.0 297.0 84 

3/30/1989 24.0 .2 0 1.2 6.8 27 5/19/1989 356.0 25.0 10.0 23.0 186.0 78 

3/31/1989 15.0 .2 0 1.1 5.6 27 5/20/1989 246.0 16.0 7.0 19.0 147.0 75 

4/1/1989 12.0 .1 0 1.3 5.1 27 5/21/1989 188.0 11.0 5.5 19.0 251.0 72 
100 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

5/22/1989 158.0 8.5 4.1 16.0 157.0 71 7/11/1989 6.7 0 0.1 2.3 9.1 53 

5/23/1989 140.0 6.4 3.1 14.0 137.0 70 7/12/1989 5.8 0 .1 2.1 7.7 52 

5/24/1989 128.0 4.8 2.6 13.0 120.0 70 7/13/1989 4.9 0 .1 2.0 6.7 51 

5/25/1989 117.0 4.1 2.2 11.0 105.0 70 7/14/1989 4.3 2.0 .1 2.0 6.0 50 

5/26/1989 106.0 3.3 1.7 9.5 88.0 69 7/15/1989 3.7 0 .1 1.7 5.0 49 

5/27/1989 91.0 3.0 1.6 8.1 74.0 69 7/16/1989 3.1 0 .1 1.6 5.0 49 

5/28/1989 80.0 2.5 1.4 7.7 69.0 68 7/17/1989 2.5 0 0 1.2 5.0 48 

5/29/1989 69.0 2.2 1.3 6.9 61.0 68 7/18/1989 1.9 0 0 1.1 4.2 48 

5/30/1989 62.0 2.0 1.2 6.4 56.0 67 7/19/1989 1.6 0 0 .9 3.8 47 

5/31/1989 54.0 1.9 1.1 5.7 50.0 66 7/20/1989 1.3 0 0 .8 3.0 46 

6/1/1989 50.0 1.9 .9 5.2 45.0 65 7/21/1989 1.2 0 0 .7 2.9 46 

6/2/1989 47.0 2.3 .7 4.6 42.0 64 7/22/1989 1.1 0 0 1.1 3.4 45 

6/3/1989 44.0 2.7 .7 4.5 38.0 64 7/23/1989 .9 0 0 1.6 3.5 45 

6/4/1989 40.0 2.7 .7 4.2 34.0 64 7/24/1989 .9 0 0 .9 5.0 45 

6/5/1989 38.0 2.8 .6 4.0 32.0 64 7/25/1989 .9 0 0 .7 5.5 44 

6/6/1989 35.0 2.5 .4 3.5 29.0 63 7/26/1989 .9 .3 0 .8 4.3 44 

6/7/1989 33.0 2.4 .4 3.3 25.0 63 7/27/1989 .9 0 0 .7 4.0 43 

6/8/1989 31.0 1.8 .4 2.8 22.0 62 7/28/1989 .8 0 0 .7 4.2 42 

6/9/1989 28.0 1.4 .4 2.6 19.0 62 7/29/1989 .8 0 0 .6 3.3 42 

6/10/1989 28.0 1.3 .4 2.5 18.0 61 7/30/1989 .8 0 0 .3 3.0 41 

6/11/1989 41.0 11.0 1.1 3.9 24.0 63 7/31/1989 .7 0 0 .2 3.0 41 

6/12/1989 34.0 1.0 .5 2.5 23.0 63 8/1/1989 .8 0 0 .2 2.8 40 

6/13/1989 30.0 2.9 .5 2.2 19.0 70 8/2/1989 1.5 3.4 0 .9 9.5 39 

6/14/1989 159.0 48.0 7.6 13.0 115.0 75 8/3/1989 1.4 0 0 .5 3.8 39 

6/15/1989 92.0 1.7 1.7 7.4 56.0 73 8/4/1989 1.2 0 0 .2 3.0 39 

6/16/1989 53.0 1.3 1.2 6.6 32.0 71 8/5/1989 1.0 0 0 .1 2.5 38 

6/17/1989 43.0 1.3 .9 6.1 27.0 70 8/6/1989 .9 0 0 .1 2.2 38 

6/18/1989 39.0 1.3 .9 5.8 24.0 70 8/7/1989 .9 0 0 .1 1.8 37 

6/19/1989 36.0 1.2 .9 5.3 24.0 69 8/8/1989 .8 0 0 .1 2.5 37 

6/20/1989 34.0 1.0 .7 5.0 23.0 69 8/9/1989 .8 0 0 .1 2.2 37 

6/21/1989 31.0 1.1 .3 4.8 21.0 68 8/10/1989 .7 0 0 .1 1.4 37 

6/22/1989 28.0 1.0 .3 4.7 20.0 67 8/11/1989 .7 0 0 .1 1.6 36 

6/23/1989 26.0 1.1 .3 4.7 20.0 66 8/12/1989 .6 0 0 0 1.5 36 

6/24/1989 27.0 2.7 .3 5.0 19.0 65 8/13/1989 .5 0 0 0 1.1 35 

6/25/1989 26.0 1.4 .4 5.3 20.0 64 8/14/1989 .5 0 0 0 1.0 35 

6/26/1989 27.0 1.8 .4 5.0 20.0 64 8/15/1989 .5 0 0 0 1.1 34 

6/27/1989 29.0 1.2 .4 4.5 19.0 63 8/16/1989 .5 0 0 0 1.5 34 

6/28/1989 27.0 .9 .3 4.1 19.0 62 8/17/1989 .4 0 0 0 2.4 34 

6/29/1989 23.0 .7 .3 4.1 18.0 61 8/18/1989 .4 0 0 0 3.1 33 

6/30/1989 20.0 .6 .3 4.2 17.0 60 8/19/1989 .4 0 0 0 3.5 33 

7/1/1989 19.0 .5 .3 4.0 17.0 59 8/20/1989 .4 0 0 0 2.7 33 

7/2/1989 17.0 .4 .2 3.7 16.0 58 8/21/1989 .3 0 0 0 2.7 32 

7/3/1989 15.0 .2 .2 3.7 15.0 58 8/22/1989 .3 0 0 0 2.4 32 

7/4/1989 13.0 .2 .2 3.4 15.0 57 8/23/1989 .3 0 0 0 2.0 31 

7/5/1989 12.0 .1 .2 3.4 14.0 57 8/24/1989 .4 0 0 0 1.6 31 

7/6/1989 11.0 0 .1 2.9 13.0 56 8/25/1989 .3 0 0 0 1.5 30 

7/7/1989 9.5 0 .2 3.0 13.0 56 8/26/1989 .2 0 0 0 1.1 30 

7/8/1989 8.9 0 .2 2.9 12.0 55 8/27/1989 .2 0 0 0 .6 30 

7/9/1989 8.1 0 .1 2.7 11.0 54 8/28/1989 .2 0 0 0 .5 29 

7/10/1989 7.3 0 .1 2.4 10.0 54 8/29/1989 .2 0 0 0 .5 29 
Appendix 2 101 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

8/30/1989 0.2 0 0 0 0.4 29 10/19/1989 0.1 0 0 0 0.1 18 

8/31/1989 .2 0 0 0 .4 29 10/20/1989 .1 0 0 0 .1 18 

9/1/1989 .2 0 0 0 .4 28 10/21/1989 .2 0 0 0 .1 18 

9/2/1989 .2 0 0 0 .3 28 10/22/1989 .2 0 0 0 .1 18 

9/3/1989 .2 0 0 0 .3 29 10/23/1989 .2 0 0 0 .1 18 

9/4/1989 .2 0 0 0 .3 28 10/24/1989 .2 0 0 0 .1 18 

9/5/1989 .2 0 0 0 .3 29 10/25/1989 .2 0 0 0 .1 18 

9/6/1989 .2 0 0 0 .4 28 10/26/1989 .2 0 0 0 .1 18 

9/7/1989 .2 0 0 0 .3 28 10/27/1989 .2 0 0 0 .1 18 

9/8/1989 .1 0 0 0 .2 27 10/28/1989 .3 0 0 0 .2 18 

9/9/1989 .1 0 0 0 .2 27 10/29/1989 .2 0 0 0 .2 18 

9/10/1989 .1 0 0 0 .2 27 10/30/1989 .4 6.2 0 .2 .3 21 

9/11/1989 .1 0 0 0 .1 27 10/31/1989 .2 0 0 .1 .2 24 

9/12/1989 .2 0 0 0 .1 27 11/1/1989 .2 0 0 .1 .2 23 

9/13/1989 .7 0 0 0 .1 27 11/2/1989 .2 0 0 0 .2 23 

9/14/1989 .2 0 0 0 .2 26 11/3/1989 .2 0 0 0 .2 22 

9/15/1989 .2 0 0 0 .3 26 11/4/1989 .2 0 0 0 .1 21 

9/16/1989 .2 0 0 0 .3 26 11/5/1989 .2 0 0 0 .1 21 

9/17/1989 .2 0 0 0 .4 26 11/6/1989 .2 0 0 0 .1 20 

9/18/1989 .2 0 0 0 .4 26 11/7/1989 .2 0 0 0 .2 19 

9/19/1989 .2 0 0 0 .4 26 11/8/1989 .2 0 0 0 .2 19 

9/20/1989 .2 0 0 0 .5 26 11/9/1989 .2 0 0 0 .2 18 

9/21/1989 .2 0 0 0 .4 26 11/10/1989 .2 0 0 0 .3 18 

9/22/1989 .2 0 0 0 .3 25 11/11/1989 .2 0 0 0 .3 18 

9/23/1989 .2 0 0 0 .3 25 11/12/1989 .2 0 0 0 .3 19 

9/24/1989 .2 0 0 0 .3 24 11/13/1989 .3 0 0 0 .3 19 

9/25/1989 .2 0 0 0 .3 24 11/14/1989 .3 0 0 0 .3 19 

9/26/1989 .1 0 0 0 .3 24 11/15/1989 .3 0 0 0 .3 19 

9/27/1989 .1 0 0 0 .3 24 11/16/1989 .2 0 0 0 .3 19 

9/28/1989 .1 0 0 0 .3 24 11/17/1989 .2 0 0 0 .3 20 

9/29/1989 .1 0 0 0 .2 23 11/18/1989 .2 0 0 0 .3 20 

9/30/1989 .1 0 0 0 .2 23 11/19/1989 .2 0 0 0 .3 20 

10/1/1989 .1 0 0 0 .2 19 11/20/1989 .2 0 0 0 .3 20 

10/2/1989 .1 0 0 0 .2 19 11/21/1989 .3 0 0 0 .3 20 

10/3/1989 .1 0 0 0 .2 18 11/22/1989 .5 2.3 0 .1 .4 23 

10/4/1989 .1 0 0 0 .2 18 11/23/1989 .2 0 0 0 .3 25 

10/5/1989 .1 0 0 0 .2 18 11/24/1989 .2 0 0 0 .3 23 

10/6/1989 .1 0 .2 0 .2 18 11/25/1989 .2 0 0 0 .3 22 

10/7/1989 .4 49.0 0 .6 1.3 19 11/26/1989 .3 0 0 0 .3 22 

10/8/1989 .1 0 0 .1 .4 19 11/27/1989 .4 0 0 0 .3 21 

10/9/1989 .1 0 0 0 .3 19 11/28/1989 .3 0 0 0 .3 21 

10/10/1989 .1 0 0 0 .3 19 11/29/1989 .2 0 0 0 .3 22 

10/11/1989 .1 0 0 0 .3 19 11/30/1989 .2 0 0 0 .3 21 

10/12/1989 .1 0 0 .1 .3 19 12/1/1989 .2 0 0 0 .3 19 

10/13/1989 .1 0 0 .1 .2 18 12/2/1989 .2 0 0 0 .3 20 

10/14/1989 .1 0 0 .1 .2 18 12/3/1989 .2 0 0 0 .3 20 

10/15/1989 .1 0 0 .1 .2 18 12/4/1989 .2 0 0 0 .3 20 

10/16/1989 .1 0 0 .1 .2 18 12/5/1989 .2 0 0 0 .3 20 

10/17/1989 .1 0 0 0 .1 18 12/6/1989 .2 0 0 0 .3 19 

10/18/1989 .1 0 0 0 .1 18 12/7/1989 .2 0 0 0 .3 18 
102 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/8/1989 0.2 0 0 0 0.3 19 1/27/1990 0.4 0 0 0 0.4 15 

12/9/1989 .2 0 0 0 .3 19 1/28/1990 .6 0 0 0 .4 16 

12/10/1989 .2 0 0 0 .3 19 1/29/1990 .6 0 0 0 .4 17 

12/11/1989 .2 0 0 0 .3 19 1/30/1990 .6 0 0 0 .4 17 

12/12/1989 .2 0 0 0 .3 19 1/31/1990 .7 0 0 0 .4 16 

12/13/1989 .2 0 0 0 .3 19 2/1/1990 4.3 8.6 0 .1 .8 22 

12/14/1989 .2 0 0 0 .3 19 2/2/1990 2.6 .2 0 0 1.5 20 

12/15/1989 .2 0 0 0 .3 19 2/3/1990 1.2 0 0 0 .8 18 

12/16/1989 .2 0 0 0 .3 19 2/4/1990 .8 0 0 0 .6 16 

12/17/1989 .2 0 0 0 .3 19 2/5/1990 .6 0 0 0 .4 17 

12/18/1989 .2 0 0 0 .3 18 2/6/1990 .6 0 0 0 .4 16 

12/19/1989 .2 0 0 0 .3 18 2/7/1990 .6 0 0 0 .4 16 

12/20/1989 .2 0 0 0 .3 17 2/8/1990 .6 0 0 0 .3 16 

12/21/1989 .2 0 0 0 .3 17 2/9/1990 .9 6.7 0 0 .5 17 

12/22/1989 .2 0 0 0 .3 18 2/10/1990 1.0 .3 0 0 .7 19 

12/23/1989 .2 0 0 0 .4 18 2/11/1990 .9 0 0 0 .6 19 

12/24/1989 .2 0 0 0 .4 18 2/12/1990 .8 0 0 0 .4 18 

12/25/1989 .2 0 0 0 .4 18 2/13/1990 .8 0 0 0 .4 17 

12/26/1989 .2 0 0 0 .3 17 2/14/1990 .7 0 0 0 .4 17 

12/27/1989 .3 0 0 0 .2 18 2/15/1990 .9 0 0 0 .4 16 

12/28/1989 .3 0 0 0 .3 17 2/16/1990 .8 0 0 0 .5 15 

12/29/1989 .3 0 0 0 .3 15 2/17/1990 .7 0 0 0 .5 15 

12/30/1989 .3 0 0 0 .3 14 2/18/1990 1.6 2.6 0 0 .7 15 

12/31/1989 .3 0 0 0 .3 15 2/19/1990 1.6 0 0 0 1.0 17 

1/1/1990 .3 0 0 0 .3 15 2/20/1990 1.1 0 0 0 .9 16 

1/2/1990 .3 0 0 0 .4 15 2/21/1990 2.3 5.5 0 0 3.4 18 

1/3/1990 .4 0 0 0 .5 16 2/22/1990 1.9 .4 0 0 2.8 17 

1/4/1990 .4 0 0 0 .4 16 2/23/1990 1.3 .2 0 0 1.0 16 

1/5/1990 .3 0 0 0 .4 16 2/24/1990 1.2 .1 0 0 .8 15 

1/6/1990 .4 0 0 0 .6 17 2/25/1990 1.2 0 0 0 .7 15 

1/7/1990 .4 0 0 0 .5 17 2/26/1990 1.3 0 0 0 .6 15 

1/8/1990 .4 0 0 0 .6 16 2/27/1990 1.4 0 0 0 .7 16 

1/9/1990 .4 0 0 0 .6 15 2/28/1990 2.1 3.5 0 0 2.4 16 

1/10/1990 .4 0 0 0 .5 15 3/1/1990 2.4 2.5 0 0 3.5 16 

1/11/1990 .4 0 0 0 .5 15 3/2/1990 2.0 .8 0 0 3.2 17 

1/12/1990 .4 0 0 0 .5 15 3/3/1990 1.8 .4 0 0 2.2 17 

1/13/1990 .3 0 0 0 .4 15 3/4/1990 1.9 .3 0 0 1.5 17 

1/14/1990 .3 0 0 0 .4 15 3/5/1990 1.9 .2 0 0 1.1 17 

1/15/1990 .3 0 0 0 .4 15 3/6/1990 1.8 .1 0 0 1.1 17 

1/16/1990 .5 0 0 0 .4 15 3/7/1990 2.1 1.4 0 .1 2.0 17 

1/17/1990 .4 0 0 0 .4 16 3/8/1990 2.8 .4 0 .1 2.6 16 

1/18/1990 .4 0 0 0 .4 16 3/9/1990 2.2 .2 0 .1 2.2 16 

1/19/1990 .5 0 0 0 .5 18 3/10/1990 2.0 .1 0 .1 1.8 16 

1/20/1990 .4 0 0 0 .4 18 3/11/1990 2.0 .4 0 .1 1.8 15 

1/21/1990 .4 0 0 0 .4 17 3/12/1990 2.0 .2 0 .1 1.7 15 

1/22/1990 .3 0 0 0 .4 16 3/13/1990 2.1 .2 0 .1 1.8 15 

1/23/1990 .3 0 0 0 .4 16 3/14/1990 23.0 34.0 .2 4.6 114.0 18 

1/24/1990 .3 0 0 0 .4 15 3/15/1990 75.0 6.4 0 4.8 53.0 25 

1/25/1990 .4 0 0 0 .3 15 3/16/1990 30.0 3.1 0 3.8 19.0 26 

1/26/1990 .4 0 0 0 .4 15 3/17/1990 20.0 1.9 0 3.3 12.0 27 
Appendix 2 103 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

3/18/1990 16.0 1.4 0 2.8 10.0 28 5/7/1990 79.0 12.0 6.7 8.7 99.0 63 

3/19/1990 14.0 1.2 0 2.6 8.8 27 5/8/1990 68.0 8.8 5.6 8.0 80.0 61 

3/20/1990 12.0 1.2 0 2.4 8.0 26 5/9/1990 61.0 6.3 4.7 7.7 73.0 59 

3/21/1990 12.0 1.1 0 2.2 8.0 26 5/10/1990 53.0 4.0 3.7 6.6 63.0 59 

3/22/1990 11.0 1.1 0 2.2 8.0 26 5/11/1990 48.0 3.4 3.5 6.4 58.0 58 

3/23/1990 11.0 1.0 0 2.2 7.6 25 5/12/1990 48.0 3.7 3.4 6.0 61.0 58 

3/24/1990 10.0 .8 0 1.9 7.1 25 5/13/1990 44.0 2.0 2.8 5.1 59.0 58 

3/25/1990 9.6 .8 0 1.7 6.8 25 5/14/1990 39.0 1.7 2.5 5.0 54.0 57 

3/26/1990 9.3 .7 0 1.7 7.4 25 5/15/1990 38.0 1.5 2.4 4.3 51.0 56 

3/27/1990 9.3 .7 0 1.7 6.5 25 5/16/1990 36.0 1.1 2.1 4.2 47.0 56 

3/28/1990 10.0 1.3 0 1.7 7.3 26 5/17/1990 34.0 1.1 1.8 4.1 44.0 56 

3/29/1990 11.0 2.0 0 1.9 7.1 26 5/18/1990 33.0 3.6 1.9 3.8 43.0 55 

3/30/1990 11.0 1.3 0 1.6 8.2 27 5/19/1990 34.0 2.2 2.3 3.5 42.0 55 

3/31/1990 11.0 .6 0 1.5 8.8 27 5/20/1990 31.0 1.4 1.8 3.3 37.0 55 

4/1/1990 11.0 1.0 0 1.5 10.0 26 5/21/1990 28.0 1.1 1.7 3.2 34.0 54 

4/2/1990 11.0 .7 0 1.5 9.7 26 5/22/1990 26.0 .8 1.4 3.0 32.0 53 

4/3/1990 9.6 .4 0 1.5 8.9 26 5/23/1990 23.0 .7 1.4 3.0 31.0 53 

4/4/1990 9.0 .2 0 1.4 9.0 26 5/24/1990 22.0 .7 1.3 3.0 30.0 52 

4/5/1990 8.9 .2 0 1.4 8.9 26 5/25/1990 20.0 .6 1.3 2.7 28.0 51 

4/6/1990 15.0 5.5 0 1.8 8.8 27 5/26/1990 18.0 .5 1.1 2.4 25.0 50 

4/7/1990 12.0 .5 0 1.6 8.0 27 5/27/1990 16.0 .4 1.0 2.4 29.0 50 

4/8/1990 9.8 .3 0 1.5 8.0 27 5/28/1990 21.0 7.1 .8 2.4 37.0 50 

4/9/1990 9.7 1.0 .1 1.4 12.0 26 5/29/1990 17.0 .6 .8 2.0 37.0 50 

4/10/1990 9.8 .6 .1 1.4 9.5 26 5/30/1990 16.0 .5 .8 1.7 37.0 49 

4/11/1990 9.5 .3 .1 1.4 8.5 26 5/31/1990 15.0 .4 .7 1.5 34.0 48 

4/12/1990 9.0 .2 .1 1.4 8.5 26 6/1/1990 13.0 .3 .7 1.3 32.0 48 

4/13/1990 8.7 .2 .1 1.4 8.9 26 6/2/1990 12.0 .3 .6 1.1 26.0 47 

4/14/1990 8.8 .3 .1 2.3 9.2 26 6/3/1990 11.0 .2 .5 .9 16.0 47 

4/15/1990 8.9 .2 .1 1.7 8.5 26 6/4/1990 15.0 3.8 .7 2.5 80.0 47 

4/16/1990 8.3 .1 .2 1.7 8.5 26 6/5/1990 41.0 .3 .6 1.8 30.0 47 

4/17/1990 8.1 .4 .2 1.7 8.5 26 6/6/1990 20.0 .1 .5 1.4 25.0 49 

4/18/1990 8.1 .3 .2 1.6 8.5 26 6/7/1990 13.0 .1 .5 .9 20.0 48 

4/19/1990 8.4 .2 .2 1.5 8.5 26 6/8/1990 10.0 .5 .5 .7 18.0 48 

4/20/1990 8.4 .1 .2 1.5 8.5 25 6/9/1990 8.7 0 .4 .6 16.0 47 

4/21/1990 8.1 .1 .2 1.5 8.9 25 6/10/1990 7.0 0 .4 .5 16.0 47 

4/22/1990 7.9 0 .1 1.5 9.5 26 6/11/1990 6.2 0 .4 .5 15.0 46 

4/23/1990 7.4 0 .1 1.5 9.5 26 6/12/1990 5.0 0 .4 .5 14.0 45 

4/24/1990 7.0 0 .2 1.5 9.5 26 6/13/1990 4.2 0 .4 .4 14.0 47 

4/25/1990 6.5 0 .3 1.5 9.5 28 6/14/1990 3.5 0 .4 .4 14.0 46 

4/26/1990 25.0 50.0 1.8 3.4 78.0 30 6/15/1990 3.0 0 .4 .3 14.0 46 

4/27/1990 76.0 7.4 .9 4.0 102.0 40 6/16/1990 2.7 0 .4 .3 13.0 45 

4/28/1990 34.0 2.8 .7 3.7 37.0 38 6/17/1990 2.3 0 .3 .3 12.0 45 

4/29/1990 25.0 1.8 .7 3.7 30.0 38 6/18/1990 1.9 0 .3 .2 13.0 45 

4/30/1990 21.0 1.3 .6 3.6 27.0 37 6/19/1990 1.7 0 .2 .2 12.0 45 

5/1/1990 22.0 10.0 .7 3.8 24.0 37 6/20/1990 1.3 0 .2 .2 12.0 44 

5/2/1990 79.0 45.0 3.1 4.6 25.0 36 6/21/1990 1.0 0 .2 .1 12.0 43 

5/3/1990 715.0 291.0 79.0 58.0 608.0 60 6/22/1990 .9 0 .2 .1 12.0 43 

5/4/1990 197.0 51.0 17.0 13.0 217.0 72 6/23/1990 .7 0 .2 .1 11.0 42 

5/5/1990 118.0 31.0 11.0 12.0 146.0 68 6/24/1990 .6 0 .1 .1 14.0 42 

5/6/1990 98.0 19.0 8.5 10.0 125.0 64 6/25/1990 .5 0 .1 .1 13.0 41 
104 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/26/1990 0.5 0 0.1 0.1 11.0 40 8/15/1990 0.5 0 0 0 1.9 26 

6/27/1990 .4 0 .1 .1 9.6 39 8/16/1990 .5 0 0 0 1.9 25 

6/28/1990 .3 0 0 0 7.7 38 8/17/1990 .5 0 0 0 2.0 25 

6/29/1990 .3 0 0 0 6.2 38 8/18/1990 .5 0 0 0 1.4 25 

6/30/1990 .5 0 0 0 5.8 37 8/19/1990 .5 0 0 0 1.4 25 

7/1/1990 .3 0 0 0 6.0 38 8/20/1990 .5 .5 0 0 1.5 25 

7/2/1990 .3 0 0 0 5.0 37 8/21/1990 .5 0 0 0 1.8 26 

7/3/1990 .3 0 0 0 4.9 36 8/22/1990 .5 0 0 0 1.8 26 

7/4/1990 .3 0 0 0 5.2 35 8/23/1990 .4 0 0 0 1.8 25 

7/5/1990 .3 0 0 0 6.2 34 8/24/1990 .4 0 0 0 1.7 24 

7/6/1990 .3 0 0 0 5.1 34 8/25/1990 .4 0 0 0 1.7 23 

7/7/1990 .3 0 0 0 4.2 33 8/26/1990 .3 0 0 0 1.7 23 

7/8/1990 .3 0 0 0 3.3 33 8/27/1990 .3 0 0 0 1.4 23 

7/9/1990 .3 0 0 0 2.5 32 8/28/1990 .3 0 0 0 1.8 23 

7/10/1990 .3 0 0 0 1.8 32 8/29/1990 .3 0 0 0 1.7 22 

7/11/1990 .3 0 0 0 1.3 31 8/30/1990 .4 0 0 0 1.4 22 

7/12/1990 .3 0 0 0 1.0 30 8/31/1990 .4 0 0 0 1.2 21 

7/13/1990 .2 0 0 0 .9 30 9/1/1990 .3 0 0 0 .8 21 

7/14/1990 .2 0 0 0 .7 29 9/2/1990 .4 0 .1 0 1.4 22 

7/15/1990 8.0 24.0 .1 0 3.3 30 9/3/1990 .4 0 0 0 1.5 22 

7/16/1990 5.6 2.7 0 0 6.5 31 9/4/1990 .4 0 0 0 1.6 23 

7/17/1990 1.6 0 0 0 3.8 32 9/5/1990 .4 0 0 0 2.9 23 

7/18/1990 5.1 0 0 0 3.2 33 9/6/1990 .5 0 0 0 2.9 22 

7/19/1990 2.7 5.0 .2 .1 3.0 34 9/7/1990 .6 0 0 0 2.7 21 

7/20/1990 2.5 .1 .1 .1 4.0 34 9/8/1990 .5 0 0 0 2.5 20 

7/21/1990 6.6 0 .1 .3 2.2 36 9/9/1990 .5 0 0 0 2.7 22 

7/22/1990 1.9 0 .1 .2 1.8 36 9/10/1990 .4 0 0 0 5.1 24 

7/23/1990 6.2 7.7 .1 .2 3.2 36 9/11/1990 .4 0 0 0 3.5 24 

7/24/1990 28.0 43.0 .2 .2 4.2 35 9/12/1990 .4 0 0 0 3.3 23 

7/25/1990 12.0 .8 .2 .2 3.2 35 9/13/1990 .4 0 0 0 3.0 23 

7/26/1990 5.6 .1 .2 .1 2.7 35 9/14/1990 .4 0 0 0 2.8 23 

7/27/1990 3.5 0 .2 .1 2.2 35 9/15/1990 .4 0 0 0 1.9 22 

7/28/1990 2.5 0 .2 0 1.8 34 9/16/1990 1.1 2.1 0 0 1.7 22 

7/29/1990 2.4 0 .2 0 1.6 34 9/17/1990 1.1 .2 0 0 1.4 22 

7/30/1990 2.0 0 .2 0 1.1 34 9/18/1990 .9 0 0 0 1.3 23 

7/31/1990 4.4 4.6 .2 0 1.0 33 9/19/1990 .6 0 0 0 1.1 23 

8/1/1990 3.0 .5 .2 0 .7 33 9/20/1990 .5 0 0 0 1.1 23 

8/2/1990 2.7 0 .2 0 .7 32 9/21/1990 .5 0 0 0 1.0 23 

8/3/1990 2.6 0 .1 0 .9 32 9/22/1990 .4 0 0 0 .9 23 

8/4/1990 1.9 0 .1 0 1.1 31 9/23/1990 .5 0 0 0 .9 22 

8/5/1990 1.6 0 .1 0 1.1 31 9/24/1990 .5 0 0 0 .7 22 

8/6/1990 1.2 0 0 0 1.1 30 9/25/1990 .4 0 0 0 .6 21 

8/7/1990 .8 0 0 0 1.2 29 9/26/1990 .4 0 0 0 .6 21 

8/8/1990 .8 0 0 0 1.4 28 9/27/1990 .4 0 0 0 .6 21 

8/9/1990 .8 0 0 0 1.4 28 9/28/1990 .4 0 0 0 .5 20 

8/10/1990 1.2 0 0 0 2.1 27 9/29/1990 .4 0 0 0 .4 20 

8/11/1990 1.1 0 0 0 2.1 27 9/30/1990 .4 0 0 0 .4 20 

8/12/1990 .9 0 0 0 2.1 27 10/1/1990 .2 0 0 0 .1 20 

8/13/1990 .6 0 0 0 2.2 26 10/2/1990 .2 0 0 0 .1 20 

8/14/1990 .5 0 0 0 2.2 26 10/3/1990 .2 0 0 0 .1 20 
Appendix 2 105 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/4/1990 0.2 0 0 0 0.1 20 11/23/1990 2.2 0 0 0 0.8 25 

10/5/1990 .3 0 0 0 .1 19 11/24/1990 1.9 0 0 0 .8 25 

10/6/1990 .4 0 0 0 .1 19 11/25/1990 1.9 0 0 0 .8 24 

10/7/1990 .3 0 0 0 .1 19 11/26/1990 1.9 0 0 0 .7 22 

10/8/1990 .3 0 0 0 .1 19 11/27/1990 2.0 0 0 0 .7 20 

10/9/1990 11.0 36.0 .4 0 1.7 23 11/28/1990 1.8 0 0 0 .7 21 

10/10/1990 2.7 0 0 0 .7 22 11/29/1990 1.6 0 0 0 .6 21 

10/11/1990 .7 0 0 0 .3 21 11/30/1990 1.4 0 0 0 .4 21 

10/12/1990 .6 0 0 0 .2 21 12/1/1990 1.4 0 0 0 .4 21 

10/13/1990 .5 0 0 0 .2 21 12/2/1990 1.4 0 0 0 .4 21 

10/14/1990 .5 0 0 0 .2 21 12/3/1990 1.4 0 0 0 .6 22 

10/15/1990 .5 0 0 0 .2 21 12/4/1990 1.2 0 0 0 .7 22 

10/16/1990 .4 0 0 0 .2 20 12/5/1990 1.1 0 0 0 .7 23 

10/17/1990 .5 0 0 0 .2 21 12/6/1990 1.1 0 0 0 .7 22 

10/18/1990 .5 0 0 0 .1 20 12/7/1990 1.1 0 0 0 .7 22 

10/19/1990 .5 0 0 0 .1 20 12/8/1990 1.1 0 0 0 .6 22 

10/20/1990 .5 0 0 0 .1 20 12/9/1990 1.1 0 0 0 .5 21 

10/21/1990 1.5 7.6 .2 0 .2 23 12/10/1990 1.1 0 0 0 .5 21 

10/22/1990 1.7 .2 0 0 .2 26 12/11/1990 1.2 0 0 0 .5 20 

10/23/1990 .9 0 0 0 .2 24 12/12/1990 1.3 0 0 0 .6 20 

10/24/1990 .7 0 0 0 .2 23 12/13/1990 1.2 0 0 0 .7 20 

10/25/1990 .6 0 0 0 .2 22 12/14/1990 1.1 0 0 0 .8 20 

10/26/1990 .6 0 0 0 .2 20 12/15/1990 1.1 0 0 0 1.2 20 

10/27/1990 .6 0 0 0 .2 19 12/16/1990 1.1 0 0 0 1.0 20 

10/28/1990 .6 0 0 0 .2 19 12/17/1990 1.2 0 0 0 .8 20 

10/29/1990 .7 0 0 0 .2 19 12/18/1990 1.4 0 0 0 .5 19 

10/30/1990 .7 0 0 0 .2 19 12/19/1990 1.2 0 0 0 .5 19 

10/31/1990 .6 0 0 0 .2 19 12/20/1990 1.1 0 0 0 .5 18 

11/1/1990 .5 0 0 0 .2 19 12/21/1990 1.1 0 0 0 .5 19 

11/2/1990 .5 0 0 0 .2 19 12/22/1990 1.1 0 0 0 .5 19 

11/3/1990 .6 0 0 0 .2 19 12/23/1990 1.0 0 0 0 .5 19 

11/4/1990 1.9 5.4 .1 0 .2 21 12/24/1990 1.0 0 0 0 .5 19 

11/5/1990 2.0 0 0 0 .2 22 12/25/1990 1.0 0 0 0 .6 20 

11/6/1990 1.2 0 0 0 .2 23 12/26/1990 1.3 0 0 0 .9 20 

11/7/1990 1.0 0 0 0 .2 24 12/27/1990 1.5 0 0 0 1.0 21 

11/8/1990 8.8 32.0 .6 0 1.9 31 12/28/1990 1.1 0 0 0 1.0 20 

11/9/1990 6.2 1.7 0 0 2.6 30 12/29/1990 1.1 0 0 0 1.0 20 

11/10/1990 2.6 .2 0 0 .8 29 12/30/1990 1.1 0 0 0 1.0 20 

11/11/1990 2.0 0 0 0 1.0 28 12/31/1990 1.1 0 0 0 .8 20 

11/12/1990 1.8 0 0 0 1.0 27 1/1/1991 1.1 0 0 0 .7 20 

11/13/1990 1.7 0 0 0 1.0 26 1/2/1991 7.9 29.0 .4 0 6.4 35 

11/14/1990 1.6 0 0 0 .9 25 1/3/1991 57.0 2.0 0 2.0 7.9 33 

11/15/1990 1.7 0 0 0 1.0 25 1/4/1991 32.0 .7 0 1.4 7.0 31 

11/16/1990 1.8 0 0 0 1.0 24 1/5/1991 20.0 .8 0 1.2 8.8 30 

11/17/1990 1.8 0 0 0 1.0 24 1/6/1991 18.0 1.4 0 1.2 11.0 29 

11/18/1990 1.8 0 0 0 .9 24 1/7/1991 18.0 .5 0 1.2 11.0 28 

11/19/1990 2.0 0 0 0 .8 24 1/8/1991 17.0 .4 0 1.2 11.0 27 

11/20/1990 2.1 0 0 0 .8 23 1/9/1991 488.0 218.0 67.0 91.0 340.0 65 

11/21/1990 1.9 0 0 0 .8 24 1/10/1991 476.0 38.0 26.0 26.0 218.0 85 

11/22/1990 2.0 0 0 0 .8 24 1/11/1991 176.0 12.0 12.0 17.0 116.0 84 
106 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/12/1991 127.0 7.6 10.0 14.0 83.0 83 3/3/1991 81.0 6.0 9.2 12.0 67.0 87 

1/13/1991 106.0 5.8 8.4 13.0 64.0 81 3/4/1991 74.0 6.0 8.7 12.0 64.0 87 

1/14/1991 88.0 4.8 7.4 11.0 54.0 80 3/5/1991 72.0 5.8 8.2 12.0 65.0 86 

1/15/1991 79.0 4.0 5.7 10.0 44.0 79 3/6/1991 68.0 5.7 7.7 11.0 63.0 86 

1/16/1991 68.0 3.3 4.9 8.8 36.0 78 3/7/1991 66.0 5.4 7.1 11.0 60.0 85 

1/17/1991 62.0 2.9 4.2 8.1 32.0 77 3/8/1991 62.0 5.6 6.6 11.0 58.0 85 

1/18/1991 235.0 48.0 42.0 36.0 169.0 85 3/9/1991 59.0 5.5 6.1 10.0 56.0 85 

1/19/1991 269.0 15.0 23.0 23.0 146.0 81 3/10/1991 57.0 5.7 5.9 9.0 55.0 85 

1/20/1991 159.0 9.1 15.0 20.0 114.0 78 3/11/1991 56.0 5.8 5.9 8.9 54.0 85 

1/21/1991 133.0 6.8 13.0 17.0 91.0 79 3/12/1991 55.0 5.5 5.5 9.6 54.0 85 

1/22/1991 121.0 6.1 12.0 16.0 89.0 79 3/13/1991 54.0 5.2 4.8 10.0 50.0 85 

1/23/1991 112.0 6.0 12.0 15.0 82.0 79 3/14/1991 52.0 4.8 4.3 8.9 48.0 84 

1/24/1991 130.0 16.0 20.0 20.0 104.0 80 3/15/1991 51.0 5.4 4.1 8.9 51.0 84 

1/25/1991 128.0 8.1 15.0 17.0 93.0 81 3/16/1991 61.0 7.6 5.9 9.7 58.0 85 

1/26/1991 115.0 6.9 13.0 17.0 87.0 82 3/17/1991 87.0 5.1 6.4 11.0 68.0 85 

1/27/1991 111.0 6.4 12.0 17.0 87.0 82 3/18/1991 63.0 4.5 4.7 9.0 59.0 85 

1/28/1991 107.0 5.7 11.0 15.0 84.0 82 3/19/1991 53.0 4.4 4.3 8.9 55.0 84 

1/29/1991 102.0 5.5 11.0 15.0 80.0 82 3/20/1991 51.0 4.2 3.5 8.5 52.0 84 

1/30/1991 93.0 5.7 9.9 13.0 70.0 82 3/21/1991 51.0 4.2 3.5 8.5 51.0 84 

1/31/1991 92.0 4.9 9.8 13.0 64.0 82 3/22/1991 49.0 3.8 3.3 8.2 49.0 84 

2/1/1991 83.0 4.4 9.4 12.0 61.0 81 3/23/1991 47.0 3.4 2.8 7.4 45.0 84 

2/2/1991 80.0 4.2 9.2 12.0 62.0 81 3/24/1991 46.0 3.3 2.8 7.4 44.0 83 

2/3/1991 77.0 3.7 9.2 12.0 64.0 82 3/25/1991 46.0 3.3 2.7 7.4 43.0 83 

2/4/1991 293.0 40.0 37.0 38.0 217.0 90 3/26/1991 46.0 3.5 2.7 7.4 45.0 83 

2/5/1991 304.0 13.0 20.0 25.0 202.0 88 3/27/1991 43.0 3.2 2.5 7.2 44.0 83 

2/6/1991 191.0 9.8 15.0 23.0 163.0 87 3/28/1991 40.0 3.1 2.6 6.5 40.0 83 

2/7/1991 160.0 7.9 12.0 20.0 146.0 86 3/29/1991 40.0 2.8 2.6 6.4 40.0 83 

2/8/1991 146.0 6.9 11.0 18.0 135.0 85 3/30/1991 39.0 2.5 2.3 6.4 38.0 82 

2/9/1991 137.0 6.1 10.0 18.0 126.0 85 3/31/1991 38.0 2.4 2.3 6.2 36.0 82 

2/10/1991 128.0 5.5 8.9 17.0 118.0 85 4/1/1991 36.0 2.4 2.3 6.1 35.0 82 

2/11/1991 120.0 5.3 8.2 15.0 107.0 85 4/2/1991 36.0 2.6 2.3 6.2 35.0 83 

2/12/1991 113.0 5.4 7.9 15.0 103.0 84 4/3/1991 36.0 2.4 1.8 5.9 35.0 82 

2/13/1991 109.0 4.7 7.8 14.0 101.0 84 4/4/1991 36.0 24.0 3.5 10.0 35.0 82 

2/14/1991 102.0 4.4 7.2 12.0 93.0 83 4/5/1991 125.0 64.0 53.0 79.0 211.0 99 

2/15/1991 91.0 4.0 6.6 11.0 86.0 83 4/6/1991 131.0 12.0 17.0 31.0 171.0 99 

2/16/1991 83.0 3.9 6.5 11.0 82.0 83 4/7/1991 133.0 32.0 45.0 50.0 207.0 98 

2/17/1991 83.0 3.9 7.0 11.0 85.0 82 4/8/1991 132.0 14.0 26.0 38.0 187.0 97 

2/18/1991 87.0 6.6 7.5 11.0 85.0 82 4/9/1991 114.0 11.0 18.0 33.0 158.0 95 

2/19/1991 126.0 8.7 13.0 15.0 118.0 86 4/10/1991 107.0 8.7 15.0 29.0 142.0 95 

2/20/1991 112.0 4.9 8.5 11.0 96.0 86 4/11/1991 106.0 9.0 15.0 29.0 138.0 95 

2/21/1991 113.0 18.0 14.0 15.0 90.0 85 4/12/1991 104.0 7.7 13.0 26.0 130.0 93 

2/22/1991 123.0 10.0 13.0 15.0 90.0 87 4/13/1991 95.0 7.6 11.0 24.0 127.0 94 

2/23/1991 109.0 8.2 12.0 13.0 83.0 87 4/14/1991 191.0 76.0 62.0 62.0 588.0 95 

2/24/1991 106.0 7.3 10.0 12.0 82.0 86 4/15/1991 152.0 12.0 22.0 32.0 273.0 99 

2/25/1991 102.0 7.4 14.0 14.0 81.0 86 4/16/1991 111.0 9.8 17.0 29.0 224.0 99 

2/26/1991 103.0 6.3 12.0 14.0 80.0 86 4/17/1991 106.0 8.8 15.0 30.0 223.0 99 

2/27/1991 97.0 5.9 11.0 13.0 77.0 86 4/18/1991 123.0 40.0 27.0 32.0 283.0 99 

2/28/1991 94.0 7.5 12.0 14.0 75.0 86 4/19/1991 204.0 26.0 30.0 30.0 223.0 99 

3/1/1991 104.0 8.5 14.0 15.0 80.0 87 4/20/1991 137.0 13.0 17.0 26.0 199.0 99 

3/2/1991 95.0 6.7 11.0 14.0 75.0 87 4/21/1991 121.0 11.0 15.0 24.0 188.0 101 
Appendix 2 107 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/22/1991 119.0 9.0 13.0 23.0 181.0 100 6/11/1991 68.0 51.0 2.8 4.9 40.0 91 

4/23/1991 110.0 7.5 10.0 20.0 164.0 100 6/12/1991 80.0 31.0 16.0 7.4 65.0 91 

4/24/1991 106.0 6.8 9.7 20.0 153.0 99 6/13/1991 51.0 4.4 2.8 5.3 56.0 91 

4/25/1991 105.0 6.3 9.0 19.0 147.0 99 6/14/1991 40.0 2.5 1.9 4.6 45.0 91 

4/26/1991 97.0 5.6 8.2 16.0 138.0 99 6/15/1991 34.0 1.9 1.6 4.2 41.0 91 

4/27/1991 91.0 5.3 7.6 16.0 134.0 99 6/16/1991 46.0 4.7 1.5 4.1 42.0 91 

4/28/1991 91.0 6.7 7.5 15.0 130.0 99 6/17/1991 99.0 5.3 2.2 4.3 67.0 91 

4/29/1991 105.0 5.0 7.0 14.0 130.0 99 6/18/1991 66.0 1.9 1.7 3.9 55.0 91 

4/30/1991 81.0 4.1 5.8 12.0 109.0 99 6/19/1991 44.0 1.7 1.4 3.9 44.0 91 

5/1/1991 69.0 3.9 5.3 12.0 101.0 99 6/20/1991 37.0 1.7 1.3 3.7 38.0 91 

5/2/1991 68.0 5.1 5.5 12.0 102.0 99 6/21/1991 33.0 1.7 1.2 3.5 35.0 91 

5/3/1991 68.0 4.7 6.4 14.0 110.0 99 6/22/1991 31.0 1.8 1.1 3.4 34.0 90 

5/4/1991 76.0 10.0 7.6 20.0 104.0 99 6/23/1991 29.0 2.5 1.7 3.7 43.0 89 

5/5/1991 99.0 5.2 8.0 18.0 151.0 99 6/24/1991 36.0 1.0 1.2 3.3 43.0 89 

5/6/1991 82.0 3.4 5.2 13.0 103.0 99 6/25/1991 33.0 1.0 1.1 3.2 40.0 89 

5/7/1991 67.0 3.1 4.8 12.0 91.0 99 6/26/1991 29.0 1.1 1.1 2.9 41.0 89 

5/8/1991 250.0 68.0 38.0 48.0 217.0 99 6/27/1991 26.0 1.1 1.0 2.7 34.0 89 

5/9/1991 261.0 24.0 17.0 29.0 218.0 99 6/28/1991 23.0 1.1 .9 2.6 31.0 89 

5/10/1991 150.0 15.0 13.0 25.0 168.0 99 6/29/1991 25.0 5.5 1.6 2.9 32.0 88 

5/11/1991 139.0 12.0 12.0 22.0 156.0 99 6/30/1991 24.0 1.0 1.5 3.0 35.0 88 

5/12/1991 131.0 9.2 10.0 20.0 143.0 99 7/1/1991 25.0 .7 1.2 2.7 33.0 87 

5/13/1991 125.0 7.8 8.9 19.0 135.0 99 7/2/1991 25.0 .5 .9 2.3 30.0 87 

5/14/1991 118.0 7.0 8.2 17.0 126.0 96 7/3/1991 19.0 .6 .8 6.5 29.0 86 

5/15/1991 115.0 6.3 7.8 16.0 121.0 93 7/4/1991 19.0 .6 .8 3.6 29.0 86 

5/16/1991 112.0 7.6 7.3 15.0 119.0 93 7/5/1991 17.0 .6 .8 2.7 31.0 85 

5/17/1991 109.0 5.2 6.9 15.0 120.0 93 7/6/1991 16.0 .6 .7 2.5 26.0 85 

5/18/1991 105.0 4.1 6.1 13.0 108.0 93 7/7/1991 15.0 .5 .5 2.3 23.0 85 

5/19/1991 95.0 6.0 6.1 13.0 102.0 92 7/8/1991 18.0 .5 .6 2.6 24.0 84 

5/20/1991 85.0 3.3 5.6 12.0 100.0 93 7/9/1991 14.0 .3 .7 2.2 27.0 84 

5/21/1991 75.0 2.4 4.9 11.0 93.0 93 7/10/1991 12.0 .2 .5 1.8 26.0 84 

5/22/1991 67.0 2.0 4.5 10.0 88.0 93 7/11/1991 12.0 .1 .4 1.5 22.0 83 

5/23/1991 62.0 1.6 4.2 8.1 82.0 93 7/12/1991 11.0 0 .4 1.5 20.0 83 

5/24/1991 60.0 1.3 3.7 8.1 77.0 93 7/13/1991 8.6 0 .4 1.5 21.0 83 

5/25/1991 55.0 1.2 3.5 7.7 74.0 93 7/14/1991 7.3 0 .3 1.4 19.0 83 

5/26/1991 50.0 1.0 3.2 7.4 68.0 93 7/15/1991 6.5 0 .3 1.2 21.0 83 

5/27/1991 45.0 .8 2.8 6.8 62.0 93 7/16/1991 5.6 0 .3 1.0 19.0 82 

5/28/1991 41.0 .7 2.5 6.0 57.0 93 7/17/1991 4.9 0 .3 1.1 17.0 82 

5/29/1991 39.0 .7 2.5 5.7 54.0 93 7/18/1991 5.1 0 .3 1.1 16.0 81 

5/30/1991 37.0 .6 2.4 5.8 53.0 92 7/19/1991 4.8 0 .3 .8 15.0 81 

5/31/1991 34.0 .6 2.3 5.5 49.0 90 7/20/1991 4.6 0 .3 .8 14.0 81 

6/1/1991 33.0 .6 2.2 5.4 46.0 92 7/21/1991 4.6 0 .3 .8 15.0 81 

6/2/1991 32.0 .5 2.1 5.2 43.0 92 7/22/1991 4.4 0 .7 .8 12.0 80 

6/3/1991 33.0 11.0 2.9 6.1 46.0 92 7/23/1991 4.2 0 .3 .9 13.0 80 

6/4/1991 41.0 1.9 3.1 6.3 58.0 92 7/24/1991 4.2 0 .3 .8 12.0 80 

6/5/1991 41.0 .7 2.3 4.9 45.0 92 7/25/1991 4.2 0 .3 .7 11.0 75 

6/6/1991 33.0 .5 2.1 4.8 41.0 92 7/26/1991 3.8 0 .3 .7 11.0 75 

6/7/1991 33.0 18.0 2.9 5.1 47.0 92 7/27/1991 3.6 0 .3 .7 11.0 79 

6/8/1991 37.0 1.0 2.3 4.6 51.0 91 7/28/1991 3.5 0 .3 .6 9.8 79 

6/9/1991 35.0 .8 2.1 4.6 42.0 90 7/29/1991 4.8 0 .3 .6 11.0 79 

6/10/1991 31.0 .8 2.1 4.5 41.0 91 7/30/1991 4.2 0 .2 .6 14.0 79 
108 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

7/31/1991 3.0 0 0.2 0.4 8.8 79 9/19/1991 103.0 0 21.0 4.7 215.0 68 

8/1/1991 2.8 0 .2 .5 7.3 76 9/20/1991 63.0 0 13.0 4.9 53.0 69 

8/2/1991 2.6 0 .2 .5 6.9 75 9/21/1991 39.0 0 9.4 4.9 37.0 70 

8/3/1991 2.6 0 .2 .4 6.7 75 9/22/1991 33.0 0 7.6 4.8 32.0 70 

8/4/1991 2.5 0 .2 .4 5.3 75 9/23/1991 31.0 0 7.0 5.0 95.0 69 

8/5/1991 2.5 0 .2 .3 4.9 75 9/24/1991 36.0 .3 7.3 5.2 81.0 68 

8/6/1991 2.4 0 .2 .3 4.9 75 9/25/1991 29.0 0 6.6 4.4 65.0 70 

8/7/1991 2.2 0 .2 .2 5.2 73 9/26/1991 26.0 0 5.5 4.3 51.0 70 

8/8/1991 2.4 0 .2 .2 5.2 71 9/27/1991 24.0 0 4.8 4.2 45.0 69 

8/9/1991 2.4 0 .2 .1 6.5 71 9/28/1991 22.0 0 4.3 4.1 40.0 69 

8/10/1991 2.2 0 .2 .1 6.1 71 9/29/1991 21.0 0 3.8 3.8 37.0 68 

8/11/1991 2.0 0 .2 .1 5.7 71 9/30/1991 21.0 0 3.8 3.8 35.0 68 

8/12/1991 2.0 0 .2 .1 5.2 71 10/1/1991 19.0 0 3.3 3.7 33.0 61 

8/13/1991 1.9 0 .2 .1 4.8 71 10/2/1991 18.0 0 3.1 3.6 31.0 67 

8/14/1991 4.1 12.0 5.9 1.7 5.0 71 10/3/1991 15.0 0 3.1 3.6 29.0 67 

8/15/1991 467.0 107.0 42.0 11.0 58.0 71 10/4/1991 17.0 0 2.8 3.5 28.0 67 

8/16/1991 73.0 .2 1.2 1.1 14.0 71 10/5/1991 16.0 .1 2.8 3.3 25.0 67 

8/17/1991 30.0 0 .3 .8 14.0 71 10/6/1991 12.0 0 2.7 3.2 23.0 66 

8/18/1991 20.0 0 .3 .8 14.0 71 10/7/1991 11.0 0 2.5 3.1 23.0 65 

8/19/1991 13.0 0 .3 .7 14.0 71 10/8/1991 11.0 0 2.5 2.8 22.0 65 

8/20/1991 9.6 0 .3 .7 12.0 71 10/9/1991 11.0 0 2.3 2.8 21.0 64 

8/21/1991 8.1 0 .3 .6 12.0 71 10/10/1991 11.0 0 2.3 2.6 20.0 64 

8/22/1991 6.7 0 .3 .5 11.0 71 10/11/1991 9.8 0 2.2 2.4 20.0 64 

8/23/1991 6.0 0 .3 .6 11.0 71 10/12/1991 9.1 0 1.8 2.4 19.0 64 

8/24/1991 9.2 0 .3 .7 10.0 72 10/13/1991 8.6 0 1.7 2.0 18.0 64 

8/25/1991 8.8 0 .3 .7 9.2 71 10/14/1991 8.3 0 1.5 2.0 17.0 63 

8/26/1991 7.4 0 .3 .6 8.3 70 10/15/1991 7.7 0 1.5 2.0 16.0 63 

8/27/1991 6.0 0 .3 .5 7.5 68 10/16/1991 7.4 0 1.4 2.0 15.0 63 

8/28/1991 5.3 0 .3 .6 7.0 70 10/17/1991 6.3 0 1.4 2.0 15.0 62 

8/29/1991 4.7 0 .3 .5 6.9 70 10/18/1991 6.2 0 1.4 2.0 14.0 62 

8/30/1991 4.3 0 .3 .3 6.5 70 10/19/1991 6.3 0 1.3 2.0 15.0 62 

8/31/1991 4.4 1.3 .8 .5 6.1 70 10/20/1991 5.9 0 1.3 1.6 14.0 62 

9/1/1991 4.8 0 .5 .8 8.8 70 10/21/1991 6.1 0 1.2 1.5 14.0 62 

9/2/1991 5.4 8.1 2.4 2.0 88.0 71 10/22/1991 6.2 0 1.1 1.6 13.0 62 

9/3/1991 67.0 .8 2.7 2.2 23.0 71 10/23/1991 6.2 0 1.1 1.5 13.0 61 

9/4/1991 23.0 0 1.6 1.4 14.0 71 10/24/1991 6.0 0 1.1 1.5 13.0 61 

9/5/1991 16.0 0 1.4 1.1 11.0 71 10/25/1991 5.8 0 1.1 1.5 12.0 61 

9/6/1991 19.0 .1 1.9 1.2 10.0 71 10/26/1991 5.8 0 1.1 1.5 12.0 60 

9/7/1991 25.0 0 1.9 1.1 8.3 71 10/27/1991 6.0 0 1.1 1.5 12.0 60 

9/8/1991 20.0 0 1.7 1.1 7.2 71 10/28/1991 9.8 2.9 1.2 1.6 12.0 60 

9/9/1991 16.0 0 1.7 1.1 6.1 70 10/29/1991 14.0 22.0 2.0 2.3 18.0 60 

9/10/1991 13.0 0 1.7 1.1 4.5 69 10/30/1991 11.0 .6 2.0 1.7 15.0 60 

9/11/1991 11.0 0 1.6 1.1 5.4 69 10/31/1991 12.0 2.6 2.0 1.7 13.0 60 

9/12/1991 10.0 0 1.8 1.1 5.0 68 11/1/1991 11.0 .2 1.6 1.5 13.0 60 

9/13/1991 11.0 0 1.7 1.1 4.6 67 11/2/1991 10.0 0 1.5 1.4 12.0 61 

9/14/1991 12.0 4.5 2.3 1.8 11.0 67 11/3/1991 8.5 0 1.3 1.4 12.0 61 

9/15/1991 22.0 .2 2.6 2.5 11.0 67 11/4/1991 7.5 0 1.3 1.2 11.0 60 

9/16/1991 19.0 0 2.0 2.2 11.0 65 11/5/1991 7.2 0 1.3 1.2 12.0 60 

9/17/1991 14.0 0 1.9 2.0 11.0 65 11/6/1991 7.1 0 1.3 1.2 12.0 60 

9/18/1991 11.0 0 4.3 2.3 12.0 67 11/7/1991 7.1 0 1.2 1.2 12.0 59 
Appendix 2 109 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

11/8/1991 6.9 0 1.0 1.1 11.0 59 12/28/1991 559.0 19.0 30.0 51.0 448.0 123 

11/9/1991 6.5 0 .8 1.1 11.0 58 12/29/1991 452.0 15.0 24.0 45.0 394.0 113 

11/10/1991 6.5 0 .8 1.1 11.0 58 12/30/1991 382.0 13.0 20.0 40.0 358.0 107 

11/11/1991 6.5 0 .8 1.1 11.0 58 12/31/1991 341.0 11.0 16.0 36.0 333.0 101 

11/12/1991 6.4 0 .8 1.1 10.0 57 1/1/1992 314.0 9.5 15.0 33.0 318.0 99 

11/13/1991 6.2 0 .8 1.1 10.0 57 1/2/1992 475.0 30.0 57.0 39.0 376.0 109 

11/14/1991 6.2 0 .9 1.1 10.0 57 1/3/1992 363.0 15.0 23.0 31.0 316.0 107 

11/15/1991 6.3 0 .9 1.1 10.0 57 1/4/1992 315.0 13.0 20.0 29.0 293.0 103 

11/16/1991 6.9 0 .9 1.1 10.0 57 1/5/1992 317.0 15.0 24.0 32.0 310.0 103 

11/17/1991 20.0 12.0 2.5 2.0 13.0 61 1/6/1992 292.0 12.0 18.0 32.0 286.0 100 

11/18/1991 15.0 .3 2.3 1.4 13.0 63 1/7/1992 268.0 10.0 16.0 33.0 278.0 97 

11/19/1991 14.0 0 1.7 1.4 12.0 62 1/8/1992 263.0 9.7 15.0 32.0 273.0 96 

11/20/1991 11.0 0 1.2 1.4 12.0 61 1/9/1992 234.0 8.0 13.0 30.0 250.0 94 

11/21/1991 9.7 0 1.2 1.4 12.0 59 1/10/1992 209.0 6.6 10.0 29.0 237.0 90 

11/22/1991 8.9 0 1.2 1.4 12.0 58 1/11/1992 192.0 6.6 10.0 28.0 230.0 88 

11/23/1991 8.0 0 .9 1.3 11.0 58 1/12/1992 204.0 7.7 14.0 31.0 244.0 85 

11/24/1991 6.9 0 .7 1.2 11.0 58 1/13/1992 186.0 5.8 10.0 29.0 220.0 82 

11/25/1991 6.6 0 .7 1.2 11.0 58 1/14/1992 163.0 5.5 8.7 26.0 203.0 80 

11/26/1991 6.5 0 .7 1.2 11.0 57 1/15/1992 155.0 4.5 8.0 19.0 195.0 78 

11/27/1991 6.5 0 .7 1.2 11.0 57 1/16/1992 146.0 3.9 7.8 19.0 183.0 75 

11/28/1991 6.5 0 .7 1.2 10.0 57 1/17/1992 148.0 5.0 7.4 19.0 186.0 75 

11/29/1991 6.5 0 .7 1.3 10.0 57 1/18/1992 199.0 12.0 6.9 24.0 238.0 75 

11/30/1991 6.5 0 .7 1.4 10.0 57 1/19/1992 222.0 9.9 17.0 23.0 227.0 75 

12/1/1991 6.4 0 .7 1.4 9.6 57 1/20/1992 184.0 8.3 16.0 22.0 212.0 75 

12/2/1991 6.2 0 .7 1.4 9.2 57 1/21/1992 190.0 15.0 15.0 27.0 223.0 75 

12/3/1991 6.0 0 .5 1.2 9.1 57 1/22/1992 262.0 15.0 28.0 29.0 258.0 75 

12/4/1991 6.3 0 .5 1.2 8.8 56 1/23/1992 222.0 11.0 18.0 25.0 226.0 75 

12/5/1991 5.8 0 .5 1.2 8.8 56 1/24/1992 198.0 8.9 15.0 24.0 217.0 75 

12/6/1991 5.8 0 .5 1.2 8.8 55 1/25/1992 186.0 7.7 14.0 23.0 213.0 75 

12/7/1991 5.8 0 .5 1.2 8.8 55 1/26/1992 381.0 50.0 74.0 82.0 697.0 84 

12/8/1991 6.1 .1 .5 1.2 8.8 55 1/27/1992 1,220.0 49.0 124.0 77.0 944.0 120 

12/9/1991 22.0 19.0 3.5 2.1 19.0 58 1/28/1992 613.0 26.0 53.0 55.0 571.0 101 

12/10/1991 21.0 .3 2.2 1.5 16.0 58 1/29/1992 533.0 22.0 42.0 49.0 509.0 81 

12/11/1991 17.0 .1 2.0 1.5 16.0 57 1/30/1992 468.0 18.0 33.0 43.0 461.0 85 

12/12/1991 14.0 .1 2.0 1.5 16.0 57 1/31/1992 399.0 14.0 24.0 37.0 400.0 85 

12/13/1991 13.0 1.6 2.5 2.0 20.0 58 2/1/1992 357.0 12.0 20.0 35.0 362.0 85 

12/14/1991 14.0 .3 2.5 2.0 21.0 58 2/2/1992 350.0 15.0 27.0 39.0 393.0 86 

12/15/1991 13.0 .1 2.5 2.0 21.0 57 2/3/1992 893.0 125.0 159.0 128.0 701.0 114 

12/16/1991 13.0 .1 2.3 2.4 21.0 57 2/4/1992 2,350.0 168.0 223.0 240.0 2,310.0 130 

12/17/1991 13.0 .6 2.3 2.8 22.0 57 2/5/1992 1,670.0 56.0 133.0 107.0 1,400.0 130 

12/18/1991 25.0 20.0 6.0 4.6 28.0 59 2/6/1992 960.0 31.0 66.0 77.0 896.0 130 

12/19/1991 325.0 182.0 184.0 100.0 370.0 59 2/7/1992 721.0 22.0 41.0 61.0 729.0 130 

12/20/1991 2,380.0 632.0 750.0 1,000.0 2,120.0 65 2/8/1992 586.0 18.0 28.0 52.0 625.0 130 

12/21/1991 7,000.0 426.0 548.0 632.0 5,060.0 100 2/9/1992 506.0 15.0 22.0 46.0 557.0 130 

12/22/1991 3,170.0 262.0 371.0 503.0 3,040.0 118 2/10/1992 439.0 14.0 19.0 41.0 501.0 128 

12/23/1991 1,410.0 52.0 108.0 112.0 1,440.0 125 2/11/1992 388.0 13.0 20.0 38.0 463.0 122 

12/24/1991 949.0 31.0 63.0 82.0 1,060.0 130 2/12/1992 364.0 12.0 17.0 36.0 413.0 120 

12/25/1991 760.0 28.0 53.0 71.0 864.0 130 2/13/1992 329.0 11.0 15.0 33.0 366.0 119 

12/26/1991 782.0 34.0 80.0 78.0 700.0 130 2/14/1992 317.0 9.8 13.0 31.0 339.0 120 

12/27/1991 701.0 25.0 46.0 62.0 540.0 128 2/15/1992 299.0 8.4 12.0 28.0 316.0 120 
110 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

2/16/1992 279.0 7.6 10.0 27.0 295.0 120 4/6/1992 146.0 4.3 7.5 16.0 163.0 99 

2/17/1992 281.0 7.1 10.0 26.0 288.0 120 4/7/1992 124.0 3.8 6.3 15.0 135.0 97 

2/18/1992 258.0 6.2 8.7 24.0 266.0 119 4/8/1992 117.0 3.7 5.9 14.0 125.0 101 

2/19/1992 241.0 5.5 8.0 23.0 248.0 119 4/9/1992 116.0 3.4 5.5 14.0 120.0 101 

2/20/1992 237.0 5.1 7.6 21.0 235.0 119 4/10/1992 114.0 3.0 5.1 14.0 116.0 99 

2/21/1992 236.0 4.9 7.2 20.0 223.0 118 4/11/1992 112.0 3.0 5.0 13.0 112.0 101 

2/22/1992 458.0 20.0 26.0 29.0 293.0 118 4/12/1992 108.0 2.9 4.6 12.0 106.0 103 

2/23/1992 370.0 12.0 13.0 22.0 249.0 120 4/13/1992 102.0 3.0 4.3 12.0 100.0 104 

2/24/1992 637.0 58.0 96.0 70.0 485.0 122 4/14/1992 94.0 2.9 4.2 11.0 95.0 106 

2/25/1992 950.0 40.0 73.0 45.0 465.0 123 4/15/1992 89.0 2.7 3.9 10.0 93.0 107 

2/26/1992 676.0 25.0 37.0 38.0 342.0 123 4/16/1992 82.0 2.2 3.6 9.7 89.0 109 

2/27/1992 600.0 19.0 28.0 35.0 319.0 123 4/17/1992 103.0 14.0 9.9 14.0 108.0 112 

2/28/1992 556.0 16.0 20.0 32.0 305.0 123 4/18/1992 137.0 6.5 8.7 14.0 123.0 111 

2/29/1992 529.0 14.0 18.0 30.0 290.0 122 4/19/1992 115.0 4.7 6.2 11.0 98.0 112 

3/1/1992 502.0 12.0 16.0 28.0 278.0 122 4/20/1992 104.0 4.0 5.2 9.8 90.0 112 

3/2/1992 486.0 11.0 15.0 27.0 273.0 121 4/21/1992 94.0 3.5 4.7 8.5 81.0 114 

3/3/1992 510.0 15.0 19.0 29.0 282.0 122 4/22/1992 85.0 3.4 4.2 8.1 75.0 115 

3/4/1992 2,910.0 140.0 212.0 204.0 2,540.0 129 4/23/1992 80.0 2.3 4.2 7.0 72.0 114 

3/5/1992 1,060.0 37.0 60.0 64.0 785.0 130 4/24/1992 75.0 2.5 4.2 7.0 70.0 110 

3/6/1992 688.0 25.0 37.0 53.0 615.0 130 4/25/1992 71.0 2.4 3.7 6.1 66.0 106 

3/7/1992 547.0 19.0 26.0 46.0 525.0 130 4/26/1992 68.0 2.0 3.6 6.1 64.0 103 

3/8/1992 472.0 16.0 22.0 43.0 480.0 130 4/27/1992 62.0 1.7 3.2 5.9 60.0 100 

3/9/1992 430.0 16.0 20.0 40.0 444.0 130 4/28/1992 58.0 1.3 3.1 5.3 57.0 97 

3/10/1992 361.0 12.0 16.0 34.0 369.0 127 4/29/1992 55.0 1.1 3.0 5.1 54.0 94 

3/11/1992 323.0 11.0 16.0 32.0 340.0 120 4/30/1992 51.0 .8 2.9 5.1 51.0 92 

3/12/1992 298.0 9.9 14.0 30.0 320.0 113 5/1/1992 49.0 1.0 2.7 4.9 49.0 88 

3/13/1992 266.0 8.2 12.0 28.0 299.0 104 5/2/1992 47.0 .8 2.6 4.6 47.0 85 

3/14/1992 244.0 7.3 11.0 26.0 285.0 90 5/3/1992 45.0 .6 2.4 4.6 46.0 83 

3/15/1992 223.0 6.2 10.0 24.0 270.0 87 5/4/1992 43.0 .5 2.4 4.2 43.0 88 

3/16/1992 203.0 5.6 9.5 23.0 245.0 86 5/5/1992 43.0 .5 2.4 4.6 41.0 91 

3/17/1992 193.0 5.8 8.7 21.0 228.0 87 5/6/1992 42.0 .3 2.0 4.0 38.0 94 

3/18/1992 216.0 10.0 11.0 23.0 245.0 87 5/7/1992 38.0 .2 1.6 3.4 36.0 96 

3/19/1992 166.0 4.8 7.2 19.0 202.0 85 5/8/1992 36.0 .2 1.7 3.2 36.0 99 

3/20/1992 151.0 4.4 6.8 18.0 185.0 85 5/9/1992 35.0 .3 1.6 3.2 36.0 97 

3/21/1992 148.0 4.4 6.8 17.0 181.0 89 5/10/1992 35.0 .2 2.0 3.4 36.0 99 

3/22/1992 146.0 4.0 6.6 17.0 176.0 91 5/11/1992 35.0 .1 1.9 3.4 36.0 98 

3/23/1992 133.0 3.5 6.0 16.0 156.0 88 5/12/1992 35.0 3.8 3.6 3.8 32.0 96 

3/24/1992 128.0 3.3 5.8 15.0 148.0 87 5/13/1992 38.0 .6 6.3 4.0 37.0 99 

3/25/1992 125.0 3.4 5.5 14.0 140.0 89 5/14/1992 48.0 14.0 26.0 12.0 145.0 99 

3/26/1992 120.0 2.9 5.1 13.0 131.0 90 5/15/1992 112.0 8.5 41.0 13.0 178.0 98 

3/27/1992 119.0 4.6 5.8 15.0 134.0 88 5/16/1992 197.0 49.0 27.0 8.2 90.0 98 

3/28/1992 175.0 12.0 16.0 28.0 258.0 85 5/17/1992 452.0 23.0 54.0 14.0 137.0 98 

3/29/1992 191.0 5.7 9.2 20.0 209.0 86 5/18/1992 528.0 328.0 155.0 68.0 96.0 97 

3/30/1992 137.0 4.3 6.9 17.0 158.0 84 5/19/1992 358.0 68.0 93.0 36.0 103.0 98 

3/31/1992 125.0 3.9 6.4 16.0 144.0 85 5/20/1992 253.0 30.0 56.0 39.0 185.0 104 

4/1/1992 123.0 3.7 6.1 16.0 139.0 87 5/21/1992 927.0 125.0 125.0 104.0 1,440.0 120 

4/2/1992 119.0 3.5 5.5 15.0 133.0 88 5/22/1992 1,070.0 53.0 98.0 69.0 661.0 130 

4/3/1992 117.0 3.2 5.5 15.0 129.0 91 5/23/1992 468.0 27.0 46.0 50.0 380.0 117 

4/4/1992 115.0 2.9 5.5 14.0 121.0 94 5/24/1992 353.0 17.0 31.0 42.0 313.0 110 

4/5/1992 127.0 8.3 11.0 20.0 165.0 97 5/25/1992 290.0 13.0 23.0 36.0 283.0 108 
Appendix 2 111 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

5/26/1992 256.0 9.6 19.0 32.0 263.0 107 7/15/1992 13.0 0 0.8 1.3 20.0 75 

5/27/1992 348.0 45.0 32.0 33.0 290.0 107 7/16/1992 12.0 0 .8 1.1 18.0 75 

5/28/1992 1,030.0 36.0 44.0 38.0 410.0 110 7/17/1992 11.0 0 .8 1.1 17.0 77 

5/29/1992 382.0 17.0 22.0 30.0 278.0 101 7/18/1992 10.0 0 .7 1.0 16.0 85 

5/30/1992 309.0 12.0 18.0 28.0 252.0 98 7/19/1992 11.0 .5 2.0 4.8 25.0 112 

5/31/1992 285.0 16.0 19.0 30.0 248.0 97 7/20/1992 69.0 7.3 3.9 7.1 48.0 123 

6/1/1992 292.0 14.0 20.0 29.0 254.0 96 7/21/1992 39.0 .6 2.1 4.5 37.0 125 

6/2/1992 1,470.0 20.0 30.0 58.0 1,360.0 118 7/22/1992 24.0 0 1.5 3.9 38.0 122 

6/3/1992 535.0 12.0 20.0 37.0 508.0 125 7/23/1992 21.0 0 1.3 3.4 31.0 123 

6/4/1992 390.0 8.0 16.0 33.0 403.0 111 7/24/1992 18.0 0 1.2 2.9 24.0 127 

6/5/1992 327.0 6.9 14.0 30.0 347.0 92 7/25/1992 14.0 0 1.0 2.7 21.0 130 

6/6/1992 297.0 12.0 22.0 31.0 318.0 90 7/26/1992 12.0 0 1.0 2.5 18.0 130 

6/7/1992 289.0 7.6 18.0 29.0 336.0 88 7/27/1992 11.0 0 .9 2.4 18.0 130 

6/8/1992 254.0 5.6 16.0 26.0 289.0 84 7/28/1992 11.0 0 .8 2.3 17.0 130 

6/9/1992 230.0 12.0 14.0 24.0 297.0 90 7/29/1992 9.7 0 .7 2.1 15.0 130 

6/10/1992 215.0 5.6 13.0 22.0 285.0 96 7/30/1992 8.9 0 .6 2.0 14.0 130 

6/11/1992 277.0 11.0 24.0 26.0 341.0 100 7/31/1992 8.4 0 .5 1.9 14.0 130 

6/12/1992 501.0 28.0 50.0 26.0 305.0 109 8/1/1992 7.8 0 .5 1.8 14.0 130 

6/13/1992 306.0 11.0 22.0 21.0 262.0 100 8/2/1992 7.2 0 .5 1.7 13.0 130 

6/14/1992 242.0 7.8 17.0 20.0 241.0 99 8/3/1992 39.0 .2 .9 2.3 13.0 129 

6/15/1992 213.0 5.8 14.0 19.0 221.0 100 8/4/1992 11.0 0 .6 1.6 13.0 129 

6/16/1992 185.0 4.4 12.0 17.0 201.0 99 8/5/1992 8.8 0 .5 1.4 13.0 129 

6/17/1992 163.0 3.4 10.0 16.0 186.0 85 8/6/1992 7.7 0 .5 1.3 12.0 129 

6/18/1992 151.0 3.0 8.4 15.0 172.0 85 8/7/1992 7.0 0 .4 1.2 11.0 129 

6/19/1992 143.0 2.5 7.5 14.0 160.0 84 8/8/1992 6.5 0 .3 1.1 10.0 129 

6/20/1992 132.0 2.2 7.0 12.0 149.0 83 8/9/1992 6.0 0 .3 1.0 9.6 129 

6/21/1992 123.0 2.0 6.3 11.0 137.0 81 8/10/1992 5.6 0 .2 .8 9.0 129 

6/22/1992 115.0 1.7 5.5 9.9 106.0 80 8/11/1992 5.3 0 .2 .9 9.2 129 

6/23/1992 108.0 1.3 4.7 8.9 98.0 80 8/12/1992 5.4 0 .2 1.1 13.0 129 

6/24/1992 99.0 1.3 4.4 7.9 90.0 79 8/13/1992 5.1 0 .1 .9 11.0 128 

6/25/1992 84.0 1.2 3.9 7.0 82.0 79 8/14/1992 5.4 0 .1 .7 11.0 128 

6/26/1992 72.0 1.1 3.6 6.4 88.0 80 8/15/1992 5.6 0 .1 .7 11.0 127 

6/27/1992 93.0 4.2 4.8 7.2 76.0 82 8/16/1992 5.6 0 .1 .7 11.0 127 

6/28/1992 69.0 1.1 4.2 6.0 70.0 83 8/17/1992 5.2 0 .1 .6 10.0 126 

6/29/1992 56.0 1.0 3.3 5.4 73.0 83 8/18/1992 4.4 0 .1 .6 10.0 125 

6/30/1992 50.0 .8 3.3 5.1 62.0 82 8/19/1992 4.2 0 0 .5 9.5 124 

7/1/1992 50.0 .8 3.2 4.8 61.0 81 8/20/1992 4.0 0 0 .5 9.5 124 

7/2/1992 47.0 .7 2.7 4.3 55.0 82 8/21/1992 3.5 0 0 .5 9.3 123 

7/3/1992 41.0 .6 2.5 3.9 55.0 82 8/22/1992 3.1 0 0 .4 8.7 123 

7/4/1992 37.0 .5 2.5 3.6 50.0 82 8/23/1992 2.8 0 0 .4 8.5 123 

7/5/1992 35.0 .3 2.3 3.3 47.0 82 8/24/1992 2.6 0 0 .3 8.0 122 

7/6/1992 31.0 0 2.0 2.9 43.0 81 8/25/1992 2.3 0 0 .2 7.9 122 

7/7/1992 28.0 0 1.7 2.6 38.0 81 8/26/1992 2.0 0 0 .1 7.3 125 

7/8/1992 27.0 0 1.5 2.3 35.0 81 8/27/1992 1.9 0 0 .1 5.9 125 

7/9/1992 24.0 0 1.3 2.1 35.0 80 8/28/1992 1.9 0 0 .1 5.0 125 

7/10/1992 22.0 0 1.1 1.9 31.0 78 8/29/1992 1.6 0 0 .1 3.9 124 

7/11/1992 20.0 0 1.0 1.7 28.0 76 8/30/1992 1.4 0 0 .1 3.5 125 

7/12/1992 18.0 0 .9 1.7 26.0 75 8/31/1992 1.3 0 0 .1 3.4 125 

7/13/1992 16.0 0 .8 1.6 23.0 75 9/1/1992 1.3 0 0 .1 2.6 124 

7/14/1992 14.0 0 .8 1.4 21.0 75 9/2/1992 1.2 0 0 .1 2.1 124 
112 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

9/3/1992 1.1 0 0 0.1 3.7 122 10/23/1992 0.5 0 0 0 2.1 114 

9/4/1992 1.3 0 0 .1 14.0 123 10/24/1992 .4 0 0 0 2.0 114 

9/5/1992 1.2 0 0 .1 10.0 124 10/25/1992 .4 0 0 0 1.7 114 

9/6/1992 1.2 0 0 .1 9.4 125 10/26/1992 .4 0 0 0 1.8 114 

9/7/1992 1.7 0 0 .1 7.8 124 10/27/1992 .4 0 0 0 1.9 113 

9/8/1992 2.0 0 0 .1 6.7 123 10/28/1992 .3 0 0 0 2.1 113 

9/9/1992 2.0 0 0 .1 5.5 124 10/29/1992 .4 0 0 0 2.6 112 

9/10/1992 1.8 0 0 .1 4.8 121 10/30/1992 2.8 0 0 0 3.4 110 

9/11/1992 1.8 0 0 .1 6.3 122 10/31/1992 .9 0 0 0 3.0 107 

9/12/1992 1.6 0 0 .1 5.9 122 11/1/1992 2.3 1.6 0 .1 5.4 107 

9/13/1992 1.4 0 0 .1 6.2 121 11/2/1992 1.2 0 0 .1 2.5 106 

9/14/1992 1.4 0 0 .1 6.9 121 11/3/1992 1.0 0 0 .1 2.0 106 

9/15/1992 1.5 0 0 .1 6.9 122 11/4/1992 .8 0 0 0 1.4 105 

9/16/1992 1.5 0 0 0 5.7 124 11/5/1992 .7 0 0 .1 1.8 105 

9/17/1992 1.4 0 0 0 6.4 124 11/6/1992 .7 0 0 .1 3.0 105 

9/18/1992 1.4 0 0 0 7.5 124 11/7/1992 .7 0 0 0 3.0 104 

9/19/1992 1.3 0 0 0 6.2 123 11/8/1992 .7 0 0 .1 3.8 104 

9/20/1992 1.0 0 0 0 5.5 123 11/9/1992 .7 0 0 .1 3.9 103 

9/21/1992 1.4 2.0 0 0 4.9 123 11/10/1992 .8 0 0 .1 4.0 102 

9/22/1992 5.8 3.7 0 0 4.6 123 11/11/1992 .8 0 0 .1 3.9 103 

9/23/1992 6.1 0 0 0 3.5 122 11/12/1992 1.1 0 0 .1 3.5 102 

9/24/1992 3.3 0 0 0 3.5 122 11/13/1992 .9 0 0 .1 3.3 102 

9/25/1992 2.7 0 0 0 3.5 122 11/14/1992 .8 0 0 .1 3.2 102 

9/26/1992 2.1 0 0 0 3.5 122 11/15/1992 .8 0 0 .1 2.9 102 

9/27/1992 1.8 0 0 0 3.5 122 11/16/1992 .8 0 0 .1 4.2 101 

9/28/1992 1.5 0 0 0 3.5 121 11/17/1992 .8 0 0 .1 2.9 101 

9/29/1992 1.1 0 0 0 2.8 120 11/18/1992 .8 0 0 .1 2.7 101 

9/30/1992 .9 0 0 0 1.7 120 11/19/1992 52.0 23.0 .1 1.9 121.0 102 

10/1/1992 .8 0 0 0 1.7 120 11/20/1992 115.0 6.0 0 1.6 80.0 105 

10/2/1992 .7 0 0 0 1.7 120 11/21/1992 40.0 0 0 .7 30.0 105 

10/3/1992 .7 0 0 0 1.6 120 11/22/1992 23.0 0 0 .4 18.0 104 

10/4/1992 .7 0 0 0 1.5 120 11/23/1992 14.0 0 0 .4 14.0 103 

10/5/1992 .6 0 0 0 1.1 119 11/24/1992 11.0 0 0 .6 13.0 103 

10/6/1992 .5 0 0 0 1.0 118 11/25/1992 8.5 0 0 .5 11.0 102 

10/7/1992 .4 0 0 0 1.3 117 11/26/1992 7.1 0 0 .4 11.0 102 

10/8/1992 .4 0 0 0 1.2 118 11/27/1992 6.2 0 0 .3 10.0 101 

10/9/1992 .5 0 0 0 1.7 118 11/28/1992 6.0 0 0 .3 9.7 101 

10/10/1992 .4 0 0 0 2.4 119 11/29/1992 5.8 0 0 .3 9.5 100 

10/11/1992 .4 0 0 0 1.7 119 11/30/1992 5.8 0 0 .3 9.5 99 

10/12/1992 .3 0 0 0 1.9 119 12/1/1992 5.4 0 0 .3 9.0 98 

10/13/1992 .3 0 0 0 2.1 118 12/2/1992 5.2 0 0 .2 8.8 98 

10/14/1992 .3 0 0 0 2.4 118 12/3/1992 5.0 0 0 .2 8.8 98 

10/15/1992 .3 0 0 0 3.3 117 12/4/1992 4.9 0 0 .3 8.6 98 

10/16/1992 .3 0 0 0 3.1 116 12/5/1992 4.6 0 0 .2 8.5 98 

10/17/1992 .3 0 0 0 1.5 116 12/6/1992 4.8 0 0 .3 8.8 98 

10/18/1992 .3 0 0 0 2.0 116 12/7/1992 5.1 0 0 .3 8.5 97 

10/19/1992 .4 0 0 0 2.3 116 12/8/1992 5.2 0 0 .3 8.5 97 

10/20/1992 .4 0 0 0 3.0 115 12/9/1992 8.1 .2 0 .6 9.5 97 

10/21/1992 .4 0 0 0 3.1 115 12/10/1992 7.1 0 0 .2 8.4 97 

10/22/1992 .4 0 0 0 2.4 114 12/11/1992 6.5 0 0 .1 8.5 96 
Appendix 2 113 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/12/1992 6.1 0 0 0.3 9.0 96 1/31/1993 114.0 2.6 8.7 6.3 83.0 101 

12/13/1992 6.0 0 0 .4 9.5 96 2/1/1993 110.0 2.6 8.7 6.3 80.0 101 

12/14/1992 16.0 2.2 0 1.8 14.0 95 2/2/1993 107.0 2.6 8.7 6.1 77.0 101 

12/15/1992 195.0 15.0 .2 7.6 176.0 97 2/3/1993 108.0 3.0 8.7 6.1 78.0 101 

12/16/1992 143.0 .7 .1 4.3 107.0 100 2/4/1993 113.0 2.5 8.7 6.3 79.0 102 

12/17/1992 87.0 .3 .2 3.6 70.0 100 2/5/1993 121.0 5.5 16.0 7.5 95.0 102 

12/18/1992 63.0 .1 .3 3.1 58.0 100 2/6/1993 144.0 4.1 16.0 7.6 108.0 102 

12/19/1992 56.0 0 .3 3.0 56.0 100 2/7/1993 137.0 3.9 15.0 7.7 101.0 103 

12/20/1992 51.0 .1 .3 2.7 49.0 100 2/8/1993 132.0 3.6 15.0 7.7 98.0 103 

12/21/1992 48.0 0 .4 2.6 47.0 100 2/9/1993 138.0 9.8 22.0 10.0 104.0 103 

12/22/1992 46.0 0 .4 2.6 44.0 99 2/10/1993 473.0 13.0 32.0 18.0 304.0 104 

12/23/1992 45.0 0 .4 2.4 43.0 99 2/11/1993 317.0 8.2 18.0 15.0 217.0 106 

12/24/1992 42.0 0 .4 2.2 41.0 99 2/12/1993 235.0 6.0 14.0 14.0 189.0 106 

12/25/1992 40.0 0 .4 2.2 39.0 99 2/13/1993 206.0 5.6 13.0 14.0 178.0 106 

12/26/1992 39.0 0 .4 2.2 38.0 98 2/14/1993 183.0 5.1 11.0 13.0 168.0 106 

12/27/1992 37.0 0 .4 2.0 37.0 98 2/15/1993 175.0 5.2 12.0 13.0 166.0 107 

12/28/1992 37.0 0 .5 2.0 36.0 98 2/16/1993 160.0 4.2 11.0 12.0 154.0 107 

12/29/1992 37.0 0 .5 2.0 36.0 97 2/17/1993 144.0 3.9 8.4 12.0 138.0 107 

12/30/1992 37.0 0 .5 2.0 35.0 96 2/18/1993 134.0 3.7 7.6 11.0 129.0 107 

12/31/1992 36.0 0 .5 1.8 34.0 96 2/19/1993 127.0 3.5 7.6 11.0 126.0 107 

1/1/1993 35.0 0 .5 1.8 33.0 96 2/20/1993 125.0 3.5 7.6 11.0 124.0 107 

1/2/1993 34.0 0 .5 1.7 32.0 96 2/21/1993 120.0 3.2 6.9 10.0 117.0 108 

1/3/1993 34.0 0 .5 1.5 32.0 96 2/22/1993 109.0 2.7 6.0 9.4 107.0 108 

1/4/1993 35.0 .2 .6 1.5 33.0 95 2/23/1993 98.0 2.6 4.5 8.9 102.0 108 

1/5/1993 34.0 0 .7 1.6 32.0 95 2/24/1993 96.0 2.7 5.5 8.9 100.0 108 

1/6/1993 33.0 .1 .7 1.5 29.0 95 2/25/1993 95.0 2.5 5.3 8.7 98.0 107 

1/7/1993 32.0 .1 .8 1.8 29.0 95 2/26/1993 88.0 1.8 3.9 7.6 90.0 107 

1/8/1993 33.0 .1 .9 1.7 30.0 95 2/27/1993 82.0 1.7 4.3 7.0 85.0 107 

1/9/1993 37.0 .9 1.3 2.1 32.0 95 2/28/1993 82.0 2.8 5.2 8.0 89.0 107 

1/10/1993 35.0 .3 1.4 2.2 31.0 95 3/1/1993 101.0 2.1 7.1 9.4 111.0 107 

1/11/1993 34.0 .3 1.4 2.2 31.0 95 3/2/1993 120.0 1.6 6.3 8.7 108.0 107 

1/12/1993 34.0 .3 2.1 2.3 32.0 95 3/3/1993 94.0 1.3 5.3 7.6 93.0 107 

1/13/1993 34.0 .4 2.4 2.2 33.0 94 3/4/1993 86.0 1.2 4.7 7.0 85.0 107 

1/14/1993 34.0 .3 2.4 2.2 33.0 94 3/5/1993 82.0 1.0 4.3 6.9 81.0 106 

1/15/1993 34.0 .3 2.5 2.3 33.0 94 3/6/1993 79.0 1.0 4.3 6.7 78.0 106 

1/16/1993 34.0 .3 2.6 2.5 33.0 94 3/7/1993 77.0 1.0 4.3 6.5 76.0 106 

1/17/1993 34.0 .3 2.6 2.6 32.0 94 3/8/1993 75.0 1.0 4.3 6.1 72.0 106 

1/18/1993 34.0 .3 2.6 2.5 32.0 94 3/9/1993 72.0 4.3 5.9 70.0 105 

1/19/1993 148.0 16.0 13.0 7.5 181.0 96 3/10/1993 68.0 4.3 5.9 69.0 106 

1/20/1993 262.0 12.0 21.0 9.0 231.0 98 3/11/1993 64.0 0 4.0 5.6 66.0 106 

1/21/1993 180.0 6.5 18.0 8.9 161.0 100 3/12/1993 66.0 0 4.2 7.3 74.0 106 

1/22/1993 148.0 4.7 15.0 8.9 134.0 100 3/13/1993 71.0 0 4.2 5.9 69.0 106 

1/23/1993 139.0 4.0 14.0 8.6 122.0 100 3/14/1993 60.0 0 4.0 5.9 65.0 106 

1/24/1993 123.0 3.1 11.0 7.5 105.0 100 3/15/1993 59.0 0 4.1 5.9 66.0 106 

1/25/1993 128.0 2.9 10.0 7.1 96.0 100 3/16/1993 60.0 0 4.3 6.1 67.0 106 

1/26/1993 123.0 2.8 9.4 7.0 92.0 100 3/17/1993 58.0 0 4.0 5.6 61.0 106 

1/27/1993 114.0 2.7 8.7 6.7 88.0 100 3/18/1993 54.0 0 4.0 5.4 59.0 106 

1/28/1993 114.0 2.8 8.1 6.7 84.0 100 3/19/1993 52.0 0 5.0 6.4 62.0 106 

1/29/1993 114.0 3.4 9.1 7.0 89.0 101 3/20/1993 54.0 0 5.9 7.4 67.0 106 

1/30/1993 120.0 2.6 9.2 6.5 90.0 101 3/21/1993 65.0 0 5.1 6.7 61.0 107 
114 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

3/22/1993 59.0 0 5.1 6.9 62.0 107 5/11/1993 62.0 0 6.4 6.1 39.0 108 

3/23/1993 59.0 0 4.8 7.6 64.0 107 5/12/1993 56.0 0 5.5 5.9 35.0 108 

3/24/1993 56.0 0 4.7 7.2 60.0 107 5/13/1993 52.0 0 5.1 5.9 33.0 108 

3/25/1993 58.0 0 4.8 7.9 60.0 107 5/14/1993 48.0 0 4.4 5.6 32.0 108 

3/26/1993 62.0 0 5.1 8.4 60.0 106 5/15/1993 46.0 0 4.1 5.6 30.0 108 

3/27/1993 61.0 0 5.1 8.1 56.0 106 5/16/1993 43.0 0 3.3 5.1 28.0 108 

3/28/1993 55.0 0 5.1 8.1 56.0 106 5/17/1993 41.0 0 3.0 4.9 26.0 108 

3/29/1993 54.0 0 4.8 8.1 55.0 107 5/18/1993 38.0 0 2.8 4.6 25.0 107 

3/30/1993 54.0 0 4.7 8.4 61.0 107 5/19/1993 35.0 0 2.8 4.2 24.0 107 

3/31/1993 58.0 0 4.3 7.3 58.0 107 5/20/1993 32.0 0 2.4 4.0 23.0 107 

4/1/1993 51.0 0 4.3 7.0 53.0 107 5/21/1993 31.0 0 2.4 4.0 22.0 108 

4/2/1993 48.0 0 4.0 7.0 51.0 107 5/22/1993 28.0 0 2.2 3.8 21.0 108 

4/3/1993 48.0 0 4.0 7.0 52.0 107 5/23/1993 37.0 0 5.0 5.2 30.0 108 

4/4/1993 51.0 0 4.6 7.5 55.0 108 5/24/1993 42.0 0 3.7 4.2 32.0 108 

4/5/1993 49.0 0 4.0 6.9 51.0 108 5/25/1993 34.0 0 2.8 4.0 26.0 108 

4/6/1993 46.0 0 4.0 6.6 50.0 108 5/26/1993 30.0 0 2.6 3.8 24.0 108 

4/7/1993 79.0 .5 9.7 12.0 87.0 108 5/27/1993 26.0 0 2.3 3.6 22.0 108 

4/8/1993 142.0 0 5.6 9.1 95.0 108 5/28/1993 25.0 0 2.2 3.6 22.0 107 

4/9/1993 86.0 0 3.6 7.3 63.0 108 5/29/1993 25.0 0 2.2 3.4 23.0 107 

4/10/1993 77.0 0 3.3 6.9 55.0 108 5/30/1993 24.0 0 2.3 4.0 23.0 107 

4/11/1993 75.0 0 3.0 6.7 53.0 108 5/31/1993 23.0 0 2.1 3.2 22.0 107 

4/12/1993 75.0 0 2.8 6.4 54.0 108 6/1/1993 21.0 0 1.5 2.6 19.0 107 

4/13/1993 74.0 0 2.7 6.4 53.0 108 6/2/1993 19.0 0 1.3 2.4 18.0 106 

4/14/1993 82.0 0 3.2 7.0 61.0 108 6/3/1993 15.0 0 1.2 2.3 17.0 106 

4/15/1993 91.0 0 2.8 6.7 58.0 108 6/4/1993 13.0 0 1.1 2.1 16.0 106 

4/16/1993 77.0 0 2.6 6.1 51.0 108 6/5/1993 12.0 0 1.0 2.2 15.0 105 

4/17/1993 72.0 0 2.6 5.9 48.0 108 6/6/1993 11.0 0 1.0 2.1 14.0 104 

4/18/1993 70.0 0 2.6 5.9 47.0 108 6/7/1993 11.0 0 .9 2.0 14.0 104 

4/19/1993 68.0 0 2.4 5.3 45.0 108 6/8/1993 10.0 0 .9 2.0 13.0 103 

4/20/1993 60.0 0 2.0 5.1 43.0 107 6/9/1993 9.9 0 .9 1.9 13.0 103 

4/21/1993 55.0 0 1.8 4.9 39.0 107 6/10/1993 9.9 0 1.2 1.4 13.0 103 

4/22/1993 52.0 0 1.8 4.9 38.0 107 6/11/1993 11.0 0 1.0 1.6 16.0 102 

4/23/1993 52.0 0 1.8 4.9 38.0 108 6/12/1993 12.0 0 1.0 1.6 15.0 102 

4/24/1993 50.0 0 1.7 4.9 38.0 108 6/13/1993 12.0 0 1.0 1.8 18.0 102 

4/25/1993 49.0 0 1.5 4.4 35.0 108 6/14/1993 12.0 0 1.5 2.5 17.0 101 

4/26/1993 45.0 0 1.3 3.8 33.0 108 6/15/1993 18.0 0 2.4 2.0 16.0 101 

4/27/1993 43.0 0 1.2 3.4 31.0 107 6/16/1993 13.0 0 1.4 1.6 14.0 101 

4/28/1993 43.0 0 1.3 3.4 31.0 107 6/17/1993 11.0 0 1.2 1.5 13.0 100 

4/29/1993 78.0 .2 3.7 5.3 40.0 107 6/18/1993 10.0 0 1.1 1.6 14.0 100 

4/30/1993 71.0 0 2.5 4.0 41.0 108 6/19/1993 9.8 0 1.4 1.8 15.0 100 

5/1/1993 51.0 0 2.0 3.8 35.0 108 6/20/1993 12.0 0 1.6 2.4 19.0 101 

5/2/1993 58.0 0 2.3 3.6 34.0 108 6/21/1993 20.0 0 2.0 2.8 25.0 102 

5/3/1993 53.0 0 2.0 3.4 31.0 108 6/22/1993 28.0 0 1.8 1.9 31.0 101 

5/4/1993 45.0 0 1.5 3.2 28.0 108 6/23/1993 23.0 0 1.7 1.8 25.0 100 

5/5/1993 57.0 1.2 4.4 8.8 52.0 108 6/24/1993 18.0 0 1.4 1.9 23.0 100 

5/6/1993 123.0 0 16.0 10.0 73.0 108 6/25/1993 17.0 0 1.4 1.8 22.0 99 

5/7/1993 99.0 0 7.8 6.7 52.0 108 6/26/1993 35.0 3.0 21.0 22.0 46.0 98 

5/8/1993 78.0 0 7.2 6.1 44.0 108 6/27/1993 38.0 0 6.9 8.0 136.0 100 

5/9/1993 73.0 0 7.0 6.7 42.0 108 6/28/1993 32.0 0 4.7 6.2 65.0 100 

5/10/1993 70.0 0 7.4 7.7 45.0 108 6/29/1993 26.0 0 3.8 5.5 48.0 99 
Appendix 2 115 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/30/1993 22.0 0 3.2 5.1 45.0 99 8/19/1993 0.2 0 0 0 0.1 83 

7/1/1993 20.0 0 2.7 4.8 39.0 99 8/20/1993 .1 0 0 0 .1 80 

7/2/1993 18.0 0 2.6 4.5 33.0 98 8/21/1993 .1 0 0 0 .1 82 

7/3/1993 16.0 0 2.3 4.2 30.0 98 8/22/1993 0 0 0 0 .2 81 

7/4/1993 15.0 0 2.2 4.0 28.0 98 8/23/1993 0 0 0 0 .2 81 

7/5/1993 14.0 0 1.9 3.7 26.0 98 8/24/1993 0 0 0 0 .2 80 

7/6/1993 13.0 0 1.5 3.4 24.0 98 8/25/1993 0 0 0 0 .2 80 

7/7/1993 12.0 0 1.4 3.2 22.0 97 8/26/1993 0 0 0 0 .2 80 

7/8/1993 11.0 0 1.1 3.1 21.0 97 8/27/1993 0 0 0 0 .2 77 

7/9/1993 10.0 0 .9 2.9 20.0 96 8/28/1993 0 0 0 0 .2 78 

7/10/1993 9.4 0 .8 2.7 19.0 96 8/29/1993 0 0 0 0 .3 78 

7/11/1993 8.9 0 .8 2.5 18.0 96 8/30/1993 0 0 0 0 .4 78 

7/12/1993 8.0 0 .7 2.4 17.0 96 8/31/1993 .1 0 0 0 .4 76 

7/13/1993 7.3 0 .6 2.1 16.0 95 9/1/1993 .1 0 0 0 .4 78 

7/14/1993 6.6 0 .6 1.9 15.0 95 9/2/1993 0 0 0 0 .4 76 

7/15/1993 6.0 0 .6 1.7 13.0 95 9/3/1993 0 0 0 0 .4 74 

7/16/1993 5.6 0 .5 1.9 13.0 94 9/4/1993 .1 0 0 0 .4 75 

7/17/1993 5.0 0 .5 1.5 12.0 94 9/5/1993 .1 0 0 0 .4 75 

7/18/1993 4.6 0 .5 1.4 11.0 94 9/6/1993 .1 0 0 0 .5 74 

7/19/1993 4.3 0 .5 1.3 10.0 94 9/7/1993 .1 0 0 0 .6 74 

7/20/1993 3.7 0 .4 1.2 10.0 94 9/8/1993 .2 0 0 0 .8 73 

7/21/1993 3.2 0 .4 1.2 9.5 93 9/9/1993 .2 0 0 0 1.2 73 

7/22/1993 2.7 0 .4 1.1 8.8 93 9/10/1993 .1 0 0 0 1.2 72 

7/23/1993 2.3 0 .3 1.0 8.4 92 9/11/1993 .1 0 0 0 1.1 72 

7/24/1993 1.8 0 .2 .9 7.9 92 9/12/1993 .1 0 0 0 1.3 72 

7/25/1993 1.5 0 .2 .7 7.4 92 9/13/1993 .2 0 0 0 1.5 72 

7/26/1993 1.4 0 .1 .7 7.0 92 9/14/1993 .1 0 0 0 1.7 71 

7/27/1993 1.3 0 .1 .7 6.4 92 9/15/1993 .1 0 0 0 1.2 71 

7/28/1993 1.2 0 .1 .6 5.4 91 9/16/1993 .1 0 0 0 .9 71 

7/29/1993 1.1 0 .1 .6 4.4 91 9/17/1993 .1 0 0 0 .8 70 

7/30/1993 1.0 0 0 .5 2.9 90 9/18/1993 .1 0 0 0 .8 70 

7/31/1993 .8 0 0 .4 1.5 90 9/19/1993 .1 0 0 0 .8 70 

8/1/1993 .6 0 0 .3 1.2 90 9/20/1993 0 0 0 0 .7 70 

8/2/1993 .5 0 0 .2 .7 89 9/21/1993 0 0 0 0 .7 68 

8/3/1993 .5 0 0 .2 .5 88 9/22/1993 0 0 0 0 .7 69 

8/4/1993 .5 0 0 .1 .4 88 9/23/1993 0 0 0 0 .7 69 

8/5/1993 .4 0 0 .1 .3 88 9/24/1993 0 0 0 0 .4 68 

8/6/1993 .4 0 0 .1 .2 87 9/25/1993 0 0 0 0 .4 68 

8/7/1993 .4 0 0 .1 .3 87 9/26/1993 0 0 0 0 .4 68 

8/8/1993 .5 0 0 .1 .5 87 9/27/1993 0 0 0 0 .4 68 

8/9/1993 .5 0 0 .1 .5 86 9/28/1993 0 0 0 0 .4 66 

8/10/1993 .4 0 0 0 .3 86 9/29/1993 0 0 0 0 .3 67 

8/11/1993 .4 0 0 0 .3 86 9/30/1993 0 0 0 0 .3 67 

8/12/1993 .4 0 0 0 .2 86 10/1/1993 0 0 0 0 .3 70 

8/13/1993 .3 0 0 0 .2 85 10/2/1993 0 0 0 0 .3 70 

8/14/1993 .3 0 0 0 .2 85 10/3/1993 0 0 0 0 .3 70 

8/15/1993 .3 0 0 0 .2 84 10/4/1993 0 0 0 0 .3 68 

8/16/1993 .2 0 0 0 .2 84 10/5/1993 0 0 0 0 .3 68 

8/17/1993 .2 0 0 0 .1 83 10/6/1993 0 0 0 0 .3 69 

8/18/1993 .2 0 0 0 .1 83 10/7/1993 0 0 0 0 .3 68 
116 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/8/1993 0 0 0 0 0.3 67 11/27/1993 0.8 0 0 0 2.9 57 

10/9/1993 0 0 0 0 .2 68 11/28/1993 .7 0 0 0 2.9 57 

10/10/1993 0 0 0 0 .2 67 11/29/1993 .8 0 0 0 2.6 56 

10/11/1993 0 0 0 0 .2 67 11/30/1993 .8 0 0 0 2.1 56 

10/12/1993 0 0 0 0 .2 67 12/1/1993 .7 0 0 0 2.1 56 

10/13/1993 0 0 0 0 1.7 67 12/2/1993 .8 0 0 0 2.3 55 

10/14/1993 .1 0 0 0 .3 66 12/3/1993 .8 0 0 0 2.4 55 

10/15/1993 .1 0 0 0 .2 65 12/4/1993 .8 0 0 0 2.0 55 

10/16/1993 .1 0 0 0 .2 66 12/5/1993 .8 0 0 0 1.7 55 

10/17/1993 .1 0 0 0 .2 66 12/6/1993 .8 0 0 0 1.8 54 

10/18/1993 .1 0 0 0 .2 66 12/7/1993 .8 0 0 0 2.1 54 

10/19/1993 .1 0 0 0 .1 66 12/8/1993 .9 0 0 0 2.4 54 

10/20/1993 .6 1.1 .7 0 13.0 66 12/9/1993 .9 0 0 0 2.6 54 

10/21/1993 .1 0 0 0 2.8 66 12/10/1993 .9 0 0 0 2.5 54 

10/22/1993 .1 0 0 0 5.3 66 12/11/1993 .9 0 0 0 2.1 54 

10/23/1993 .2 0 0 0 5.8 65 12/12/1993 .9 0 0 0 2.2 54 

10/24/1993 .2 0 0 0 5.2 64 12/13/1993 1.0 0 0 0 2.5 53 

10/25/1993 .2 0 0 0 4.4 64 12/14/1993 .9 0 0 0 1.7 53 

10/26/1993 .2 0 0 0 3.9 63 12/15/1993 .9 0 0 0 1.7 53 

10/27/1993 .2 0 0 0 3.1 63 12/16/1993 .9 0 0 0 2.1 53 

10/28/1993 .2 0 0 0 3.1 63 12/17/1993 1.0 0 0 0 2.6 53 

10/29/1993 .2 0 0 0 3.5 64 12/18/1993 1.0 0 0 0 2.4 53 

10/30/1993 .2 0 0 0 2.8 64 12/19/1993 1.0 0 0 0 2.1 53 

10/31/1993 .2 0 0 0 3.0 64 12/20/1993 1.1 0 0 0 2.1 53 

11/1/1993 .2 0 0 0 3.3 64 12/21/1993 1.0 0 0 0 2.3 53 

11/2/1993 .2 0 0 0 3.5 62 12/22/1993 1.7 0 0 0 4.2 53 

11/3/1993 .3 0 0 0 4.7 63 12/23/1993 1.7 0 0 0 3.0 53 

11/4/1993 .3 0 0 0 4.1 64 12/24/1993 1.4 0 0 0 2.5 52 

11/5/1993 .3 0 0 0 3.7 63 12/25/1993 1.1 0 0 0 2.1 52 

11/6/1993 .3 0 0 0 3.5 62 12/26/1993 1.1 0 0 0 2.1 52 

11/7/1993 .3 0 0 0 3.5 62 12/27/1993 1.1 0 0 0 2.1 52 

11/8/1993 .4 0 0 0 4.4 60 12/28/1993 1.1 0 0 0 2.1 51 

11/9/1993 .3 0 0 0 4.0 58 12/29/1993 1.2 0 0 0 2.1 51 

11/10/1993 .3 0 0 0 4.0 58 12/30/1993 1.4 0 0 0 1.8 51 

11/11/1993 .4 0 0 0 4.0 58 12/31/1993 1.4 0 0 0 1.7 51 

11/12/1993 .6 0 0 0 4.0 58 1/1/1994 1.5 0 0 0 2.1 51 

11/13/1993 .5 0 0 0 4.1 58 1/2/1994 1.5 0 0 0 2.5 50 

11/14/1993 .6 0 0 0 3.5 57 1/3/1994 1.6 0 0 0 3.1 52 

11/15/1993 .6 0 0 0 3.0 58 1/4/1994 1.7 0 0 0 2.6 53 

11/16/1993 .7 0 0 0 3.0 59 1/5/1994 1.5 0 0 0 2.1 54 

11/17/1993 .6 0 0 0 3.0 59 1/6/1994 1.5 0 0 0 2.3 54 

11/18/1993 .6 0 0 0 2.9 59 1/7/1994 1.5 0 0 0 2.1 53 

11/19/1993 .6 0 0 0 3.1 59 1/8/1994 1.5 0 0 0 2.1 53 

11/20/1993 .6 0 0 0 2.9 58 1/9/1994 1.5 0 0 0 1.8 53 

11/21/1993 .6 0 0 0 2.8 58 1/10/1994 1.5 0 0 0 2.0 52 

11/22/1993 .6 0 0 0 3.1 57 1/11/1994 1.5 0 0 0 2.0 52 

11/23/1993 .7 0 0 0 3.2 57 1/12/1994 1.6 0 0 0 1.7 52 

11/24/1993 .7 0 0 0 3.1 57 1/13/1994 1.8 0 0 0 1.8 52 

11/25/1993 .7 0 0 0 3.0 57 1/14/1994 1.7 0 0 0 1.7 52 

11/26/1993 .8 0 0 0 2.6 57 1/15/1994 1.7 0 0 0 1.9 52 
Appendix 2 117 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/16/1994 1.7 0 0 0 1.7 52 3/7/1994 4.6 0 0 0.1 4.4 48 

1/17/1994 1.7 0 0 0 1.6 51 3/8/1994 4.2 0 0 .1 4.5 48 

1/18/1994 1.7 0 0 0 1.4 51 3/9/1994 6.6 0 0 .2 5.2 47 

1/19/1994 1.5 0 0 0 1.4 51 3/10/1994 5.3 0 0 .1 4.4 47 

1/20/1994 1.6 0 0 0 1.8 51 3/11/1994 5.0 0 0 .1 4.4 47 

1/21/1994 2.3 0 0 0 2.1 51 3/12/1994 5.5 0 0 .1 4.9 47 

1/22/1994 2.3 0 0 0 2.3 52 3/13/1994 6.9 0 0 .2 5.7 47 

1/23/1994 2.2 0 0 0 2.1 52 3/14/1994 6.4 0 0 .2 6.0 47 

1/24/1994 2.3 0 0 0 2.9 52 3/15/1994 8.3 0 0 .3 7.2 47 

1/25/1994 2.5 0 0 0 2.3 52 3/16/1994 9.3 0 0 .4 8.9 47 

1/26/1994 2.5 0 0 0 1.8 51 3/17/1994 8.4 0 0 .4 9.3 47 

1/27/1994 2.7 0 0 0 1.8 51 3/18/1994 8.4 0 0 .4 10.0 47 

1/28/1994 3.5 0 0 0 1.4 51 3/19/1994 8.2 0 0 .5 10.0 47 

1/29/1994 3.0 0 0 0 1.6 51 3/20/1994 7.6 0 0 .4 11.0 48 

1/30/1994 2.6 0 0 0 1.4 50 3/21/1994 7.2 0 0 .3 10.0 47 

1/31/1994 2.5 0 0 0 1.4 50 3/22/1994 6.9 0 0 .3 9.9 47 

2/1/1994 2.5 0 0 0 1.4 50 3/23/1994 7.0 0 0 .4 10.0 47 

2/2/1994 2.5 0 0 0 1.4 50 3/24/1994 7.3 0 0 .5 10.0 47 

2/3/1994 2.3 0 0 0 1.3 50 3/25/1994 6.9 0 0 .2 9.3 47 

2/4/1994 2.4 0 0 0 1.1 50 3/26/1994 6.8 0 0 .5 9.2 47 

2/5/1994 2.4 0 0 0 1.1 50 3/27/1994 7.0 0 0 .4 9.4 47 

2/6/1994 2.4 0 0 0 1.1 49 3/28/1994 6.9 0 0 .3 8.9 47 

2/7/1994 2.3 0 0 0 1.1 49 3/29/1994 6.7 0 0 .4 8.8 47 

2/8/1994 2.3 0 0 0 1.1 49 3/30/1994 6.5 0 0 .3 8.6 47 

2/9/1994 2.2 0 0 0 1.3 50 3/31/1994 6.2 0 0 .1 8.3 47 

2/10/1994 2.1 1.6 0 0 1.6 50 4/1/1994 6.2 0 0 .1 8.3 47 

2/11/1994 2.1 0 0 0 1.5 49 4/2/1994 6.1 0 0 .1 8.3 47 

2/12/1994 2.0 0 0 0 1.4 49 4/3/1994 5.5 0 0 .1 8.2 47 

2/13/1994 1.9 0 0 0 1.2 48 4/4/1994 5.4 0 0 .1 8.3 47 

2/14/1994 1.8 0 0 0 1.0 48 4/5/1994 6.9 0 0 .2 9.5 47 

2/15/1994 1.8 0 0 0 1.1 48 4/6/1994 6.7 0 0 .3 8.4 47 

2/16/1994 1.8 0 0 0 1.1 48 4/7/1994 5.5 0 0 .2 8.3 46 

2/17/1994 1.8 0 0 0 1.1 48 4/8/1994 5.2 0 0 .2 8.3 46 

2/18/1994 1.8 0 0 0 1.3 48 4/9/1994 4.9 0 0 .3 8.2 46 

2/19/1994 1.8 0 0 0 1.4 48 4/10/1994 4.8 0 0 .3 8.0 46 

2/20/1994 1.9 0 0 0 1.8 50 4/11/1994 4.9 0 0 .3 8.1 46 

2/21/1994 1.9 0 0 0 1.8 52 4/12/1994 4.5 0 0 .3 8.0 46 

2/22/1994 3.9 0 0 .8 18.0 53 4/13/1994 4.4 0 0 .2 7.9 46 

2/23/1994 3.0 0 0 .8 9.2 53 4/14/1994 4.4 0 0 .2 7.9 45 

2/24/1994 2.4 0 0 .6 7.0 52 4/15/1994 4.5 0 0 .2 8.1 45 

2/25/1994 2.5 0 0 .4 6.1 52 4/16/1994 4.5 0 0 .2 7.7 45 

2/26/1994 3.4 0 0 .3 5.4 51 4/17/1994 4.4 0 0 .1 7.8 45 

2/27/1994 3.4 0 0 .3 5.3 52 4/18/1994 4.3 0 0 .1 7.5 44 

2/28/1994 3.3 0 0 .3 5.5 52 4/19/1994 4.7 0 0 .1 7.8 44 

3/1/1994 6.9 0 0 .6 6.2 51 4/20/1994 4.7 0 0 .2 7.9 44 

3/2/1994 5.3 0 0 .5 5.6 51 4/21/1994 4.2 0 0 .2 7.8 45 

3/3/1994 4.1 0 0 .2 4.8 50 4/22/1994 3.8 0 0 .2 7.6 45 

3/4/1994 5.0 0 0 .3 4.6 49 4/23/1994 4.0 0 0 .2 7.5 45 

3/5/1994 5.2 0 0 .2 4.4 48 4/24/1994 3.4 0 0 .2 7.5 45 

3/6/1994 4.9 0 0 .1 4.4 48 4/25/1994 3.3 0 0 .2 7.5 44 
118 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/26/1994 3.2 0 0 0.1 7.3 44 6/15/1994 2.5 0 0 0.6 7.4 44 

4/27/1994 2.9 0 0 .1 7.0 44 6/16/1994 2.1 0 0 .5 7.0 43 

4/28/1994 2.9 0 0 .1 7.2 45 6/17/1994 1.7 0 0 .4 6.2 43 

4/29/1994 4.4 0 0 .4 7.7 46 6/18/1994 1.7 0 0 .2 5.5 43 

4/30/1994 3.5 0 0 .3 7.3 45 6/19/1994 1.4 0 0 .1 4.9 43 

5/1/1994 3.4 0 0 .1 7.1 44 6/20/1994 1.3 0 .2 .1 5.4 43 

5/2/1994 4.0 0 0 .2 7.5 43 6/21/1994 1.2 0 0 .3 6.1 43 

5/3/1994 3.8 0 0 .2 7.2 42 6/22/1994 1.2 0 0 .3 6.4 43 

5/4/1994 3.6 0 0 .2 7.0 42 6/23/1994 1.1 0 0 .3 5.2 43 

5/5/1994 4.3 0 0 .2 7.6 43 6/24/1994 1.1 0 0 .2 4.4 43 

5/6/1994 4.4 0 0 .1 7.8 43 6/25/1994 .9 0 0 .1 4.2 43 

5/7/1994 4.3 0 0 .1 7.6 43 6/26/1994 .7 0 0 .1 3.5 43 

5/8/1994 3.6 0 0 .1 7.3 43 6/27/1994 .6 0 0 .1 3.1 43 

5/9/1994 3.4 0 0 .1 6.7 42 6/28/1994 .6 0 0 0 3.7 42 

5/10/1994 3.4 0 0 .1 6.1 42 6/29/1994 .5 0 0 0 3.4 42 

5/11/1994 3.2 0 0 .1 5.9 42 6/30/1994 .4 0 0 0 1.8 42 

5/12/1994 3.0 0 0 .1 5.8 42 7/1/1994 .4 0 0 0 2.3 40 

5/13/1994 4.9 .2 .9 3.2 28.0 42 7/2/1994 .3 0 0 0 2.1 40 

5/14/1994 7.4 0 .7 .7 26.0 42 7/3/1994 .3 0 0 0 2.1 40 

5/15/1994 12.0 3.1 .2 6.8 46.0 43 7/4/1994 .3 0 0 0 2.1 40 

5/16/1994 11.0 0 .1 3.0 35.0 43 7/5/1994 .3 0 0 0 2.1 39 

5/17/1994 10.0 0 0 2.5 30.0 44 7/6/1994 .3 0 0 0 2.1 38 

5/18/1994 9.9 0 0 2.1 26.0 44 7/7/1994 .3 0 0 0 2.0 39 

5/19/1994 8.7 0 0 1.7 27.0 45 7/8/1994 .3 0 0 0 1.7 39 

5/20/1994 7.2 0 0 1.5 23.0 45 7/9/1994 .3 0 0 0 1.4 39 

5/21/1994 6.2 0 0 1.3 20.0 45 7/10/1994 .3 0 0 0 2.1 39 

5/22/1994 5.4 0 0 1.0 17.0 45 7/11/1994 .3 0 0 0 1.5 39 

5/23/1994 4.8 0 0 .9 16.0 45 7/12/1994 .3 0 0 0 1.0 38 

5/24/1994 4.3 0 0 .8 15.0 45 7/13/1994 .2 0 0 0 .9 39 

5/25/1994 4.0 0 0 .7 14.0 45 7/14/1994 .2 0 0 0 .9 38 

5/26/1994 3.8 0 0 .7 14.0 45 7/15/1994 .2 0 0 0 .8 38 

5/27/1994 3.7 0 0 .7 12.0 45 7/16/1994 .2 0 0 0 .5 37 

5/28/1994 3.5 0 .3 .8 11.0 45 7/17/1994 .2 0 0 0 .5 37 

5/29/1994 3.4 0 .3 .7 11.0 45 7/18/1994 .2 0 0 0 .4 37 

5/30/1994 7.0 .2 .1 2.5 17.0 45 7/19/1994 .2 0 0 0 .3 36 

5/31/1994 4.5 0 0 .8 12.0 45 7/20/1994 .2 0 0 0 .4 36 

6/1/1994 3.8 0 0 .7 10.0 44 7/21/1994 .1 0 0 0 .4 36 

6/2/1994 3.8 0 0 .8 9.5 44 7/22/1994 .1 0 0 0 .7 36 

6/3/1994 16.0 0 0 .9 9.3 44 7/23/1994 .1 0 0 0 .6 36 

6/4/1994 7.2 0 0 .8 9.3 44 7/24/1994 .1 0 0 0 .3 36 

6/5/1994 5.4 0 0 .7 9.1 44 7/25/1994 .1 0 0 0 .2 35 

6/6/1994 4.5 0 0 .7 8.9 44 7/26/1994 .1 0 0 0 .4 35 

6/7/1994 4.0 0 0 .5 8.4 44 7/27/1994 .1 0 0 0 .3 35 

6/8/1994 3.6 0 .3 .4 8.2 44 7/28/1994 .1 0 0 0 .2 35 

6/9/1994 3.3 0 .5 .4 8.0 44 7/29/1994 .1 0 0 0 .2 34 

6/10/1994 3.0 0 .3 .5 6.1 44 7/30/1994 .1 0 0 0 .3 34 

6/11/1994 2.8 0 0 .4 6.3 44 7/31/1994 .1 0 0 0 .3 34 

6/12/1994 2.5 0 0 .4 6.3 44 8/1/1994 .1 0 0 0 .3 34 

6/13/1994 2.7 0 0 .4 6.7 44 8/2/1994 .1 0 0 0 .5 33 

6/14/1994 2.8 0 0 .7 6.6 44 8/3/1994 .1 0 0 0 .2 34 
Appendix 2 119 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

8/4/1994 0.1 0 0 0 0.4 33 9/23/1994 0.3 0 0 0 0 26 

8/5/1994 .1 0 0 0 .6 33 9/24/1994 .3 0 0 0 0 26 

8/6/1994 .1 0 0 0 1.9 33 9/25/1994 .3 0 0 0 0 26 

8/7/1994 .1 0 0 0 .4 33 9/26/1994 .2 0 0 0 0 25 

8/8/1994 .1 0 0 0 .7 33 9/27/1994 .2 0 0 0 0 25 

8/9/1994 7.1 17.0 1.0 0 1.3 33 9/28/1994 .2 0 0 0 0 25 

8/10/1994 2.1 0 0 0 2.0 33 9/29/1994 .2 0 0 0 0 25 

8/11/1994 1.1 0 0 0 .1 33 9/30/1994 .2 0 0 0 0 25 

8/12/1994 1.1 0 0 0 0 34 10/1/1994 .2 0 0 0 0 25 

8/13/1994 1.1 0 0 0 0 34 10/2/1994 .2 0 0 0 0 25 

8/14/1994 1.0 0 0 0 0 34 10/3/1994 .2 0 0 0 0 25 

8/15/1994 .9 0 0 0 0 34 10/4/1994 .2 0 0 0 0 25 

8/16/1994 .8 0 0 0 0 34 10/5/1994 .2 0 0 0 0 25 

8/17/1994 .8 0 0 0 0 34 10/6/1994 .2 0 0 0 0 25 

8/18/1994 .8 0 0 0 0 34 10/7/1994 51.0 43.0 4.9 .3 .3 25 

8/19/1994 .7 0 0 0 0 34 10/8/1994 476.0 73.0 99.0 33.0 30.0 30 

8/20/1994 .7 0 0 0 0 33 10/9/1994 72.0 0 0 22.0 28.0 35 

8/21/1994 .8 0 .1 0 0 32 10/10/1994 31.0 0 0 5.2 13.0 39 

8/22/1994 .8 0 0 0 0 32 10/11/1994 22.0 0 0 1.4 8.9 35 

8/23/1994 .5 0 0 0 0 32 10/12/1994 18.0 0 0 .2 6.3 33 

8/24/1994 .5 0 0 0 0 32 10/13/1994 15.0 0 0 .1 5.5 33 

8/25/1994 .5 0 0 0 0 32 10/14/1994 14.0 0 0 0 5.0 31 

8/26/1994 .5 0 0 0 0 32 10/15/1994 19.0 0 0 0 7.3 33 

8/27/1994 .5 0 0 0 0 30 10/16/1994 21.0 0 0 0 7.3 34 

8/28/1994 .4 0 0 0 0 30 10/17/1994 22.0 0 0 0 5.7 34 

8/29/1994 .4 0 0 0 0 30 10/18/1994 53.0 4.0 11.0 10.0 8.3 35 

8/30/1994 .4 0 0 0 0 30 10/19/1994 61.0 0 10.0 4.5 16.0 39 

8/31/1994 .4 0 0 0 0 30 10/20/1994 42.0 0 6.3 3.3 12.0 43 

9/1/1994 .4 0 0 0 0 30 10/21/1994 38.0 0 4.2 2.8 11.0 42 

9/2/1994 .4 0 0 0 0 29 10/22/1994 31.0 0 3.5 2.2 10.0 38 

9/3/1994 .4 0 0 0 0 29 10/23/1994 25.0 0 2.5 1.8 9.3 37 

9/4/1994 .4 0 0 0 0 29 10/24/1994 21.0 0 2.2 1.7 8.7 36 

9/5/1994 .4 0 0 0 0 29 10/25/1994 214.0 33.0 135.0 23.0 792.0 51 

9/6/1994 .3 0 0 0 0 29 10/26/1994 145.0 .9 35.0 18.0 174.0 51 

9/7/1994 .3 0 0 0 0 29 10/27/1994 79.0 0 23.0 13.0 66.0 54 

9/8/1994 1.2 2.4 .5 0 0 29 10/28/1994 65.0 0 20.0 9.8 56.0 55 

9/9/1994 1.2 1.8 .5 0 0 29 10/29/1994 55.0 0 14.0 9.0 47.0 55 

9/10/1994 .6 0 0 0 0 29 10/30/1994 49.0 0 9.3 8.0 40.0 54 

9/11/1994 .5 0 0 0 0 30 10/31/1994 44.0 0 7.6 6.8 37.0 54 

9/12/1994 .5 0 0 0 0 30 11/1/1994 40.0 0 6.7 6.0 34.0 53 

9/13/1994 .6 0 0 0 0 29 11/2/1994 38.0 0 6.3 5.3 32.0 52 

9/14/1994 .6 0 0 0 0 29 11/3/1994 37.0 0 5.4 4.9 30.0 51 

9/15/1994 .8 0 0 0 0 29 11/4/1994 34.0 0 5.2 3.3 29.0 50 

9/16/1994 .7 0 0 .1 0 29 11/5/1994 74.0 5.0 70.0 21.0 95.0 57 

9/17/1994 .5 0 0 .1 0 29 11/6/1994 88.0 0 18.0 9.3 67.0 57 

9/18/1994 .4 0 0 0 0 28 11/7/1994 54.0 0 14.0 5.6 49.0 58 

9/19/1994 .4 0 0 0 0 28 11/8/1994 47.0 0 13.0 5.3 44.0 57 

9/20/1994 .4 0 0 0 0 28 11/9/1994 41.0 0 10.0 5.2 41.0 58 

9/21/1994 .4 0 0 0 0 27 11/10/1994 36.0 0 8.9 4.7 37.0 57 

9/22/1994 .4 0 0 0 0 27 11/11/1994 34.0 0 7.9 4.5 35.0 56 
120 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

11/12/1994 33.0 0 7.2 4.0 34.0 56 1/1/1995 138.0 0 21.0 20.0 178.0 33 

11/13/1994 32.0 0 7.2 4.0 33.0 56 1/2/1995 127.0 0 18.0 18.0 161.0 35 

11/14/1994 32.0 0 6.8 4.0 33.0 55 1/3/1995 126.0 0 16.0 18.0 151.0 35 

11/15/1994 31.0 0 6.7 4.0 31.0 53 1/4/1995 117.0 0 12.0 16.0 137.0 35 

11/16/1994 32.0 0 7.1 3.8 33.0 53 1/5/1995 107.0 0 11.0 15.0 124.0 35 

11/17/1994 31.0 0 6.7 3.7 33.0 53 1/6/1995 107.0 0 10.0 15.0 123.0 35 

11/18/1994 30.0 0 6.5 3.8 31.0 53 1/7/1995 97.0 0 7.3 13.0 106.0 35 

11/19/1994 30.0 0 6.8 3.6 32.0 52 1/8/1995 85.0 0 7.2 13.0 101.0 35 

11/20/1994 28.0 0 6.1 3.2 31.0 52 1/9/1995 79.0 0 6.4 12.0 96.0 35 

11/21/1994 26.0 0 4.5 3.0 29.0 52 1/10/1995 74.0 0 6.3 11.0 93.0 35 

11/22/1994 25.0 0 4.0 3.0 27.0 50 1/11/1995 70.0 0 6.0 10.0 90.0 35 

11/23/1994 23.0 0 4.0 2.8 26.0 49 1/12/1995 73.0 2.9 8.4 11.0 88.0 37 

11/24/1994 22.0 0 4.0 2.6 25.0 48 1/13/1995 76.0 .4 8.0 11.0 89.0 45 

11/25/1994 22.0 0 3.8 2.6 25.0 48 1/14/1995 69.0 0 5.2 9.6 81.0 45 

11/26/1994 21.0 0 3.6 2.4 24.0 47 1/15/1995 60.0 0 4.6 8.9 77.0 45 

11/27/1994 20.0 0 2.9 2.3 24.0 48 1/16/1995 56.0 0 4.0 8.8 76.0 42 

11/28/1994 18.0 0 2.6 2.2 23.0 49 1/17/1995 55.0 0 3.7 8.5 75.0 40 

11/29/1994 17.0 0 2.5 2.1 21.0 48 1/18/1995 52.0 0 3.5 7.9 72.0 40 

11/30/1994 17.0 0 2.1 1.9 21.0 48 1/19/1995 50.0 0 3.5 7.3 68.0 40 

12/1/1994 16.0 0 2.0 1.6 20.0 46 1/20/1995 47.0 0 3.6 6.9 66.0 44 

12/2/1994 16.0 0 2.3 1.9 20.0 46 1/21/1995 45.0 0 3.3 6.7 62.0 44 

12/3/1994 16.0 0 2.7 2.0 22.0 46 1/22/1995 44.0 0 3.0 6.6 62.0 43 

12/4/1994 15.0 0 2.2 1.7 21.0 46 1/23/1995 42.0 0 3.0 6.2 59.0 42 

12/5/1994 14.0 0 2.0 1.6 20.0 46 1/24/1995 40.0 0 3.0 5.9 58.0 41 

12/6/1994 14.0 0 2.0 1.5 20.0 45 1/25/1995 40.0 0 2.8 5.9 59.0 41 

12/7/1994 14.0 0 2.0 1.5 21.0 45 1/26/1995 41.0 0 2.9 6.0 62.0 41 

12/8/1994 13.0 0 1.8 1.5 22.0 45 1/27/1995 40.0 0 3.0 6.0 61.0 42 

12/9/1994 14.0 0 2.0 1.7 25.0 46 1/28/1995 38.0 0 2.9 5.4 55.0 42 

12/10/1994 17.0 0 2.1 1.3 28.0 45 1/29/1995 35.0 0 2.8 5.3 50.0 41 

12/11/1994 16.0 0 2.0 1.1 26.0 42 1/30/1995 31.0 0 2.8 5.1 48.0 41 

12/12/1994 16.0 0 2.0 1.1 25.0 40 1/31/1995 27.0 0 2.8 5.1 47.0 41 

12/13/1994 15.0 0 2.1 1.1 26.0 40 2/1/1995 27.0 0 2.8 4.8 46.0 41 

12/14/1994 15.0 0 2.7 1.6 27.0 40 2/2/1995 27.0 0 2.6 4.4 44.0 40 

12/15/1994 34.0 24.0 93.0 37.0 57.0 40 2/3/1995 26.0 0 2.6 4.2 42.0 39 

12/16/1994 109.0 14.0 90.0 22.0 209.0 40 2/4/1995 25.0 0 2.5 3.8 40.0 38 

12/17/1994 91.0 1.0 38.0 15.0 138.0 40 2/5/1995 23.0 0 2.7 3.8 39.0 37 

12/18/1994 66.0 0 24.0 14.0 114.0 40 2/6/1995 23.0 0 2.8 3.8 36.0 37 

12/19/1994 58.0 0 18.0 13.0 101.0 40 2/7/1995 23.0 0 2.8 3.7 36.0 35 

12/20/1994 54.0 0 15.0 12.0 93.0 40 2/8/1995 22.0 0 2.6 3.5 33.0 34 

12/21/1994 52.0 0 11.0 11.0 84.0 39 2/9/1995 22.0 0 2.6 3.6 31.0 34 

12/22/1994 50.0 0 7.9 10.0 76.0 40 2/10/1995 21.0 0 2.6 3.7 32.0 34 

12/23/1994 48.0 0 6.8 9.8 70.0 40 2/11/1995 21.0 0 2.6 3.6 31.0 34 

12/24/1994 47.0 0 6.2 9.3 68.0 40 2/12/1995 20.0 0 2.6 3.4 29.0 33 

12/25/1994 44.0 0 4.8 8.7 63.0 40 2/13/1995 20.0 0 2.5 3.5 29.0 33 

12/26/1994 44.0 0 4.4 8.1 59.0 40 2/14/1995 21.0 0 2.4 3.6 29.0 33 

12/27/1994 44.0 0 4.4 7.7 58.0 39 2/15/1995 21.0 0 2.5 3.5 30.0 33 

12/28/1994 210.0 22.0 127.0 48.0 370.0 39 2/16/1995 20.0 0 2.6 3.3 30.0 33 

12/29/1994 392.0 8.2 66.0 28.0 313.0 40 2/17/1995 19.0 0 2.6 3.1 28.0 33 

12/30/1994 193.0 3.2 41.0 24.0 235.0 40 2/18/1995 18.0 0 2.6 3.0 26.0 33 

12/31/1994 156.0 1.5 30.0 22.0 207.0 37 2/19/1995 17.0 0 2.6 3.0 26.0 32 
Appendix 2 121 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

2/20/1995 17.0 0 2.6 2.8 24.0 32 4/11/1995 65.0 0 7.9 13.0 90.0 83 

2/21/1995 17.0 0 2.6 2.7 24.0 32 4/12/1995 57.0 0 6.7 12.0 75.0 83 

2/22/1995 16.0 0 2.4 2.6 24.0 32 4/13/1995 52.0 0 6.4 11.0 68.0 83 

2/23/1995 16.0 0 2.6 2.6 24.0 32 4/14/1995 51.0 0 6.2 10.0 63.0 83 

2/24/1995 16.0 0 2.6 4.9 22.0 32 4/15/1995 49.0 0 5.5 10.0 60.0 80 

2/25/1995 26.0 .2 2.6 5.7 22.0 34 4/16/1995 48.0 0 5.5 10.0 60.0 82 

2/26/1995 42.0 0 2.8 5.7 24.0 36 4/17/1995 48.0 0 5.6 9.8 59.0 83 

2/27/1995 36.0 0 2.8 5.0 30.0 38 4/18/1995 53.0 0 6.4 10.0 58.0 84 

2/28/1995 30.0 0 3.0 4.7 28.0 40 4/19/1995 61.0 .1 12.0 11.0 58.0 84 

3/1/1995 26.0 0 3.0 4.6 26.0 42 4/20/1995 67.0 3.1 35.0 20.0 58.0 86 

3/2/1995 25.0 0 2.8 4.6 25.0 44 4/21/1995 61.0 0 11.0 12.0 59.0 85 

3/3/1995 26.0 0 2.8 4.6 25.0 44 4/22/1995 51.0 0 10.0 12.0 58.0 85 

3/4/1995 27.0 0 2.8 4.6 26.0 44 4/23/1995 49.0 0 7.9 11.0 53.0 85 

3/5/1995 28.0 0 2.8 4.8 26.0 46 4/24/1995 46.0 0 7.5 10.0 50.0 84 

3/6/1995 28.0 0 2.7 5.9 25.0 49 4/25/1995 43.0 0 6.7 9.5 48.0 85 

3/7/1995 30.0 .1 2.6 9.1 27.0 49 4/26/1995 41.0 0 6.5 9.2 47.0 85 

3/8/1995 34.0 0 2.6 6.5 27.0 54 4/27/1995 39.0 0 6.1 8.6 45.0 85 

3/9/1995 34.0 0 2.6 6.4 26.0 59 4/28/1995 38.0 0 5.3 8.1 43.0 85 

3/10/1995 31.0 0 2.6 6.5 27.0 59 4/29/1995 37.0 0 4.4 7.8 42.0 84 

3/11/1995 31.0 0 2.6 6.4 28.0 59 4/30/1995 35.0 0 4.0 7.5 40.0 85 

3/12/1995 31.0 0 2.6 7.3 29.0 59 5/1/1995 33.0 0 3.9 7.2 38.0 85 

3/13/1995 114.0 9.7 45.0 15.0 88.0 69 5/2/1995 31.0 0 3.6 6.5 35.0 85 

3/14/1995 109.0 0 11.0 10.0 77.0 84 5/3/1995 30.0 0 3.6 6.7 34.0 85 

3/15/1995 69.0 .5 9.4 9.8 60.0 86 5/4/1995 30.0 0 3.5 6.7 34.0 85 

3/16/1995 72.0 .4 10.0 9.8 61.0 84 5/5/1995 31.0 0 3.3 6.3 33.0 85 

3/17/1995 68.0 0 8.0 9.3 59.0 82 5/6/1995 32.0 0 3.4 6.2 32.0 83 

3/18/1995 63.0 0 7.3 9.1 57.0 81 5/7/1995 34.0 0 3.3 5.9 32.0 84 

3/19/1995 62.0 0 7.2 8.8 56.0 80 5/8/1995 214.0 26.0 111.0 22.0 89.0 86 

3/20/1995 61.0 0 6.9 8.5 54.0 79 5/9/1995 132.0 0 17.0 10.0 66.0 88 

3/21/1995 58.0 0 6.5 8.0 52.0 78 5/10/1995 67.0 0 12.0 8.6 42.0 89 

3/22/1995 56.0 0 6.4 7.7 51.0 78 5/11/1995 49.0 0 10.0 7.7 37.0 88 

3/23/1995 54.0 0 6.4 7.2 49.0 78 5/12/1995 45.0 0 10.0 9.6 35.0 88 

3/24/1995 52.0 0 6.4 7.1 47.0 77 5/13/1995 45.0 0 9.8 8.6 35.0 88 

3/25/1995 52.0 0 6.4 7.3 48.0 78 5/14/1995 44.0 0 7.2 7.5 33.0 88 

3/26/1995 51.0 0 6.2 7.4 47.0 77 5/15/1995 40.0 0 6.2 6.5 31.0 88 

3/27/1995 49.0 0 5.0 6.8 43.0 77 5/16/1995 38.0 0 5.5 6.0 29.0 88 

3/28/1995 46.0 0 4.5 6.6 41.0 77 5/17/1995 37.0 0 4.8 5.9 28.0 87 

3/29/1995 45.0 0 4.3 6.6 42.0 77 5/18/1995 35.0 0 5.9 7.1 34.0 87 

3/30/1995 44.0 0 4.3 6.6 41.0 77 5/19/1995 33.0 0 3.9 5.1 29.0 88 

3/31/1995 44.0 0 4.3 6.1 40.0 77 5/20/1995 31.0 0 3.6 5.0 25.0 87 

4/1/1995 44.0 0 4.3 6.2 41.0 77 5/21/1995 29.0 0 3.4 4.6 23.0 87 

4/2/1995 42.0 0 3.8 6.1 39.0 76 5/22/1995 27.0 0 3.3 4.6 22.0 87 

4/3/1995 41.0 0 3.7 6.0 39.0 76 5/23/1995 26.0 0 3.2 4.5 22.0 87 

4/4/1995 48.0 1.4 10.0 11.0 47.0 79 5/24/1995 27.0 0 3.4 4.5 23.0 87 

4/5/1995 126.0 4.7 45.0 57.0 460.0 79 5/25/1995 28.0 0 3.3 4.4 24.0 86 

4/6/1995 163.0 0 16.0 20.0 270.0 80 5/26/1995 26.0 0 3.0 4.1 22.0 86 

4/7/1995 95.0 0 12.0 18.0 170.0 83 5/27/1995 27.0 0 3.3 4.1 25.0 86 

4/8/1995 79.0 0 10.0 16.0 127.0 83 5/28/1995 29.0 0 3.0 3.9 29.0 86 

4/9/1995 71.0 0 9.1 15.0 118.0 83 5/29/1995 303.0 33.0 78.0 16.0 73.0 86 

4/10/1995 68.0 0 8.4 14.0 113.0 83 5/30/1995 1,340.0 169.0 400.0 244.0 3,400.0 87 
122 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

5/31/1995 920.0 46.0 288.0 56.0 1,400.0 90 7/20/1995 9.1 0 0.7 1.8 14.0 88 

6/1/1995 1,910.0 101.0 256.0 112.0 2,500.0 95 7/21/1995 7.9 0 .6 1.8 13.0 89 

6/2/1995 708.0 18.0 167.0 52.0 515.0 100 7/22/1995 6.9 0 .6 1.6 13.0 89 

6/3/1995 515.0 6.1 106.0 42.0 374.0 105 7/23/1995 5.9 0 .5 1.5 12.0 87 

6/4/1995 416.0 1.3 71.0 36.0 326.0 105 7/24/1995 5.5 0 .4 1.4 11.0 88 

6/5/1995 347.0 .1 57.0 32.0 294.0 104 7/25/1995 4.9 0 .3 1.4 10.0 87 

6/6/1995 285.0 0 49.0 28.0 267.0 104 7/26/1995 4.2 0 .2 1.3 10.0 87 

6/7/1995 236.0 0 40.0 25.0 239.0 104 7/27/1995 3.7 0 .2 1.1 10.0 86 

6/8/1995 196.0 0 34.0 23.0 211.0 102 7/28/1995 3.2 0 .1 1.0 9.6 86 

6/9/1995 163.0 0 27.0 20.0 178.0 102 7/29/1995 2.6 0 .1 1.0 8.8 86 

6/10/1995 149.0 0 24.0 18.0 164.0 100 7/30/1995 2.4 0 .2 1.1 8.3 85 

6/11/1995 281.0 12.0 108.0 32.0 160.0 102 7/31/1995 3.2 0 .4 1.6 9.9 86 

6/12/1995 199.0 .6 43.0 21.0 172.0 102 8/1/1995 4.4 0 .4 1.3 9.4 84 

6/13/1995 152.0 0 34.0 18.0 154.0 100 8/2/1995 5.6 0 .4 1.1 9.9 83 

6/14/1995 140.0 0 28.0 17.0 140.0 99 8/3/1995 7.6 0 .4 1.2 10.0 82 

6/15/1995 127.0 0 25.0 16.0 119.0 98 8/4/1995 6.0 0 .3 1.0 13.0 85 

6/16/1995 117.0 0 21.0 14.0 109.0 98 8/5/1995 6.2 0 .1 .8 12.0 85 

6/17/1995 108.0 0 20.0 13.0 100.0 98 8/6/1995 5.3 0 .1 .7 11.0 83 

6/18/1995 99.0 0 18.0 12.0 96.0 98 8/7/1995 4.3 0 .1 .7 9.7 83 

6/19/1995 87.0 0 18.0 11.0 95.0 98 8/8/1995 3.6 0 0 .7 9.2 83 

6/20/1995 77.0 0 18.0 10.0 88.0 98 8/9/1995 3.0 0 0 .6 8.0 80 

6/21/1995 67.0 0 16.0 9.4 79.0 97 8/10/1995 2.5 0 0 .6 7.2 80 

6/22/1995 59.0 0 15.0 8.4 71.0 97 8/11/1995 2.0 0 0 .6 6.3 82 

6/23/1995 52.0 0 14.0 7.4 65.0 97 8/12/1995 1.8 0 0 .6 6.1 83 

6/24/1995 49.0 0 14.0 6.5 60.0 97 8/13/1995 1.8 0 0 .7 6.2 82 

6/25/1995 46.0 0 13.0 6.1 55.0 96 8/14/1995 2.0 0 0 .6 5.3 82 

6/26/1995 42.0 0 9.5 5.7 50.0 96 8/15/1995 1.6 0 0 .6 4.7 81 

6/27/1995 39.0 0 8.7 5.3 48.0 96 8/16/1995 1.5 0 0 .6 4.7 80 

6/28/1995 37.0 0 8.7 5.2 45.0 96 8/17/1995 1.3 0 0 .5 4.0 80 

6/29/1995 62.0 0 22.0 8.5 52.0 96 8/18/1995 1.2 0 0 .5 3.6 80 

6/30/1995 83.0 0 15.0 6.2 57.0 96 8/19/1995 1.0 0 0 .4 3.4 80 

7/1/1995 46.0 0 13.0 5.7 47.0 95 8/20/1995 .9 0 0 .3 3.1 80 

7/2/1995 39.0 0 11.0 5.2 42.0 95 8/21/1995 .8 0 0 .2 2.7 79 

7/3/1995 36.0 0 9.8 4.9 40.0 95 8/22/1995 .7 0 0 .2 2.8 78 

7/4/1995 31.0 0 7.7 4.6 38.0 95 8/23/1995 .7 0 0 .1 2.6 78 

7/5/1995 29.0 0 6.9 4.4 36.0 95 8/24/1995 .7 0 0 .1 2.6 78 

7/6/1995 28.0 0 7.2 4.3 34.0 94 8/25/1995 .7 0 0 .1 2.8 78 

7/7/1995 28.0 0 7.3 4.2 46.0 94 8/26/1995 .7 0 0 .3 2.5 78 

7/8/1995 30.0 0 5.1 3.9 37.0 94 8/27/1995 .7 0 0 .1 2.4 76 

7/9/1995 24.0 0 3.5 3.6 31.0 93 8/28/1995 .6 0 0 .1 2.9 77 

7/10/1995 21.0 0 2.7 3.3 28.0 93 8/29/1995 .6 0 0 .1 2.6 75 

7/11/1995 20.0 0 2.1 3.1 25.0 92 8/30/1995 .6 0 0 .1 2.2 73 

7/12/1995 17.0 0 1.4 3.0 23.0 92 8/31/1995 .6 0 .1 .1 13.0 73 

7/13/1995 15.0 0 1.0 2.8 21.0 91 9/1/1995 .6 0 0 .2 23.0 75 

7/14/1995 14.0 0 .9 2.8 20.0 91 9/2/1995 .6 0 0 .1 13.0 76 

7/15/1995 13.0 0 .9 2.8 19.0 90 9/3/1995 .6 0 0 .1 9.8 75 

7/16/1995 12.0 0 .8 2.4 18.0 90 9/4/1995 .5 0 0 .1 7.9 73 

7/17/1995 11.0 0 .7 2.3 17.0 89 9/5/1995 .5 0 0 .1 6.9 73 

7/18/1995 11.0 0 .6 2.0 16.0 88 9/6/1995 .5 0 0 .1 5.9 73 

7/19/1995 10.0 0 .7 1.9 15.0 88 9/7/1995 .5 0 0 .2 5.8 73 
Appendix 2 123 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/8/1995 0.5 0 0 0.3 7.0 74 10/28/1995 0.4 0 0 0 1.6 48 

9/9/1995 .4 0 0 .1 5.3 73 10/29/1995 .4 0 0 0 2.1 48 

9/10/1995 .5 0 0 .1 5.2 73 10/30/1995 .4 0 0 0 2.5 48 

9/11/1995 .5 0 0 .1 5.3 72 10/31/1995 .5 0 0 .1 6.4 50 

9/12/1995 .5 0 0 .1 4.8 71 11/1/1995 3.2 1.6 .2 .9 24.0 55 

9/13/1995 .5 0 0 .1 4.4 69 11/2/1995 1.2 0 0 .4 6.5 56 

9/14/1995 .5 0 0 0 5.7 70 11/3/1995 .6 0 0 .2 3.6 56 

9/15/1995 .4 0 0 0 6.5 68 11/4/1995 .7 0 0 .1 3.7 55 

9/16/1995 .4 0 0 .1 5.9 68 11/5/1995 .7 0 0 .2 4.8 55 

9/17/1995 .4 0 0 0 5.6 69 11/6/1995 .8 0 0 .1 4.6 55 

9/18/1995 .4 0 0 0 3.8 70 11/7/1995 .9 0 0 .1 4.1 53 

9/19/1995 .4 0 0 0 3.7 65 11/8/1995 .9 0 0 .1 3.3 53 

9/20/1995 .6 0 0 .1 5.4 68 11/9/1995 .9 0 0 .1 3.1 52 

9/21/1995 .6 0 0 .1 5.7 68 11/10/1995 1.0 0 0 .1 3.6 50 

9/22/1995 .5 0 0 .1 5.3 63 11/11/1995 .8 0 0 .1 2.7 49 

9/23/1995 .6 0 0 .1 3.5 67 11/12/1995 .8 0 0 .1 2.5 49 

9/24/1995 .7 0 0 0 3.7 59 11/13/1995 .8 0 0 .1 2.6 49 

9/25/1995 .7 0 0 0 3.8 59 11/14/1995 .9 0 0 .1 2.6 49 

9/26/1995 .7 0 0 0 3.7 65 11/15/1995 .8 0 0 .1 2.6 49 

9/27/1995 .6 0 0 0 3.7 65 11/16/1995 .8 0 0 .1 3.6 48 

9/28/1995 .6 0 0 0 4.0 63 11/17/1995 2.3 0 0 .1 4.2 49 

9/29/1995 .6 0 0 0 3.4 59 11/18/1995 3.4 0 0 .2 4.6 49 

9/30/1995 .6 0 0 0 3.1 59 11/19/1995 1.7 0 0 .1 3.9 49 

10/1/1995 .6 0 0 0 3.3 58 11/20/1995 1.7 0 0 .1 3.9 49 

10/2/1995 .6 0 0 0 3.2 57 11/21/1995 1.5 0 0 .1 3.9 48 

10/3/1995 .6 0 0 0 3.2 55 11/22/1995 1.3 0 0 .1 4.1 48 

10/4/1995 .6 0 0 0 3.3 53 11/23/1995 1.2 0 0 .1 3.9 48 

10/5/1995 .6 0 0 0 3.1 52 11/24/1995 1.2 0 0 .1 3.9 48 

10/6/1995 .6 0 0 0 2.3 50 11/25/1995 1.3 0 0 .1 3.9 47 

10/7/1995 .6 0 0 0 2.3 50 11/26/1995 1.2 0 0 .1 4.0 47 

10/8/1995 .6 0 0 0 2.3 50 11/27/1995 1.2 0 0 .1 4.4 47 

10/9/1995 .6 0 0 0 2.0 49 11/28/1995 1.0 0 0 .1 4.0 46 

10/10/1995 .5 0 0 0 2.5 51 11/29/1995 1.1 0 0 .1 4.1 46 

10/11/1995 .5 0 0 0 2.1 50 11/30/1995 1.1 0 0 .1 4.5 46 

10/12/1995 .5 0 0 0 1.6 50 12/1/1995 1.2 0 0 .1 5.8 42 

10/13/1995 .5 0 0 0 2.0 48 12/2/1995 1.3 0 0 .1 5.6 43 

10/14/1995 .5 0 0 0 1.9 49 12/3/1995 1.3 0 0 .1 6.2 43 

10/15/1995 .4 0 0 0 1.6 50 12/4/1995 1.2 0 0 .1 5.7 43 

10/16/1995 .4 0 0 0 2.0 49 12/5/1995 1.2 0 0 0 5.9 43 

10/17/1995 .4 0 0 0 1.9 50 12/6/1995 1.2 0 0 0 5.8 42 

10/18/1995 .4 0 0 0 2.2 47 12/7/1995 1.1 0 0 0 5.3 42 

10/19/1995 .4 0 0 0 2.2 50 12/8/1995 1.3 0 0 0 5.5 41 

10/20/1995 .4 0 0 0 1.6 51 12/9/1995 1.3 0 0 .1 5.2 42 

10/21/1995 .4 0 0 0 1.1 51 12/10/1995 1.3 0 0 .1 4.9 42 

10/22/1995 .4 0 0 0 1.5 52 12/11/1995 1.2 0 0 .1 5.0 42 

10/23/1995 .4 0 0 0 1.5 52 12/12/1995 1.2 0 0 .1 5.6 42 

10/24/1995 .3 0 0 0 1.5 51 12/13/1995 1.2 0 0 .1 5.6 42 

10/25/1995 .4 0 0 0 1.7 52 12/14/1995 1.2 0 0 .1 5.6 41 

10/26/1995 .4 0 0 0 1.9 52 12/15/1995 1.2 0 0 .1 5.6 39 

10/27/1995 .4 0 0 0 2.1 48 12/16/1995 1.1 0 0 .1 5.3 39 
124 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/17/1995 1.2 0 0 0.1 5.4 40 2/5/1996 1.0 0 0 0.1 3.0 30 

12/18/1995 1.2 0 0 .1 5.5 39 2/6/1996 1.0 0 0 .1 3.4 29 

12/19/1995 1.1 0 0 .1 4.6 40 2/7/1996 1.0 0 0 .1 3.9 29 

12/20/1995 1.2 0 0 .1 4.6 39 2/8/1996 1.2 0 0 .1 3.9 29 

12/21/1995 1.1 0 0 .1 4.6 39 2/9/1996 1.0 0 0 .1 3.9 28 

12/22/1995 1.3 0 0 .1 4.7 37 2/10/1996 1.0 0 0 .1 3.9 29 

12/23/1995 1.2 0 0 .1 4.6 34 2/11/1996 1.0 0 0 .1 3.9 29 

12/24/1995 1.1 0 0 .1 4.6 34 2/12/1996 .9 0 0 .1 3.7 29 

12/25/1995 1.2 0 0 .1 4.7 34 2/13/1996 1.0 0 0 .1 3.6 29 

12/26/1995 1.1 0 0 .1 4.6 34 2/14/1996 1.1 0 0 .1 3.6 29 

12/27/1995 1.2 0 0 .1 4.6 34 2/15/1996 1.1 0 0 .1 3.6 29 

12/28/1995 1.1 0 0 .1 4.6 34 2/16/1996 .8 0 0 .1 3.5 27 

12/29/1995 1.1 0 0 .1 4.6 34 2/17/1996 .7 0 0 .1 3.5 28 

12/30/1995 1.2 0 0 .1 4.6 34 2/18/1996 .8 0 0 .1 3.6 28 

12/31/1995 1.2 0 0 .1 4.6 34 2/19/1996 .9 0 0 .1 3.6 28 

1/1/1996 1.1 0 0 .1 4.5 34 2/20/1996 .9 0 0 .1 3.6 27 

1/2/1996 1.1 0 0 .1 3.9 34 2/21/1996 1.0 0 0 .1 3.5 26 

1/3/1996 1.0 0 0 .1 3.9 34 2/22/1996 1.0 0 0 .1 3.5 24 

1/4/1996 1.1 0 0 .1 4.0 34 2/23/1996 .9 0 0 .1 3.5 22 

1/5/1996 1.0 0 0 .1 4.2 34 2/24/1996 .9 0 0 .1 3.1 21 

1/6/1996 1.0 0 0 .1 3.9 34 2/25/1996 .9 0 0 .1 3.5 23 

1/7/1996 1.0 0 0 .1 3.9 34 2/26/1996 .9 0 0 .1 3.6 24 

1/8/1996 .9 0 0 .1 3.9 33 2/27/1996 1.0 0 0 .1 3.6 24 

1/9/1996 1.0 0 0 .1 3.9 33 2/28/1996 .9 0 0 .1 3.3 23 

1/10/1996 1.2 0 0 .1 3.9 33 2/29/1996 1.5 0 0 .1 3.5 22 

1/11/1996 1.0 0 0 .1 3.8 33 3/1/1996 1.7 0 0 .1 3.9 22 

1/12/1996 1.0 0 0 .1 3.4 33 3/2/1996 1.2 0 0 .1 3.6 21 

1/13/1996 1.0 0 0 .1 3.2 33 3/3/1996 .9 0 0 .1 3.3 23 

1/14/1996 1.0 0 0 .1 3.2 33 3/4/1996 .9 0 0 .1 3.2 23 

1/15/1996 1.0 0 0 .1 3.3 33 3/5/1996 1.1 0 0 .1 3.6 22 

1/16/1996 .9 0 0 .1 3.0 33 3/6/1996 1.0 0 0 .1 3.6 22 

1/17/1996 1.0 0 0 .3 3.3 32 3/7/1996 .9 0 0 .1 3.1 21 

1/18/1996 .9 0 0 .6 3.2 32 3/8/1996 .8 0 0 .1 2.7 21 

1/19/1996 .8 0 0 .3 2.6 32 3/9/1996 .8 0 0 .1 2.6 21 

1/20/1996 .9 0 0 .4 2.6 33 3/10/1996 .7 0 0 .1 2.4 22 

1/21/1996 .9 0 0 .4 3.1 32 3/11/1996 .7 0 0 .1 2.3 23 

1/22/1996 1.0 0 0 .4 3.4 31 3/12/1996 .7 0 0 .1 2.4 22 

1/23/1996 1.0 0 0 .3 3.4 31 3/13/1996 .8 0 0 .1 2.8 23 

1/24/1996 .9 0 0 .1 3.7 31 3/14/1996 .9 0 0 .1 2.9 24 

1/25/1996 .9 0 0 .1 3.3 31 3/15/1996 .8 0 0 .1 3.1 24 

1/26/1996 .9 0 0 .1 3.7 30 3/16/1996 .7 0 0 .1 3.2 25 

1/27/1996 .9 0 0 .1 3.6 30 3/17/1996 .8 0 0 .1 3.3 26 

1/28/1996 .9 0 0 .1 3.2 30 3/18/1996 .9 0 0 .1 2.9 26 

1/29/1996 1.0 0 0 .1 3.5 30 3/19/1996 .7 0 0 .1 2.3 25 

1/30/1996 1.0 0 0 .1 3.9 30 3/20/1996 .6 0 0 .1 2.4 25 

1/31/1996 .9 0 0 .1 3.7 30 3/21/1996 .6 0 0 .1 2.4 25 

2/1/1996 .9 0 0 .1 3.6 30 3/22/1996 .6 0 0 .1 2.5 25 

2/2/1996 .9 0 0 .1 3.5 30 3/23/1996 .6 0 0 .1 2.7 26 

2/3/1996 .9 0 0 .1 2.6 30 3/24/1996 .6 0 0 .1 2.7 26 

2/4/1996 1.0 0 0 .1 2.7 30 3/25/1996 .6 0 0 .1 2.6 25 
Appendix 2 125 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

3/26/1996 0.6 0 0 0.1 2.4 24 5/15/1996 0.2 0 0 0 0.3 19 

3/27/1996 .8 0 0 .1 2.2 25 5/16/1996 .2 0 0 0 .3 19 

3/28/1996 1.0 0 0 .1 2.1 26 5/17/1996 .2 0 0 0 .3 20 

3/29/1996 .9 0 0 .1 2.3 25 5/18/1996 .2 0 0 0 .3 19 

3/30/1996 .8 0 0 .1 2.5 25 5/19/1996 .2 0 0 0 .2 19 

3/31/1996 .8 0 0 .1 2.6 26 5/20/1996 .2 0 0 0 .3 19 

4/1/1996 .8 0 0 .1 2.6 26 5/21/1996 .2 0 0 0 .3 19 

4/2/1996 .8 0 0 .1 2.4 26 5/22/1996 .2 0 0 0 .3 19 

4/3/1996 .8 0 0 .1 2.3 25 5/23/1996 .2 0 0 0 .3 19 

4/4/1996 .9 0 0 .1 2.5 25 5/24/1996 .2 0 0 0 .2 19 

4/5/1996 1.1 0 0 .1 2.6 26 5/25/1996 .2 0 0 0 .2 19 

4/6/1996 1.8 0 0 .1 2.6 28 5/26/1996 .2 0 0 0 .2 19 

4/7/1996 1.3 0 0 .1 1.6 29 5/27/1996 .4 0 0 0 .2 26 

4/8/1996 1.1 0 0 .1 1.4 26 5/28/1996 .2 0 0 0 .2 26 

4/9/1996 1.0 0 0 .1 1.2 26 5/29/1996 .2 0 0 0 .2 24 

4/10/1996 1.0 0 0 .1 1.0 25 5/30/1996 3.3 7.7 .8 .1 .2 24 

4/11/1996 1.0 0 0 .1 1.1 25 5/31/1996 1.1 0 0 0 .2 25 

4/12/1996 .9 0 0 .1 1.1 25 6/1/1996 .7 0 0 0 .2 26 

4/13/1996 .9 0 0 .1 1.0 26 6/2/1996 .5 0 0 0 .1 26 

4/14/1996 .9 0 0 .1 1.0 26 6/3/1996 .4 0 0 0 .1 26 

4/15/1996 .7 0 0 0 1.0 25 6/4/1996 .5 0 0 0 .1 26 

4/16/1996 .7 0 0 0 .9 25 6/5/1996 .4 0 0 0 .1 25 

4/17/1996 .6 0 0 0 .9 24 6/6/1996 .4 0 0 0 .1 25 

4/18/1996 .7 0 0 0 .8 25 6/7/1996 12.0 3.0 .1 0 .1 33 

4/19/1996 .7 0 0 0 .8 24 6/8/1996 4.9 0 0 0 .1 34 

4/20/1996 .6 0 0 0 .7 25 6/9/1996 2.2 0 0 0 .1 31 

4/21/1996 .7 0 0 0 .6 25 6/10/1996 1.6 0 0 0 0 31 

4/22/1996 .7 0 0 0 .6 25 6/11/1996 1.3 0 0 0 .1 28 

4/23/1996 .7 0 0 .1 .6 24 6/12/1996 1.2 0 0 0 .1 26 

4/24/1996 .7 0 0 0 .6 24 6/13/1996 1.2 0 0 0 .1 26 

4/25/1996 .7 0 0 0 .6 24 6/14/1996 1.2 0 0 0 .1 25 

4/26/1996 .7 0 0 0 .5 23 6/15/1996 1.1 0 0 0 .1 25 

4/27/1996 .7 0 0 0 .5 23 6/16/1996 .9 0 0 0 .1 24 

4/28/1996 .7 0 0 0 .5 24 6/17/1996 .8 0 0 0 .1 24 

4/29/1996 .6 0 0 0 .5 26 6/18/1996 .7 0 0 0 .1 23 

4/30/1996 .6 0 0 0 .5 25 6/19/1996 .6 0 0 0 .1 24 

5/1/1996 .6 0 0 0 .2 24 6/20/1996 .5 0 0 0 .1 24 

5/2/1996 .6 0 0 0 .4 24 6/21/1996 .5 0 0 0 .1 24 

5/3/1996 .5 0 0 0 .4 21 6/22/1996 .4 0 0 0 .1 24 

5/4/1996 .5 0 0 0 .4 21 6/23/1996 .4 0 0 0 .1 24 

5/5/1996 .4 0 0 0 .3 21 6/24/1996 .4 0 0 0 .1 24 

5/6/1996 .4 0 0 0 .3 19 6/25/1996 .4 0 0 0 .1 24 

5/7/1996 .4 0 0 0 .3 19 6/26/1996 2.9 .1 0 0 .1 25 

5/8/1996 .3 0 0 0 .3 19 6/27/1996 2.4 0 0 0 .1 29 

5/9/1996 .3 0 0 0 .3 20 6/28/1996 .8 0 0 0 .1 27 

5/10/1996 .4 0 0 0 .3 20 6/29/1996 .5 0 0 0 .1 26 

5/11/1996 .3 0 0 0 .3 21 6/30/1996 .5 0 0 0 0 26 

5/12/1996 .3 0 0 0 .3 20 7/1/1996 .4 0 0 0 0 26 

5/13/1996 .3 0 0 0 .3 20 7/2/1996 .4 0 0 0 0 25 

5/14/1996 .3 0 0 0 .3 19 7/3/1996 .3 0 0 0 0 24 
126 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

7/4/1996 0.3 0 0 0 0 23 8/23/1996 0.5 0 0 0 0 30 

7/5/1996 .3 0 0 0 0 22 8/24/1996 .3 0 0 0 0 34 

7/6/1996 .3 0 0 0 0 22 8/25/1996 .2 0 0 0 0 35 

7/7/1996 .3 0 0 0 0 23 8/26/1996 .3 .7 0 0 0 27 

7/8/1996 .2 0 0 0 0 24 8/27/1996 .3 0 0 0 0 27 

7/9/1996 .2 0 0 0 0 22 8/28/1996 .3 0 0 0 0 26 

7/10/1996 .2 0 0 0 0 21 8/29/1996 .7 0 0 0 0 25 

7/11/1996 .2 0 0 0 0 21 8/30/1996 1.6 0 0 .1 0 24 

7/12/1996 .2 0 0 0 .1 20 8/31/1996 11.0 .1 0 .2 1.5 25 

7/13/1996 .2 0 0 0 .1 20 9/1/1996 34.0 .9 0 2.5 6.0 26 

7/14/1996 .2 0 0 0 .1 21 9/2/1996 7.8 0 0 1.2 1.8 26 

7/15/1996 .2 0 0 0 .1 21 9/3/1996 5.2 0 0 1.0 .9 26 

7/16/1996 .1 0 0 0 .1 20 9/4/1996 4.9 0 0 .9 .7 26 

7/17/1996 .1 0 0 0 .1 19 9/5/1996 4.9 0 0 .7 .6 26 

7/18/1996 .1 0 0 0 .1 20 9/6/1996 4.2 0 0 .6 .6 25 

7/19/1996 .1 0 0 0 .1 19 9/7/1996 3.8 0 0 .6 .6 25 

7/20/1996 .1 0 0 0 .1 19 9/8/1996 3.6 0 0 .6 .6 25 

7/21/1996 .1 0 0 0 .1 19 9/9/1996 3.3 0 0 .6 .6 28 

7/22/1996 .1 0 0 0 .2 19 9/10/1996 3.2 0 0 .5 .6 35 

7/23/1996 .1 0 0 0 .3 19 9/11/1996 3.1 0 0 .3 .7 35 

7/24/1996 .1 0 0 0 .3 19 9/12/1996 3.1 0 0 .1 .7 35 

7/25/1996 .1 0 0 0 .3 20 9/13/1996 3.2 0 0 .1 .7 33 

7/26/1996 .1 0 0 0 .4 21 9/14/1996 3.1 0 0 .1 .7 33 

7/27/1996 .1 0 0 0 .4 21 9/15/1996 2.8 0 0 .1 1.0 34 

7/28/1996 .1 0 0 0 .2 21 9/16/1996 2.5 0 0 0 1.0 34 

7/29/1996 .1 0 0 0 .4 21 9/17/1996 1.9 0 0 0 .8 34 

7/30/1996 .1 0 0 0 .3 20 9/18/1996 1.6 0 0 0 .9 34 

7/31/1996 .1 0 0 0 .2 19 9/19/1996 1.5 0 0 0 1.1 34 

8/1/1996 .1 0 0 0 .1 20 9/20/1996 2.6 .1 .1 1.1 2.8 35 

8/2/1996 .1 0 0 0 0 20 9/21/1996 14.0 0 0 2.5 2.7 41 

8/3/1996 .1 0 0 0 0 19 9/22/1996 5.8 0 0 1.2 2.2 41 

8/4/1996 .1 0 0 0 0 19 9/23/1996 3.9 0 0 .9 1.7 39 

8/5/1996 0 0 0 0 0 19 9/24/1996 2.9 0 0 .8 1.6 36 

8/6/1996 0 0 0 0 0 18 9/25/1996 3.2 0 0 .7 1.6 36 

8/7/1996 0 0 0 0 0 18 9/26/1996 3.1 0 0 .7 1.5 36 

8/8/1996 .2 0 0 0 0 18 9/27/1996 3.0 0 0 .7 1.7 35 

8/9/1996 .2 0 0 0 0 18 9/28/1996 2.9 0 0 .7 1.4 35 

8/10/1996 .2 0 0 0 0 18 9/29/1996 2.3 0 0 .7 1.3 35 

8/11/1996 .2 0 0 0 0 18 9/30/1996 2.0 0 0 .7 1.2 34 

8/12/1996 .2 0 0 0 0 19 10/1/1996 2.1 0 0 .7 1.2 34 

8/13/1996 .2 0 0 0 0 18 10/2/1996 1.9 0 0 .6 1.1 34 

8/14/1996 .2 0 0 0 0 18 10/3/1996 1.9 0 0 .5 1.0 34 

8/15/1996 .2 0 0 0 0 18 10/4/1996 1.8 0 0 .5 1.2 33 

8/16/1996 .2 0 0 0 0 18 10/5/1996 1.8 0 0 .5 1.7 32 

8/17/1996 .2 0 0 0 0 18 10/6/1996 2.0 0 0 .6 1.2 32 

8/18/1996 .2 0 0 0 0 18 10/7/1996 1.8 0 0 .6 1.2 32 

8/19/1996 .2 0 0 0 0 18 10/8/1996 1.6 0 0 .5 1.1 32 

8/20/1996 .2 0 0 0 0 17 10/9/1996 1.4 0 0 .4 .9 32 

8/21/1996 .2 0 0 0 0 17 10/10/1996 1.3 0 0 .4 .9 32 

8/22/1996 .3 0 0 0 0 29 10/11/1996 1.2 0 0 .2 .9 32 
Appendix 2 127 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/12/1996 1.2 0 0 0.1 0.8 32 12/1/1996 5.4 0 0 0.7 0.3 31 

10/13/1996 1.2 0 0 .1 .7 32 12/2/1996 4.4 0 0 .6 .3 31 

10/14/1996 1.1 0 0 .1 .6 32 12/3/1996 3.9 0 0 .7 .3 31 

10/15/1996 1.1 0 0 .1 .5 31 12/4/1996 4.0 0 0 .6 .3 31 

10/16/1996 1.2 0 0 .1 .6 31 12/5/1996 4.2 0 0 .6 .3 31 

10/17/1996 1.1 0 0 .1 .6 31 12/6/1996 3.9 0 0 .6 .3 31 

10/18/1996 1.0 0 0 .2 .6 31 12/7/1996 3.7 0 0 .5 .3 31 

10/19/1996 .8 0 0 .1 .6 31 12/8/1996 3.5 0 0 .5 .5 31 

10/20/1996 .9 0 0 .1 .6 31 12/9/1996 3.4 0 0 .5 .5 30 

10/21/1996 .8 0 0 .1 .6 31 12/10/1996 3.4 0 0 .5 .5 30 

10/22/1996 .8 0 0 .1 .5 31 12/11/1996 3.3 0 0 .5 .4 30 

10/23/1996 .7 0 0 .1 .4 31 12/12/1996 3.1 0 0 .6 .4 30 

10/24/1996 .7 0 0 .1 .3 31 12/13/1996 2.9 0 0 .6 .4 30 

10/25/1996 .8 0 0 .1 .3 30 12/14/1996 2.8 0 0 .5 .4 30 

10/26/1996 .9 0 0 .2 .3 29 12/15/1996 16.0 .5 .3 2.3 .5 36 

10/27/1996 .8 0 0 .2 .3 29 12/16/1996 23.0 0 .1 1.5 .9 42 

10/28/1996 1.0 0 0 .3 .3 29 12/17/1996 22.0 0 0 1.3 1.3 42 

10/29/1996 1.0 0 0 .3 .3 30 12/18/1996 21.0 0 0 1.3 1.9 42 

10/30/1996 .9 0 0 .1 .3 30 12/19/1996 18.0 0 0 1.3 2.0 38 

10/31/1996 .8 0 0 .1 .3 31 12/20/1996 15.0 0 0 1.4 1.6 36 

11/1/1996 .8 0 0 .1 .4 30 12/21/1996 14.0 0 0 1.4 1.4 36 

11/2/1996 .7 0 0 .1 .3 30 12/22/1996 13.0 0 0 1.3 1.5 36 

11/3/1996 .7 0 0 .1 .3 30 12/23/1996 12.0 0 0 1.2 1.5 36 

11/4/1996 .7 0 0 .1 .3 30 12/24/1996 11.0 0 0 1.2 1.7 36 

11/5/1996 .7 0 0 .1 .3 31 12/25/1996 11.0 0 0 1.1 1.8 36 

11/6/1996 .7 0 0 .1 .3 31 12/26/1996 11.0 0 0 1.1 2.0 36 

11/7/1996 1.3 0 0 .2 .4 31 12/27/1996 10.0 0 0 1.1 2.2 36 

11/8/1996 1.1 0 0 .2 .3 31 12/28/1996 9.5 0 0 1.1 2.0 36 

11/9/1996 .9 0 0 .1 .3 31 12/29/1996 9.3 0 0 1.0 1.8 36 

11/10/1996 .9 0 0 .1 .3 31 12/30/1996 8.8 0 0 .9 1.7 36 

11/11/1996 .9 0 0 .1 .3 31 12/31/1996 8.5 0 0 .9 2.0 36 

11/12/1996 .9 0 0 .1 .2 31 1/1/1997 8.2 0 0 .9 2.0 36 

11/13/1996 .8 0 0 .1 .2 31 1/2/1997 8.1 0 0 .9 2.1 36 

11/14/1996 .9 0 0 .1 .2 31 1/3/1997 7.9 0 0 .9 2.2 36 

11/15/1996 .9 0 0 .1 .2 31 1/4/1997 7.8 0 0 .9 2.5 36 

11/16/1996 .9 0 0 .1 .2 31 1/5/1997 7.4 0 0 .9 2.5 36 

11/17/1996 1.0 0 0 .1 .2 32 1/6/1997 6.9 0 0 .8 3.3 36 

11/18/1996 1.1 0 0 .1 .2 33 1/7/1997 8.4 0 0 1.3 4.9 36 

11/19/1996 1.1 0 0 .1 .2 33 1/8/1997 11.0 0 0 1.5 5.2 36 

11/20/1996 1.0 0 0 .1 .2 32 1/9/1997 13.0 0 0 1.1 4.7 36 

11/21/1996 1.0 0 0 .1 .2 32 1/10/1997 13.0 0 0 1.1 5.5 36 

11/22/1996 .9 0 0 .1 .2 31 1/11/1997 13.0 0 0 .9 5.7 36 

11/23/1996 1.0 0 0 .1 .1 31 1/12/1997 13.0 0 0 .9 6.1 36 

11/24/1996 4.1 0 .2 .9 .2 31 1/13/1997 12.0 0 0 .9 5.7 36 

11/25/1996 2.6 0 0 .7 .2 31 1/14/1997 12.0 0 0 .9 5.8 36 

11/26/1996 1.9 0 0 .4 .2 31 1/15/1997 12.0 0 0 1.0 6.1 36 

11/27/1996 2.0 0 0 .3 .2 31 1/16/1997 12.0 0 0 1.1 6.1 36 

11/28/1996 2.4 0 0 .3 .2 31 1/17/1997 11.0 0 0 1.0 6.2 36 

11/29/1996 7.6 0 .2 .8 .2 31 1/18/1997 11.0 0 0 .9 6.0 36 

11/30/1996 8.1 0 0 .7 .3 31 1/19/1997 11.0 0 0 .9 6.4 36 
128 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/20/1997 11.0 0 0 0.9 7.2 36 3/11/1997 52.0 0.1 1.9 5.1 58.0 54 

1/21/1997 11.0 0 0 .8 7.1 36 3/12/1997 118.0 0 2.3 5.7 119.0 57 

1/22/1997 11.0 0 0 .8 6.9 36 3/13/1997 124.0 0 2.4 6.8 108.0 58 

1/23/1997 11.0 0 0 .8 7.1 36 3/14/1997 96.0 0 2.6 7.0 95.0 58 

1/24/1997 10.0 0 0 .8 7.2 36 3/15/1997 77.0 0 2.6 7.1 86.0 58 

1/25/1997 9.7 0 0 .8 6.7 36 3/16/1997 74.0 0 2.9 7.0 86.0 58 

1/26/1997 9.5 0 0 .8 7.0 36 3/17/1997 75.0 0 3.3 7.1 90.0 59 

1/27/1997 9.4 0 0 .8 7.2 36 3/18/1997 74.0 0 3.2 7.1 86.0 60 

1/28/1997 11.0 0 0 .8 6.0 36 3/19/1997 67.0 0 3.0 7.3 78.0 59 

1/29/1997 8.0 0 0 .8 6.0 36 3/20/1997 61.0 0 3.1 7.3 74.0 60 

1/30/1997 7.8 0 0 .8 6.7 36 3/21/1997 57.0 0 3.0 7.1 72.0 60 

1/31/1997 7.7 0 0 .8 6.1 36 3/22/1997 54.0 0 2.8 6.9 68.0 60 

2/1/1997 7.3 0 0 .8 5.8 36 3/23/1997 51.0 0 2.7 6.8 65.0 60 

2/2/1997 7.3 0 0 .8 5.9 36 3/24/1997 49.0 0 2.6 6.6 63.0 60 

2/3/1997 7.1 0 0 .8 5.8 36 3/25/1997 54.0 .2 3.6 6.9 66.0 60 

2/4/1997 6.9 0 0 .7 5.8 36 3/26/1997 66.0 0 3.4 6.3 75.0 62 

2/5/1997 6.6 0 0 .7 5.6 36 3/27/1997 54.0 0 3.1 6.1 65.0 62 

2/6/1997 6.6 0 0 .7 6.3 36 3/28/1997 50.0 0 2.9 6.1 62.0 61 

2/7/1997 8.7 0 0 2.4 6.9 37 3/29/1997 48.0 0 2.7 6.2 58.0 61 

2/8/1997 8.5 0 0 3.6 5.5 36 3/30/1997 46.0 0 2.6 6.2 56.0 60 

2/9/1997 8.9 0 0 3.2 6.3 36 3/31/1997 44.0 0 2.5 6.2 53.0 60 

2/10/1997 9.0 0 0 .8 6.4 36 4/1/1997 45.0 0 2.8 6.1 55.0 60 

2/11/1997 8.9 0 0 .9 6.5 36 4/2/1997 46.0 .1 3.0 6.3 56.0 62 

2/12/1997 26.0 4.6 .5 4.0 11.0 36 4/3/1997 52.0 .1 7.0 9.7 76.0 62 

2/13/1997 46.0 .1 .4 3.6 21.0 50 4/4/1997 1,000.0 38.0 74.0 36.0 814.0 63 

2/14/1997 43.0 0 .2 3.8 26.0 54 4/5/1997 995.0 28.0 59.0 41.0 768.0 64 

2/15/1997 35.0 0 .1 3.6 24.0 54 4/6/1997 560.0 3.3 31.0 39.0 376.0 66 

2/16/1997 31.0 0 0 3.4 22.0 54 4/7/1997 412.0 0 22.0 36.0 301.0 68 

2/17/1997 29.0 0 0 3.5 21.0 54 4/8/1997 337.0 0 18.0 34.0 275.0 70 

2/18/1997 28.0 0 0 3.5 21.0 54 4/9/1997 283.0 0 15.0 32.0 255.0 72 

2/19/1997 28.0 0 0 3.7 22.0 54 4/10/1997 243.0 0 14.0 30.0 239.0 74 

2/20/1997 36.0 0 .2 3.9 56.0 54 4/11/1997 218.0 0 13.0 29.0 230.0 76 

2/21/1997 64.0 0 .1 3.8 62.0 55 4/12/1997 173.0 0 9.7 27.0 203.0 77 

2/22/1997 44.0 0 .1 3.7 48.0 56 4/13/1997 151.0 0 8.4 25.0 184.0 76 

2/23/1997 39.0 0 .1 3.7 42.0 56 4/14/1997 139.0 0 6.4 24.0 173.0 76 

2/24/1997 38.0 0 .1 3.8 41.0 56 4/15/1997 126.0 0 4.6 23.0 162.0 76 

2/25/1997 41.0 0 .2 3.8 44.0 56 4/16/1997 116.0 0 4.2 22.0 148.0 76 

2/26/1997 49.0 0 .5 4.0 57.0 56 4/17/1997 105.0 0 3.7 20.0 135.0 77 

2/27/1997 59.0 0 .6 3.9 60.0 56 4/18/1997 91.0 0 3.6 19.0 125.0 77 

2/28/1997 54.0 0 .6 3.9 57.0 56 4/19/1997 82.0 0 3.6 19.0 119.0 77 

3/1/1997 52.0 0 1.1 3.8 56.0 56 4/20/1997 74.0 0 3.3 18.0 108.0 77 

3/2/1997 50.0 0 1.1 3.8 59.0 56 4/21/1997 69.0 0 3.1 17.0 104.0 77 

3/3/1997 48.0 0 1.2 3.8 56.0 56 4/22/1997 63.0 0 2.9 16.0 95.0 76 

3/4/1997 47.0 0 1.3 3.8 54.0 56 4/23/1997 57.0 0 2.8 15.0 86.0 76 

3/5/1997 45.0 0 1.3 3.8 54.0 56 4/24/1997 54.0 0 2.8 14.0 82.0 76 

3/6/1997 43.0 0 1.2 3.7 50.0 55 4/25/1997 73.0 2.4 8.0 15.0 113.0 76 

3/7/1997 41.0 0 1.3 3.7 49.0 55 4/26/1997 674.0 22.0 44.0 29.0 662.0 77 

3/8/1997 44.0 0 1.4 3.7 54.0 55 4/27/1997 462.0 8.0 23.0 18.0 311.0 78 

3/9/1997 47.0 0 1.4 3.6 59.0 55 4/28/1997 306.0 2.5 18.0 18.0 250.0 80 

3/10/1997 47.0 0 1.4 3.6 55.0 55 4/29/1997 222.0 0 13.0 17.0 220.0 81 
Appendix 2 129 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

4/30/1997 169.0 0 10.0 16.0 209.0 82 6/19/1997 285.0 0 17.0 32.0 266.0 103 

5/1/1997 145.0 0 6.9 16.0 202.0 83 6/20/1997 244.0 0 15.0 28.0 240.0 105 

5/2/1997 137.0 0 5.7 15.0 196.0 83 6/21/1997 351.0 44.0 68.0 50.0 626.0 107 

5/3/1997 122.0 0 4.1 14.0 184.0 83 6/22/1997 2,270.0 58.0 87.0 90.0 3,610.0 108 

5/4/1997 112.0 0 3.8 14.0 176.0 83 6/23/1997 1,190.0 27.0 71.0 65.0 1,500.0 108 

5/5/1997 104.0 0 3.7 14.0 169.0 83 6/24/1997 855.0 16.0 61.0 50.0 953.0 109 

5/6/1997 95.0 0 3.6 14.0 162.0 82 6/25/1997 655.0 9.1 46.0 43.0 795.0 110 

5/7/1997 89.0 0 3.5 14.0 159.0 82 6/26/1997 539.0 5.4 35.0 37.0 707.0 110 

5/8/1997 84.0 0 3.3 14.0 152.0 82 6/27/1997 451.0 3.5 29.0 34.0 624.0 110 

5/9/1997 201.0 7.1 15.0 15.0 172.0 82 6/28/1997 382.0 2.0 25.0 29.0 564.0 111 

5/10/1997 181.0 .1 9.1 14.0 169.0 84 6/29/1997 322.0 .9 21.0 26.0 510.0 111 

5/11/1997 126.0 0 4.9 14.0 136.0 85 6/30/1997 273.0 0 17.0 23.0 455.0 111 

5/12/1997 108.0 0 4.5 14.0 122.0 85 7/1/1997 228.0 0 15.0 20.0 390.0 112 

5/13/1997 92.0 0 4.1 14.0 113.0 85 7/2/1997 189.0 0 14.0 18.0 332.0 112 

5/14/1997 81.0 0 3.8 14.0 102.0 84 7/3/1997 160.0 0 13.0 17.0 305.0 112 

5/15/1997 78.0 7.9 14.0 13.0 95.0 84 7/4/1997 149.0 0 11.0 16.0 278.0 112 

5/16/1997 164.0 8.2 21.0 13.0 186.0 88 7/5/1997 137.0 0 9.9 15.0 254.0 112 

5/17/1997 118.0 0 10.0 13.0 94.0 88 7/6/1997 126.0 0 8.9 14.0 228.0 112 

5/18/1997 87.0 0 8.3 13.0 78.0 86 7/7/1997 118.0 0 7.6 13.0 196.0 112 

5/19/1997 83.0 16.0 15.0 18.0 70.0 87 7/8/1997 109.0 0 6.6 11.0 160.0 113 

5/20/1997 656.0 84.0 61.0 18.0 213.0 87 7/9/1997 97.0 0 6.0 10.0 130.0 113 

5/21/1997 308.0 18.0 36.0 15.0 110.0 88 7/10/1997 85.0 0 5.2 9.3 114.0 113 

5/22/1997 224.0 8.4 30.0 14.0 91.0 89 7/11/1997 75.0 0 4.6 8.8 101.0 113 

5/23/1997 295.0 66.0 59.0 25.0 112.0 89 7/12/1997 66.0 0 4.3 8.1 89.0 113 

5/24/1997 366.0 40.0 52.0 20.0 135.0 90 7/13/1997 59.0 0 4.0 7.6 80.0 113 

5/25/1997 282.0 15.0 38.0 18.0 103.0 91 7/14/1997 52.0 0 3.7 7.1 76.0 113 

5/26/1997 202.0 5.2 30.0 17.0 92.0 92 7/15/1997 49.0 0 3.5 6.7 69.0 113 

5/27/1997 259.0 19.0 67.0 56.0 256.0 93 7/16/1997 47.0 0 3.4 6.3 63.0 113 

5/28/1997 1,020.0 17.0 55.0 26.0 920.0 94 7/17/1997 42.0 0 3.1 6.0 56.0 113 

5/29/1997 465.0 5.7 37.0 23.0 271.0 95 7/18/1997 38.0 0 2.9 5.7 49.0 113 

5/30/1997 362.0 1.9 30.0 21.0 227.0 96 7/19/1997 34.0 0 2.8 5.3 45.0 113 

5/31/1997 302.0 0 27.0 19.0 195.0 97 7/20/1997 32.0 0 2.7 5.0 43.0 113 

6/1/1997 249.0 0 23.0 18.0 163.0 96 7/21/1997 29.0 0 2.6 4.8 39.0 112 

6/2/1997 207.0 0 20.0 17.0 145.0 97 7/22/1997 27.0 0 2.5 4.6 37.0 112 

6/3/1997 171.0 0 18.0 16.0 132.0 97 7/23/1997 24.0 0 2.4 4.4 34.0 112 

6/4/1997 151.0 0 17.0 15.0 112.0 97 7/24/1997 21.0 0 2.2 4.3 32.0 112 

6/5/1997 141.0 0 16.0 15.0 100.0 97 7/25/1997 19.0 0 2.1 4.1 29.0 112 

6/6/1997 161.0 3.3 41.0 120.0 460.0 97 7/26/1997 17.0 0 2.1 3.9 28.0 112 

6/7/1997 858.0 7.7 55.0 213.0 700.0 97 7/27/1997 15.0 0 2.0 3.8 27.0 111 

6/8/1997 392.0 1.3 40.0 224.0 335.0 97 7/28/1997 14.0 0 1.9 3.9 25.0 111 

6/9/1997 1,990.0 84.0 184.0 199.0 3,100.0 97 7/29/1997 14.0 0 1.8 3.7 24.0 110 

6/10/1997 3,680.0 76.0 564.0 250.0 2,610.0 97 7/30/1997 14.0 0 1.9 3.8 22.0 110 

6/11/1997 1,330.0 28.0 81.0 101.0 1,060.0 97 7/31/1997 16.0 0 2.2 3.5 24.0 110 

6/12/1997 862.0 14.0 55.0 86.0 710.0 97 8/1/1997 15.0 0 2.0 3.3 23.0 109 

6/13/1997 682.0 6.9 43.0 76.0 571.0 97 8/2/1997 14.0 0 1.9 3.2 21.0 109 

6/14/1997 588.0 3.2 34.0 66.0 487.0 97 8/3/1997 11.0 0 1.8 3.0 21.0 109 

6/15/1997 531.0 2.5 34.0 60.0 449.0 98 8/4/1997 10.0 0 1.7 2.8 20.0 108 

6/16/1997 441.0 .6 28.0 52.0 375.0 98 8/5/1997 9.5 0 1.6 2.6 18.0 108 

6/17/1997 438.0 .4 24.0 45.0 325.0 100 8/6/1997 8.6 0 1.6 2.4 17.0 107 

6/18/1997 335.0 0 20.0 38.0 291.0 102 8/7/1997 11.0 .2 1.7 2.4 17.0 107 
130 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

8/8/1997 13.0 0.2 1.9 2.5 20.0 109 9/27/1997 0.1 0 0 0.1 2.5 90 

8/9/1997 14.0 0 2.0 2.4 22.0 109 9/28/1997 .1 0 0 .1 2.6 90 

8/10/1997 13.0 0 1.8 2.1 20.0 109 9/29/1997 .2 0 0 .1 2.6 90 

8/11/1997 11.0 0 1.7 2.0 18.0 108 9/30/1997 .1 0 0 .1 2.3 90 

8/12/1997 9.4 0 1.6 1.9 16.0 106 10/1/1997 .1 0 0 0 1.7 90 

8/13/1997 8.1 0 1.5 1.6 15.0 106 10/2/1997 .1 0 0 0 1.5 90 

8/14/1997 7.3 0 1.5 1.2 13.0 106 10/3/1997 .1 0 0 .1 1.7 92 

8/15/1997 6.4 0 1.4 .9 12.0 105 10/4/1997 .1 0 0 0 1.8 92 

8/16/1997 5.5 0 1.4 1.0 12.0 105 10/5/1997 .1 0 0 .1 1.7 92 

8/17/1997 4.5 0 1.3 .9 11.0 104 10/6/1997 .2 0 0 0 1.6 92 

8/18/1997 4.1 0 1.3 .8 9.9 104 10/7/1997 .4 .1 0 .1 2.0 92 

8/19/1997 3.7 0 1.3 .7 9.3 102 10/8/1997 1.0 .1 0 .1 2.3 92 

8/20/1997 3.3 0 1.2 .7 8.7 102 10/9/1997 1.1 0 0 .2 2.7 92 

8/21/1997 2.6 0 1.2 .7 8.2 102 10/10/1997 2.1 .2 .2 .1 2.6 92 

8/22/1997 2.2 0 1.1 .6 8.0 102 10/11/1997 5.5 .2 .1 .3 2.6 93 

8/23/1997 2.4 0 1.2 .6 7.8 102 10/12/1997 7.0 .1 .2 1.0 2.6 95 

8/24/1997 2.9 0 1.1 .5 7.5 102 10/13/1997 5.3 0 .1 1.4 3.0 95 

8/25/1997 2.1 0 1.1 .5 7.1 102 10/14/1997 4.2 0 0 1.5 2.8 94 

8/26/1997 1.7 0 1.0 .4 6.7 102 10/15/1997 3.7 0 0 1.5 2.5 93 

8/27/1997 1.5 0 .9 .4 6.6 102 10/16/1997 3.5 0 0 1.5 2.1 92 

8/28/1997 1.3 0 .9 .4 6.0 100 10/17/1997 3.4 0 0 1.5 2.1 91 

8/29/1997 1.1 0 .9 .3 5.4 98 10/18/1997 3.3 0 0 1.3 1.9 90 

8/30/1997 1.0 0 .8 .3 4.8 97 10/19/1997 4.0 0 0 1.2 1.7 90 

8/31/1997 .9 0 .8 .3 4.4 97 10/20/1997 4.3 0 0 1.2 1.5 89 

9/1/1997 .8 0 .7 .3 4.1 97 10/21/1997 4.3 0 0 1.1 1.6 89 

9/2/1997 .7 0 .7 .3 4.0 96 10/22/1997 4.3 0 0 1.1 1.6 89 

9/3/1997 .6 0 .7 .3 3.7 96 10/23/1997 4.3 0 0 1.1 1.8 89 

9/4/1997 .5 0 .6 .3 3.7 96 10/24/1997 4.1 0 0 1.1 1.7 88 

9/5/1997 .5 0 .6 .3 3.9 95 10/25/1997 4.0 0 0 1.0 1.8 88 

9/6/1997 .4 0 .4 .2 3.8 95 10/26/1997 3.6 0 0 1.0 1.5 87 

9/7/1997 .4 0 .4 .2 3.8 95 10/27/1997 3.5 0 0 1.0 1.7 87 

9/8/1997 .4 0 .3 .2 3.5 95 10/28/1997 3.4 0 0 1.0 2.0 87 

9/9/1997 .3 0 .2 .2 3.1 95 10/29/1997 3.4 0 0 1.0 2.2 86 

9/10/1997 .3 0 .1 .2 3.1 94 10/30/1997 3.4 0 0 1.0 2.2 86 

9/11/1997 .3 0 .1 .2 3.1 94 10/31/1997 3.3 0 0 .9 2.1 85 

9/12/1997 .2 0 0 .2 2.6 93 11/1/1997 3.0 0 0 .8 1.9 85 

9/13/1997 .2 0 0 .2 1.9 93 11/2/1997 2.7 0 0 .8 2.2 84 

9/14/1997 .2 0 0 .2 1.4 93 11/3/1997 2.6 0 0 .8 2.5 84 

9/15/1997 .2 0 0 .2 1.0 93 11/4/1997 2.7 0 0 .8 2.8 84 

9/16/1997 .2 0 0 .1 .8 92 11/5/1997 2.6 0 0 .8 3.1 84 

9/17/1997 .2 0 0 .1 .6 92 11/6/1997 2.4 0 0 .7 3.0 83 

9/18/1997 .2 0 0 .1 .5 92 11/7/1997 2.4 0 0 .7 3.2 82 

9/19/1997 .2 0 0 .1 .5 91 11/8/1997 2.4 0 0 .7 3.2 82 

9/20/1997 .2 0 0 .1 .5 91 11/9/1997 2.8 .1 0 1.0 3.6 82 

9/21/1997 .2 0 0 .1 .5 91 11/10/1997 5.8 0 .1 1.1 4.6 83 

9/22/1997 .2 0 0 .2 1.9 91 11/11/1997 5.0 .1 .1 1.1 3.4 82 

9/23/1997 .2 0 0 .1 4.5 91 11/12/1997 8.7 .1 .2 1.4 6.1 84 

9/24/1997 .2 0 0 .1 2.6 91 11/13/1997 11.0 .1 .1 1.3 5.3 84 

9/25/1997 .2 0 0 .1 2.6 91 11/14/1997 13.0 0 0 1.1 4.4 83 

9/26/1997 .1 0 0 .1 2.6 90 11/15/1997 12.0 0 0 1.1 4.8 82 
Appendix 2 131 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

11/16/1997 11.0 0 0 1.1 6.7 81 1/5/1998 31.0 0 3.2 4.5 28.0 82 

11/17/1997 9.9 0 0 1.1 7.2 80 1/6/1998 854.0 24.0 46.0 200.0 798.0 82 

11/18/1997 9.3 0 0 1.1 7.7 80 1/7/1998 754.0 18.0 43.0 30.0 341.0 83 

11/19/1997 8.8 0 0 1.1 7.9 80 1/8/1998 332.0 3.9 25.0 22.0 202.0 84 

11/20/1997 8.5 0 0 1.1 9.3 79 1/9/1998 226.0 .1 17.0 19.0 164.0 85 

11/21/1997 8.0 0 0 1.1 11.0 78 1/10/1998 180.0 0 13.0 17.0 141.0 85 

11/22/1997 7.6 0 0 1.1 10.0 78 1/11/1998 159.0 0 12.0 16.0 128.0 86 

11/23/1997 6.8 0 0 1.1 11.0 77 1/12/1998 149.0 0 11.0 14.0 115.0 87 

11/24/1997 6.6 0 0 1.1 10.0 77 1/13/1998 139.0 0 8.9 13.0 103.0 86 

11/25/1997 6.4 0 0 1.1 12.0 77 1/14/1998 130.0 0 8.5 13.0 97.0 87 

11/26/1997 6.2 0 0 1.1 12.0 76 1/15/1998 123.0 0 6.6 11.0 92.0 87 

11/27/1997 6.0 0 0 1.1 12.0 76 1/16/1998 115.0 0 5.1 9.9 83.0 86 

11/28/1997 7.3 0 0 1.2 13.0 76 1/17/1998 107.0 0 4.4 8.9 77.0 86 

11/29/1997 8.0 0 0 1.1 9.8 76 1/18/1998 100.0 0 4.2 8.4 70.0 86 

11/30/1997 6.7 0 0 1.2 12.0 76 1/19/1998 90.0 0 3.8 7.7 66.0 86 

12/1/1997 6.4 0 0 .9 13.0 75 1/20/1998 85.0 0 4.0 7.8 65.0 86 

12/2/1997 6.7 0 0 .9 13.0 75 1/21/1998 77.0 0 3.9 7.0 67.0 86 

12/3/1997 8.2 0 0 .9 14.0 75 1/22/1998 71.0 0 3.6 6.3 63.0 86 

12/4/1997 8.8 0 0 .7 14.0 74 1/23/1998 65.0 0 3.5 6.0 60.0 86 

12/5/1997 8.1 0 0 .7 12.0 72 1/24/1998 59.0 0 3.3 5.5 57.0 86 

12/6/1997 7.7 0 0 .7 12.0 72 1/25/1998 56.0 0 3.3 5.4 55.0 86 

12/7/1997 8.7 0 0 1.0 14.0 72 1/26/1998 53.0 0 3.2 4.9 53.0 86 

12/8/1997 8.3 0 0 .8 14.0 72 1/27/1998 51.0 0 3.0 4.5 49.0 86 

12/9/1997 7.4 0 0 .8 14.0 71 1/28/1998 47.0 0 3.0 4.4 47.0 86 

12/10/1997 7.1 0 0 .7 16.0 71 1/29/1998 46.0 0 3.1 4.2 47.0 85 

12/11/1997 6.5 0 0 .7 16.0 70 1/30/1998 43.0 0 3.1 4.0 45.0 86 

12/12/1997 6.2 0 0 .7 16.0 70 1/31/1998 72.0 8.5 24.0 56.0 127.0 87 

12/13/1997 6.1 0 0 .7 17.0 69 2/1/1998 123.0 .4 16.0 12.0 181.0 90 

12/14/1997 6.0 0 0 .7 17.0 69 2/2/1998 86.0 0 13.0 9.7 114.0 89 

12/15/1997 6.0 0 0 .7 17.0 69 2/3/1998 71.0 0 11.0 9.0 95.0 89 

12/16/1997 6.0 0 0 .6 18.0 68 2/4/1998 67.0 0 9.7 8.2 89.0 89 

12/17/1997 5.8 0 0 .6 17.0 68 2/5/1998 71.0 0 12.0 14.0 95.0 89 

12/18/1997 5.8 0 0 .7 16.0 67 2/6/1998 100.0 0 13.0 12.0 111.0 89 

12/19/1997 6.0 0 0 .8 17.0 66 2/7/1998 88.0 0 11.0 10.0 98.0 89 

12/20/1997 52.0 27.0 43.0 173.0 80.0 68 2/8/1998 77.0 0 10.0 10.0 95.0 89 

12/21/1997 262.0 10.0 23.0 25.0 171.0 76 2/9/1998 73.0 0 9.6 9.7 92.0 89 

12/22/1997 94.0 0 3.3 8.2 74.0 79 2/10/1998 94.0 .5 15.0 17.0 104.0 89 

12/23/1997 63.0 .1 3.7 8.2 57.0 80 2/11/1998 114.0 0 13.0 14.0 104.0 90 

12/24/1997 53.0 0 3.8 7.0 49.0 80 2/12/1998 102.0 0 12.0 14.0 99.0 90 

12/25/1997 47.0 0 3.2 6.3 41.0 80 2/13/1998 104.0 0 13.0 15.0 107.0 90 

12/26/1997 45.0 .1 4.1 7.2 41.0 80 2/14/1998 117.0 4.6 26.0 39.0 149.0 90 

12/27/1997 45.0 0 3.9 6.4 40.0 81 2/15/1998 190.0 3.3 33.0 29.0 239.0 92 

12/28/1997 43.0 0 3.6 6.1 39.0 81 2/16/1998 179.0 6.2 41.0 37.0 233.0 93 

12/29/1997 40.0 0 3.2 5.8 35.0 81 2/17/1998 172.0 2.5 32.0 29.0 220.0 93 

12/30/1997 38.0 0 3.1 5.4 33.0 81 2/18/1998 157.0 1.5 27.0 27.0 205.0 93 

12/31/1997 34.0 0 2.9 4.7 30.0 81 2/19/1998 152.0 1.2 24.0 24.0 196.0 94 

1/1/1998 32.0 0 3.0 4.9 29.0 81 2/20/1998 145.0 1.2 21.0 21.0 182.0 94 

1/2/1998 33.0 0 3.3 5.3 30.0 81 2/21/1998 198.0 184.0 41.0 72.0 364.0 95 

1/3/1998 33.0 0 3.2 4.8 30.0 81 2/22/1998 572.0 166.0 53.0 38.0 358.0 97 

1/4/1998 32.0 0 3.2 4.6 29.0 81 2/23/1998 302.0 12.0 36.0 31.0 241.0 97 
132 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

2/24/1998 247.0 3.7 29.0 28.0 224.0 97 4/15/1998 68.0 0 7.4 6.5 86.0 98 

2/25/1998 231.0 14.0 31.0 127.0 220.0 97 4/16/1998 64.0 0 5.7 5.9 82.0 98 

2/26/1998 495.0 28.0 72.0 75.0 477.0 98 4/17/1998 59.0 0 4.9 5.5 76.0 97 

2/27/1998 325.0 9.6 42.0 36.0 273.0 99 4/18/1998 55.0 0 4.8 5.4 74.0 97 

2/28/1998 269.0 5.9 32.0 31.0 251.0 99 4/19/1998 54.0 0 4.5 5.2 72.0 97 

3/1/1998 232.0 4.5 27.0 28.0 237.0 99 4/20/1998 51.0 0 4.2 5.0 69.0 97 

3/2/1998 210.0 3.5 24.0 25.0 225.0 99 4/21/1998 49.0 0 3.9 4.7 65.0 97 

3/3/1998 189.0 2.5 22.0 23.0 213.0 98 4/22/1998 46.0 0 3.7 4.5 62.0 97 

3/4/1998 174.0 1.9 21.0 21.0 205.0 98 4/23/1998 44.0 0 3.5 4.3 60.0 96 

3/5/1998 164.0 .8 20.0 19.0 194.0 98 4/24/1998 42.0 0 3.3 4.1 57.0 96 

3/6/1998 155.0 .4 19.0 17.0 177.0 98 4/25/1998 40.0 0 3.2 4.1 55.0 96 

3/7/1998 151.0 .8 18.0 19.0 177.0 98 4/26/1998 40.0 0 3.5 4.3 56.0 96 

3/8/1998 150.0 .8 16.0 16.0 184.0 98 4/27/1998 46.0 0 3.5 4.0 57.0 97 

3/9/1998 139.0 .1 14.0 14.0 156.0 98 4/28/1998 39.0 0 3.1 3.8 54.0 97 

3/10/1998 129.0 0 13.0 12.0 137.0 98 4/29/1998 36.0 0 2.9 3.7 49.0 97 

3/11/1998 122.0 0 12.0 12.0 130.0 98 4/30/1998 33.0 0 2.8 3.4 46.0 97 

3/12/1998 118.0 0 11.0 11.0 126.0 98 5/1/1998 31.0 .1 2.8 3.4 43.0 96 

3/13/1998 116.0 0 12.0 11.0 126.0 98 5/2/1998 31.0 0 2.7 3.4 41.0 96 

3/14/1998 118.0 .9 15.0 12.0 135.0 98 5/3/1998 30.0 0 2.7 2.9 40.0 96 

3/15/1998 123.0 .9 18.0 45.0 145.0 98 5/4/1998 28.0 0 2.6 3.1 40.0 95 

3/16/1998 1,330.0 60.0 96.0 168.0 1,040.0 98 5/5/1998 26.0 0 2.6 3.0 38.0 95 

3/17/1998 513.0 26.0 46.0 34.0 371.0 99 5/6/1998 25.0 0 2.5 2.9 36.0 95 

3/18/1998 379.0 14.0 36.0 30.0 301.0 99 5/7/1998 23.0 0 2.3 2.5 34.0 94 

3/19/1998 321.0 9.9 30.0 27.0 280.0 99 5/8/1998 21.0 0 2.3 2.5 31.0 93 

3/20/1998 271.0 7.2 25.0 24.0 258.0 98 5/9/1998 19.0 0 2.2 2.2 30.0 93 

3/21/1998 240.0 5.3 23.0 22.0 243.0 98 5/10/1998 18.0 0 2.1 2.0 25.0 93 

3/22/1998 216.0 4.1 21.0 20.0 231.0 99 5/11/1998 16.0 0 2.1 1.7 21.0 92 

3/23/1998 195.0 2.7 19.0 18.0 220.0 99 5/12/1998 14.0 0 2.1 1.7 20.0 92 

3/24/1998 176.0 1.7 18.0 16.0 209.0 99 5/13/1998 14.0 0 2.1 1.9 19.0 92 

3/25/1998 163.0 .1 16.0 15.0 198.0 99 5/14/1998 14.0 0 2.0 1.8 18.0 92 

3/26/1998 155.0 0 16.0 14.0 188.0 98 5/15/1998 13.0 0 2.0 1.5 19.0 91 

3/27/1998 151.0 .6 15.0 13.0 180.0 98 5/16/1998 12.0 0 2.0 1.5 19.0 91 

3/28/1998 146.0 0 14.0 12.0 170.0 98 5/17/1998 12.0 0 1.9 1.4 18.0 91 

3/29/1998 140.0 0 14.0 11.0 161.0 98 5/18/1998 11.0 0 1.8 1.3 17.0 91 

3/30/1998 134.0 .8 17.0 12.0 155.0 98 5/19/1998 10.0 0 1.7 1.2 17.0 91 

3/31/1998 188.0 1.9 19.0 11.0 223.0 98 5/20/1998 9.5 0 1.7 1.1 16.0 91 

4/1/1998 144.0 0 13.0 9.2 164.0 98 5/21/1998 8.7 0 1.6 1.1 16.0 91 

4/2/1998 130.0 0 13.0 8.8 148.0 98 5/22/1998 7.6 0 1.5 1.0 15.0 90 

4/3/1998 125.0 0 13.0 11.0 137.0 98 5/23/1998 6.8 0 1.5 1.1 14.0 90 

4/4/1998 118.0 0 12.0 11.0 128.0 98 5/24/1998 6.3 0 1.5 1.0 14.0 90 

4/5/1998 116.0 0 12.0 10.0 123.0 98 5/25/1998 6.0 0 1.5 1.0 13.0 90 

4/6/1998 112.0 0 12.0 9.9 119.0 98 5/26/1998 5.7 0 1.5 1.0 13.0 90 

4/7/1998 109.0 0 11.0 9.6 115.0 98 5/27/1998 6.3 .1 1.4 1.0 12.0 90 

4/8/1998 109.0 .1 12.0 11.0 137.0 98 5/28/1998 6.4 0 1.4 .8 12.0 90 

4/9/1998 109.0 0 10.0 8.6 117.0 98 5/29/1998 6.0 0 1.3 .7 11.0 90 

4/10/1998 92.0 0 9.3 8.1 104.0 98 5/30/1998 5.6 0 1.2 .7 10.0 89 

4/11/1998 85.0 0 9.0 7.7 99.0 98 5/31/1998 5.0 0 1.2 .6 9.6 89 

4/12/1998 79.0 0 8.9 7.5 96.0 98 6/1/1998 4.2 0 1.1 .5 8.0 88 

4/13/1998 76.0 0 8.4 7.2 93.0 98 6/2/1998 3.4 0 1.0 .4 7.1 88 

4/14/1998 73.0 0 7.9 6.8 90.0 98 6/3/1998 2.8 0 1.0 .4 6.6 88 
Appendix 2 133 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

6/4/1998 2.3 0 0.9 0.4 6.4 88 7/24/1998 0 0 0 0 2.3 72 

6/5/1998 1.9 0 .9 .6 6.0 88 7/25/1998 0 0 0 0 2.1 71 

6/6/1998 1.6 0 .9 .5 5.5 88 7/26/1998 0 0 0 0 2.0 71 

6/7/1998 1.4 0 .9 .5 5.1 87 7/27/1998 0 0 0 0 2.1 70 

6/8/1998 1.1 0 .9 .4 5.0 87 7/28/1998 0 0 0 0 2.0 70 

6/9/1998 .9 0 .9 .3 4.2 87 7/29/1998 0 0 0 0 1.9 69 

6/10/1998 .7 0 .8 .2 3.7 86 7/30/1998 0 0 0 0 1.8 69 

6/11/1998 1.5 .2 .9 .6 4.6 87 7/31/1998 0 0 0 0 1.6 68 

6/12/1998 1.3 0 .8 .3 4.3 87 8/1/1998 0 0 0 0 1.5 68 

6/13/1998 1.1 0 .7 .1 4.1 86 8/2/1998 0 0 0 0 1.4 67 

6/14/1998 .7 .1 .6 .1 4.1 86 8/3/1998 0 0 0 0 1.4 67 

6/15/1998 .5 0 .5 .1 3.7 85 8/4/1998 0 0 0 0 1.4 66 

6/16/1998 .5 0 .3 .1 3.5 85 8/5/1998 0 0 0 0 1.4 66 

6/17/1998 .3 0 .3 0 3.4 84 8/6/1998 0 .1 0 0 2.2 66 

6/18/1998 .3 0 .2 0 3.3 84 8/7/1998 0 0 0 0 2.0 65 

6/19/1998 .2 0 .2 0 3.2 84 8/8/1998 0 0 0 0 1.9 67 

6/20/1998 .2 0 .1 0 3.0 83 8/9/1998 0 0 0 0 1.7 66 

6/21/1998 .2 0 0 0 2.8 83 8/10/1998 0 0 0 0 1.6 65 

6/22/1998 .2 0 0 0 2.7 83 8/11/1998 0 0 0 0 1.4 64 

6/23/1998 .1 0 0 0 2.4 82 8/12/1998 0 0 0 0 1.3 63 

6/24/1998 .1 0 0 0 2.7 82 8/13/1998 0 0 0 0 1.3 63 

6/25/1998 .1 0 0 0 2.8 82 8/14/1998 0 0 0 0 1.1 62 

6/26/1998 .1 0 0 0 2.7 81 8/15/1998 0 0 0 0 1.4 62 

6/27/1998 .1 0 0 0 2.7 81 8/16/1998 0 0 0 0 1.3 61 

6/28/1998 0 0 0 0 2.6 81 8/17/1998 0 0 0 0 1.6 62 

6/29/1998 0 0 0 0 3.0 81 8/18/1998 .1 0 0 0 1.8 61 

6/30/1998 0 0 0 0 3.0 80 8/19/1998 0 0 0 0 1.9 60 

7/1/1998 0 0 0 0 2.3 80 8/20/1998 0 0 0 0 1.5 60 

7/2/1998 0 0 0 0 1.9 79 8/21/1998 0 0 0 0 1.3 59 

7/3/1998 0 0 .1 .1 2.3 80 8/22/1998 0 .3 0 0 3.3 61 

7/4/1998 .2 .3 .2 .6 375.0 81 8/23/1998 0 .1 0 0 4.5 62 

7/5/1998 38.0 0 0 .1 74.0 81 8/24/1998 0 0 0 0 7.0 62 

7/6/1998 22.0 0 0 .1 24.0 80 8/25/1998 0 0 0 0 14.0 60 

7/7/1998 12.0 0 0 .1 12.0 79 8/26/1998 0 0 0 0 7.7 59 

7/8/1998 7.5 0 0 0 8.2 78 8/27/1998 0 0 0 0 6.5 59 

7/9/1998 5.0 0 0 0 7.3 78 8/28/1998 0 0 0 0 5.9 59 

7/10/1998 3.2 0 0 0 5.9 77 8/29/1998 0 0 0 0 5.3 59 

7/11/1998 2.0 0 0 0 5.1 77 8/30/1998 0 0 0 0 5.0 58 

7/12/1998 1.3 0 0 0 4.4 77 8/31/1998 0 0 0 0 4.9 58 

7/13/1998 1.1 .1 .3 0 4.2 77 9/1/1998 0 0 0 0 4.8 57 

7/14/1998 1.2 0 0 .1 3.9 77 9/2/1998 0 0 0 0 4.5 57 

7/15/1998 1.0 0 0 .1 3.5 76 9/3/1998 0 0 0 0 4.2 56 

7/16/1998 .7 0 0 0 3.1 76 9/4/1998 0 0 0 0 3.9 56 

7/17/1998 .5 0 0 0 2.7 75 9/5/1998 0 0 0 0 3.9 56 

7/18/1998 .3 0 0 0 2.7 75 9/6/1998 0 0 0 0 3.6 55 

7/19/1998 .2 0 0 0 2.8 74 9/7/1998 0 0 0 0 3.3 55 

7/20/1998 .1 0 0 0 2.6 74 9/8/1998 0 0 0 0 3.2 54 

7/21/1998 .1 0 0 0 2.5 73 9/9/1998 0 0 0 0 3.0 54 

7/22/1998 .1 0 0 0 2.6 73 9/10/1998 0 0 0 0 2.9 54 

7/23/1998 0 0 0 0 2.5 73 9/11/1998 .4 .9 .4 0 7.0 57 
134 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/12/1998 0.1 0.1 0 0 73.0 61 11/1/1998 688.0 48.0 43.0 94.0 899.0 99 

9/13/1998 .2 0 0 0 65.0 60 11/2/1998 373.0 12.0 7.9 39.0 424.0 107 

9/14/1998 .5 0 0 0 43.0 59 11/3/1998 243.0 5.1 3.1 34.0 355.0 105 

9/15/1998 .7 .1 0 0 81.0 60 11/4/1998 197.0 1.9 2.7 30.0 316.0 103 

9/16/1998 4.2 .4 .1 0 142.0 64 11/5/1998 195.0 2.9 3.2 33.0 352.0 103 

9/17/1998 4.4 0 0 0 201.0 65 11/6/1998 167.0 1.3 2.4 29.0 308.0 102 

9/18/1998 3.6 0 0 0 135.0 62 11/7/1998 159.0 0 2.7 30.0 313.0 102 

9/19/1998 3.9 0 0 0 106.0 61 11/8/1998 157.0 0 2.5 28.0 304.0 102 

9/20/1998 3.6 0 0 .1 89.0 60 11/9/1998 148.0 0 2.3 26.0 293.0 102 

9/21/1998 3.4 0 0 .1 76.0 60 11/10/1998 142.0 0 2.1 24.0 276.0 102 

9/22/1998 3.3 0 0 .1 68.0 59 11/11/1998 131.0 0 1.8 21.0 253.0 101 

9/23/1998 3.1 0 0 .1 62.0 59 11/12/1998 132.0 4.9 4.4 28.0 266.0 101 

9/24/1998 3.1 0 0 .1 56.0 59 11/13/1998 152.0 7.9 11.0 42.0 307.0 103 

9/25/1998 2.8 0 0 .1 51.0 59 11/14/1998 247.0 20.0 31.0 54.0 429.0 103 

9/26/1998 2.5 0 0 .1 47.0 58 11/15/1998 318.0 19.0 22.0 48.0 457.0 105 

9/27/1998 2.2 0 0 0 44.0 58 11/16/1998 246.0 8.6 8.8 42.0 422.0 106 

9/28/1998 1.9 0 0 0 41.0 58 11/17/1998 209.0 4.3 4.0 36.0 395.0 105 

9/29/1998 1.7 0 0 0 37.0 58 11/18/1998 185.0 1.7 3.1 33.0 350.0 105 

9/30/1998 1.5 0 0 0 34.0 58 11/19/1998 165.0 0 2.7 29.0 319.0 105 

10/1/1998 1.4 0 0 0 32.0 59 11/20/1998 154.0 .5 2.5 27.0 297.0 105 

10/2/1998 1.5 0 0 .1 30.0 59 11/21/1998 146.0 1.2 2.4 24.0 280.0 105 

10/3/1998 1.4 0 0 .1 29.0 59 11/22/1998 140.0 0 2.2 23.0 266.0 105 

10/4/1998 1.2 0 0 .1 27.0 58 11/23/1998 135.0 0 2.0 21.0 255.0 106 

10/5/1998 1.2 0 0 0 26.0 58 11/24/1998 130.0 0 1.9 20.0 243.0 106 

10/6/1998 113.0 25.0 .5 7.9 174.0 76 11/25/1998 126.0 0 1.9 18.0 230.0 106 

10/7/1998 81.0 0 0 1.6 96.0 77 11/26/1998 121.0 0 1.7 17.0 215.0 106 

10/8/1998 35.0 0 0 1.4 63.0 75 11/27/1998 116.0 0 1.7 16.0 207.0 106 

10/9/1998 25.0 0 0 1.3 53.0 74 11/28/1998 113.0 0 1.7 15.0 199.0 106 

10/10/1998 20.0 0 0 1.1 49.0 73 11/29/1998 110.0 0 1.6 14.0 189.0 106 

10/11/1998 17.0 0 0 1.1 46.0 72 11/30/1998 104.0 0 1.5 13.0 174.0 106 

10/12/1998 16.0 0 0 1.0 43.0 71 12/1/1998 96.0 0 1.4 13.0 160.0 106 

10/13/1998 15.0 0 0 .9 40.0 70 12/2/1998 93.0 0 1.5 12.0 152.0 107 

10/14/1998 14.0 0 0 .9 38.0 70 12/3/1998 90.0 0 1.5 12.0 149.0 107 

10/15/1998 13.0 0 0 .9 36.0 69 12/4/1998 95.0 0 1.7 14.0 146.0 107 

10/16/1998 13.0 0 0 .9 33.0 69 12/5/1998 83.0 0 1.5 11.0 133.0 107 

10/17/1998 2,300.0 455.0 570.0 800.0 4,100.0 68 12/6/1998 77.0 0 1.4 10.0 124.0 107 

10/18/1998 1,590.0 136.0 112.0 147.0 1,900.0 99 12/7/1998 72.0 0 1.4 9.4 114.0 107 

10/19/1998 854.0 74.0 74.0 78.0 858.0 115 12/8/1998 67.0 0 1.3 8.6 103.0 107 

10/20/1998 783.0 48.0 61.0 66.0 644.0 116 12/9/1998 64.0 0 1.3 8.5 97.0 107 

10/21/1998 515.0 23.0 51.0 54.0 521.0 113 12/10/1998 82.0 .2 1.8 12.0 122.0 108 

10/22/1998 392.0 7.4 32.0 45.0 472.0 106 12/11/1998 116.0 1.8 2.5 15.0 141.0 108 

10/23/1998 296.0 .7 21.0 38.0 436.0 100 12/12/1998 109.0 0 2.0 12.0 122.0 108 

10/24/1998 233.0 0 15.0 33.0 410.0 101 12/13/1998 93.0 0 1.8 11.0 106.0 108 

10/25/1998 188.0 0 11.0 29.0 359.0 100 12/14/1998 85.0 0 1.7 10.0 98.0 107 

10/26/1998 161.0 0 9.0 26.0 319.0 99 12/15/1998 78.0 0 1.6 9.6 93.0 104 

10/27/1998 148.0 0 7.5 24.0 289.0 99 12/16/1998 75.0 0 1.5 9.3 89.0 104 

10/28/1998 141.0 0 6.0 22.0 273.0 99 12/17/1998 71.0 0 1.4 8.9 85.0 104 

10/29/1998 134.0 0 4.8 20.0 255.0 99 12/18/1998 70.0 0 1.5 9.0 84.0 104 

10/30/1998 127.0 0 4.3 18.0 237.0 99 12/19/1998 67.0 0 1.5 8.6 83.0 104 

10/31/1998 121.0 0 4.0 17.0 223.0 98 12/20/1998 63.0 0 1.4 8.1 79.0 104 
Appendix 2 135 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/21/1998 62.0 0 1.4 8.1 78.0 104 2/9/1999 16.0 0 0.7 1.9 25.0 96 

12/22/1998 58.0 0 1.3 7.3 72.0 104 2/10/1999 15.0 0 .7 1.9 24.0 96 

12/23/1998 57.0 0 1.4 7.5 72.0 104 2/11/1999 14.0 0 .6 1.8 24.0 96 

12/24/1998 56.0 0 1.4 7.5 71.0 104 2/12/1999 13.0 0 .6 1.7 22.0 95 

12/25/1998 54.0 0 1.4 7.3 69.0 104 2/13/1999 13.0 0 .6 1.7 21.0 95 

12/26/1998 52.0 0 1.3 7.1 67.0 104 2/14/1999 13.0 0 .6 1.7 21.0 95 

12/27/1998 52.0 0 1.3 6.9 67.0 104 2/15/1999 13.0 0 .6 1.7 21.0 95 

12/28/1998 50.0 0 1.2 6.5 66.0 104 2/16/1999 12.0 0 .6 1.7 21.0 95 

12/29/1998 49.0 0 1.2 6.2 64.0 104 2/17/1999 12.0 0 .6 1.7 21.0 95 

12/30/1998 47.0 0 1.2 5.8 61.0 104 2/18/1999 12.0 0 .6 1.7 20.0 95 

12/31/1998 46.0 0 1.2 5.8 61.0 103 2/19/1999 11.0 0 .6 1.7 19.0 95 

1/1/1999 46.0 0 1.2 5.8 61.0 103 2/20/1999 11.0 0 .6 1.7 19.0 95 

1/2/1999 45.0 0 1.1 5.3 59.0 103 2/21/1999 10.0 0 .5 1.6 18.0 95 

1/3/1999 42.0 0 1.2 4.8 55.0 103 2/22/1999 10.0 0 .6 1.6 18.0 95 

1/4/1999 40.0 0 1.3 4.7 53.0 103 2/23/1999 10.0 0 .5 1.6 18.0 94 

1/5/1999 39.0 0 1.2 4.7 53.0 103 2/24/1999 10.0 0 .5 1.7 18.0 94 

1/6/1999 39.0 0 1.2 4.7 53.0 102 2/25/1999 9.9 0 .5 1.6 18.0 94 

1/7/1999 39.0 0 1.2 4.4 51.0 102 2/26/1999 10.0 0 .6 1.5 18.0 93 

1/8/1999 39.0 0 1.1 4.3 52.0 102 2/27/1999 10.0 0 .6 1.5 18.0 93 

1/9/1999 36.0 0 1.0 3.8 48.0 102 2/28/1999 10.0 0 .5 1.4 17.0 92 

1/10/1999 33.0 0 1.0 3.7 46.0 102 3/1/1999 10.0 0 .6 1.4 16.0 92 

1/11/1999 32.0 0 1.0 3.7 46.0 102 3/2/1999 9.4 0 .5 1.4 16.0 91 

1/12/1999 33.0 0 1.0 3.8 46.0 102 3/3/1999 8.5 0 .5 1.3 15.0 91 

1/13/1999 32.0 0 1.0 3.6 45.0 102 3/4/1999 8.3 0 .5 1.4 16.0 91 

1/14/1999 30.0 0 .9 3.4 42.0 102 3/5/1999 8.4 0 .6 1.5 16.0 91 

1/15/1999 29.0 0 1.0 3.3 40.0 102 3/6/1999 8.3 0 .5 1.4 16.0 90 

1/16/1999 28.0 0 1.0 3.4 41.0 102 3/7/1999 8.1 0 .5 1.3 15.0 91 

1/17/1999 27.0 0 .9 3.2 40.0 102 3/8/1999 8.6 0 .6 1.4 16.0 90 

1/18/1999 26.0 0 .8 2.9 38.0 102 3/9/1999 8.5 0 .5 1.3 15.0 90 

1/19/1999 25.0 0 .9 3.2 37.0 102 3/10/1999 8.5 0 .5 1.3 17.0 90 

1/20/1999 25.0 0 .9 3.0 37.0 102 3/11/1999 8.5 0 .6 1.3 16.0 90 

1/21/1999 25.0 0 .9 2.7 38.0 102 3/12/1999 9.2 .1 .6 1.9 16.0 90 

1/22/1999 25.0 0 .8 2.7 36.0 102 3/13/1999 11.0 0 .7 1.9 18.0 91 

1/23/1999 23.0 0 .7 2.5 34.0 101 3/14/1999 9.4 0 .6 1.3 18.0 91 

1/24/1999 21.0 0 .7 2.5 32.0 101 3/15/1999 9.0 0 .6 1.3 16.0 90 

1/25/1999 21.0 0 .8 2.5 32.0 101 3/16/1999 7.6 0 .6 1.3 15.0 90 

1/26/1999 20.0 0 .8 2.5 32.0 100 3/17/1999 7.3 0 .6 1.3 15.0 90 

1/27/1999 20.0 0 .8 2.5 32.0 100 3/18/1999 8.3 .2 .9 2.7 17.0 90 

1/28/1999 20.0 0 .8 2.5 32.0 99 3/19/1999 12.0 .9 1.6 2.8 26.0 92 

1/29/1999 21.0 0 .8 2.6 32.0 99 3/20/1999 12.0 0 .9 1.7 25.0 92 

1/30/1999 21.0 0 .8 2.3 31.0 99 3/21/1999 12.0 0 .8 1.6 19.0 92 

1/31/1999 20.0 0 .7 2.2 29.0 99 3/22/1999 11.0 0 .8 1.6 17.0 91 

2/1/1999 19.0 0 .7 2.2 28.0 98 3/23/1999 8.9 0 .8 1.6 17.0 90 

2/2/1999 18.0 0 .7 2.1 28.0 98 3/24/1999 8.2 0 .7 1.6 15.0 90 

2/3/1999 17.0 0 .7 2.0 28.0 98 3/25/1999 7.8 0 .7 1.5 15.0 90 

2/4/1999 17.0 0 .7 2.0 27.0 97 3/26/1999 7.4 0 .7 1.5 14.0 89 

2/5/1999 17.0 0 .7 2.0 28.0 97 3/27/1999 7.4 0 .7 1.7 14.0 89 

2/6/1999 17.0 0 .7 2.0 28.0 97 3/28/1999 11.0 0 .9 2.6 18.0 89 

2/7/1999 16.0 0 .7 2.0 27.0 97 3/29/1999 11.0 0 .8 1.7 22.0 89 

2/8/1999 16.0 0 .7 1.9 25.0 97 3/30/1999 12.0 0 .8 1.7 19.0 88 
136 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

3/31/1999 11.0 0 0.7 1.7 17.0 88 5/20/1999 11.0 0 0.3 0.7 4.6 74 

4/1/1999 10.0 0 .7 1.7 17.0 88 5/21/1999 8.3 0 .3 .7 4.4 73 

4/2/1999 10.0 0 .7 1.7 16.0 88 5/22/1999 7.5 0 .3 .7 4.1 72 

4/3/1999 9.9 0 .7 1.7 16.0 88 5/23/1999 6.6 0 .3 .6 3.9 71 

4/4/1999 9.1 0 .7 1.6 15.0 88 5/24/1999 6.2 0 .4 2.3 3.9 71 

4/5/1999 8.6 0 .7 1.6 15.0 87 5/25/1999 31.0 0 .5 2.6 9.8 74 

4/6/1999 8.1 0 .6 1.5 14.0 87 5/26/1999 45.0 4.1 5.7 1.3 4.6 74 

4/7/1999 7.6 0 .6 1.5 14.0 87 5/27/1999 106.0 .1 2.7 1.5 8.2 76 

4/8/1999 7.5 0 .6 1.5 13.0 87 5/28/1999 54.0 .7 3.4 2.1 7.8 76 

4/9/1999 7.3 0 .6 1.4 13.0 86 5/29/1999 76.0 0 2.4 2.4 7.4 78 

4/10/1999 6.8 0 .6 1.4 12.0 86 5/30/1999 51.0 0 2.0 2.0 6.8 77 

4/11/1999 6.2 0 .6 1.4 10.0 86 5/31/1999 35.0 0 1.9 1.6 5.3 76 

4/12/1999 5.6 0 .6 1.4 10.0 85 6/1/1999 27.0 0 1.6 1.5 5.0 75 

4/13/1999 5.5 0 .6 1.5 9.8 85 6/2/1999 21.0 0 1.4 1.4 4.9 73 

4/14/1999 5.5 0 .6 1.4 9.6 85 6/3/1999 16.0 0 1.4 1.3 4.6 72 

4/15/1999 4.9 0 .6 1.3 8.3 85 6/4/1999 14.0 0 1.3 1.3 4.3 71 

4/16/1999 4.6 0 .6 1.2 8.1 85 6/5/1999 12.0 0 1.3 1.2 4.2 70 

4/17/1999 4.6 0 .6 1.3 7.7 84 6/6/1999 10.0 0 1.3 1.1 3.8 70 

4/18/1999 4.0 0 .5 1.2 7.3 84 6/7/1999 9.6 0 1.2 1.1 3.8 69 

4/19/1999 3.9 0 .5 1.2 7.3 84 6/8/1999 8.4 0 1.2 1.0 3.5 68 

4/20/1999 3.6 0 .5 1.2 7.2 84 6/9/1999 7.6 0 1.2 1.0 3.4 68 

4/21/1999 3.4 0 .5 1.2 7.2 84 6/10/1999 6.9 0 1.1 1.0 3.4 67 

4/22/1999 3.3 0 .5 1.2 7.1 83 6/11/1999 6.3 0 1.1 .9 3.3 66 

4/23/1999 3.1 0 .5 1.2 6.8 83 6/12/1999 6.0 0 1.1 .9 3.2 65 

4/24/1999 2.9 0 .4 1.2 6.2 83 6/13/1999 5.4 0 1.0 .9 3.2 65 

4/25/1999 3.4 0 .5 1.3 7.2 82 6/14/1999 5.3 0 1.0 .9 3.4 66 

4/26/1999 5.6 0 .6 1.4 7.7 83 6/15/1999 4.9 0 1.0 .9 3.3 65 

4/27/1999 5.9 0 .5 1.2 6.5 83 6/16/1999 4.8 0 1.0 .8 3.3 68 

4/28/1999 5.2 0 .5 1.1 6.1 82 6/17/1999 4.1 0 .9 .8 3.1 68 

4/29/1999 4.9 0 .4 1.0 6.2 82 6/18/1999 3.7 0 .9 .8 3.1 67 

4/30/1999 4.2 0 .4 1.0 6.1 82 6/19/1999 13.0 0 .9 .7 3.2 65 

5/1/1999 4.4 0 .4 .9 6.2 81 6/20/1999 32.0 0 1.0 3.9 14.0 65 

5/2/1999 4.1 0 .4 1.0 6.1 81 6/21/1999 101.0 0 1.0 2.5 11.0 68 

5/3/1999 3.8 0 .4 1.0 6.1 80 6/22/1999 75.0 0 1.0 1.8 34.0 70 

5/4/1999 3.7 0 .4 1.0 5.9 80 6/23/1999 59.0 0 1.0 1.7 26.0 71 

5/5/1999 3.2 0 .3 .9 5.0 79 6/24/1999 48.0 0 .9 1.7 20.0 71 

5/6/1999 2.7 0 .3 .8 4.3 79 6/25/1999 52.0 .1 1.0 1.9 19.0 70 

5/7/1999 2.5 0 .3 .8 4.2 78 6/26/1999 42.0 0 1.0 1.8 17.0 71 

5/8/1999 2.1 0 .3 .8 4.4 78 6/27/1999 39.0 0 .9 1.7 15.0 71 

5/9/1999 2.0 0 .3 .8 4.3 78 6/28/1999 34.0 0 .8 1.6 13.0 70 

5/10/1999 7.8 0 .5 2.0 8.6 77 6/29/1999 28.0 0 .8 1.6 11.0 69 

5/11/1999 8.7 0 .4 1.2 6.7 77 6/30/1999 24.0 0 .8 1.6 9.7 68 

5/12/1999 7.2 0 .4 1.0 6.3 76 7/1/1999 21.0 0 .7 1.5 8.0 67 

5/13/1999 6.7 0 .4 .9 6.0 76 7/2/1999 18.0 0 .7 1.4 6.7 67 

5/14/1999 6.9 0 .4 .9 5.6 76 7/3/1999 15.0 0 .7 1.4 5.9 66 

5/15/1999 6.0 0 .3 .8 5.6 75 7/4/1999 12.0 0 .7 1.6 6.4 65 

5/16/1999 5.0 0 .3 .8 5.4 75 7/5/1999 13.0 0 .8 1.6 6.7 65 

5/17/1999 8.6 .1 .3 .8 5.1 74 7/6/1999 15.0 0 .7 1.4 5.7 64 

5/18/1999 50.0 0 .5 .8 5.4 74 7/7/1999 13.0 0 .7 1.4 5.2 65 

5/19/1999 17.0 0 .4 .8 4.8 74 7/8/1999 12.0 0 .7 1.3 5.0 64 
Appendix 2 137 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

7/9/1999 11.0 0 0.7 1.2 4.5 64 8/28/1999 0.2 0 0 0.1 1.9 50 

7/10/1999 14.0 .1 .8 1.8 5.2 63 8/29/1999 .1 0 0 .1 1.9 49 

7/11/1999 38.0 .3 1.0 2.6 51.0 66 8/30/1999 .1 0 0 .1 1.9 49 

7/12/1999 63.0 0 1.0 11.0 71.0 68 8/31/1999 .1 0 0 .1 1.8 49 

7/13/1999 48.0 0 .9 4.6 39.0 69 9/1/1999 .1 0 0 0 1.7 48 

7/14/1999 33.0 0 .9 3.9 30.0 69 9/2/1999 .1 0 0 0 1.7 48 

7/15/1999 26.0 0 .8 3.4 26.0 69 9/3/1999 .1 0 0 0 2.0 49 

7/16/1999 22.0 0 .8 3.0 23.0 68 9/4/1999 .1 0 0 0 1.9 49 

7/17/1999 20.0 0 .8 3.0 22.0 67 9/5/1999 .1 0 0 0 1.9 47 

7/18/1999 18.0 0 .8 3.1 21.0 68 9/6/1999 .1 0 0 0 2.1 46 

7/19/1999 16.0 0 .8 4.0 20.0 67 9/7/1999 .1 0 0 0 2.2 46 

7/20/1999 16.0 0 .8 3.3 19.0 67 9/8/1999 .1 0 0 0 2.1 45 

7/21/1999 18.0 0 .8 3.0 18.0 67 9/9/1999 .1 0 0 0 2.3 45 

7/22/1999 25.0 0 .8 2.7 22.0 68 9/10/1999 .1 0 0 0 2.5 44 

7/23/1999 25.0 0 .7 2.3 20.0 67 9/11/1999 .1 0 0 0 2.5 43 

7/24/1999 18.0 0 .7 2.0 18.0 67 9/12/1999 .1 0 0 0 2.3 43 

7/25/1999 13.0 0 .7 1.9 16.0 66 9/13/1999 .1 0 0 0 2.2 43 

7/26/1999 11.0 0 .6 1.8 15.0 65 9/14/1999 .1 0 0 0 2.0 42 

7/27/1999 11.0 0 .6 1.7 14.0 64 9/15/1999 .1 0 0 0 1.7 42 

7/28/1999 8.0 0 .6 1.6 12.0 64 9/16/1999 0 0 0 0 1.5 41 

7/29/1999 6.7 0 .5 1.4 11.0 63 9/17/1999 0 0 0 0 1.3 41 

7/30/1999 5.8 0 .5 1.2 10.0 63 9/18/1999 0 0 0 0 1.3 41 

7/31/1999 5.0 0 .5 1.1 8.9 62 9/19/1999 0 0 0 0 1.2 40 

8/1/1999 4.1 0 .4 1.0 7.4 62 9/20/1999 0 0 0 0 1.2 40 

8/2/1999 3.3 0 .4 1.0 6.2 61 9/21/1999 0 0 0 0 1.2 39 

8/3/1999 2.8 0 .4 .9 5.8 60 9/22/1999 0 0 0 0 1.0 39 

8/4/1999 2.4 0 .4 .8 5.3 60 9/23/1999 0 0 0 0 1.0 39 

8/5/1999 2.0 0 .4 .8 5.0 59 9/24/1999 0 0 0 0 1.0 39 

8/6/1999 1.5 0 .4 .7 4.4 59 9/25/1999 0 0 0 0 1.1 38 

8/7/1999 1.5 0 .3 .6 4.3 59 9/26/1999 0 0 0 0 1.2 38 

8/8/1999 1.2 0 .3 .6 3.7 58 9/27/1999 0 0 0 0 1.3 37 

8/9/1999 1.0 0 .3 .6 3.6 58 9/28/1999 0 0 0 0 1.3 37 

8/10/1999 .9 0 .2 .5 3.4 57 9/29/1999 0 0 0 0 1.3 38 

8/11/1999 .8 0 .1 .4 3.4 57 9/30/1999 0 0 0 0 1.5 37 

8/12/1999 .7 0 .1 .4 3.3 57 10/1/1999 0 0 0 0 .2 37 

8/13/1999 .6 0 0 .4 3.2 56 10/2/1999 0 0 0 0 .2 36 

8/14/1999 .5 0 0 .3 3.0 56 10/3/1999 0 0 0 0 .2 36 

8/15/1999 .4 0 0 .3 2.9 56 10/4/1999 0 0 0 0 .2 36 

8/16/1999 .4 0 0 .2 2.9 55 10/5/1999 0 0 0 0 .2 36 

8/17/1999 .4 0 0 .2 2.8 54 10/6/1999 0 0 0 0 .2 35 

8/18/1999 .3 0 0 .2 2.8 54 10/7/1999 0 0 0 0 .2 34 

8/19/1999 .3 0 0 .2 2.8 53 10/8/1999 0 0 0 0 .2 34 

8/20/1999 .3 0 0 .1 2.6 53 10/9/1999 0 0 0 0 .2 34 

8/21/1999 .2 0 0 .1 2.5 53 10/10/1999 0 0 0 0 .2 34 

8/22/1999 .2 0 0 .1 2.4 52 10/11/1999 0 0 0 0 .2 34 

8/23/1999 .3 0 0 .1 2.5 52 10/12/1999 0 0 0 0 .3 33 

8/24/1999 .2 0 0 .2 2.8 51 10/13/1999 0 0 0 0 .2 33 

8/25/1999 .2 0 0 .2 2.4 51 10/14/1999 0 0 0 0 .2 33 

8/26/1999 .2 0 0 .1 2.0 50 10/15/1999 0 0 0 0 .2 33 

8/27/1999 .2 0 0 .2 2.1 50 10/16/1999 0 0 0 0 .2 33 
138 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/17/1999 0 0 0 0 0.2 33 12/6/1999 0.3 0 0 0 0.2 30 

10/18/1999 .1 0 0 0 .2 33 12/7/1999 .3 0 0 0 .2 30 

10/19/1999 0 0 0 0 .2 33 12/8/1999 .4 0 0 0 .2 30 

10/20/1999 0 0 0 0 .2 33 12/9/1999 .4 0 0 0 .2 30 

10/21/1999 0 0 0 0 .2 33 12/10/1999 .4 0 0 0 .2 29 

10/22/1999 0 0 0 0 .2 32 12/11/1999 .4 0 0 0 .2 29 

10/23/1999 0 0 0 0 .2 32 12/12/1999 .6 0 0 0 .2 30 

10/24/1999 0 0 0 0 .2 32 12/13/1999 .4 0 0 0 .2 30 

10/25/1999 0 0 0 0 .2 32 12/14/1999 .4 0 0 0 .2 30 

10/26/1999 0 0 0 0 .2 32 12/15/1999 .4 0 0 0 .2 30 

10/27/1999 0 0 0 0 .2 32 12/16/1999 .5 0 0 0 .2 30 

10/28/1999 0 0 0 0 .2 31 12/17/1999 .6 0 0 0 .2 29 

10/29/1999 0 0 0 0 .2 31 12/18/1999 .5 0 0 0 .2 28 

10/30/1999 .2 0 0 0 .2 31 12/19/1999 .6 0 0 0 .2 28 

10/31/1999 0 0 0 0 .2 34 12/20/1999 .6 0 0 0 .2 28 

11/1/1999 0 0 0 0 .2 33 12/21/1999 .6 0 0 0 .2 29 

11/2/1999 0 0 0 0 .2 32 12/22/1999 .6 0 0 0 .2 29 

11/3/1999 .1 0 0 0 .2 33 12/23/1999 .6 0 0 0 .2 28 

11/4/1999 .1 0 0 0 .2 33 12/24/1999 .6 0 0 0 .2 28 

11/5/1999 .1 0 0 0 .2 31 12/25/1999 .6 0 0 0 .2 28 

11/6/1999 .1 0 0 0 .2 31 12/26/1999 .6 0 0 0 .2 28 

11/7/1999 .1 0 0 0 .2 31 12/27/1999 .6 0 0 0 .2 28 

11/8/1999 .1 0 0 0 .2 30 12/28/1999 .6 0 0 0 .2 28 

11/9/1999 .1 0 0 0 .2 30 12/29/1999 .6 0 0 0 .2 29 

11/10/1999 .2 0 0 0 .2 31 12/30/1999 .7 0 0 0 .2 29 

11/11/1999 .2 0 0 0 .2 31 12/31/1999 .7 0 0 0 .2 28 

11/12/1999 .2 0 0 0 .2 30 1/1/2000 .7 0 0 0 .2 28 

11/13/1999 .3 0 0 0 .2 30 1/2/2000 .7 0 0 0 .2 28 

11/14/1999 .3 0 0 0 .2 30 1/3/2000 .7 0 0 0 .2 28 

11/15/1999 .3 0 0 0 .2 30 1/4/2000 .6 0 0 0 .2 28 

11/16/1999 .3 0 0 0 .2 31 1/5/2000 .7 0 0 0 .2 28 

11/17/1999 .3 0 0 0 .2 31 1/6/2000 1.0 0 0 0 .2 27 

11/18/1999 .3 0 0 0 .2 31 1/7/2000 1.4 .1 0 0 .2 29 

11/19/1999 .3 0 0 0 .2 31 1/8/2000 3.3 0 0 0 .3 34 

11/20/1999 .3 0 0 0 .2 31 1/9/2000 1.8 0 0 0 .3 33 

11/21/1999 .3 0 0 0 .2 31 1/10/2000 1.6 0 0 0 .3 31 

11/22/1999 .3 0 0 0 .2 30 1/11/2000 1.5 0 0 0 .3 30 

11/23/1999 .3 0 0 0 .2 30 1/12/2000 1.5 0 0 0 .3 30 

11/24/1999 .3 0 0 0 .2 31 1/13/2000 1.5 0 0 0 .3 29 

11/25/1999 .3 0 0 0 .2 31 1/14/2000 1.5 0 0 0 .2 29 

11/26/1999 .3 0 0 0 .2 31 1/15/2000 1.4 0 0 0 .2 29 

11/27/1999 .3 0 0 0 .2 31 1/16/2000 1.4 0 0 0 .3 29 

11/28/1999 .3 0 0 0 .2 30 1/17/2000 1.4 0 0 0 .3 28 

11/29/1999 .3 0 0 0 .2 29 1/18/2000 1.5 0 0 0 .3 28 

11/30/1999 .3 0 0 0 .2 29 1/19/2000 1.4 0 0 0 .3 28 

12/1/1999 .3 0 0 0 .2 29 1/20/2000 1.4 0 0 0 .3 28 

12/2/1999 .3 0 0 0 .2 29 1/21/2000 1.4 0 0 0 .3 29 

12/3/1999 .3 0 0 0 .2 30 1/22/2000 1.4 0 0 0 .3 29 

12/4/1999 .3 0 0 0 .2 30 1/23/2000 1.4 0 0 0 .3 29 

12/5/1999 .3 0 0 0 .2 29 1/24/2000 1.2 0 0 0 .3 28 
Appendix 2 139 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/25/2000 1.3 0 0 0 0.3 28 3/15/2000 1.4 0 0 0.1 0.3 26 

1/26/2000 1.4 0 0 0 .3 27 3/16/2000 1.4 0 0 0 .3 26 

1/27/2000 3.2 0 0 0 .3 28 3/17/2000 2.1 0 0 .1 .4 28 

1/28/2000 3.5 0 0 0 .3 30 3/18/2000 1.7 0 0 .1 .3 29 

1/29/2000 2.3 0 0 0 .3 29 3/19/2000 1.6 0 0 .1 .3 28 

1/30/2000 2.0 0 0 0 .3 29 3/20/2000 1.6 0 0 .1 .3 28 

1/31/2000 2.0 0 0 0 .3 28 3/21/2000 1.6 0 0 .1 .6 28 

2/1/2000 2.1 0 0 0 .3 28 3/22/2000 1.7 0 0 .1 1.2 28 

2/2/2000 2.1 0 0 0 .3 29 3/23/2000 1.7 0 0 .1 1.2 27 

2/3/2000 2.1 0 0 0 .3 29 3/24/2000 1.7 0 0 .1 .5 26 

2/4/2000 2.0 0 0 0 .3 28 3/25/2000 1.7 0 0 .1 .3 26 

2/5/2000 2.0 0 0 0 .3 28 3/26/2000 1.7 0 0 .1 .3 26 

2/6/2000 1.9 0 0 0 .3 27 3/27/2000 1.6 0 0 .1 .3 26 

2/7/2000 1.9 0 0 0 .3 27 3/28/2000 1.6 0 0 .1 .3 26 

2/8/2000 1.9 0 0 0 .3 27 3/29/2000 1.7 0 0 .2 .4 26 

2/9/2000 1.9 0 0 0 .3 27 3/30/2000 1.7 0 0 .1 .5 26 

2/10/2000 2.0 0 0 0 .3 27 3/31/2000 1.6 0 0 .1 .3 26 

2/11/2000 1.8 0 0 0 .3 26 4/1/2000 1.6 0 0 .1 .3 25 

2/12/2000 1.7 0 0 0 .3 26 4/2/2000 2.1 0 0 .1 .3 26 

2/13/2000 1.7 0 0 0 .3 26 4/3/2000 3.9 0 .1 .2 .3 30 

2/14/2000 1.9 0 0 0 .3 26 4/4/2000 3.3 0 0 .1 .4 31 

2/15/2000 3.5 0 0 0 .3 25 4/5/2000 3.0 0 0 .1 .3 29 

2/16/2000 3.2 0 0 0 .3 25 4/6/2000 2.9 0 0 .1 .3 28 

2/17/2000 3.1 0 0 .1 .2 25 4/7/2000 2.8 0 0 .1 .3 27 

2/18/2000 3.0 0 0 .1 .2 25 4/8/2000 2.8 0 0 .1 .3 26 

2/19/2000 3.0 0 0 .1 .2 25 4/9/2000 2.8 0 0 .1 .3 26 

2/20/2000 2.5 0 0 0 .2 25 4/10/2000 2.8 0 0 0 .3 26 

2/21/2000 1.6 0 0 .1 .2 25 4/11/2000 2.8 0 0 .1 .3 26 

2/22/2000 1.5 0 0 .1 .2 25 4/12/2000 3.9 0 0 .1 .3 28 

2/23/2000 2.4 0 .1 .2 .3 29 4/13/2000 3.3 0 0 .1 .3 28 

2/24/2000 1.7 0 0 .1 .3 29 4/14/2000 3.1 0 0 .1 .3 27 

2/25/2000 1.6 0 0 .1 .3 27 4/15/2000 3.0 0 0 .1 .3 27 

2/26/2000 3.9 0 .1 .1 .3 29 4/16/2000 2.9 0 0 0 .3 26 

2/27/2000 2.7 0 0 .1 .3 29 4/17/2000 2.7 0 0 0 .2 26 

2/28/2000 2.1 0 0 .1 .3 28 4/18/2000 2.3 0 0 0 .2 26 

2/29/2000 2.0 0 0 .1 .4 28 4/19/2000 2.2 0 0 .1 .3 25 

3/1/2000 1.9 0 0 .1 .3 28 4/20/2000 2.1 0 0 0 .2 24 

3/2/2000 1.8 0 0 .1 .3 28 4/21/2000 2.0 0 0 0 .2 24 

3/3/2000 1.7 0 0 .1 .3 28 4/22/2000 1.9 0 0 0 .2 24 

3/4/2000 1.7 0 0 .1 .3 28 4/23/2000 1.7 0 0 0 .2 24 

3/5/2000 1.7 0 0 0 .3 28 4/24/2000 1.6 0 0 0 .2 24 

3/6/2000 1.6 0 0 .1 .3 27 4/25/2000 1.5 0 0 0 .2 23 

3/7/2000 1.6 0 0 .1 .3 27 4/26/2000 1.5 0 0 0 .2 23 

3/8/2000 1.5 0 0 .1 .4 28 4/27/2000 1.5 0 0 0 .2 22 

3/9/2000 1.5 0 0 .1 .4 28 4/28/2000 1.3 0 0 0 .2 22 

3/10/2000 1.4 0 0 .1 .4 27 4/29/2000 1.2 0 0 0 .2 21 

3/11/2000 1.3 0 0 .1 .4 27 4/30/2000 1.2 0 0 0 .2 18 

3/12/2000 1.3 0 0 .1 .4 26 5/1/2000 5.3 1.4 .1 .1 .3 27 

3/13/2000 1.3 0 0 .1 .3 26 5/2/2000 22.0 5.6 .2 4.6 1.4 39 

3/14/2000 1.4 0 0 .1 .3 26 5/3/2000 11.0 0 0 .8 .7 39 
140 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

5/4/2000 8.4 0 0 0.6 0.4 35 6/23/2000 25.0 0 5.9 3.4 3.1 61 

5/5/2000 7.0 0 0 .5 .3 33 6/24/2000 21.0 0 4.0 3.1 2.9 57 

5/6/2000 6.3 0 0 .4 .3 31 6/25/2000 17.0 0 3.4 2.7 2.7 56 

5/7/2000 5.6 0 0 .3 .6 30 6/26/2000 14.0 0 3.1 2.4 2.6 55 

5/8/2000 5.1 0 0 .2 1.4 28 6/27/2000 12.0 0 2.8 2.2 2.3 54 

5/9/2000 4.8 0 0 .2 1.5 27 6/28/2000 10.0 0 2.5 2.1 2.3 53 

5/10/2000 4.7 0 0 .2 1.5 26 6/29/2000 9.3 0 2.2 1.9 2.2 51 

5/11/2000 4.4 0 0 .2 1.4 25 6/30/2000 8.3 0 2.1 1.7 2.1 49 

5/12/2000 4.3 0 0 .1 1.7 24 7/1/2000 7.3 0 1.9 1.6 1.2 48 

5/13/2000 4.7 0 0 .1 1.8 24 7/2/2000 6.2 0 1.7 1.5 1.1 48 

5/14/2000 4.4 0 0 .1 1.4 24 7/3/2000 5.6 0 1.6 1.4 .9 47 

5/15/2000 4.0 0 0 .1 1.4 24 7/4/2000 4.9 0 1.5 1.3 .8 46 

5/16/2000 3.6 0 0 .1 1.5 24 7/5/2000 4.4 0 1.4 1.1 .7 45 

5/17/2000 3.3 0 0 .1 1.4 24 7/6/2000 4.0 0 1.3 1.0 .6 44 

5/18/2000 3.0 0 0 .1 1.4 23 7/7/2000 3.5 0 1.1 .9 .7 43 

5/19/2000 3.3 .1 0 .1 1.4 23 7/8/2000 3.1 0 1.0 .8 .6 43 

5/20/2000 3.4 0 0 .1 1.8 25 7/9/2000 2.7 0 .9 .7 .6 43 

5/21/2000 3.1 0 0 .1 1.6 24 7/10/2000 2.4 0 .8 .7 .5 42 

5/22/2000 2.8 0 0 .1 1.4 23 7/11/2000 2.2 0 .7 .6 .3 42 

5/23/2000 2.7 0 0 .1 1.4 22 7/12/2000 2.0 0 .7 .6 .3 41 

5/24/2000 2.5 0 0 .1 1.2 22 7/13/2000 1.9 0 .6 .5 .3 34 

5/25/2000 2.3 0 0 0 .8 21 7/14/2000 1.8 0 .5 .5 .3 36 

5/26/2000 2.2 0 0 0 .7 22 7/15/2000 1.7 0 .4 .4 .3 35 

5/27/2000 2.1 0 0 0 .8 22 7/16/2000 1.6 0 .4 .4 .3 36 

5/28/2000 1.9 0 0 0 .9 22 7/17/2000 1.5 0 .3 .4 .3 36 

5/29/2000 1.8 0 0 0 .8 22 7/18/2000 1.5 0 .3 .4 .3 36 

5/30/2000 1.6 0 0 0 .8 21 7/19/2000 1.3 0 .3 .4 .3 35 

5/31/2000 1.5 0 0 0 .7 21 7/20/2000 1.2 0 .2 .3 .2 34 

6/1/2000 1.3 0 0 0 .5 20 7/21/2000 1.1 0 .2 .3 .2 34 

6/2/2000 1.2 0 0 0 .4 20 7/22/2000 1.0 0 .2 .3 .2 33 

6/3/2000 1.1 0 0 0 .4 21 7/23/2000 1.1 0 .1 .3 .2 33 

6/4/2000 1.7 1.3 .1 .1 .6 23 7/24/2000 1.0 0 .1 .2 .2 33 

6/5/2000 1.4 0 0 0 1.4 26 7/25/2000 .8 0 .1 .2 .2 33 

6/6/2000 .8 0 0 0 1.1 25 7/26/2000 .7 0 0 .2 .2 32 

6/7/2000 .7 0 0 0 .7 24 7/27/2000 .7 0 0 .2 .2 32 

6/8/2000 2.2 .1 0 0 .6 21 7/28/2000 .6 0 0 .2 .2 32 

6/9/2000 276.0 79.0 151.0 57.0 28.0 37 7/29/2000 .5 0 0 .2 .2 33 

6/10/2000 284.0 15.0 49.0 15.0 40.0 63 7/30/2000 .4 0 0 .2 .2 33 

6/11/2000 107.0 2.6 31.0 12.0 69.0 65 7/31/2000 .3 0 0 .2 .2 33 

6/12/2000 63.0 0 9.6 8.1 36.0 64 8/1/2000 .3 0 0 .2 .2 32 

6/13/2000 44.0 0 5.1 6.5 25.0 63 8/2/2000 .2 0 0 .1 .2 32 

6/14/2000 35.0 0 2.9 5.5 18.0 62 8/3/2000 .2 0 0 .1 .2 31 

6/15/2000 28.0 0 2.4 4.7 14.0 61 8/4/2000 .2 0 0 .1 .2 29 

6/16/2000 24.0 0 2.2 4.1 11.0 61 8/5/2000 .1 0 0 .1 .2 29 

6/17/2000 20.0 0 2.0 3.8 8.4 60 8/6/2000 .1 0 0 .1 .2 28 

6/18/2000 21.0 0 2.2 3.6 6.9 59 8/7/2000 .1 0 0 .1 .2 28 

6/19/2000 47.0 0 36.0 9.9 6.6 59 8/8/2000 .1 0 0 .1 .1 28 

6/20/2000 49.0 0 23.0 5.4 5.2 63 8/9/2000 .1 0 0 .1 .1 29 

6/21/2000 36.0 0 14.0 4.6 4.2 64 8/10/2000 .1 0 0 .1 .1 29 

6/22/2000 30.0 0 8.9 4.0 3.6 63 8/11/2000 .1 0 0 .1 .1 28 
Appendix 2 141 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

8/12/2000 0 0 0 0.1 0.1 28 10/1/2000 0 0 0 0 0 20 

8/13/2000 0 0 0 .1 .1 28 10/2/2000 0 0 0 0 0 18 

8/14/2000 0 0 0 0 .1 26 10/3/2000 0 0 0 0 0 17 

8/15/2000 0 0 0 0 .1 24 10/4/2000 0 0 0 0 0 17 

8/16/2000 0 0 0 0 .1 24 10/5/2000 0 0 0 0 0 16 

8/17/2000 0 0 0 0 .1 23 10/6/2000 0 0 0 0 0 16 

8/18/2000 0 0 0 0 .1 24 10/7/2000 0 0 0 0 0 18 

8/19/2000 0 0 0 0 .1 25 10/8/2000 0 0 0 0 0 24 

8/20/2000 0 0 0 0 .1 25 10/9/2000 0 0 0 0 0 24 

8/21/2000 0 0 0 0 .1 24 10/10/2000 0 0 0 0 0 24 

8/22/2000 0 0 0 0 .1 24 10/11/2000 0 0 0 0 0 22 

8/23/2000 0 0 0 0 .1 26 10/12/2000 0 0 0 0 0 18 

8/24/2000 0 0 0 0 .1 25 10/13/2000 0 0 0 0 0 18 

8/25/2000 0 0 0 0 .1 25 10/14/2000 0 0 0 0 0 19 

8/26/2000 0 0 0 0 .1 25 10/15/2000 0 0 0 0 0 20 

8/27/2000 0 0 0 0 .1 25 10/16/2000 0 0 0 0 0 26 

8/28/2000 0 0 0 0 .1 25 10/17/2000 0 0 0 0 0 26 

8/29/2000 0 0 0 0 .1 24 10/18/2000 0 0 0 0 0 26 

8/30/2000 0 0 0 0 .1 24 10/19/2000 0 0 0 0 0 24 

8/31/2000 0 0 0 0 .1 24 10/20/2000 0 0 0 0 0 25 

9/1/2000 0 0 0 0 .1 22 10/21/2000 .3 .1 0 .1 0 30 

9/2/2000 0 0 0 0 .1 24 10/22/2000 3.8 .5 0 1.8 0 41 

9/3/2000 0 0 0 0 0 23 10/23/2000 4.7 0 0 3.0 0 47 

9/4/2000 0 0 0 0 0 23 10/24/2000 7.4 0 0 1.0 0 46 

9/5/2000 0 0 0 0 0 22 10/25/2000 5.8 0 0 .7 0 45 

9/6/2000 0 0 0 0 0 22 10/26/2000 4.0 0 0 .6 .1 44 

9/7/2000 0 0 0 0 0 21 10/27/2000 3.7 0 0 .5 .1 41 

9/8/2000 0 0 0 0 0 19 10/28/2000 3.9 0 0 .5 .1 41 

9/9/2000 0 0 0 0 0 20 10/29/2000 3.1 0 0 .5 .1 40 

9/10/2000 0 0 0 0 0 20 10/30/2000 2.1 0 0 .4 .1 38 

9/11/2000 0 0 0 0 0 21 10/31/2000 1.7 0 0 .4 .1 37 

9/12/2000 0 0 0 0 0 20 11/1/2000 1.5 0 0 .4 .1 37 

9/13/2000 0 0 0 0 0 22 11/2/2000 8.6 33.0 12.0 109.0 551.0 44 

9/14/2000 0 0 0 0 0 20 11/3/2000 454.0 179.0 113.0 127.0 615.0 51 

9/15/2000 0 0 0 0 0 19 11/4/2000 255.0 34.0 41.0 36.0 129.0 58 

9/16/2000 0 0 0 0 0 19 11/5/2000 118.0 26.0 29.0 66.0 103.0 62 

9/17/2000 0 0 0 0 0 25 11/6/2000 619.0 51.0 69.0 97.0 374.0 64 

9/18/2000 0 0 0 0 0 25 11/7/2000 307.0 21.0 46.0 52.0 148.0 67 

9/19/2000 0 0 0 0 0 24 11/8/2000 334.0 9.8 43.0 44.0 140.0 69 

9/20/2000 0 0 0 0 0 24 11/9/2000 232.0 3.5 20.0 32.0 106.0 70 

9/21/2000 0 0 0 0 0 21 11/10/2000 171.0 .1 10.0 26.0 90.0 72 

9/22/2000 0 0 0 0 0 18 11/11/2000 140.0 0 6.2 22.0 80.0 73 

9/23/2000 0 0 0 0 0 19 11/12/2000 115.0 .7 5.9 21.0 74.0 75 

9/24/2000 0 0 0 0 0 19 11/13/2000 98.0 0 3.7 17.0 66.0 76 

9/25/2000 0 0 0 0 0 19 11/14/2000 87.0 0 3.2 16.0 60.0 77 

9/26/2000 0 0 0 0 0 20 11/15/2000 81.0 0 3.1 15.0 58.0 78 

9/27/2000 0 0 0 0 0 21 11/16/2000 78.0 0 3.3 14.0 56.0 79 

9/28/2000 0 0 0 0 0 20 11/17/2000 73.0 0 3.2 13.0 52.0 79 

9/29/2000 0 0 0 0 0 19 11/18/2000 92.0 4.2 26.0 22.0 67.0 80 

9/30/2000 0 0 0 0 0 21 11/19/2000 126.0 1.8 26.0 21.0 94.0 80 
142 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

11/20/2000 115.0 0.5 15.0 17.0 81.0 81 1/9/2001 75.0 0 4.8 12.0 69.0 89 

11/21/2000 105.0 .1 10.0 16.0 75.0 81 1/10/2001 137.0 17.0 45.0 45.0 214.0 89 

11/22/2000 94.0 0 10.0 15.0 74.0 82 1/11/2001 326.0 5.3 37.0 24.0 239.0 92 

11/23/2000 97.0 0 14.0 16.0 77.0 82 1/12/2001 174.0 2.3 27.0 20.0 149.0 93 

11/24/2000 119.0 1.2 24.0 19.0 101.0 82 1/13/2001 163.0 2.1 28.0 21.0 137.0 93 

11/25/2000 112.0 .2 15.0 16.0 95.0 83 1/14/2001 156.0 1.4 25.0 19.0 128.0 93 

11/26/2000 99.0 0 11.0 15.0 87.0 83 1/15/2001 144.0 .9 20.0 17.0 119.0 94 

11/27/2000 94.0 0 9.6 14.0 82.0 84 1/16/2001 138.0 .5 19.0 17.0 115.0 94 

11/28/2000 90.0 0 9.9 13.0 79.0 84 1/17/2001 148.0 1.4 26.0 20.0 135.0 93 

11/29/2000 86.0 0 8.8 13.0 75.0 84 1/18/2001 199.0 2.7 35.0 21.0 159.0 94 

11/30/2000 78.0 0 7.4 12.0 71.0 84 1/19/2001 191.0 2.1 33.0 20.0 144.0 95 

12/1/2000 73.0 0 7.5 12.0 70.0 84 1/20/2001 164.0 1.0 26.0 19.0 128.0 95 

12/2/2000 68.0 0 5.2 11.0 65.0 84 1/21/2001 157.0 .6 23.0 17.0 125.0 95 

12/3/2000 63.0 0 5.0 11.0 63.0 85 1/22/2001 151.0 .3 20.0 16.0 119.0 96 

12/4/2000 62.0 0 5.3 11.0 63.0 84 1/23/2001 145.0 .1 19.0 16.0 116.0 96 

12/5/2000 61.0 0 4.5 10.0 61.0 84 1/24/2001 144.0 0 16.0 15.0 110.0 96 

12/6/2000 59.0 0 4.4 10.0 60.0 84 1/25/2001 139.0 0 14.0 14.0 105.0 96 

12/7/2000 54.0 0 4.1 9.7 57.0 84 1/26/2001 142.0 0 13.0 14.0 104.0 96 

12/8/2000 51.0 0 3.9 9.6 54.0 84 1/27/2001 147.0 .5 18.0 15.0 108.0 96 

12/9/2000 47.0 0 3.9 9.2 52.0 84 1/28/2001 160.0 .3 22.0 15.0 127.0 97 

12/10/2000 44.0 0 3.8 9.0 52.0 84 1/29/2001 175.0 2.7 31.0 16.0 138.0 98 

12/11/2000 43.0 0 3.8 8.8 50.0 85 1/30/2001 168.0 1.0 23.0 15.0 124.0 98 

12/12/2000 34.0 0 3.5 8.2 44.0 85 1/31/2001 149.0 .4 19.0 14.0 114.0 98 

12/13/2000 48.0 .4 15.0 11.0 66.0 86 2/1/2001 139.0 .1 17.0 13.0 110.0 99 

12/14/2000 63.0 0 11.0 10.0 65.0 85 2/2/2001 134.0 .1 14.0 13.0 106.0 99 

12/15/2000 58.0 0 8.7 10.0 59.0 85 2/3/2001 126.0 0 14.0 13.0 104.0 99 

12/16/2000 56.0 0 6.9 9.4 57.0 85 2/4/2001 122.0 0 11.0 12.0 100.0 99 

12/17/2000 51.0 0 4.8 8.9 50.0 85 2/5/2001 114.0 0 9.7 12.0 97.0 99 

12/18/2000 50.0 0 5.3 8.8 50.0 85 2/6/2001 111.0 0 9.1 12.0 95.0 99 

12/19/2000 50.0 0 3.9 8.5 47.0 85 2/7/2001 106.0 0 7.8 11.0 93.0 99 

12/20/2000 48.0 0 3.8 8.5 48.0 85 2/8/2001 103.0 0 7.8 11.0 93.0 100 

12/21/2000 48.0 0 3.4 8.2 45.0 85 2/9/2001 103.0 0 6.9 11.0 90.0 100 

12/22/2000 45.0 0 3.3 8.1 42.0 83 2/10/2001 95.0 0 5.2 10.0 84.0 100 

12/23/2000 45.0 0 3.4 8.1 43.0 83 2/11/2001 91.0 0 5.2 10.0 83.0 100 

12/24/2000 45.0 0 3.4 8.0 44.0 83 2/12/2001 89.0 0 5.2 10.0 81.0 100 

12/25/2000 46.0 3.7 19.0 16.0 62.0 83 2/13/2001 85.0 0 5.2 10.0 80.0 100 

12/26/2000 194.0 23.0 68.0 38.0 157.0 86 2/14/2001 84.0 0 5.1 10.0 79.0 100 

12/27/2000 156.0 14.0 51.0 29.0 155.0 90 2/15/2001 82.0 0 4.9 10.0 78.0 99 

12/28/2000 186.0 5.1 37.0 24.0 123.0 90 2/16/2001 108.0 1.2 16.0 12.0 104.0 100 

12/29/2000 150.0 1.8 28.0 21.0 109.0 90 2/17/2001 114.0 0 8.9 10.0 86.0 100 

12/30/2000 137.0 .8 24.0 19.0 102.0 90 2/18/2001 92.0 0 7.8 10.0 80.0 100 

12/31/2000 137.0 .5 21.0 18.0 99.0 90 2/19/2001 87.0 0 7.5 10.0 79.0 100 

1/1/2001 122.0 .3 18.0 16.0 95.0 90 2/20/2001 85.0 0 6.4 9.9 77.0 100 

1/2/2001 107.0 .1 16.0 15.0 90.0 90 2/21/2001 83.0 0 6.3 9.6 76.0 100 

1/3/2001 102.0 0 15.0 15.0 87.0 90 2/22/2001 81.0 0 5.7 9.3 73.0 100 

1/4/2001 99.0 0 13.0 14.0 85.0 90 2/23/2001 81.0 0 6.9 9.5 73.0 99 

1/5/2001 94.0 0 10.0 14.0 82.0 90 2/24/2001 83.0 0 7.2 9.5 78.0 99 

1/6/2001 87.0 0 9.3 13.0 79.0 89 2/25/2001 77.0 0 5.2 8.9 71.0 99 

1/7/2001 83.0 0 8.3 13.0 77.0 89 2/26/2001 70.0 0 5.1 8.9 67.0 99 

1/8/2001 77.0 0 6.3 12.0 72.0 89 2/27/2001 70.0 0 5.2 8.9 67.0 99 
Appendix 2 143 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

2/28/2001 71.0 0 5.1 8.9 65.0 99 4/19/2001 76.0 0 4.7 5.3 43.0 103 

3/1/2001 75.0 0 6.3 9.4 69.0 99 4/20/2001 71.0 0 4.3 5.0 42.0 103 

3/2/2001 81.0 0 7.2 9.3 71.0 99 4/21/2001 68.0 0 3.9 4.7 39.0 103 

3/3/2001 118.0 4.2 27.0 16.0 111.0 99 4/22/2001 66.0 0 3.6 4.6 36.0 103 

3/4/2001 159.0 1.0 24.0 13.0 113.0 99 4/23/2001 79.0 0 4.6 5.7 55.0 103 

3/5/2001 132.0 .1 20.0 12.0 98.0 99 4/24/2001 98.0 0 3.8 4.8 53.0 103 

3/6/2001 125.0 0 19.0 12.0 95.0 99 4/25/2001 69.0 0 3.3 4.5 38.0 103 

3/7/2001 122.0 0 18.0 12.0 94.0 99 4/26/2001 59.0 0 3.0 4.3 33.0 102 

3/8/2001 123.0 0 19.0 12.0 94.0 99 4/27/2001 53.0 0 2.9 4.1 30.0 102 

3/9/2001 124.0 0 18.0 12.0 93.0 100 4/28/2001 49.0 0 2.7 4.0 27.0 102 

3/10/2001 118.0 0 16.0 12.0 91.0 100 4/29/2001 46.0 0 2.5 3.9 25.0 102 

3/11/2001 116.0 0 16.0 12.0 90.0 100 4/30/2001 44.0 0 2.3 3.9 24.0 102 

3/12/2001 201.0 27.0 59.0 37.0 268.0 101 5/1/2001 43.0 0 2.2 3.8 23.0 102 

3/13/2001 170.0 2.1 32.0 15.0 225.0 101 5/2/2001 40.0 0 2.0 3.6 21.0 102 

3/14/2001 171.0 8.6 45.0 20.0 228.0 102 5/3/2001 39.0 0 1.9 3.6 19.0 102 

3/15/2001 209.0 4.2 40.0 19.0 227.0 102 5/4/2001 37.0 0 1.9 3.6 17.0 102 

3/16/2001 171.0 1.3 32.0 16.0 205.0 102 5/5/2001 52.0 0 3.0 4.5 33.0 103 

3/17/2001 160.0 .9 29.0 16.0 194.0 102 5/6/2001 74.0 11.0 6.4 5.4 53.0 103 

3/18/2001 185.0 3.3 34.0 19.0 197.0 102 5/7/2001 257.0 9.1 20.0 13.0 1,040.0 105 

3/19/2001 223.0 1.3 32.0 18.0 194.0 103 5/8/2001 116.0 .9 5.4 7.9 215.0 105 

3/20/2001 175.0 .5 27.0 16.0 171.0 102 5/9/2001 131.0 0 4.7 6.6 195.0 105 

3/21/2001 173.0 .1 24.0 14.0 157.0 102 5/10/2001 84.0 0 3.5 5.4 162.0 105 

3/22/2001 161.0 0 22.0 13.0 150.0 102 5/11/2001 70.0 0 3.1 4.9 147.0 104 

3/23/2001 154.0 0 20.0 12.0 143.0 102 5/12/2001 64.0 0 2.9 4.7 159.0 104 

3/24/2001 151.0 .1 20.0 12.0 136.0 102 5/13/2001 67.0 0 2.7 4.6 175.0 103 

3/25/2001 141.0 0 18.0 11.0 124.0 102 5/14/2001 65.0 0 2.6 4.4 135.0 103 

3/26/2001 134.0 0 17.0 10.0 118.0 102 5/15/2001 55.0 0 2.4 4.3 125.0 103 

3/27/2001 188.0 4.3 30.0 12.0 126.0 103 5/16/2001 50.0 0 2.4 4.1 116.0 103 

3/28/2001 307.0 2.6 36.0 14.0 154.0 104 5/17/2001 48.0 0 2.2 4.0 112.0 102 

3/29/2001 240.0 1.2 29.0 12.0 133.0 103 5/18/2001 43.0 0 2.1 3.8 106.0 102 

3/30/2001 222.0 .7 26.0 12.0 118.0 103 5/19/2001 40.0 0 2.0 3.9 103.0 102 

3/31/2001 216.0 .3 24.0 11.0 111.0 103 5/20/2001 38.0 0 2.1 3.8 101.0 102 

4/1/2001 195.0 .1 22.0 11.0 105.0 103 5/21/2001 37.0 0 1.8 3.8 96.0 102 

4/2/2001 182.0 0 21.0 10.0 104.0 104 5/22/2001 34.0 0 1.6 3.4 87.0 102 

4/3/2001 170.0 0 20.0 10.0 101.0 103 5/23/2001 30.0 0 1.6 3.2 76.0 102 

4/4/2001 162.0 0 19.0 10.0 97.0 103 5/24/2001 28.0 0 1.5 3.1 72.0 102 

4/5/2001 157.0 0 18.0 9.5 93.0 103 5/25/2001 30.0 0 1.6 3.2 88.0 102 

4/6/2001 150.0 0 16.0 9.0 89.0 103 5/26/2001 39.0 0 1.8 3.4 79.0 102 

4/7/2001 143.0 0 15.0 8.5 84.0 103 5/27/2001 43.0 0 1.7 3.3 71.0 103 

4/8/2001 137.0 0 14.0 8.1 80.0 103 5/28/2001 36.0 0 1.4 2.9 64.0 103 

4/9/2001 128.0 0 13.0 7.9 75.0 103 5/29/2001 30.0 0 1.3 2.8 58.0 102 

4/10/2001 120.0 0 12.0 7.6 70.0 103 5/30/2001 26.0 0 1.2 2.7 55.0 102 

4/11/2001 114.0 0 11.0 7.2 66.0 103 5/31/2001 26.0 0 1.1 2.6 53.0 101 

4/12/2001 106.0 0 10.0 7.1 62.0 103 6/1/2001 22.0 0 1.1 2.5 53.0 100 

4/13/2001 102.0 0 9.6 7.0 61.0 103 6/2/2001 21.0 0 1.1 2.4 51.0 100 

4/14/2001 99.0 0 9.0 6.6 57.0 103 6/3/2001 21.0 0 1.0 2.2 41.0 100 

4/15/2001 92.0 0 7.6 6.1 52.0 103 6/4/2001 17.0 0 .9 2.1 36.0 99 

4/16/2001 87.0 0 5.5 5.7 49.0 103 6/5/2001 15.0 0 .9 2.0 33.0 99 

4/17/2001 81.0 0 4.9 5.5 46.0 102 6/6/2001 14.0 0 .9 2.0 33.0 98 

4/18/2001 80.0 0 5.0 5.4 45.0 103 6/7/2001 14.0 0 .8 1.9 30.0 98 
144 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

6/8/2001 13.0 0 0.9 2.0 29.0 97 7/28/2001 0.1 0 0 0 1.8 83 

6/9/2001 13.0 0 .9 1.9 31.0 97 7/29/2001 0 0 0 0 1.5 83 

6/10/2001 13.0 0 .8 1.7 29.0 97 7/30/2001 0 0 0 0 1.2 83 

6/11/2001 12.0 0 .8 1.6 26.0 96 7/31/2001 0 0 0 0 1.3 82 

6/12/2001 11.0 0 .7 1.5 24.0 96 8/1/2001 0 0 0 0 1.3 82 

6/13/2001 8.9 0 .7 1.3 23.0 96 8/2/2001 0 0 0 0 1.4 81 

6/14/2001 6.9 0 .7 1.2 21.0 95 8/3/2001 0 0 0 0 1.3 80 

6/15/2001 6.3 0 .7 1.3 20.0 95 8/4/2001 0 0 0 0 1.2 80 

6/16/2001 5.8 0 .7 1.1 20.0 95 8/5/2001 0 0 0 0 1.2 79 

6/17/2001 5.8 0 .6 1.0 18.0 95 8/6/2001 0 0 0 0 1.2 79 

6/18/2001 5.8 0 .6 .9 17.0 95 8/7/2001 0 0 0 0 1.2 78 

6/19/2001 5.0 0 .5 .8 16.0 94 8/8/2001 0 0 0 0 1.0 78 

6/20/2001 4.2 0 .5 .8 15.0 94 8/9/2001 0 0 0 0 1.0 78 

6/21/2001 3.4 0 .5 .7 14.0 94 8/10/2001 0 0 0 0 .8 77 

6/22/2001 3.6 0 .5 .7 14.0 94 8/11/2001 0 0 0 0 .7 77 

6/23/2001 3.3 0 .5 .6 13.0 94 8/12/2001 0 0 0 0 .6 76 

6/24/2001 3.1 0 .4 .6 12.0 94 8/13/2001 0 0 0 0 .5 76 

6/25/2001 2.8 0 .4 .5 12.0 94 8/14/2001 0 0 0 0 .4 75 

6/26/2001 2.5 0 .3 .4 11.0 93 8/15/2001 0 0 0 0 .4 75 

6/27/2001 2.1 0 .3 .4 9.3 93 8/16/2001 0 0 0 0 .4 74 

6/28/2001 1.7 0 .3 .4 8.4 93 8/17/2001 0 0 0 0 .5 73 

6/29/2001 1.3 0 .2 .3 7.8 93 8/18/2001 0 0 0 0 .5 73 

6/30/2001 1.2 0 .2 .3 7.3 93 8/19/2001 0 0 0 0 .4 72 

7/1/2001 1.3 0 .2 .3 7.5 93 8/20/2001 0 0 0 0 .4 72 

7/2/2001 1.2 0 .2 .2 7.0 93 8/21/2001 0 0 0 0 .3 71 

7/3/2001 1.3 0 .2 .2 6.5 93 8/22/2001 0 0 0 0 .3 71 

7/4/2001 1.1 0 .2 .2 6.0 93 8/23/2001 0 0 0 0 .3 70 

7/5/2001 1.2 0 .1 .2 5.6 92 8/24/2001 0 0 0 0 .3 70 

7/6/2001 1.0 0 .1 .2 5.1 92 8/25/2001 0 0 0 0 .3 69 

7/7/2001 1.0 0 0 .1 4.6 92 8/26/2001 1.5 47.0 .1 0 3.0 69 

7/8/2001 .8 0 0 .1 4.3 91 8/27/2001 .6 .4 .1 1.2 5.0 76 

7/9/2001 .7 0 0 .1 4.2 91 8/28/2001 .1 0 0 .4 1.4 78 

7/10/2001 .6 0 0 .1 4.3 91 8/29/2001 .1 0 0 .5 1.4 79 

7/11/2001 .5 0 0 0 4.4 90 8/30/2001 1.2 5.7 .2 1.3 3.2 80 

7/12/2001 .4 0 0 .1 4.2 90 8/31/2001 10.0 32.0 1.2 24.0 60.0 80 

7/13/2001 .4 0 0 0 4.0 89 9/1/2001 3.0 0 0 2.7 64.0 80 

7/14/2001 .4 0 0 0 3.6 89 9/2/2001 5.1 0 0 1.7 26.0 81 

7/15/2001 .4 0 0 0 3.3 89 9/3/2001 4.0 0 0 1.3 13.0 81 

7/16/2001 .5 0 0 0 3.0 88 9/4/2001 15.0 0 0 1.5 13.0 82 

7/17/2001 .3 0 0 0 3.0 88 9/5/2001 21.0 1.0 .1 1.7 20.0 82 

7/18/2001 .3 0 0 0 2.8 87 9/6/2001 15.0 0 0 1.8 15.0 81 

7/19/2001 .3 0 0 0 2.7 87 9/7/2001 12.0 0 0 1.0 12.0 81 

7/20/2001 .3 0 0 0 2.7 87 9/8/2001 9.8 0 0 .9 10.0 80 

7/21/2001 .3 0 0 0 2.5 86 9/9/2001 8.5 0 0 .9 9.7 80 

7/22/2001 .2 0 0 0 2.3 86 9/10/2001 8.4 0 0 .8 8.0 79 

7/23/2001 .2 0 0 0 2.1 85 9/11/2001 8.0 0 0 .8 7.7 79 

7/24/2001 .2 0 0 0 2.0 85 9/12/2001 8.2 0 0 .7 7.6 78 

7/25/2001 .2 0 0 0 2.0 84 9/13/2001 7.5 0 0 .7 7.0 78 

7/26/2001 .2 0 0 0 1.8 84 9/14/2001 7.2 0 0 .7 6.4 77 

7/27/2001 .1 0 0 0 1.8 84 9/15/2001 6.3 0 0 .7 5.9 77 
Appendix 2 145 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

9/16/2001 5.9 0 0 0.7 5.4 77 11/5/2001 6.6 0 0 0.5 4.4 62 

9/17/2001 5.4 0 0 .6 5.1 76 11/6/2001 6.5 0 0 .4 4.4 61 

9/18/2001 4.7 0 0 .6 4.6 76 11/7/2001 5.9 0 0 .4 4.4 61 

9/19/2001 4.4 0 0 .6 4.4 75 11/8/2001 5.4 0 0 .4 4.4 61 

9/20/2001 4.0 0 0 .5 4.4 75 11/9/2001 6.4 0 0 .5 4.6 61 

9/21/2001 4.3 0 .1 .6 4.3 75 11/10/2001 5.4 0 0 .5 4.4 61 

9/22/2001 3.7 0 0 .6 4.1 75 11/11/2001 5.0 0 0 .5 4.8 61 

9/23/2001 4.0 0 0 .6 3.7 75 11/12/2001 5.1 0 0 .5 5.1 61 

9/24/2001 3.8 0 0 .5 3.8 75 11/13/2001 4.7 0 0 .5 4.9 62 

9/25/2001 3.8 0 0 .5 3.6 74 11/14/2001 3.9 0 .1 .6 5.2 62 

9/26/2001 3.5 0 .1 .5 3.7 74 11/15/2001 1,090.0 102.0 41.0 101.0 3,550.0 75 

9/27/2001 3.8 0 .1 .5 3.9 73 11/16/2001 2,930.0 90.0 23.0 30.0 815.0 88 

9/28/2001 4.0 0 .1 .5 3.8 73 11/17/2001 256.0 6.9 3.0 13.0 298.0 94 

9/29/2001 3.5 0 .1 .4 3.6 72 11/18/2001 182.0 0 2.5 11.0 196.0 95 

9/30/2001 3.0 0 0 .4 3.2 72 11/19/2001 140.0 0 2.2 10.0 148.0 96 

10/1/2001 2.8 0 0 .4 3.2 71 11/20/2001 119.0 0 2.0 8.9 130.0 97 

10/2/2001 2.5 0 0 .4 3.2 70 11/21/2001 107.0 0 1.9 8.4 115.0 97 

10/3/2001 2.6 0 0 .4 3.2 70 11/22/2001 97.0 0 1.9 8.1 106.0 98 

10/4/2001 2.4 0 0 .4 3.3 70 11/23/2001 91.0 0 1.9 7.9 99.0 98 

10/5/2001 2.2 0 0 .3 3.4 69 11/24/2001 85.0 0 1.8 6.9 89.0 98 

10/6/2001 1.8 0 0 .3 3.5 69 11/25/2001 77.0 0 1.8 6.3 79.0 99 

10/7/2001 1.7 0 0 .3 3.4 68 11/26/2001 73.0 0 1.7 6.2 75.0 99 

10/8/2001 1.5 0 0 .3 3.4 68 11/27/2001 67.0 0 1.7 5.6 69.0 99 

10/9/2001 1.4 0 0 .3 3.7 67 11/28/2001 70.0 13.0 8.0 17.0 94.0 100 

10/10/2001 1.3 0 0 .3 3.7 67 11/29/2001 88.0 1.4 3.6 12.0 83.0 101 

10/11/2001 5.5 0 .1 .6 5.2 68 11/30/2001 83.0 0 3.1 11.0 74.0 102 

10/12/2001 13.0 0 0 .4 4.6 69 12/1/2001 75.0 0 2.8 9.9 69.0 102 

10/13/2001 57.0 1.5 .2 1.3 57.0 71 12/2/2001 82.0 5.9 13.0 28.0 119.0 103 

10/14/2001 52.0 0 .1 .7 37.0 72 12/3/2001 129.0 1.9 15.0 27.0 144.0 103 

10/15/2001 36.0 0 .1 .6 20.0 70 12/4/2001 121.0 .1 12.0 24.0 126.0 103 

10/16/2001 25.0 0 .1 .5 14.0 70 12/5/2001 116.0 0 8.8 21.0 114.0 103 

10/17/2001 19.0 0 .1 .5 13.0 69 12/6/2001 111.0 0 6.0 19.0 106.0 103 

10/18/2001 16.0 0 .1 .6 12.0 69 12/7/2001 106.0 0 4.6 18.0 102.0 103 

10/19/2001 15.0 0 .1 .5 12.0 68 12/8/2001 485.0 68.0 102.0 119.0 418.0 102 

10/20/2001 14.0 0 .1 .5 11.0 68 12/9/2001 268.0 18.0 45.0 42.0 215.0 103 

10/21/2001 13.0 0 .1 .6 11.0 67 12/10/2001 216.0 6.0 29.0 34.0 183.0 103 

10/22/2001 11.0 0 .1 .6 10.0 67 12/11/2001 207.0 17.0 42.0 43.0 184.0 103 

10/23/2001 11.0 0 .1 .6 10.0 67 12/12/2001 235.0 11.0 42.0 40.0 197.0 103 

10/24/2001 11.0 0 .1 .6 9.7 66 12/13/2001 211.0 9.0 42.0 39.0 187.0 103 

10/25/2001 8.5 0 .1 .6 8.0 65 12/14/2001 208.0 4.9 32.0 34.0 175.0 103 

10/26/2001 8.0 0 .1 .5 7.8 65 12/15/2001 351.0 67.0 145.0 170.0 289.0 103 

10/27/2001 8.1 0 .1 .4 7.0 64 12/16/2001 463.0 50.0 96.0 89.0 321.0 103 

10/28/2001 7.7 0 .1 .4 6.7 64 12/17/2001 337.0 19.0 62.0 58.0 240.0 103 

10/29/2001 7.3 0 .1 .5 6.3 64 12/18/2001 277.0 8.7 48.0 48.0 214.0 103 

10/30/2001 6.7 0 .1 .5 5.6 64 12/19/2001 241.0 3.5 38.0 39.0 194.0 103 

10/31/2001 6.9 0 .1 .5 5.6 63 12/20/2001 214.0 1.5 32.0 34.0 175.0 108 

11/1/2001 7.9 0 .1 .5 5.2 63 12/21/2001 196.0 1.0 30.0 31.0 165.0 109 

11/2/2001 7.9 0 .1 .5 4.8 63 12/22/2001 183.0 .6 28.0 28.0 154.0 110 

11/3/2001 7.2 0 .1 .7 4.6 62 12/23/2001 159.0 .3 24.0 25.0 133.0 110 

11/4/2001 7.7 0 0 .6 4.9 62 12/24/2001 149.0 .2 22.0 23.0 120.0 110 
146 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

12/25/2001 143.0 0.1 21.0 21.0 114.0 110 2/13/2002 36.0 0 2.8 4.3 35.0 111 

12/26/2001 134.0 .1 19.0 19.0 109.0 110 2/14/2002 36.0 0 2.8 4.1 34.0 111 

12/27/2001 121.0 .1 17.0 18.0 106.0 110 2/15/2002 34.0 0 2.7 4.1 33.0 111 

12/28/2001 113.0 0 16.0 18.0 104.0 111 2/16/2002 32.0 0 2.6 3.7 31.0 111 

12/29/2001 104.0 0 15.0 16.0 99.0 111 2/17/2002 31.0 0 2.7 3.7 31.0 110 

12/30/2001 96.0 0 13.0 15.0 95.0 111 2/18/2002 32.0 0 2.7 3.7 31.0 110 

12/31/2001 91.0 0 13.0 14.0 92.0 111 2/19/2002 31.0 0 2.7 3.7 32.0 110 

1/1/2002 85.0 0 12.0 13.0 89.0 111 2/20/2002 30.0 0 2.4 3.3 30.0 110 

1/2/2002 82.0 0 11.0 13.0 86.0 111 2/21/2002 27.0 0 2.3 3.2 29.0 109 

1/3/2002 80.0 0 10.0 12.0 83.0 111 2/22/2002 25.0 0 2.1 3.3 27.0 108 

1/4/2002 77.0 0 9.7 12.0 81.0 111 2/23/2002 24.0 0 2.1 3.2 27.0 108 

1/5/2002 150.0 16.0 42.0 28.0 138.0 111 2/24/2002 24.0 0 2.0 3.1 27.0 108 

1/6/2002 135.0 1.7 21.0 16.0 103.0 111 2/25/2002 24.0 0 2.0 3.0 26.0 97 

1/7/2002 101.0 .8 17.0 14.0 92.0 111 2/26/2002 21.0 0 1.8 2.8 23.0 95 

1/8/2002 92.0 .5 17.0 14.0 88.0 112 2/27/2002 21.0 0 1.8 2.9 22.0 95 

1/9/2002 88.0 .3 16.0 13.0 85.0 112 2/28/2002 21.0 0 1.8 3.0 24.0 95 

1/10/2002 87.0 .1 15.0 13.0 83.0 112 3/1/2002 22.0 0 1.9 3.2 26.0 95 

1/11/2002 84.0 0 13.0 12.0 78.0 112 3/2/2002 22.0 0 1.8 3.2 27.0 95 

1/12/2002 79.0 0 13.0 11.0 76.0 112 3/3/2002 21.0 0 1.5 2.8 23.0 95 

1/13/2002 77.0 0 12.0 11.0 74.0 112 3/4/2002 20.0 0 1.5 2.9 22.0 95 

1/14/2002 72.0 0 9.9 10.0 71.0 112 3/5/2002 26.0 0 1.5 2.9 22.0 96 

1/15/2002 70.0 0 8.7 9.8 68.0 112 3/6/2002 32.0 0 1.5 2.8 22.0 96 

1/16/2002 68.0 0 8.6 9.6 68.0 112 3/7/2002 32.0 0 1.5 2.7 23.0 95 

1/17/2002 66.0 0 8.3 9.5 66.0 112 3/8/2002 20.0 0 1.5 2.7 23.0 99 

1/18/2002 64.0 0 7.8 8.9 64.0 112 3/9/2002 18.0 0 1.4 2.5 22.0 106 

1/19/2002 62.0 0 6.5 8.6 64.0 112 3/10/2002 17.0 0 1.3 2.2 20.0 107 

1/20/2002 60.0 0 5.6 8.2 61.0 112 3/11/2002 17.0 0 1.4 2.4 21.0 107 

1/21/2002 58.0 0 4.9 8.1 59.0 112 3/12/2002 17.0 0 1.3 2.3 21.0 106 

1/22/2002 55.0 0 5.0 8.1 58.0 112 3/13/2002 17.0 0 1.3 2.2 19.0 106 

1/23/2002 56.0 0 4.8 8.1 58.0 112 3/14/2002 17.0 0 1.3 2.2 19.0 105 

1/24/2002 56.0 0 4.6 7.5 56.0 112 3/15/2002 16.0 0 1.3 2.2 19.0 105 

1/25/2002 53.0 0 4.1 6.6 54.0 112 3/16/2002 15.0 0 1.2 2.0 17.0 104 

1/26/2002 49.0 0 3.9 6.1 51.0 112 3/17/2002 14.0 0 1.2 2.1 17.0 104 

1/27/2002 48.0 0 3.8 5.9 50.0 112 3/18/2002 14.0 0 1.2 2.3 18.0 104 

1/28/2002 47.0 0 3.8 5.9 49.0 112 3/19/2002 18.0 1.2 1.3 2.9 19.0 104 

1/29/2002 46.0 0 3.6 5.7 49.0 112 3/20/2002 23.0 .6 1.4 3.2 27.0 104 

1/30/2002 47.0 0 3.5 5.5 48.0 112 3/21/2002 21.0 0 1.1 2.4 22.0 104 

1/31/2002 48.0 0 3.6 5.6 49.0 112 3/22/2002 19.0 0 1.1 2.2 19.0 103 

2/1/2002 44.0 0 3.2 5.0 45.0 112 3/23/2002 16.0 0 1.1 2.2 18.0 103 

2/2/2002 41.0 0 3.2 4.9 42.0 112 3/24/2002 18.0 0 1.0 2.2 18.0 103 

2/3/2002 41.0 0 3.2 4.9 43.0 112 3/25/2002 16.0 0 1.0 2.2 18.0 102 

2/4/2002 40.0 0 3.1 4.8 41.0 112 3/26/2002 14.0 0 .9 2.0 17.0 102 

2/5/2002 47.0 0 5.3 5.9 46.0 112 3/27/2002 14.0 0 .9 1.9 17.0 101 

2/6/2002 55.0 0 5.4 6.1 56.0 112 3/28/2002 14.0 0 .9 1.9 16.0 101 

2/7/2002 52.0 0 3.7 5.4 48.0 112 3/29/2002 13.0 0 .9 2.0 17.0 101 

2/8/2002 45.0 0 3.4 5.0 43.0 112 3/30/2002 23.0 .2 1.0 2.5 20.0 101 

2/9/2002 42.0 0 3.3 4.9 43.0 111 3/31/2002 29.0 0 .9 2.1 36.0 101 

2/10/2002 39.0 0 2.9 4.6 38.0 111 4/1/2002 29.0 0 .8 2.0 24.0 101 

2/11/2002 38.0 0 2.9 4.4 35.0 111 4/2/2002 23.0 0 .8 1.9 20.0 101 

2/12/2002 37.0 0 3.0 4.4 34.0 111 4/3/2002 18.0 0 .8 1.7 19.0 100 
Appendix 2 147 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Date Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

Date 

Barton 

Creek 

Williamson 

Creek 

Slaughter 

Creek 

Bear 

Creek 

Onion 

Creek 

Barton 

Springs 

4/4/2002 16.0 0 0.8 1.6 18.0 100 5/24/2002 .9 0 0.1 0.2 3.6 88 

4/5/2002 15.0 0 .8 1.6 18.0 100 5/25/2002 .9 0 .1 .2 3.7 88 

4/6/2002 14.0 0 .8 1.6 18.0 99 5/26/2002 .8 0 0 .2 3.4 87 

4/7/2002 16.0 0 .8 2.5 19.0 99 5/27/2002 .8 0 0 .2 3.4 87 

4/8/2002 21.0 0 .9 2.9 27.0 100 5/28/2002 3.7 0 .1 .7 3.8 88 

4/9/2002 25.0 0 .7 1.9 24.0 100 5/29/2002 7.2 0 0 .6 3.5 87 

4/10/2002 23.0 0 .7 1.7 19.0 99 5/30/2002 6.4 0 0 .4 3.5 87 

4/11/2002 19.0 0 .7 1.7 17.0 99 5/31/2002 5.3 0 0 .3 3.0 86 

4/12/2002 18.0 0 .7 1.6 17.0 99 6/1/2002 4.8 0 0 .2 2.9 86 

4/13/2002 17.0 0 .6 1.6 16.0 98 6/2/2002 3.9 0 0 .2 2.7 85 

4/14/2002 16.0 0 .6 1.6 16.0 98 6/3/2002 2.9 0 0 .3 2.6 85 

4/15/2002 15.0 0 .6 1.6 16.0 98 6/4/2002 2.3 0 0 .1 2.5 84 

4/16/2002 14.0 0 .6 1.6 16.0 98 6/5/2002 1.7 0 0 .1 2.3 83 

4/17/2002 14.0 0 .6 1.5 15.0 98 6/6/2002 1.3 0 0 .1 2.2 83 

4/18/2002 13.0 0 .6 1.5 15.0 98 6/7/2002 1.0 0 0 0 2.2 83 

4/19/2002 12.0 0 .6 1.4 15.0 98 6/8/2002 1.1 0 0 0 2.2 83 

4/20/2002 12.0 0 .5 1.2 14.0 97 6/9/2002 1.5 0 0 0 2.2 82 

4/21/2002 11.0 0 .5 1.2 14.0 97 6/10/2002 1.4 0 0 0 2.3 82 

4/22/2002 11.0 0 .5 1.3 14.0 97 6/11/2002 .8 0 0 0 2.2 82 

4/23/2002 11.0 0 .5 1.1 13.0 96 6/12/2002 .6 0 0 0 2.1 81 

4/24/2002 11.0 0 .5 1.0 13.0 96 6/13/2002 .6 0 0 0 2.0 80 

4/25/2002 10.0 0 .4 1.0 12.0 96 6/14/2002 .5 0 0 0 1.9 80 

4/26/2002 9.9 0 .4 1.0 12.0 96 6/15/2002 .4 0 0 0 1.8 79 

4/27/2002 9.5 0 .4 1.0 12.0 96 6/16/2002 1.6 0 0 0 1.9 80 

4/28/2002 8.7 0 .4 .9 12.0 95 6/17/2002 1.1 0 0 0 2.2 80 

4/29/2002 7.6 0 .4 .9 11.0 95 6/18/2002 .8 0 0 0 2.0 79 

4/30/2002 6.6 0 .3 .8 10.0 95 6/19/2002 .6 0 0 0 1.8 78 

5/1/2002 6.2 0 .3 .8 9.6 95 6/20/2002 .5 0 0 0 1.7 77 

5/2/2002 5.9 0 .3 .7 9.1 94 6/21/2002 .4 0 0 0 1.7 77 

5/3/2002 10.0 0 .3 .8 8.8 94 6/22/2002 .4 0 0 0 1.5 76 

5/4/2002 8.9 0 .3 .8 8.6 94 6/23/2002 .3 0 0 0 1.2 76 

5/5/2002 6.4 0 .3 .8 8.0 94 6/24/2002 .4 0 0 0 1.1 75 

5/6/2002 5.2 0 .3 .7 7.7 93 6/25/2002 .3 0 0 0 1.0 75 

5/7/2002 4.4 0 .2 .6 7.4 93 6/26/2002 4.6 7.0 .1 0 1.2 74 

5/8/2002 4.1 0 .2 .6 7.1 93 6/27/2002 19.0 2.4 0 0 2.2 78 

5/9/2002 3.7 0 .2 .6 6.8 92 6/28/2002 7.1 0 0 .1 2.2 77 

5/10/2002 3.2 0 .2 .5 6.3 92 6/29/2002 3.9 0 0 .1 1.9 76 

5/11/2002 2.7 0 .2 .4 5.7 92 6/30/2002 551.0 50.0 1.4 164.0 694.0 76 

5/12/2002 2.4 0 .2 .4 5.2 92 7/1/2002 332.0 31.0 34.0 175.0 436.0 77 

5/13/2002 2.1 0 .1 .4 5.2 92 7/2/2002 5,770.0 177.0 396.0 997.0 3,790.0 79 

5/14/2002 1.9 0 .1 .4 4.2 92 7/3/2002 2,400.0 89.0 167.0 147.0 1,930.0 81 

5/15/2002 1.5 0 .1 .4 3.9 91 7/4/2002 1,060.0 27.0 83.0 59.0 597.0 83 

5/16/2002 1.7 0 .1 .4 4.0 91 7/5/2002 1,580.0 13.0 55.0 54.0 3,200.0 84 

5/17/2002 1.8 0 .1 .3 3.9 91 7/6/2002 751.0 4.0 36.0 42.0 916.0 87 

5/18/2002 1.2 0 .1 .3 3.7 90 7/7/2002 673.0 .7 24.0 35.0 664.0 88 

5/19/2002 1.0 0 .1 .3 3.7 90 7/8/2002 454.0 .2 16.0 30.0 489.0 89 

5/20/2002 1.1 0 .1 .2 3.4 89 7/9/2002 393.0 .4 14.0 26.0 435.0 90 

5/21/2002 1.5 0 .1 .2 3.4 89 7/10/2002 402.0 3.9 13.0 24.0 400.0 91 

5/22/2002 1.4 0 .1 .2 3.4 88 7/11/2002 391.0 1.2 11.0 22.0 353.0 93 

5/23/2002 1.0 0 .1 .2 3.6 88 7/12/2002 272.0 .4 5.9 22.0 299.0 94 
148 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

7/13/2002 237.0 0.1 4.4 21.0 299.0 96 9/1/2002 13.0 0 0.2 1.4 18.0 95 

7/14/2002 218.0 1.1 4.2 19.0 267.0 97 9/2/2002 9.6 0 .2 1.3 15.0 94 

7/15/2002 189.0 .1 4.4 18.0 245.0 99 9/3/2002 7.5 0 .2 1.2 13.0 94 

7/16/2002 311.0 5.6 20.0 21.0 312.0 100 9/4/2002 6.5 0 .1 1.1 12.0 94 

7/17/2002 335.0 7.7 33.0 31.0 392.0 102 9/5/2002 6.0 0 .1 1.0 11.0 94 

7/18/2002 383.0 3.3 31.0 25.0 372.0 103 9/6/2002 5.6 0 .1 .9 11.0 95 

7/19/2002 302.0 1.1 19.0 23.0 276.0 105 9/7/2002 7.6 0 .3 2.8 23.0 95 

7/20/2002 260.0 .3 13.0 21.0 244.0 105 9/8/2002 14.0 0 .3 4.7 44.0 96 

7/21/2002 240.0 0 11.0 19.0 222.0 105 9/9/2002 33.0 0 .3 3.4 41.0 96 

7/22/2002 198.0 0 7.4 17.0 204.0 105 9/10/2002 30.0 0 .2 2.1 31.0 95 

7/23/2002 165.0 0 4.5 16.0 187.0 105 9/11/2002 19.0 0 .2 1.8 23.0 94 

7/24/2002 160.0 0 3.8 15.0 171.0 105 9/12/2002 15.0 0 .2 1.5 20.0 94 

7/25/2002 135.0 0 3.3 14.0 158.0 105 9/13/2002 12.0 0 .2 1.3 18.0 94 

7/26/2002 123.0 0 3.0 13.0 145.0 105 9/14/2002 10.0 0 .2 1.1 16.0 94 

7/27/2002 146.0 0 2.6 12.0 134.0 105 9/15/2002 9.2 0 .2 1.1 15.0 93 

7/28/2002 150.0 0 2.3 11.0 122.0 105 9/16/2002 8.9 0 .2 1.2 16.0 93 

7/29/2002 104.0 0 2.1 11.0 111.0 105 9/17/2002 8.8 0 .2 1.2 18.0 92 

7/30/2002 116.0 0 1.9 10.0 106.0 105 9/18/2002 8.2 0 .2 1.1 17.0 91 

7/31/2002 114.0 0 1.7 9.2 98.0 105 9/19/2002 8.7 0 .4 3.3 43.0 90 

8/1/2002 105.0 0 1.7 8.7 93.0 105 9/20/2002 8.4 0 .3 2.1 47.0 92 

8/2/2002 95.0 0 1.5 8.1 88.0 105 9/21/2002 9.1 0 .2 1.3 28.0 91 

8/3/2002 95.0 0 1.4 7.5 80.0 104 9/22/2002 9.5 0 .2 1.1 21.0 91 

8/4/2002 69.0 0 1.3 7.2 73.0 104 9/23/2002 7.2 0 .2 1.1 18.0 91 

8/5/2002 51.0 0 1.1 6.9 69.0 105 9/24/2002 5.9 0 .2 1.0 16.0 90 

8/6/2002 48.0 0 1.1 6.3 65.0 104 9/25/2002 5.2 0 .2 .9 16.0 90 

8/7/2002 44.0 0 .9 5.7 62.0 104 9/26/2002 4.7 0 .2 .9 16.0 89 

8/8/2002 43.0 0 .9 5.4 59.0 104 9/27/2002 4.3 0 .2 .9 14.0 87 

8/9/2002 49.0 0 .9 5.2 66.0 104 9/28/2002 3.8 0 .1 .8 13.0 85 

8/10/2002 45.0 0 .9 4.9 59.0 104 9/29/2002 3.8 0 .1 .9 12.0 85 

8/11/2002 43.0 0 .8 4.8 63.0 103 9/30/2002 3.6 0 .1 .9 12.0 85 

8/12/2002 38.0 0 .7 4.5 58.0 103 10/1/2002 3.5 0 .1 .8 11.0 85 

8/13/2002 35.0 0 .6 4.1 49.0 102 10/2/2002 3.5 0 .1 .8 9.6 85 

8/14/2002 31.0 0 .6 3.8 44.0 102 10/3/2002 3.2 0 .1 .8 9.3 85 

8/15/2002 27.0 0 .5 3.7 41.0 102 10/4/2002 3.2 0 .1 .7 9.4 85 

8/16/2002 25.0 0 .5 3.4 39.0 101 10/5/2002 2.9 0 .1 .7 8.4 84 

8/17/2002 23.0 0 .4 3.1 36.0 101 10/6/2002 2.7 0 .1 .6 8.4 84 

8/18/2002 21.0 0 .4 2.9 34.0 100 10/7/2002 2.6 0 .1 .9 8.1 84 

8/19/2002 19.0 0 .4 2.7 32.0 100 10/8/2002 3.0 0 .1 .8 38.0 84 

8/20/2002 17.0 0 .4 2.5 30.0 99 10/9/2002 6.9 0 .1 1.7 73.0 85 

8/21/2002 16.0 0 .4 2.4 27.0 99 10/10/2002 21.0 0 .1 1.1 39.0 84 

8/22/2002 15.0 0 .3 2.2 26.0 98 10/11/2002 16.0 0 .1 .6 24.0 84 

8/23/2002 13.0 0 .3 2.1 24.0 98 10/12/2002 11.0 0 .1 .7 19.0 83 

8/24/2002 12.0 0 .3 1.9 23.0 97 10/13/2002 8.1 0 .1 .6 18.0 83 

8/25/2002 11.0 0 .3 1.8 21.0 98 10/14/2002 7.0 0 .1 .7 18.0 82 

8/26/2002 11.0 0 .3 1.6 18.0 97 10/15/2002 6.5 0 .1 .7 18.0 82 

8/27/2002 10.0 0 .2 1.4 16.0 96 10/16/2002 6.2 0 .1 .6 15.0 81 

8/28/2002 8.6 0 .2 1.4 15.0 96 10/17/2002 6.0 0 .1 .6 14.0 81 

8/29/2002 8.8 0 .3 2.2 19.0 96 10/18/2002 6.1 0 .1 .6 14.0 80 

8/30/2002 9.0 0 .2 1.7 25.0 95 10/19/2002 31.0 8.5 .5 10.0 183.0 82 

8/31/2002 11.0 0 .2 1.5 23.0 95 10/20/2002 74.0 0 .3 4.9 102.0 85 
Appendix 2 149 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

10/21/2002 40.0 0 0.2 2.7 47.0 85 12/10/2002 289.0 11.0 31.0 38.0 279.0 105 

10/22/2002 45.0 0 .5 4.8 72.0 86 12/11/2002 203.0 2.0 25.0 35.0 245.0 106 

10/23/2002 79.0 0 .7 7.1 93.0 87 12/12/2002 203.0 4.6 29.0 38.0 246.0 106 

10/24/2002 185.0 5.4 13.0 37.0 309.0 89 12/13/2002 220.0 1.0 25.0 34.0 246.0 106 

10/25/2002 269.0 .1 12.0 20.0 322.0 92 12/14/2002 182.0 .1 21.0 31.0 229.0 107 

10/26/2002 148.0 0 8.0 21.0 244.0 92 12/15/2002 167.0 0 19.0 29.0 222.0 108 

10/27/2002 123.0 0 5.4 19.0 230.0 92 12/16/2002 157.0 0 17.0 27.0 217.0 108 

10/28/2002 113.0 0 4.9 18.0 213.0 92 12/17/2002 148.0 0 16.0 26.0 212.0 108 

10/29/2002 102.0 0 4.5 16.0 198.0 92 12/18/2002 139.0 0 15.0 24.0 206.0 108 

10/30/2002 90.0 0 3.9 15.0 179.0 93 12/19/2002 127.0 0 14.0 22.0 194.0 108 

10/31/2002 79.0 0 3.6 14.0 163.0 93 12/20/2002 114.0 0 13.0 20.0 184.0 108 

11/1/2002 75.0 0 3.5 14.0 155.0 93 12/21/2002 109.0 0 13.0 19.0 180.0 108 

11/2/2002 76.0 0 5.6 15.0 160.0 94 12/22/2002 106.0 0 11.0 18.0 173.0 108 

11/3/2002 106.0 0 11.0 18.0 200.0 95 12/23/2002 146.0 3.2 15.0 20.0 198.0 109 

11/4/2002 164.0 17.0 31.0 39.0 257.0 97 12/24/2002 149.0 0 13.0 18.0 188.0 111 

11/5/2002 286.0 10.0 33.0 38.0 298.0 100 12/25/2002 122.0 0 12.0 17.0 169.0 111 

11/6/2002 201.0 .3 23.0 31.0 243.0 101 12/26/2002 114.0 0 11.0 16.0 162.0 111 

11/7/2002 169.0 0 19.0 28.0 226.0 101 12/27/2002 110.0 0 9.7 15.0 156.0 110 

11/8/2002 151.0 0 17.0 26.0 214.0 101 12/28/2002 103.0 0 8.7 15.0 150.0 110 

11/9/2002 136.0 0 15.0 24.0 203.0 101 12/29/2002 100.0 0 8.7 15.0 149.0 110 

11/10/2002 126.0 0 14.0 22.0 191.0 98 12/30/2002 109.0 0 9.8 14.0 153.0 110 

11/11/2002 114.0 0 13.0 21.0 174.0 98 12/31/2002 218.0 0 11.0 15.0 222.0 110 

11/12/2002 105.0 0 11.0 18.0 161.0 98 1/1/2003 146.0 0 8.4 14.0 170.0 110 

11/13/2002 96.0 0 10.0 17.0 154.0 97 1/2/2003 120.0 0 5.8 13.0 154.0 109 

11/14/2002 90.0 0 9.7 17.0 148.0 96 1/3/2003 109.0 0 5.5 11.0 148.0 107 

11/15/2002 84.0 0 8.5 16.0 140.0 97 1/4/2003 110.0 0 5.3 11.0 144.0 107 

11/16/2002 77.0 0 6.7 15.0 131.0 97 1/5/2003 107.0 0 5.1 10.0 140.0 107 

11/17/2002 72.0 0 5.9 14.0 124.0 98 1/6/2003 107.0 0 4.7 10.0 135.0 107 

11/18/2002 69.0 0 5.0 14.0 119.0 99 1/7/2003 94.0 0 4.2 9.6 130.0 107 

11/19/2002 65.0 0 4.7 13.0 111.0 98 1/8/2003 91.0 0 4.1 9.4 129.0 107 

11/20/2002 62.0 0 4.4 13.0 107.0 98 1/9/2003 90.0 0 4.0 9.1 126.0 108 

11/21/2002 58.0 0 4.0 12.0 103.0 98 1/10/2003 85.0 0 3.4 8.5 116.0 107 

11/22/2002 55.0 0 3.8 11.0 99.0 97 1/11/2003 84.0 0 3.8 8.6 116.0 107 

11/23/2002 53.0 0 3.6 11.0 95.0 98 1/12/2003 172.0 6.5 16.0 18.0 181.0 109 

11/24/2002 51.0 0 3.5 10.0 94.0 98 1/13/2003 233.0 1.5 16.0 15.0 183.0 109 

11/25/2002 49.0 0 3.2 10.0 88.0 99 1/14/2003 183.0 .4 15.0 14.0 163.0 109 

11/26/2002 68.0 0 5.4 13.0 117.0 99 1/15/2003 164.0 .1 14.0 13.0 159.0 109 

11/27/2002 110.0 0 5.5 11.0 119.0 100 1/16/2003 155.0 0 13.0 13.0 156.0 109 

11/28/2002 72.0 0 3.7 10.0 96.0 100 1/17/2003 147.0 0 12.0 12.0 147.0 109 

11/29/2002 63.0 0 3.4 10.0 90.0 100 1/18/2003 139.0 0 11.0 12.0 147.0 109 

11/30/2002 59.0 0 3.2 9.6 86.0 100 1/19/2003 133.0 0 10.0 11.0 143.0 109 

12/1/2002 55.0 0 2.9 8.6 80.0 101 1/20/2003 129.0 0 9.5 11.0 141.0 109 

12/2/2002 51.0 0 2.9 8.5 78.0 101 1/21/2003 125.0 0 8.6 10.0 139.0 110 

12/3/2002 52.0 0 3.1 9.1 83.0 101 1/22/2003 115.0 0 6.4 9.4 130.0 110 

12/4/2002 58.0 0 3.7 10.0 90.0 101 1/23/2003 107.0 0 5.1 8.8 122.0 110 

12/5/2002 58.0 0 3.4 9.5 82.0 102 1/24/2003 95.0 0 5.2 8.5 119.0 110 

12/6/2002 52.0 0 3.2 9.0 79.0 102 1/25/2003 92.0 0 5.2 8.7 120.0 110 

12/7/2002 51.0 0 3.1 8.7 78.0 101 1/26/2003 95.0 0 6.2 8.9 120.0 110 

12/8/2002 51.0 0 3.4 9.3 80.0 101 1/27/2003 90.0 0 5.2 8.6 114.0 110 

12/9/2002 254.0 38.0 55.0 88.0 367.0 105 1/28/2003 88.0 0 5.0 8.5 113.0 110 
150 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Barton Williamson Slaughter Bear Onion Barton Date Date Creek Creek Creek Creek Creek Springs Creek Creek Creek Creek Creek Springs 

1/29/2003 83.0 0 4.6 8.2 109.0 110 3/20/2003 98.0 0 5.2 10.0 126.0 114 

1/30/2003 79.0 0 4.1 7.8 104.0 110 3/21/2003 94.0 0 4.9 9.5 119.0 114 

1/31/2003 77.0 0 4.0 7.6 102.0 110 3/22/2003 91.0 0 4.8 9.3 117.0 114 

2/1/2003 73.0 0 4.0 7.3 99.0 110 3/23/2003 90.0 0 4.3 8.8 115.0 114 

2/2/2003 72.0 0 4.1 6.6 98.0 110 3/24/2003 85.0 0 4.0 8.4 109.0 113 

2/3/2003 70.0 0 3.7 5.3 96.0 110 3/25/2003 82.0 0 3.9 8.3 106.0 114 

2/4/2003 67.0 0 3.4 4.8 90.0 110 3/26/2003 81.0 0 3.7 8.0 104.0 114 

2/5/2003 64.0 0 3.4 4.9 89.0 110 3/27/2003 78.0 0 3.5 7.6 100.0 114 

2/6/2003 69.0 0 4.7 5.6 98.0 111 3/28/2003 75.0 0 3.3 7.1 95.0 114 

2/7/2003 69.0 0 3.8 4.8 91.0 110 3/29/2003 69.0 0 3.0 6.6 88.0 113 

2/8/2003 66.0 0 3.7 4.8 88.0 110 3/30/2003 66.0 0 2.8 6.4 86.0 113 

2/9/2003 67.0 0 3.7 4.7 90.0 110 3/31/2003 64.0 0 2.8 6.1 84.0 113 

2/10/2003 61.0 0 3.3 4.1 85.0 110 4/1/2003 64.0 0 2.7 5.7 81.0 113 

2/11/2003 57.0 0 3.1 3.9 82.0 110 4/2/2003 62.0 0 2.6 5.6 80.0 112 

2/12/2003 57.0 0 3.1 3.9 81.0 110 4/3/2003 61.0 0 2.5 5.5 78.0 112 

2/13/2003 56.0 0 3.2 4.1 81.0 110 4/4/2003 60.0 0 2.3 5.3 75.0 111 

2/14/2003 57.0 0 3.4 4.1 83.0 110 4/5/2003 60.0 0 2.2 5.1 72.0 111 

2/15/2003 56.0 0 3.1 4.6 81.0 109 4/6/2003 56.0 0 2.2 5.0 69.0 111 

2/16/2003 52.0 0 2.8 5.0 74.0 109 4/7/2003 54.0 0 2.0 4.9 67.0 111 

2/17/2003 48.0 0 2.8 5.0 72.0 109 4/8/2003 51.0 0 1.7 4.5 61.0 110 

2/18/2003 46.0 0 2.8 5.0 74.0 109 4/9/2003 49.0 0 1.7 4.3 58.0 110 

2/19/2003 46.0 0 2.8 5.2 74.0 109 4/10/2003 47.0 0 1.7 4.3 56.0 110 

2/20/2003 537.0 69.0 81.0 162.0 630.0 111 4/11/2003 47.0 0 1.6 4.2 56.0 110 

2/21/2003 566.0 60.0 87.0 59.0 385.0 120 4/12/2003 44.0 0 1.5 4.0 53.0 109 

2/22/2003 454.0 31.0 56.0 46.0 314.0 125 4/13/2003 42.0 0 1.4 3.8 51.0 109 

2/23/2003 345.0 13.0 34.0 37.0 268.0 125 4/14/2003 39.0 0 1.3 3.7 49.0 109 

2/24/2003 294.0 6.9 26.0 33.0 252.0 125 4/15/2003 36.0 0 1.3 3.7 46.0 109 

2/25/2003 282.0 7.5 26.0 32.0 251.0 125 4/16/2003 36.0 0 1.2 3.6 45.0 108 

2/26/2003 265.0 5.7 26.0 31.0 246.0 124 4/17/2003 34.0 0 1.1 3.6 42.0 108 

2/27/2003 274.0 5.8 27.0 30.0 246.0 123 4/18/2003 33.0 0 1.1 3.5 42.0 106 

2/28/2003 254.0 2.2 23.0 27.0 236.0 122 4/19/2003 32.0 0 1.1 3.5 42.0 102 

3/1/2003 242.0 1.3 22.0 26.0 231.0 121 4/20/2003 31.0 0 1.0 3.5 41.0 103 

3/2/2003 228.0 1.0 20.0 25.0 225.0 120 4/21/2003 30.0 0 .9 3.3 37.0 103 

3/3/2003 228.0 1.8 21.0 25.0 224.0 119 4/22/2003 29.0 0 .9 3.4 35.0 103 

3/4/2003 234.0 1.2 20.0 24.0 222.0 118 4/23/2003 28.0 0 .9 3.5 36.0 103 

3/5/2003 214.0 .7 18.0 22.0 213.0 117 4/24/2003 28.0 0 .8 3.3 35.0 104 

3/6/2003 198.0 .4 16.0 21.0 205.0 116 4/25/2003 26.0 0 .7 2.9 31.0 104 

3/7/2003 179.0 .2 15.0 19.0 197.0 116 4/26/2003 24.0 0 .6 2.7 28.0 104 

3/8/2003 169.0 .1 14.0 18.0 192.0 116 4/27/2003 23.0 0 .6 2.6 26.0 104 

3/9/2003 166.0 0 13.0 17.0 188.0 116 4/28/2003 21.0 0 .6 2.4 25.0 103 

3/10/2003 157.0 0 12.0 17.0 181.0 116 4/29/2003 20.0 0 .6 2.4 24.0 103 

3/11/2003 151.0 0 12.0 16.0 176.0 115 4/30/2003 20.0 0 .6 2.3 24.0 103 

3/12/2003 142.0 0 12.0 16.0 174.0 115 5/1/2003 19.0 0 .5 2.2 23.0 103 

3/13/2003 134.0 0 11.0 15.0 167.0 115 5/2/2003 18.0 0 .5 2.1 21.0 103 

3/14/2003 129.0 0 10.0 14.0 160.0 115 5/3/2003 18.0 0 .5 2.0 20.0 103 

3/15/2003 118.0 0 9.4 13.0 155.0 115 5/4/2003 17.0 0 .5 1.9 21.0 103 

3/16/2003 116.0 0 8.6 12.0 151.0 115 5/5/2003 16.0 0 .4 1.8 20.0 103 

3/17/2003 113.0 0 8.0 11.0 146.0 116 5/6/2003 16.0 0 .4 1.7 18.0 102 

3/18/2003 118.0 0 8.7 11.0 144.0 116 5/7/2003 15.0 0 .4 1.7 18.0 102 

3/19/2003 106.0 0 6.9 10.0 136.0 115 5/8/2003 15.0 0 .4 1.6 17.0 102 
Appendix 2 151
 

Appendix 2. Daily mean streamflow for the five creeks providing recharge to the Barton Springs segment of the Edwards aquifer and 

daily mean discharge for Barton Springs, Austin, Texas, 1978–2003—Continued. 

Barton Williamson Slaughter Bear Onion Barton Date Creek Creek Creek Creek Creek Springs 

5/9/2003 14.0 0 0.3 1.4 15.0 102
 

5/10/2003 13.0 0 .3 1.3 13.0 102
 

5/11/2003 12.0 0 .3 1.3 12.0 102
 

5/12/2003 12.0 0 .3 1.3 12.0 102
 

5/13/2003 11.0 0 .3 1.3 12.0 102
 

5/14/2003 10.0 0 .3 1.1 11.0 102
 

5/15/2003 9.4 0 .2 1.0 9.9 101
 

5/16/2003 8.7 0 .2 .9 8.7 101
 

5/17/2003 7.7 0 .2 .8 7.5 101
 

5/18/2003 6.9 0 .2 .8 7.2 101
 

5/19/2003 6.1 0 .1 .8 7.2 101
 

5/20/2003 5.6 0 .1 .7 6.7 99
 

5/21/2003 5.3 0 .1 .7 6.1 98
 

5/22/2003 5.1 0 .1 .7 5.9 98
 

5/23/2003 5.0 0 .1 .7 5.6 97
 

5/24/2003 4.7 0 .1 .6 5.4 97
 

5/25/2003 4.6 0 .1 .6 5.2 97
 

5/26/2003 8.2 0 .1 .6 6.0 97
 

5/27/2003 14.0 0 .1 .6 5.6 97
 

5/28/2003 9.4 0 .1 .5 5.5 97
 

5/29/2003 8.1 0 .1 .5 5.2 97
 

5/30/2003 6.7 0 .1 .5 5.0 97
 

5/31/2003 5.3 0 .1 .4 4.6 97
 
Blank Page 
Appendix 3—Results of Statistical 

Correlation Tests 
Blank Page 
Appendix 3. Results of Spearman’s rho correlation tests for samples from wells in the Barton Springs segment of the Edwards aquifer,

Austin, Texas, 1978–2003—Continued.

Specific Conductance, 

and Associated Major 

Ion and Nitrate

Geochemistry, Edwards 

Aquifer, Austin, Texas, 

1978–2003

Appendix 3

Appendix 3 155 

Appendix 3. Results of Spearman’s rho correlation tests for samples from wells in the Barton Springs segment of the Edwards aquifer, 

Austin, Texas, 1978–2003. 

[Bold—significant correlation, p < .05] 

Well Num- Well Num­ Specific conductance Spearman’s Specific conductance Spearman’s identifier 

compared to 

ber of rho p-value identifier 

compared to ber of rho p-value 

(fig. 1) samples (fig. 1) samples 

BCK Barton Springs discharge 6 -0.35 .50 HND Onion Creek streamflow 14 -0.44 .11 

BCK Barton Creek streamflow 5 -.56 .32 HND Slaughter Creek streamflow 15 -.14 .63 

BCK Bear Creek streamflow 5 -.10 .87 HND Williamson Creek streamflow 15 -.34 .22 

BCK Onion Creek streamflow 5 -.30 .62 HWD Barton Springs discharge 6 -.52 .29 

BCK Slaughter Creek streamflow 6 -.22 .67 HWD Barton Creek streamflow 5 -.67 .22 

BCK Williamson Creek streamflow 6 .18 .74 HWD Bear Creek streamflow 5 -.90 .04

BDW Barton Springs discharge 22 -.20 .38 HWD Onion Creek streamflow 5 -.70 .19 

BDW Barton Creek streamflow 22 -.39 .07 HWD Slaughter Creek streamflow 6 -.61 .20 

BDW Bear Creek streamflow 22 -.47 .03 HWD Williamson Creek streamflow 6 -.76 .08 

BDW Onion Creek streamflow 22 -.38 .08 ISD Barton Springs discharge 6 -.49 .33 

BDW Slaughter Creek streamflow 22 -.37 .09 ISD Barton Creek streamflow 4 -.80 .20 

BDW Williamson Creek streamflow 22 -.23 .31 ISD Bear Creek streamflow 5 -.20 .75 

BPS Barton Springs discharge 52 .14 .33 ISD Onion Creek streamflow 5 -.20 .75 

BPS Barton Creek streamflow 31 .10 .61 ISD Slaughter Creek streamflow 6 -.46 .35 

BPS Bear Creek streamflow 50 -.07 .64 ISD Williamson Creek streamflow 6 -.27 .60 

BPS Onion Creek streamflow 50 0 .98 JBS Barton Springs discharge 13 .16 .60 

BPS Slaughter Creek streamflow 52 -.03 .85 JBS Barton Creek streamflow 8 .07 .86 

BPS Williamson Creek streamflow 52 -.07 .62 JBS Bear Creek streamflow 12 .20 .53 

CNE Barton Springs discharge 6 .14 .78 JBS Onion Creek streamflow 12 .24 .46 

CNE Barton Creek streamflow 4 .20 .80 JBS Slaughter Creek streamflow 13 .32 .29 

CNE Bear Creek streamflow 5 .56 .32 JBS Williamson Creek streamflow 13 .27 .37 

CNE Onion Creek streamflow 5 .56 .32 KCH Barton Springs discharge 60 -.39 0

CNE Slaughter Creek streamflow 6 .75 .08 KCH Barton Creek streamflow 45 .01 .96 

CNE Williamson Creek streamflow 6 .79 .06 KCH Bear Creek streamflow 59 -.20 .14 

FMW Barton Springs discharge 31 -.72 0 KCH Onion Creek streamflow 59 -.47 0

FMW Barton Creek streamflow 18 -.44 .07 KCH Slaughter Creek streamflow 60 -.26 .05

FMW Bear Creek streamflow 31 -.32 .08 KCH Williamson Creek streamflow 60 -.05 .71 

FMW Onion Creek streamflow 31 -.48 .01 LWK Barton Springs discharge 6 .88 .02

FMW Slaughter Creek streamflow 31 -.55 0 LWK Barton Creek streamflow 5 .56 .32 

FMW Williamson Creek streamflow 31 -.15 .41 LWK Bear Creek streamflow 5 .78 .12 

FOW Barton Springs discharge 42 .32 .04 LWK Onion Creek streamflow 5 .78 .12 

FOW Barton Creek streamflow 29 .50 .01 LWK Slaughter Creek streamflow 6 .25 .64 

FOW Bear Creek streamflow 41 .14 .40 LWK Williamson Creek streamflow 6 0 1.00 

FOW Onion Creek streamflow 41 .21 .20 MCH Barton Springs discharge 47 -.12 .43 

FOW Slaughter Creek streamflow 42 .28 .07 MCH Barton Creek streamflow 31 -.46 .01

FOW Williamson Creek streamflow 42 .19 .24 MCH Bear Creek streamflow 45 -.44 0

GHW Barton Springs discharge 24 .41 .05 MCH Onion Creek streamflow 46 -.42 0

GHW Barton Creek streamflow 8 .48 .23 MCH Slaughter Creek streamflow 47 -.43 0

GHW Bear Creek streamflow 23 .40 .06 MCH Williamson Creek streamflow 47 -.42 0

GHW Onion Creek streamflow 23 .34 .12 PLS Barton Springs discharge 31 .07 .70 

GHW Slaughter Creek streamflow 24 .25 .25 PLS Barton Creek streamflow 27 .02 .93 

GHW Williamson Creek streamflow 24 .33 .11 PLS Bear Creek streamflow 31 -.02 .93 

HND Barton Springs discharge 15 .30 .28 PLS Onion Creek streamflow 31 -.09 .64 

HND Barton Creek streamflow 4 .80 .20 PLS Slaughter Creek streamflow 31 -.09 .65 

HND Bear Creek streamflow 14 -.32 .27 PLS Williamson Creek streamflow 31 -.17 .37 
156 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 3. Results of Spearman’s rho correlation tests for samples from wells in the Barton Springs segment of the Edwards aquifer, 

Austin, Texas, 1978–2003—Continued. 

Well Num- Well Numidentifier Specific conductance ber of Spearman’s 

p-value identifier Specific conductance ber of Spearman’s 

p-value 

(fig. 1) compared to 

samples 

rho (fig. 1) compared to 

samples 

rho 

RAB Barton Springs discharge 15 0.18 .52 SVW Onion Creek streamflow 63 -0.31 .01

RAB Barton Creek streamflow 15 .10 .72 SVW Slaughter Creek streamflow 64 -.41 0

RAB Bear Creek streamflow 15 -.01 .98 SVW Williamson Creek streamflow 64 -.28 .03

RAB Onion Creek streamflow 15 -.20 .46 TNR Barton Springs discharge 26 .25 .22 

RAB Slaughter Creek streamflow 15 .01 .98 TNR Barton Creek streamflow 10 .07 .85 

RAB Williamson Creek streamflow 15 .40 .14 TNR Bear Creek streamflow 25 .06 .77 

ROL Barton Springs discharge 39 .46 0 TNR Onion Creek streamflow 25 .21 .32 

ROL Barton Creek streamflow 24 .53 .01 TNR Slaughter Creek streamflow 26 0 .98 

ROL Bear Creek streamflow 38 .25 .14 TNR Williamson Creek streamflow 26 -.13 .53 

ROL Onion Creek streamflow 38 .30 .07 WBG Barton Springs discharge 6 .43 .40 

ROL Slaughter Creek streamflow 39 .33 .04 WBG Barton Creek streamflow 4 -.20 .80 

ROL Williamson Creek streamflow 39 .16 .33 WBG Bear Creek streamflow 4 -.40 .60 

SLR Barton Springs discharge 18 -.63 .01 WBG Onion Creek streamflow 5 -.40 .50 

SLR Barton Creek streamflow 5 -.80 .10 WBG Slaughter Creek streamflow 6 .09 .87 

SLR Bear Creek streamflow 16 -.63 .01 WBG Williamson Creek streamflow 6 .21 .69 

SLR Onion Creek streamflow 17 -.41 .10 WGF Barton Springs discharge 6 .94 0

SLR Slaughter Creek streamflow 18 -.44 .07 WGF Barton Creek streamflow 5 .80 .10 

SLR Williamson Creek streamflow 18 -.17 .50 WGF Bear Creek streamflow 5 .60 .28 

SNL Barton Springs discharge 6 .38 .46 WGF Onion Creek streamflow 5 .67 .22 

SNL Barton Creek streamflow 5 .10 .87 WGF Slaughter Creek streamflow 6 .72 .10 

SNL Bear Creek streamflow 5 -.30 .62 WGF Williamson Creek streamflow 6 .29 .58 

SNL Onion Creek streamflow 5 -.21 .74 

SNL Slaughter Creek streamflow 6 .20 .70 

SNL Williamson Creek streamflow 6 .20 .70 

SVE Barton Springs discharge 48 -.69 0

SVE Barton Creek streamflow 34 -.50 0

SVE Bear Creek streamflow 47 -.39 .01

SVE Onion Creek streamflow 47 -.40 .01

SVE Slaughter Creek streamflow 48 -.44 0

SVE Williamson Creek streamflow 48 -.15 .30 

SVN Barton Springs discharge 34 .02 .93 

SVN Barton Creek streamflow 23 -.50 .01

SVN Bear Creek streamflow 33 -.35 .04

SVN Onion Creek streamflow 33 -.41 .02

SVN Slaughter Creek streamflow 34 -.54 0

SVN Williamson Creek streamflow 34 -.63 0

SVS Barton Springs discharge 50 .29 .04

SVS Barton Creek streamflow 35 -.07 .67 

SVS Bear Creek streamflow 49 -.10 .49 

SVS Onion Creek streamflow 49 -.10 .49 

SVS Slaughter Creek streamflow 50 0 .98 

SVS Williamson Creek streamflow 50 -.23 .11 

SVW Barton Springs discharge 64 -.05 .68 

SVW Barton Creek streamflow 49 -.39 .01

SVW Bear Creek streamflow 63 -.47 0
Appendix 4—Major Ion and Nitrate Water 

Analysis Data 
Blank Page 
Specific Conductance, and 

Associated Major Ion and Nitrate 

Geochemistry, Edwards Aquifer, 

Austin, Texas, 1978–2003

Appendix 4

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards

aquifer, Austin, Texas, 1978–2003—Continued.

Appendix 4 159 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003. 

[μS/cm, microsiemens per centimeter at 25 degrees Celsius; Ca, calcium; mg/L, milligrams per liter; Mg, magnesium; Na, sodium; K, potassium; HCO3, 

bicarbonate; Cl, chloride; SO4, sulfate; NO3, nitrate; N, nitrogen; --, no data. Incomplete water analyses were excluded from this dataset (ignoring nitrate). 

Analyses with charge balance errors greater than 5 percent were excluded.] 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

BCK 8/28/1980 1000 7.1 659 67 34 6.3 2.1 331 8.5 50.0 0.2 

BCK 8/11/1981 0830 7.2 538 70 30 4.6 1.0 366 7.5 1.0 .8 

BCK 8/10/1982 0920 6.8 618 64 33 6.5 2.1 329 8.6 58.0 .4 

BDW 3/19/1991 1020 7.1 565 85 25 6.8 .8 366 12.0 7.3 1.1 

BDW 1/22/1993 1220 6.8 590 88 21 6.0 .6 366 10.0 6.7 -­

BDW 1/25/1993 1342 6.8 589 88 21 6.0 .6 366 10.0 7.0 -­
 

BDW 8/18/1993 1200 6.8 594 96 20 6.1 .6 354 9.4 7.0 1.6
 

BDW 4/15/1994 1000 7.0 591 90 20 6.1 .6 366 10.0 7.3 1.6
 

BDW 6/14/1995 1055 7.2 590 83 27 5.8 .8 366 9.3 6.6 1.1
 

BDW 4/25/1996 0930 7.3 582 92 21 6.0 .6 342 9.9 6.5 

BDW 7/8/1997 1615 7.2 585 75 27 5.9 .7 329 10.1 6.5 1.3 

BDW 4/21/1998 1130 7.1 587 80 31 6.0 .8 366 10.2 7.2 1.4 

BDW 6/11/1999 0945 7.0 595 88 18 5.5 .6 342 10.9 7.0 1.5 

BDW 6/2/2000 1300 7.0 591 88 19 5.6 .6 354 9.2 6.8 1.4 

BDW 6/5/2001 1300 7.0 595 79 27 6.0 .8 364 9.3 6.9 

BDW 6/5/2002 1300 7.0 606 90 20 5.7 .6 362 9.6 7.3 1.3 

BDW 5/20/2003 1300 7.1 577 76 26 5.5 .8 348 9.4 5.8 1.0 

BPS 8/24/1979 1410 7.0 588 73 26 6.1 1.2 331 11.0 31.0 1.4 

BPS 8/1/1980 1315 7.1 583 72 25 6.1 1.2 331 9.6 22.0 1.6 

BPS 8/29/1980 0815 7.6 578 73 26 6.4 1.0 331 11.0 27.0 

BPS 7/30/1981 1400 7.0 583 74 26 6.5 1.2 329 10.0 28.0 .1 

BPS 8/12/1981 0810 7.3 568 74 25 5.9 1.3 342 10.0 25.0 1.2 

BPS 7/19/1982 1130 7.0 586 75 25 6.4 1.2 329 11.0 23.0 1.5 

BPS 7/22/1983 1215 7.8 539 76 26 6.5 1.3 329 12.0 27.0 1.4 

BPS 2/20/1985 1159 7.8 586 77 25 6.1 1.2 329 11.0 25.0 

BPS 8/9/1985 1345 7.4 598 74 25 6.1 1.2 333 11.0 25.0 1.4 

BPS 1/14/1986 0845 7.2 579 75 26 6.6 1.1 338 11.0 24.0 1.4 

BPS 6/24/1986 1420 7.4 591 75 25 6.4 1.2 326 9.0 27.0 1.5 

BPS 9/3/1986 0849 7.2 589 75 26 6.7 1.1 337 11.0 26.0 1.4 

BPS 2/11/1987 0930 7.1 588 76 26 6.4 1.1 337 12.0 27.0 

BPS 8/19/1987 1335 7.1 605 76 26 6.5 1.2 346 10.0 27.0 1.4 

BPS 2/29/1988 0845 7.0 589 77 26 6.4 1.3 340 11.0 26.0 1.4 

BPS 8/17/1988 0955 7.3 597 74 26 6.2 1.1 331 11.0 27.0 1.4 

BPS 2/27/1989 1520 7.1 596 73 26 6.3 1.2 332 9.9 27.0 1.3 

BPS 7/17/1989 1240 7.1 563 75 26 6.4 1.2 343 10.0 24.0 

BPS 8/29/1989 1145 7.0 581 78 26 6.5 1.1 338 9.6 25.0 1.3 

BPS 1/29/1990 1320 6.9 585 72 25 6.2 1.2 328 10.0 26.0 1.3 

BPS 8/14/1990 1355 7.1 566 76 26 6.4 1.1 342 13.0 25.0 1.2 

BPS 3/22/1991 0825 7.2 586 76 24 5.9 1.3 329 9.9 27.0 1.2 

BPS 4/30/1992 1240 6.9 589 81 24 6.0 1.2 342 13.0 28.0 

BPS 8/28/1992 1100 7.2 584 77 24 6.4 1.3 342 14.0 27.0 1.4 

BPS 8/19/1993 1220 7.4 539 76 25 6.3 1.1 342 10.0 26.0 1.3 

BPS 8/20/1993 0805 7.0 579 79 25 6.6 1.2 329 10.0 26.0 1.4 

BPS 4/14/1994 1215 7.1 578 74 24 5.9 1.2 317 10.0 25.0 1.3 

BPS 6/14/1995 0930 7.2 585 78 25 6.3 1.2 329 11.0 23.0 

1.6 

1.1 

.3 

1.4 

1.4 

1.3 

1.3 

1.3 
160 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

BPS 5/9/1996 0900 7.2 576 76 26 6.3 1.1 317 11.0 25.0 0.8 

BPS 7/8/1997 1435 7.2 575 72 24 6.2 1.2 317 10.7 23.6 1.3 

BPS 4/22/1998 0830 7.1 565 80 23 5.9 1.1 329 10.4 23.8 1.4 

BPS 6/11/1999 0800 7.0 591 74 24 6.4 1.1 329 12.3 25.1 1.3 

BPS 6/2/2000 1500 7.1 592 74 24 6.2 1.1 329 10.9 25.4 

BPS 6/12/2001 1100 7.1 593 77 24 6.5 1.3 333 10.3 25.3 1.3 

BPS 6/6/2002 1100 7.1 596 75 24 6.3 1.1 343 11.3 25.0 1.3 

CNE 7/24/1978 1015 7.3 1,040 65 41 93.0 7.8 290 96.0 160.0 0 

CNE 9/4/1980 0900 7.5 1,030 61 39 99.0 7.9 293 98.0 170.0 0 

CNE 8/12/1981 1230 7.8 996 59 38 92.0 8.2 281 92.0 170.0 

CNE 8/11/1982 0930 7.7 1,020 59 39 98.0 7.3 281 91.0 180.0 .1 

CNE 7/21/1983 1425 7.6 1,060 59 38 97.0 7.4 281 93.0 170.0 .1 

FMW 8/11/1981 0950 7.2 531 82 19 4.6 .8 342 7.9 1.0 1.5 

FMW 8/4/1982 1340 6.9 566 80 22 5.6 .6 342 12.0 7.0 1.7 

FMW 7/19/1983 1245 7.0 568 83 23 6.2 .7 342 10.0 7.6 

FMW 8/8/1985 0930 7.1 567 82 22 5.7 .6 350 9.8 5.8 1.7 

FMW 1/15/1986 1235 7.1 545 81 22 5.4 .5 346 12.0 6.2 1.7 

FMW 9/3/1986 1020 7.2 568 83 21 5.7 .6 353 10.0 6.4 1.7 

FMW 2/9/1987 1230 7.4 552 84 19 4.3 .8 348 7.9 5.7 1.7 

FMW 8/18/1987 1410 7.5 564 84 19 4.8 .8 350 7.3 7.1 

FMW 2/25/1988 0910 7.1 573 84 23 6.1 .6 354 11.0 6.7 1.7 

FMW 2/23/1989 1335 6.9 560 82 23 6.2 .6 340 10.0 6.5 1.6 

FMW 8/21/1989 1345 7.3 587 83 23 6.0 .6 356 9.6 6.0 1.5 

FMW 3/5/1991 1320 7.1 571 79 21 5.6 .6 354 11.0 5.4 1.6 

FMW 4/28/1992 1130 7.2 545 81 18 4.6 .7 329 11.0 6.9 

FMW 1/21/1993 1550 6.9 536 81 18 4.3 .8 342 7.3 7.8 -­

FMW 1/24/1993 1215 7.0 537 82 19 4.5 .8 342 7.4 6.9 -­

FMW 1/28/1993 0830 6.8 537 86 19 4.7 .8 342 7.4 6.7 -­

FMW 5/8/1993 0820 7.3 535 86 19 4.5 .8 342 7.1 6.8 

FMW 8/16/1993 1230 7.0 537 87 19 4.4 .8 329 6.6 6.5 

FMW 4/8/1994 0750 7.1 563 79 22 5.7 .6 342 9.8 6.6 1.7 

FOW 6/28/1978 1255 7.2 620 73 35 7.4 1.5 360 15.0 48.0 .7 

FOW 7/10/1979 1340 6.6 620 77 35 7.6 1.2 350 15.0 36.0 1.1 

FOW 8/28/1980 1145 7.2 686 78 35 8.0 1.2 360 15.0 53.0 .1 

FOW 8/11/1981 1055 7.2 595 75 31 7.5 .8 366 16.0 9.0 

FOW 8/10/1982 1115 7.0 595 72 30 8.1 .7 354 16.0 8.0 1.1 

FOW 7/19/1983 1330 7.1 597 75 31 8.1 .8 366 16.0 6.6 1.1 

FOW 8/8/1985 0915 7.0 641 80 37 8.3 1.9 354 15.0 52.0 .7 

FOW 1/14/1986 0700 7.1 624 75 33 8.0 .7 370 20.0 16.0 1.0 

FOW 9/3/1986 0700 7.2 610 75 31 8.9 .8 354 17.0 7.9 

FOW 2/10/1987 1030 7.5 625 76 32 8.4 .9 368 12.0 21.0 1.0 

FOW 8/26/1987 1055 7.3 687 75 37 8.0 1.8 356 14.0 58.0 .8 

FOW 8/17/1988 0905 7.2 705 76 38 7.8 1.9 350 14.0 61.0 .6 

FOW 2/27/1989 1045 6.9 660 77 34 9.0 1.1 368 15.0 28.0 1.0 

FOW 2/9/1990 0930 7.0 658 77 37 8.5 1.8 359 14.0 56.0 

1.1 

0 

1.5 

1.6 

1.3 

1.4 

1.5 

.9 

1.1 

.8 
Appendix 4 161 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

FOW 5/1/1992 1130 6.9 771 84 45 7.1 4.0 342 14.0 150.0 0.2
 

FOW 1/21/1993 1225 6.9 863 80 54 7.5 5.8 342 10.0 190.0 -­
 

FOW 1/24/1993 1015 7.0 895 85 56 8.7 4.7 342 12.0 200.0 -­
 

FOW 5/7/1993 1135 7.3 775 75 48 6.3 4.5 329 8.7 150.0 .1
 

FOW 4/18/1994 1030 6.9 645 78 33 9.2 1.0 366 18.0 30.0 

FOW 6/19/1995 1110 7.1 760 78 42 7.9 3.2 342 13.0 110.0 .5 

FOW 5/7/1996 0845 7.2 635 81 34 9.8 1.0 354 18.0 31.0 1.0 

FOW 7/9/1997 1310 7.0 616 71 30 9.2 .8 329 18.3 12.3 1.1 

FOW 4/23/1998 0730 7.1 652 89 35 9.4 .8 354 18.1 33.7 4.6 

FOW 6/11/1999 1100 7.0 654 75 31 9.4 .9 329 18.8 31.2 

FOW 6/19/2001 1000 7.0 742 77 33 9.7 .9 359 17.9 32.7 1.1 

FOW 6/5/2002 1000 6.9 660 75 31 9.6 .8 357 18.3 17.1 1.2 

FOW 5/21/2003 1000 6.9 747 87 40 10.6 1.7 367 18.5 76.8 1.2 

GHW 7/9/1979 0950 7.2 670 80 37 6.4 1.6 410 13.0 19.0 1.0 

GHW 8/29/1980 1030 7.9 666 78 36 5.5 1.3 410 12.0 14.0 

GHW 8/12/1981 0905 7.2 650 78 37 6.6 1.7 415 16.0 1.0 .7 

GHW 8/16/1982 1015 6.9 666 80 36 6.9 1.3 415 12.0 17.0 .9 

GHW 7/21/1983 0950 7.2 667 88 35 6.9 1.3 415 14.0 16.0 1.1 

GHW 8/9/1985 1245 7.1 648 75 35 6.5 1.5 394 10.0 19.0 .9 

GHW 1/13/1986 1210 7.0 644 76 38 7.0 1.4 416 13.0 15.0 

GHW 9/2/1986 1320 7.3 671 81 36 7.0 1.3 416 12.0 16.0 .9 

GHW 2/11/1987 1315 7.2 672 80 37 6.7 1.5 420 13.0 16.0 .8 

GHW 8/19/1987 1515 7.1 683 81 37 6.8 1.5 403 11.0 17.0 .8 

GHW 2/24/1988 1245 6.9 655 82 38 6.7 1.6 422 12.0 17.0 .9 

GHW 8/10/1988 1115 7.1 635 77 37 6.5 1.4 410 11.0 15.0 

GHW 2/23/1989 0950 7.1 640 82 37 6.7 1.4 404 10.0 16.0 .9 

GHW 8/30/1989 1015 7.1 640 80 36 6.7 1.4 412 11.0 14.0 .8 

HND 7/11/1979 1400 6.6 580 88 21 7.8 1.1 320 15.0 22.0 2.1 

HND 9/8/1980 1330 7.1 559 72 28 6.1 1.1 340 11.0 20.0 .9 

HND 8/11/1981 1440 7.2 589 88 20 8.1 1.1 342 17.0 13.0 

HND 8/10/1982 1430 7.1 575 72 28 6.5 1.1 342 12.0 19.0 .9 

HND 7/20/1983 1330 7.4 475 69 17 6.8 1.2 268 10.0 18.0 .6 

HND 8/8/1985 1130 7.1 580 89 21 7.8 1.1 351 13.0 22.0 1.6 

HND 1/13/1986 1020 7.0 575 83 22 7.8 1.3 340 14.0 17.0 1.5 

HND 9/3/1986 1140 7.2 600 84 23 8.1 1.2 338 14.0 20.0 

HND 2/11/1987 1145 7.2 607 89 19 8.1 1.3 348 12.0 20.0 2.0 

HWD 7/9/1979 1310 7.1 560 77 22 6.0 .9 331 12.0 17.0 1.5 

HWD 8/28/1980 1115 7.1 575 79 21 6.4 .9 331 10.0 13.0 1.7 

HWD 8/18/1981 1415 7.2 551 79 23 6.9 1.1 342 18.0 1.0 1.6 

HWD 8/4/1982 1250 7.1 563 79 24 6.6 .9 329 11.0 12.0 

HWD 7/22/1983 0950 7.5 553 85 23 6.7 .9 342 13.0 12.0 1.6 

ISD 7/11/1979 0820 6.9 480 48 25 4.8 1.2 220 8.0 21.0 .4 

ISD 9/4/1980 1154 7.3 487 56 27 5.4 1.0 300 9.6 15.0 .6 

ISD 8/12/1981 1340 7.3 482 55 27 5.5 1.1 293 8.9 15.0 .4 

ISD 8/11/1982 1035 7.0 495 53 27 5.8 1.0 293 9.0 17.0 

1.1 

1.2 

0 

.8 

.8 

1.8 

2.1 

1.5 

.5 
162 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

ISD 7/22/1983 1130 7.8 489 56 28 5.6 1.2 293 9.0 16.0 0.5 

JBS 7/16/1979 1440 6.7 580 90 20 8.0 1.2 320 14.0 32.0 1.7 

JBS 8/27/1980 1115 7.4 587 86 20 8.4 1.1 320 13.0 26.0 .6 

JBS 8/4/1981 0955 7.3 570 86 21 8.8 1.1 317 12.0 30.0 3.0 

JBS 8/9/1982 1155 6.9 592 84 20 8.6 1.1 317 14.0 31.0 

JBS 7/18/1983 1205 7.4 586 85 21 9.1 1.2 317 16.0 28.0 1.7 

KCH 7/10/1979 1300 6.6 620 82 26 13.0 1.0 320 18.0 40.0 6.4 

KCH 8/28/1980 1045 7.2 660 87 25 16.0 1.0 310 21.0 48.0 4.7 

KCH 8/11/1981 0925 7.2 621 82 25 16.0 .9 329 19.0 42.0 4.0 

KCH 8/10/1982 1015 7.0 652 83 24 16.0 .9 317 23.0 45.0 

KCH 7/19/1983 1210 7.0 670 88 25 17.0 1.0 329 23.0 45.0 4.7 

KCH 8/7/1985 1230 7.2 635 86 24 14.0 .9 322 19.0 35.0 4.4 

KCH 8/29/1986 1400 7.3 674 89 25 15.0 .8 328 19.0 42.0 4.5 

KCH 2/9/1987 1120 7.3 641 83 25 14.0 .9 325 18.0 35.0 7.1 

KCH 8/19/1987 1125 7.4 675 83 25 14.0 .9 322 18.0 35.0 

KCH 3/9/1988 1030 7.2 655 90 26 18.0 1.0 316 22.0 60.0 4.9 

KCH 8/11/1988 1200 7.1 691 85 26 18.0 .8 318 22.0 52.0 4.7 

KCH 2/27/1989 1145 6.9 690 90 25 18.0 .9 325 20.0 44.0 4.7 

KCH 8/29/1989 1400 7.2 668 89 24 18.0 .9 326 27.0 45.0 4.6 

KCH 2/7/1990 1000 7.0 622 88 25 15.0 1.0 325 20.0 31.0 

KCH 3/11/1991 1150 7.1 642 90 25 14.0 1.0 342 20.0 29.0 4.2
 

KCH 4/29/1992 1130 6.5 623 77 24 12.0 .9 329 23.0 33.0 3.8
 

KCH 1/20/1993 1115 7.0 652 82 25 16.0 .8 317 20.0 44.0 -­
 

KCH 1/23/1993 1000 6.9 650 83 25 15.0 .9 317 21.0 44.0 -­
 

KCH 1/26/1993 1300 7.2 652 83 25 16.0 .9 317 20.0 47.0 -­

KCH 5/6/1993 1507 7.2 641 88 26 15.0 .9 317 18.0 43.0 4.6 

KCH 8/18/1993 0745 6.9 664 92 25 15.0 .9 317 19.0 51.0 4.8 

KCH 4/12/1994 1220 7.0 652 91 24 15.0 .9 317 23.0 45.0 5.6 

KCH 10/10/1994 0930 6.7 652 85 23 15.0 1.1 317 22.0 38.0 5.0 

KCH 10/10/1994 1500 6.7 660 86 23 15.0 .8 329 22.0 37.0 

KCH 10/10/1994 2020 6.7 651 86 23 15.0 .8 329 22.0 38.0 5.1 

KCH 10/11/1994 0820 7.0 657 89 24 16.0 .9 329 22.0 38.0 5.0 

KCH 10/11/1994 2030 6.8 652 88 24 16.0 1.0 317 21.0 39.0 5.1 

KCH 10/12/1994 0850 6.8 653 90 25 16.0 .9 305 23.0 38.0 5.1 

KCH 10/12/1994 2030 7.0 653 88 24 16.0 1.0 317 21.0 38.0 

KCH 10/13/1994 0830 6.8 655 86 24 15.0 1.0 317 21.0 38.0 4.9 

KCH 10/13/1994 2045 7.0 655 91 27 16.0 1.1 317 21.0 39.0 4.9 

KCH 10/14/1994 1900 6.9 657 92 26 17.0 .9 317 22.0 40.0 5.2 

KCH 10/15/1994 1900 7.9 658 89 24 16.0 .9 317 22.0 40.0 5.1 

KCH 10/16/1994 1230 8.0 660 89 25 16.0 .9 317 23.0 41.0 

KCH 6/19/1995 1300 7.1 641 84 24 15.0 .9 305 19.0 34.0 5.1 

KCH 5/6/1996 1200 7.2 648 89 23 16.0 .8 305 22.0 39.0 5.1 

KCH 7/8/1997 1350 7.5 568 66 26 9.2 .9 293 13.6 16.8 3.9 

KCH 4/21/1998 0920 7.1 628 89 25 15.1 .9 305 21.4 37.3 5.9 

LWK 7/11/1979 1225 6.9 499 60 23 6.4 1.3 270 12.0 24.0 

1.6 

4.8 

8.6 

4.7 

5.0 

4.9 

5.3 

1.6 
Appendix 4 163 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

LWK 8/29/1980 0850 7.6 496 59 22 6.4 1.3 270 7.6 18.0 0.4 

LWK 8/18/1981 1020 7.3 499 62 23 6.8 1.3 293 11.0 9.1 1.6 

LWK 8/17/1982 1130 6.9 493 59 23 6.7 1.3 268 11.0 22.0 1.5 

LWK 7/21/1983 1330 7.4 499 60 23 6.7 1.4 281 12.0 19.0 1.6 

MCH 7/5/1979 0745 7.0 540 85 17 8.3 1.0 320 11.0 18.0 

MCH 8/28/1980 1245 7.1 570 79 19 6.3 .9 320 11.0 12.0 1.3 

MCH 8/11/1981 1345 7.1 537 82 18 6.5 .8 329 11.0 10.0 .9 

MCH 8/11/1982 1255 7.6 528 77 20 6.5 1.0 329 10.0 14.0 1.1 

MCH 7/20/1983 0930 7.5 476 71 17 6.6 1.2 268 11.0 16.0 .5 

MCH 8/9/1985 1045 7.1 540 80 18 6.6 1.0 305 12.0 15.0 

MCH 1/13/1986 1345 7.1 537 79 18 6.9 .9 327 12.0 14.0 .9 

MCH 9/2/1986 1020 7.2 550 85 21 6.7 3.3 338 12.0 15.0 1.1 

MCH 2/10/1987 0930 7.1 554 87 18 6.7 .9 331 12.0 16.0 .9 

MCH 8/17/1987 1505 7.2 560 84 20 6.7 1.0 342 11.0 16.0 1.0 

MCH 2/22/1988 1425 7.1 519 81 20 6.9 1.0 312 12.0 22.0 

MCH 8/10/1988 1210 7.1 552 78 21 6.5 .9 328 11.0 15.0 1.0 

MCH 2/21/1989 1400 7.2 584 83 23 7.0 1.1 334 11.0 21.0 .9 

MCH 8/29/1989 1045 7.1 547 81 20 6.6 1.0 326 13.0 15.0 .9 

MCH 1/31/1990 1005 6.9 587 81 23 6.1 .9 346 10.0 13.0 1.2 

MCH 3/13/1991 1250 7.3 518 81 17 7.6 1.1 293 14.0 24.0 

MCH 4/30/1992 0920 6.9 564 94 17 6.4 .9 329 15.0 19.0 .8
 

MCH 1/22/1993 1120 6.9 504 75 16 6.5 1.0 293 11.0 18.0 -­
 

MCH 1/25/1993 1300 6.9 503 75 16 6.4 .9 293 10.0 19.0 -­
 

MCH 5/8/1993 1045 7.3 521 81 17 6.7 1.0 305 11.0 19.0 .5
 

MCH 8/18/1993 0950 6.8 550 83 19 6.4 1.3 317 10.0 15.0 

MCH 4/15/1994 0820 7.0 506 71 18 6.9 1.0 268 12.0 26.0 .5 

MCH 6/14/1995 1220 7.1 550 89 16 6.0 .9 317 9.8 13.0 .5 

MCH 5/7/1996 1045 7.6 555 80 22 6.5 .9 317 10.0 14.0 .9 

MCH 7/8/1997 1545 7.2 555 87 15 6.0 .9 293 10.3 13.0 .7 

MCH 4/22/1998 1350 7.0 534 83 18 7.1 .9 293 11.3 19.1 

MCH 6/6/1999 1150 7.0 545 83 20 7.2 .9 305 12.3 18.2 .8 

MCH 6/29/2000 0900 7.0 538 79 18 6.5 1.3 305 11.2 17.9 .7 

MCH 6/20/2001 1100 6.8 554 80 18 6.8 1.0 311 11.7 18.0 .6 

MCH 6/4/2002 1100 7.3 558 73 20 9.9 1.0 293 13.8 16.9 1.0 

MCH 5/20/2003 1200 7.1 565 85 18 7.2 1.0 312 12.4 18.6 

PLS 2/26/1988 0830 7.1 568 74 24 6.7 1.2 332 12.0 17.0 1.5 

PLS 8/11/1988 0845 7.2 564 73 25 6.7 1.1 320 11.0 16.0 1.4 

PLS 2/28/1989 1455 7.1 548 75 25 7.5 1.2 328 11.0 18.0 1.4 

PLS 8/30/1989 1330 7.0 542 76 24 6.8 1.1 328 11.0 17.0 1.4 

PLS 2/7/1990 1500 7.0 550 76 24 6.9 1.3 328 10.0 17.0 

PLS 3/18/1991 1545 7.2 533 76 24 7.2 1.0 317 12.0 18.0 1.5
 

PLS 5/1/1992 0950 7.0 543 79 24 6.5 1.1 317 15.0 20.0 1.4
 

PLS 1/21/1993 1130 6.8 560 72 24 6.9 1.1 329 12.0 17.0 -­
 

PLS 1/24/1993 0850 7.0 559 73 24 7.2 1.1 329 12.0 17.0 -­
 

PLS 1/28/1993 1146 6.8 559 77 25 7.5 1.1 329 12.0 17.0 -­

1.1 

.8 

.8 

.6 

.9 

4.0 

.7 

1.5 
164 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

PLS 8/17/1993 1030 6.9 560 78 24 7.0 1.1 317 11.0 17.0 1.4 

PLS 4/12/1994 0900 7.0 546 78 24 6.8 1.1 329 12.0 17.0 1.6 

PLS 6/19/1995 1640 7.2 561 75 23 6.9 1.1 317 12.0 16.0 1.5 

PLS 4/25/1996 1200 6.9 544 76 25 6.8 1.1 305 11.0 16.0 1.5 

PLS 7/8/1997 1220 7.3 550 72 24 7.0 1.1 317 12.0 16.3 

PLS 4/21/1998 1320 7.1 528 81 25 7.0 1.1 329 12.1 17.2 1.4 

PLS 6/1/2000 1500 7.1 573 75 24 6.8 1.0 329 12.1 16.9 1.4 

PLS 6/8/2001 1100 7.0 590 77 24 7.2 1.1 299 12.9 18.6 1.4 

PLS 5/23/2002 1100 7.1 570 78 24 7.1 1.1 296 13.0 18.1 1.5 

PLS 5/21/2003 1200 7.0 576 77 24 7.4 1.2 315 12.8 16.8 

RAB 5/6/1993 1400 7.3 596 77 25 12.0 1.6 256 16.0 81.0 .6 

RAB 4/15/1994 1215 7.3 522 67 21 8.7 1.2 268 15.0 37.0 .8 

RAB 6/27/1995 1015 7.4 507 66 19 8.8 1.2 244 16.0 31.0 .7 

RAB 5/6/1996 0945 7.3 504 67 21 9.5 1.2 244 16.0 37.0 .6 

RAB 7/9/1997 0740 7.2 542 67 22 10.7 1.4 232 17.8 48.9 

RAB 4/21/1998 0757 7.3 525 66 20 10.5 1.3 281 18.4 32.8 .6 

RAB 6/8/1999 0900 7.2 755 75 23 12.6 1.5 244 20.6 69.7 .6 

RAB 5/31/2000 1300 7.2 555 71 21 11.0 1.3 256 19.0 51.2 .6 

RAB 6/7/2001 1600 7.2 532 67 21 11.5 1.3 250 20.1 41.2 .6 

RAB 6/3/2002 1100 7.3 617 70 21 12.0 1.5 239 21.9 47.9 

RAB 5/30/2003 1000 7.0 1,190 140 49 26.5 3.5 271 36.8 287.0 .4 

ROL 7/10/1979 0950 6.7 521 72 20 7.1 1.0 290 13.0 23.0 1.1 

ROL 8/27/1980 1045 7.3 559 74 21 7.2 1.2 320 12.0 17.0 .3 

ROL 8/4/1981 0915 7.5 528 76 22 7.9 1.0 305 12.0 19.0 1.1 

ROL 8/9/1982 1110 7.0 532 72 20 7.5 1.1 293 13.0 25.0 

ROL 7/18/1983 0845 7.1 546 77 22 7.9 1.1 293 15.0 24.0 1.1 

ROL 8/7/1985 0900 7.4 586 86 22 8.9 1.1 320 18.0 30.0 1.2 

ROL 1/15/1986 1000 7.1 610 84 23 8.6 1.0 310 22.0 32.0 1.3 

ROL 9/3/1986 1300 7.4 586 83 22 8.8 1.1 312 17.0 31.0 1.2 

ROL 2/9/1987 0830 7.2 624 88 22 9.8 1.1 316 21.0 35.0 

ROL 8/17/1987 1010 7.2 642 91 22 10.0 1.2 321 19.0 40.0 1.5 

ROL 2/22/1988 0910 7.0 587 89 23 9.7 1.2 326 19.0 34.0 1.3 

ROL 8/16/1988 0920 7.0 596 85 23 9.3 1.0 314 18.0 33.0 1.3 

ROL 2/27/1989 1245 7.3 583 81 22 9.0 1.1 309 16.0 30.0 1.0 

ROL 8/25/1989 1115 7.2 607 86 22 9.9 1.1 318 19.0 32.0 

ROL 1/30/1990 1115 6.9 572 78 21 8.6 1.2 300 17.0 29.0 1.0 

ROL 3/13/1991 0925 7.2 612 89 22 11.0 1.2 317 28.0 35.0 1.5 

ROL 4/29/1992 1315 6.9 694 94 21 14.0 1.1 317 41.0 45.0 2.0 

ROL 1/20/1993 1300 7.2 654 86 21 12.0 1.1 317 25.0 40.0 -­

ROL 1/23/1993 1140 6.9 630 88 22 12.0 1.1 317 26.0 42.0 -­

ROL 1/26/1993 1043 6.8 625 86 21 12.0 1.1 317 24.0 41.0 -­
 

ROL 5/6/1993 1230 7.9 635 93 22 12.0 1.1 317 26.0 41.0 1.4
 

ROL 8/13/1993 1200 6.9 660 98 23 12.0 1.1 329 25.0 43.0 1.5
 

ROL 4/12/1994 1130 7.1 597 88 22 10.0 1.1 305 22.0 38.0 1.2
 

SLR 7/5/1979 0845 6.9 630 100 19 5.6 .5 400 8.8 7.2 

1.5 

1.3 

.6 

.6 

1.0 

1.6 

1.2 

.3 
Appendix 4 165 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

SLR 9/4/1980 1306 7.1 680 100 20 5.5 0.6 400 9.2 35.0 0.5 

SLR 8/18/1981 0830 7.1 583 97 19 5.7 .6 378 8.9 1.0 .5 

SLR 8/17/1982 0920 7.0 625 98 21 5.7 .6 390 9.0 9.0 1.2 

SLR 7/20/1983 0830 7.3 600 98 19 5.3 .6 378 8.7 9.6 .7 

SLR 9/2/1986 1130 7.1 655 110 21 5.5 .6 414 9.5 11.0 

SLR 2/10/1987 0830 7.0 624 110 20 5.3 .5 440 9.5 13.0 .7 

SLR 8/18/1987 0834 7.1 636 100 18 5.4 .5 403 8.8 9.5 .4 

SLR 2/22/1988 1325 7.1 575 100 22 5.5 .5 399 8.9 12.0 1.1 

SLR 8/9/1988 1030 7.1 727 110 25 5.5 .6 416 8.8 56.0 .1 

SLR 2/21/1989 1310 7.0 736 105 27 5.6 .9 409 8.0 60.0 

SNL 6/26/1978 1220 7.2 460 67 19 7.4 1.0 281 15.0 22.0 .4 

SNL 7/10/1979 0900 6.8 525 70 20 8.4 1.0 260 15.0 33.0 .5 

SNL 8/27/1980 0930 7.4 503 65 18 8.5 1.0 260 14.0 24.0 .1 

SNL 8/4/1981 1045 7.6 462 65 19 7.9 1.0 281 11.0 23.0 .4 

SNL 8/9/1982 1020 7.0 468 62 18 7.9 1.0 244 14.0 25.0 

SNL 7/18/1983 1045 7.8 494 67 19 8.6 1.1 256 14.0 26.0 .1 

SVE 7/18/1979 1230 6.8 445 58 18 11.0 2.9 220 14.0 42.0 1.0 

SVE 8/19/1981 1310 7.3 638 74 29 11.0 2.2 329 12.0 42.0 1.3 

SVE 8/30/1982 1400 7.4 1,530 140 80 100.0 11.0 317 46.0 570.0 1.6 

SVE 8/12/1985 1000 7.2 936 97 38 44.0 3.8 336 46.0 160.0 

SVE 1/15/1986 1430 7.1 913 92 37 48.0 3.2 334 46.0 160.0 1.4 

SVE 8/29/1986 0900 7.1 874 92 35 44.0 3.0 318 45.0 130.0 1.4 

SVE 2/10/1987 1130 7.4 610 73 30 9.0 1.7 346 16.0 38.0 1.3 

SVE 8/19/1987 0815 7.5 603 67 28 9.7 1.8 303 15.0 26.0 1.2 

SVE 2/24/1988 1435 7.1 704 90 34 14.0 2.7 326 20.0 96.0 

SVE 8/9/1988 0850 7.0 917 96 40 39.0 3.7 332 31.0 170.0 1.7 

SVE 2/21/1989 1030 6.9 857 90 37 34.0 3.5 334 27.0 150.0 1.8 

SVE 8/25/1989 0955 6.9 949 100 39 40.0 4.0 326 34.0 180.0 1.7 

SVE 1/30/1990 0945 6.9 942 98 41 41.0 4.3 332 31.0 190.0 1.8 

SVE 3/5/1991 0935 7.3 916 100 38 40.0 4.2 342 32.0 180.0 

SVE 4/28/1992 1330 7.1 601 71 29 11.0 2.0 305 22.0 48.0 


SVE 1/21/1993 0900 6.9 620 74 29 10.0 1.5 329 16.0 43.0 -­


SVE 1/24/1993 0700 7.0 616 75 29 11.0 2.3 329 17.0 50.0 -­


SVE 1/28/1993 1300 6.9 618 76 29 9.6 1.5 342 16.0 37.0 -­


SVE 5/7/1993 1430 7.3 616 80 29 10.0 1.5 329 17.0 38.0 

SVE 8/16/1993 0750 7.1 652 85 30 11.0 2.8 256 15.0 110.0 .4 

SVE 4/12/1994 0735 7.0 1,020 110 46 51.0 5.7 329 35.0 250.0 2.0 

SVE 6/14/1995 1430 7.1 867 92 32 29.0 2.3 317 37.0 97.0 1.4 

SVE 5/9/1996 1100 7.4 840 97 36 34.0 3.4 390 32.0 140.0 1.3 

SVE 7/9/1997 1000 7.2 674 77 29 18.5 1.9 293 27.6 56.7 

SVE 4/22/1998 1110 7.2 596 75 30 10.0 1.5 305 17.3 35.9 1.4 

SVE 5/31/2000 0900 7.2 850 95 34 30.6 3.1 317 29.5 134.0 .1 

SVE 6/14/2001 1200 7.1 770 90 31 33.3 .1 334 40.3 92.7 1.6 

SVE 8/7/2002 1200 7.0 760 89 30 28.1 2.0 322 36.0 79.2 1.6 

SVE 5/28/2003 1200 7.1 626 81 28 10.2 1.5 345 16.8 32.4 

1.1 

.1 

.3 

1.6 

.9 

1.6 

1.3 

1.6 

1.4 

1.5 
166 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

SVN 7/17/1979 0715 6.8 480 70 18 6.8 1.4 260 11.0 25.0 0.3 

SVN 8/19/1981 1210 7.2 517 70 20 8.2 1.3 293 14.0 16.0 .3 

SVN 8/7/1985 1005 6.9 496 69 18 7.4 1.3 283 14.0 22.0 .4 

SVN 1/15/1986 0900 7.4 466 66 19 7.9 1.0 259 17.0 21.0 .3 

SVN 8/29/1986 1000 6.8 514 72 19 7.5 1.2 281 12.0 24.0 

SVN 2/10/1987 1200 7.3 388 58 5 5.4 13.0 212 4.7 15.0 .2 

SVN 8/19/1987 0915 7.4 630 77 17 7.9 3.2 288 12.0 32.0 .8 

SVN 2/24/1988 1530 7.2 510 72 21 8.4 1.3 281 14.0 32.0 .3 

SVN 3/5/1991 1020 7.5 560 75 19 15.0 1.5 256 30.0 44.0 .2 

SVN 1/20/1993 0945 6.9 453 59 15 11.0 1.4 220 16.0 32.0 -­

SVN 1/23/1993 0800 6.8 461 60 15 11.0 1.4 232 16.0 31.0 -­
 

SVN 1/26/1993 0930 6.8 455 65 16 12.0 1.6 232 15.0 32.0 -­
 

SVN 5/6/1993 1610 7.5 447 60 16 11.0 1.2 220 16.0 29.0 .1
 

SVN 8/16/1993 1000 7.1 549 77 20 11.0 1.5 281 17.0 34.0 .5
 

SVN 6/19/1995 0805 7.1 460 62 16 12.0 2.0 232 17.0 25.0 

SVN 7/9/1997 1200 7.2 533 67 18 12.2 1.6 244 20.6 29.5 .1 

SVN 4/22/1998 1230 7.4 507 67 18 13.7 1.2 244 21.8 42.2 .6 

SVN 6/15/2001 1100 6.8 710 97 21 20.0 1.3 338 38.1 49.5 .3 

SVN 8/7/2002 1000 7.2 507 64 17 15.2 1.6 231 26.1 33.3 .1 

SVN 5/28/2003 1000 7.2 603 84 20 17.1 1.4 272 29.6 44.7 

SVS 8/8/1978 0750 7.0 540 69 30 8.4 1.3 360 12.0 6.3 2.3 

SVS 7/17/1979 1200 6.8 580 71 25 9.1 1.2 331 11.0 17.0 4.0 

SVS 8/28/1980 0930 7.0 620 70 28 9.4 1.2 350 13.0 5.1 1.1 

SVS 8/10/1981 1407 7.3 585 77 27 9.9 1.2 342 14.0 7.0 3.5 

SVS 8/9/1982 1355 6.7 584 68 29 9.0 1.3 342 12.0 7.0 

SVS 7/19/1983 1000 6.9 582 70 30 9.3 1.3 342 13.0 8.8 2.6 

SVS 8/7/1985 1100 7.1 592 73 29 9.3 1.3 360 12.0 6.3 2.7 

SVS 1/13/1986 0830 7.0 589 73 29 9.1 1.0 356 14.0 9.4 3.0 

SVS 8/29/1986 1300 7.2 596 75 29 10.0 1.2 356 13.0 8.1 3.1 

SVS 2/9/1987 1015 7.1 578 77 26 9.9 1.3 350 14.0 10.0 

SVS 8/17/1987 1350 7.3 603 79 24 9.7 1.2 350 12.0 16.0 3.9 

SVS 2/22/1988 1120 7.1 593 82 28 10.0 1.2 362 13.0 16.0 4.3 

SVS 8/11/1988 1100 7.2 607 72 31 9.5 1.1 353 11.0 7.9 2.7 

SVS 2/21/1989 1140 7.1 607 71 31 9.4 1.3 348 11.0 8.1 2.5 

SVS 8/25/1989 1320 7.0 595 71 29 9.8 1.2 356 12.0 8.0 

SVS 1/30/1990 1340 6.9 602 71 29 9.2 1.2 356 11.0 8.0 2.7 

SVS 3/5/1991 1130 7.1 560 73 30 9.3 1.3 354 13.0 7.4 2.3 

SVS 5/1/1992 0820 7.1 584 82 25 9.3 1.1 342 19.0 20.0 3.5 

SVS 1/22/1993 0825 6.7 603 77 27 8.9 1.1 366 12.0 9.6 -­

SVS 1/25/1993 1020 7.0 610 79 27 9.1 1.1 366 12.0 9.8 -­

SVS 5/7/1993 0946 7.1 614 78 26 9.3 1.1 366 12.0 10.0 3.7 

SVS 8/17/1993 0915 7.0 618 83 27 9.3 1.1 366 12.0 9.3 3.9 

SVS 4/8/1994 0830 7.0 594 71 29 9.2 1.2 354 12.0 8.3 3.1 

SVS 6/19/1995 1440 7.1 611 79 27 9.6 1.1 342 12.0 8.6 3.7 

SVS 5/2/1996 1100 7.7 592 73 30 9.5 1.2 329 12.0 8.1 

.4 

.2 

.3 

2.7 

3.8 

2.6 

3.0 
Appendix 4 167 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

SVS 7/8/1997 1045 7.2 585 74 27 9.3 1.1 342 12.6 9.2 3.5 

SVS 4/22/1998 0931 7.0 616 78 28 9.6 1.1 354 13.1 11.6 3.6 

SVS 6/11/1999 1340 7.0 599 79 27 8.9 1.1 342 12.5 7.3 3.1 

SVS 6/1/2000 1400 7.0 610 72 28 8.8 1.1 354 11.6 7.6 2.8 

SVS 6/6/2002 1300 7.0 622 83 27 9.0 1.0 359 12.6 9.7 

SVS 5/19/2003 1300 6.9 620 87 26 9.0 1.3 333 13.9 14.5 2.7 

SVW 6/27/1978 1220 6.6 560 78 24 10.0 1.0 331 18.0 15.0 1.9 

SVW 7/12/1979 0900 6.9 620 73 24 21.0 1.0 340 32.0 14.0 1.7 

SVW 8/28/1980 0900 7.0 592 79 24 8.5 .9 342 14.0 7.3 1.8 

SVW 8/10/1981 1340 7.2 569 77 23 9.0 .9 329 19.0 7.0 

SVW 8/10/1982 0815 6.8 597 80 24 10.0 1.0 329 21.0 20.0 1.7 

SVW 7/19/1983 0805 6.9 601 79 23 12.0 1.2 317 22.0 23.0 1.2 

SVW 8/9/1985 0830 7.1 657 89 24 14.0 1.1 348 31.0 23.0 1.8 

SVW 1/15/1986 1130 7.0 622 85 25 13.0 .8 331 32.0 20.0 1.6 

SVW 8/29/1986 1200 7.0 659 91 24 12.0 1.0 359 22.0 22.0 

SVW 2/9/1987 0915 7.4 591 79 24 11.0 .9 331 17.0 21.0 1.4 

SVW 8/17/1987 1215 7.3 614 82 23 12.0 .9 337 21.0 18.0 1.9 

SVW 2/22/1988 1010 7.1 637 93 25 14.0 1.1 354 24.0 35.0 1.5 

SVW 8/11/1988 1010 7.1 658 89 25 12.0 1.0 353 21.0 23.0 2.1 

SVW 2/27/1989 1350 7.1 630 81 25 12.0 1.0 337 23.0 23.0 

SVW 8/29/1989 0905 7.1 678 93 24 13.0 1.0 360 28.0 23.0 2.1 

SVW 1/30/1990 1250 6.8 688 93 25 14.0 1.2 368 26.0 27.0 2.3 

SVW 3/11/1991 1320 7.2 658 90 25 15.0 .9 317 37.0 41.0 1.5 

SVW 4/29/1992 0830 7.0 639 82 23 13.0 1.0 329 29.0 32.0 1.6 

SVW 1/22/1993 0920 6.8 655 86 23 15.0 1.0 329 31.0 31.0 -­

SVW 1/25/1993 1130 6.8 621 82 24 13.0 1.0 329 25.0 27.0 -­
 

SVW 1/28/1993 1350 6.9 608 79 24 12.0 .9 329 24.0 23.0 -­
 

SVW 8/20/1993 1030 6.9 670 98 25 13.0 .9 354 23.0 24.0 2.1
 

SVW 4/11/1994 0730 7.0 645 94 25 12.0 1.0 342 27.0 21.0 2.8
 

SVW 10/9/1994 0700 6.3 570 85 18 9.7 1.5 293 16.0 23.0 

SVW 10/9/1994 1305 6.3 582 86 18 9.3 1.3 305 17.0 25.0 1.5 

SVW 10/9/1994 1855 6.4 592 87 19 9.4 1.3 317 17.0 26.0 1.5 

SVW 10/10/1994 0710 6.3 611 88 19 10.0 1.2 329 18.0 27.0 1.6 

SVW 10/10/1994 1300 6.4 620 89 20 10.0 1.2 342 18.0 27.0 1.6 

SVW 10/10/1994 1905 6.4 612 91 20 10.0 1.3 329 18.0 27.0 

SVW 10/11/1994 0705 6.8 624 93 21 11.0 1.1 342 19.0 27.0 1.7 

SVW 10/11/1994 1305 7.2 678 97 21 13.0 1.2 342 26.0 28.0 2.2 

SVW 10/11/1994 1900 6.8 634 90 22 12.0 1.0 317 26.0 22.0 2.2 

SVW 10/12/1994 0730 6.8 600 86 23 11.0 1.2 317 22.0 18.0 1.9 

SVW 10/12/1994 1900 7.0 598 80 22 10.0 1.2 317 23.0 16.0 

SVW 10/13/1994 0700 6.9 601 84 24 11.0 1.1 317 23.0 16.0 2.0 

SVW 10/13/1994 1930 6.9 619 88 24 10.0 1.2 329 20.0 22.0 1.8 

SVW 10/14/1994 0730 7.2 596 79 23 11.0 1.0 305 23.0 15.0 2.1 

SVW 10/15/1994 1230 6.9 645 96 25 12.0 1.1 342 24.0 25.0 2.0 

SVW 6/27/1995 0820 7.0 647 87 23 13.0 .9 329 24.0 30.0 

3.1 

1.4 

2.0 

1.9 

1.5 

1.7 

2.0 

1.4 
168 Specific Conductance, and Associated Major Ion and Nitrate Geochemistry, Edwards Aquifer, Austin, Texas, 1978–2003 

Appendix 4. Charge balanced major ion and nitrate water analysis data from wells in the Barton Springs segment of the Edwards 

aquifer, Austin, Texas, 1978–2003—Continued. 

Well Specific Ca Mg Na K HCO3 Cl SO4 NO3-N identifier Date Time pH conductance 

(fig. 1) (μS/cm) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) 

SVW 5/2/1996 0900 7.1 643 90 25 13.0 1.0 354 29.0 19.0 2.6 

SVW 7/9/1997 1105 7.1 580 73 23 9.3 .9 281 22.4 12.5 2.2 

SVW 4/21/1998 1430 7.2 568 80 24 9.4 .8 305 23.8 12.3 2.3 

SVW 6/1/2000 1000 6.9 662 91 23 10.4 .9 354 22.6 20.4 2.2 

SVW 6/6/2001 1200 6.8 659 95 26 12.7 1.0 348 26.5 28.9 

SVW 6/3/2002 1400 7.0 646 92 25 11.9 1.0 331 24.6 24.2 2.0 

SVW 5/19/2003 1000 6.9 644 93 25 13.0 1.1 364 25.9 28.6 1.9 

TNR 7/9/1979 1215 6.9 580 78 27 5.7 .9 360 11.0 12.0 1.3 

TNR 8/29/1980 0930 7.7 592 89 19 12.0 .6 360 13.0 3.1 1.3 

TNR 8/18/1981 0920 7.1 576 79 26 7.0 .8 366 14.0 1.0 

TNR 8/16/1982 0915 6.9 584 91 20 7.0 .6 366 11.0 7.0 1.7 

TNR 7/21/1983 1115 7.4 590 81 27 7.4 .8 366 14.0 6.5 1.2 

TNR 8/9/1985 1145 7.1 604 82 27 6.9 .8 366 14.0 20.0 1.2 

TNR 1/13/1986 1310 7.0 576 73 29 7.7 .8 370 13.0 9.4 1.1 

TNR 9/2/1986 1215 7.2 607 89 23 7.3 .8 368 13.0 7.0 

TNR 2/11/1987 1030 7.1 597 79 28 6.6 .7 370 11.0 21.0 1.1 

TNR 8/18/1987 1015 7.2 606 84 25 6.4 .8 368 12.0 7.3 1.4 

TNR 2/25/1988 1020 7.1 597 93 21 6.9 .7 372 12.0 7.6 1.7 

TNR 8/9/1988 1125 7.1 600 92 21 6.4 .7 368 10.0 7.4 1.7 

TNR 2/23/1989 1130 6.9 579 92 21 6.5 .6 362 10.0 7.4 

TNR 8/30/1989 1130 7.0 590 93 20 6.6 .5 368 9.7 7.0 1.6 

TNR 2/7/1990 1330 6.9 558 94 20 6.5 .7 362 9.3 7.0 1.7 

WBG 7/10/1978 0940 6.2 700 62 34 32.0 3.0 281 28.0 110.0 0 

WBG 7/5/1979 1005 7.4 799 63 34 44.0 3.8 260 23.0 140.0 .1 

WBG 8/28/1980 1330 7.5 826 64 35 50.0 4.2 281 38.0 140.0 

WBG 8/10/1982 1330 6.9 766 62 34 43.0 3.3 281 32.0 130.0 .1 

WBG 7/20/1983 1415 7.5 767 61 33 38.0 2.9 281 29.0 130.0 .1 

WGF 6/28/1978 1100 6.7 480 62 23 6.2 1.3 290 15.0 12.0 1.1 

WGF 7/17/1979 1415 6.9 520 73 20 7.5 1.4 300 11.0 15.0 1.5 

WGF 8/27/1980 1415 7.4 500 64 22 6.7 1.2 290 11.0 7.4 

WGF 8/10/1981 1315 7.4 537 74 22 9.7 1.4 317 18.0 6.0 1.6 

WGF 8/9/1982 1320 7.0 505 62 22 7.3 1.2 293 15.0 12.0 1.3 

WGF 7/19/1983 0918 7.1 514 66 23 8.0 1.4 293 16.0 13.0 1.7 

1.9 

1.2 

1.4 

1.6 

0 

.6 
Appendix 5—Quality Assurance Data
 
Blank Page 
Specific Conductance, and 

Associated Major Ion and Nitrate 

Geochemistry, Edwards Aquifer, 

Austin, Texas, 1978–2003

Appendix 5

Appendix 5 171 

Appendix 5. Quality assurance data, Barton Springs segment of the Edwards aquifer, Austin, Texas, 1978–2003. 

[μS/cm, microsiemens per centimeter at 25 degrees Celsius; Ca, calcium; mg/L, milligrams per liter; Mg, magnesium; Na, sodium; K, potassium; HCO3, 

bicarbonate; Cl, chloride; SO4, sulfate; NO3, nitrate; N, nitrogen; <, less than; --, no data; E, estimated. Blank samples show acceptably low background levels for 

samples collected from 2001 onward. Replicate samples suggest that collection and analysis procedures were reproducible. Sequential replicate samples, which 

were not truly designed as quality control samples, show that analytical methods have been reproducible thought the period of study, to within 5 percent.] 

Well 

identifier 

(fig. 1) 

SVE 

SVE 

Date 

6/14/2001 

8/8/2002 

Specific 

conductance 

(μS/cm) 

<3 

<3 

Ca 

(mg/L) 

0.02 

E.01 

Mg 

(mg/L) 

Na 

(mg/L) 

Blank samples 

<0.008 <0.06 

<.008 <.09 

K 

(mg/L) 

<0.09 

<.1 

HCO3 

(mg/L) 

--

--

Cl 

(mg/L) 

<0.08 

<.3 

SO4 

(mg/L) 

<0.1 

<.1 

NO3-N 

(mg/L) 

<0.05 

<.05 

PLS 

PLS 

5/23/2002 

5/23/2002 

570 

572 

78 

78 

Replicate samples 

24 7 

24 7 

1.1 

1.1 

296 

--

13 

13 

18 

18 

1.5 

1.4 

BPS 

BPS 

8/1/1980 

8/29/1980 

583 

578 

72 

73 

Sequential samples 

25 6 

26 6 

1.2 

1.0 

331 

331 

10 

11 

22 

27 

1.6 

.3 

BPS 

BPS 

7/30/1981 

8/12/1981 

583 

568 

74 

74 

26 

25 

7 

6 

1.2 

1.3 

329 

342 

10 

10 

28 

25 

.1 

1.2 

BPS 

BPS 

7/17/1989 

8/29/1989 

563 

581 

75 

78 

26 

26 

6 

7 

1.2 

1.1 

343 

338 

10 

10 

24 

25 

1.3 

1.3 

BPS 

BPS 

8/19/1993 

8/20/1993 

539 

579 

76 

79 

25 

25 

6 

7 

1.1 

1.2 

342 

329 

10 

10 

26 

26 

1.3 

1.4