In Cooperation with the New Mexico Interstate Stream Commission

Estimates of Mean-Annual Streamflow and Flow Loss 

for Ephemeral Channels in the Salt Basin, 

Southeastern New Mexico, 2009

U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2011–5062

Estimates of Mean-Annual Streamflow and 

Flow Loss for Ephemeral Channels in the 

Salt Basin, Southeastern New Mexico, 2009

By Anne Tillery

In Cooperation with the New Mexico Interstate Stream Commission

Scientific Investigations Report 2011–5062

U.S. Department of the Interior

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

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011

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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:

Tillery, Anne, 2011, Estimates of mean-annual streamflow and flow loss for ephemeral channels in the Salt Basin, 

southeastern New Mexico, 2009: U.S. Geological Survey Scientific Investigations Report 2011–5062, 20 p.
iii

Contents

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

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

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

Study Area..............................................................................................................................................2

Acknowledgments................................................................................................................................2

Methods Used To Estimate Mean-Annual Streamflow...........................................................................4

Active-Channel Width..........................................................................................................................4

Site Selection ...............................................................................................................................4

Collection and Compilation of Data ..........................................................................................5

Basin Characteristics...........................................................................................................................5

Analysis of Data ....................................................................................................................................6

Field Observations .......................................................................................................................6

Measurements from Aerial Photography ................................................................................6

Limitations of the Equations.......................................................................................................6

Estimates of Mean-Annual Streamflow and Flow Loss ..........................................................................7

Sacramento River Subbasin ...............................................................................................................7

Cornucopia Draw Subbasin ................................................................................................................9

Piñon Creek Subbasin..........................................................................................................................9

Big Dog Canyon Subbasin...................................................................................................................9

Outlier Measurements .......................................................................................................................13

Comparison of Annual-Flow and Flow-Loss Estimates .........................................................................15

Summary........................................................................................................................................................16

References....................................................................................................................................................16

Appendix........................................................................................................................................................19

Figures

1. Salt Basin study area in southeastern New Mexico showing location

of surface-water subbasins measured for this study.............................................................3

2. Typical channel cross section in the northern Salt Basin, N. Mex. .....................................5

3. Typical substrate material of ephemeral channels in the

northern Salt Basin, N. Mex........................................................................................................6

4. Histogram of percent error in remote channel-geometry measurements

for 52 sites in the Salt Basin, N. Mex. ...............................................................................................7

5. Log-log scatter plot comparing basin area to active-channel width

for all 52 sites measured in the Salt Basin, N. Mex.....................................................................7

6. A, Estimates of mean-annual streamflow for eachSacramento River, 

N. Mex., subbasin site displayed categorically by increasing basin area. 

B, Sacramento River subbasin. C, Trends of mean-annual streamflow 

estimates compared to basin area for the two methods used at the study 

sites in the Sacramento River, N. Mex., subbasin.......................................................................8
iv

7. A, Estimates of mean-annual streamflow for each Cornucopia Draw, 

N. Mex., subbasin site displayed categorically by increasing basin 

area. B, Cornucopia Draw subbasin. C, Trends of mean-annual

streamflow estimates compared to basin area for the two methods

used at the study sites in the Cornucopia Draw, N. Mex., subbasin..................................10

8. A, Estimates of mean-annual streamflow for each Piñon Creek, 

N. Mex., subbasin site displayed categorically by increasing basin 

area. B, Piñon Creek subbasin. C, Trends of mean-annual streamflow 

estimates compared to basin area for the two methods used at the 

study sites in the Piñon Creek, N. Mex., subbasin ................................................................11

9. Typical Big Dog Canyon, N. Mex., channel section...................................................................13

Tables

1. Sacramento River, N. Mex., active-channel widths and mean-annual 

streamflow estimates...................................................................................................................9

2. Cornucopia Draw, N. Mex., active-channel widths and mean-annual 

streamflow estimates.................................................................................................................12

3. Piñon Creek, N. Mex., active-channel widths and subbasin mean-annual 

streamflow estimates.................................................................................................................12

4. Big Dog Canyon, N. Mex., active-channel widths and mean-annual 

streamflow estimates.................................................................................................................14

5. Southeastern New Mexico outlier active-channel widths and mean-annual 

streamflow estimates.................................................................................................................14

6. Basin characteristics associated with location of maximum active-channel 

width in each of the main subbasins measured in southeastern New Mexico...............15

7. Flow losses and associated distances for the four main subbasins studied in 

southeastern New Mexico........................................................................................................16
v

Conversion Factors

Inch/Pound to SI

Multiply By To obtain

Length

inch

foot (ft)

mile (mi)

25.40

0.3048

1.609

millimeter (mm)

meter (m)

kilometer (km)

Area

acre 4,047 square meter (m2

)

acre 0.4047 hectare (ha)

acre 0.4047 square hectometer (hm2

) 

acre 0.004047 square kilometer (km2

)

square mile (mi2

) 259.0 hectare (ha)

square mile (mi2

) 2.590 square kilometer (km2) 

Volume

acre-foot (acre-ft) 1,233 cubic meter (m3

)

acre-foot (acre-ft) 0.001233 cubic hectometer (hm3

)

Flow rate

acre-foot per day (acre-ft/d) 0.01427 cubic meter per second (m3

/s)

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year (m3

/yr)

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

cubic foot per second per square 

mile [(ft3

/s)mi2]

0.01093 cubic meter per second per

square kilometer [(m3/s)/km2]

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

Estimates of Mean-Annual Streamflow and Flow Loss

for Ephemeral Channels in the Salt Basin,

Southeastern New Mexico, 2009

By Anne Tillery

Abstract

As much as 57 million acre-feet of groundwater may 

be stored in the subsurface of the New Mexico part of the 

Salt Basin in southern Otero County, N. Mex. Recharge to a 

system such as the Salt Basin aquifer can result largely from 

focused recharge of surface water in channels and at mountain 

fronts. The Salt Basin is a closed basin that covers about 2,400 

square miles of southeastern New Mexico and continues 

across the State line into Texas. A graben underlies the central 

valley, which is buried by hundreds of feet of alluvial deposits. 

Bedrock that underlies the alluvial deposits and forms the 

surrounding plateaus is composed primarily of carbonate and 

mixed carbonate/evaporate units that can be karst forming in 

places. Karst features in the downstream parts of some areas of 

the Salt Basin also may provide opportunities for substantial 

recharge. Annual recharge to an aquifer such as the Salt Basin 

aquifer is commonly estimated in groundwater models by 

mean-annual streamflow. In 2009, the U.S. Geological Survey 

(USGS), in cooperation with the New Mexico Interstate 

Stream Commission, estimated mean-annual streamflow for 

selected channels in the Salt Basin.

Mean-annual streamflow was estimated for four main 

subbasins in the internally drained Salt Basin in southeastern 

New Mexico. These four main subbasins account for 30 

percent of the Salt Basin area in New Mexico. Estimates of 

mean-annual streamflow were generated at multiple sites down 

the length of each basin by using two regional regression 

equations based on channel geometry and one based on the 

basin characteristics of area and precipitation. Results indicate 

that, on average, an estimated 60,414 acre-feet of flow is 

generated annually among the four main subbasins in the New 

Mexico part of the Salt Basin. 

The use of the channel-geometry method at multiple 

locations down the length of each channel also provided 

information on the locations of flow accumulation and 

losses. By contrast, application of the basin-characteristics 

method will always produce increased runoff estimates with 

downstream distance in a single basin; therefore, the method 

is not sensitive to flow losses. Channels that were measured 

achieved maximum active-channel widths from 6 to 16 stream 

miles upstream from the locations in which channels bifurcate 

and lose shape altogether when they reach the lowlands of the 

internally drained basin. Active-channel-width measurements 

indicate that each of the four main subbasin channels studied 

loses between 27 and 56 percent of annual flow from the point 

of maximum active-channel width to the most downstream 

measureable section in the channel.

Introduction

As much as 57 million acre-feet (acre-ft) of groundwater 

may be stored in the subsurface of the New Mexico part of 

the Salt Basin in southern Otero County, N. Mex. Of this 

groundwater, 15 million acre-ft is potentially recoverable 

and potable (Livingston Associates and John Shomaker and 

Associates, 2002); however, a better understanding of the 

water budget hydrologic processes occurring in the Salt 

Basin would allow for the most effective management of 

these resources. 

As documented by Huff and Chace (2006), much 

previous work has been conducted to describe groundwater 

conditions in the Salt Basin, and despite the large number of 

studies, groundwater-recharge estimates remain wide ranging. 

Recharge to a system such as the Salt Basin aquifer can result 

largely from focused recharge of surface water in channels 

and at mountain fronts (Anderholm, 2000); however, karst and 

fractured-rock features in the downstream parts of some of the 

basins also may provide opportunities for substantial recharge. 

Mean-annual streamflow is commonly used in groundwater 

models as an estimate of the potential annual recharge to an 

aquifer (Waltemeyer, 2001). Characterization of mean-annual 

streamflow would, therefore, be an important contribution 

to estimates of potential recharge for the Salt Basin aquifer. 

In 2009, the U.S. Geological Survey (USGS), in cooperation 

with the New Mexico Interstate Stream Commission (ISC), 

estimated mean-annual streamflow for selected channels in 

the Salt Basin.
2 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Conventional streamflow-gaging stations can be used 

to obtain mean-annual streamflow, but it takes many years 

of data collection to establish a reliable estimate. The karst 

and fractured-rock features that dissect parts of the Salt Basin 

may affect channel-flow losses and groundwater recharge. 

Determination of channel flow in the Salt Basin at any one 

point along a reach does not provide information about flow 

losses upstream, downstream, or in the overbank areas of 

that reach. It would, therefore, take installation of numerous 

streamgages in each channel to address the question of 

flow loss.

Because direct methods of measuring the annual 

surface-water flow for the entire Salt Basin are not practical 

(prohibitively expensive), indirect methods were applied. Two 

indirect methods applied were based on channel geometry, 

and one method was based on the basin characteristics of area 

and precipitation. Although the use of basin characteristics to 

estimate flow is common, the method of estimating long-term 

streamflow characteristics based on channel geometry also has 

been applied in numerous studies in the United States since the 

1950s (Wahl, 1984). The channel-geometry method is based 

on the principle that channel-geometry characteristics, such as 

channel width, are determined or altered by forces operating 

within the channel over an extended period of time. 

Precipitation increases with elevation in the desert 

Southwest; therefore, the higher elevation subbasins of the Salt 

Basin, such as the Sacramento River subbasin, have greater 

runoff and potential for greater recharge. Although some 

channelized flow is probably lost through evapotranspiration, 

the short streamflow duration of the ephemeral channels may 

limit these losses. If evapotranspiration losses in the channels 

are minimal, the total mean-annual runoff from ephemeral 

channels in the Salt Basin can be considered a maximum 

potential basin recharge. Application of the channel-geometry 

method in multiple locations down the length of the stream 

can provide information on where annual flow is decreasing 

downstream and where recharge might be concentrating.

Purpose and Scope

This report presents estimates of mean-annual streamflow 

and flow loss of select, representative, ephemeral surfacewater channels in the Salt Basin. The channels evaluated in 

this study were mainly contained in four main subbasins of 

the Salt Basin. Estimates were calculated by using separate 

regional regression equations developed on the basis of 

channel-geometry measurements and basin and climatic 

characteristics. Channel losses were identified as decreases in 

annual-flow estimates in downstream reaches compared with 

upstream reaches. The study area is the part of the Salt Basin 

that lies within New Mexico.

Study Area

The Salt Basin (fig. 1) is a closed basin that covers about 

2,400 square miles (mi2

) of southeastern New Mexico and 

continues across the State line into Texas. The New Mexico 

part of the basin is bounded to the north by the Sacramento 

Mountains, to the east by a steep westward-facing escarpment 

that grades into the Guadalupe Mountains, and to the west by 

the Otero Mesa. A graben underlies the east-central valley, 

which is buried by as much as 750 feet (ft) of alluvial deposits. 

Bedrock that underlies the alluvial deposits and forms the 

surrounding plateaus is composed primarily of carbonate 

and mixed carbonate/evaporate units of Permian age 

(Huff and Chace, 2006). 

Elevations in the Salt Basin range from 9,255 ft at 

Sacramento Peak to 3,600 ft in the dry salt flats 15 miles (mi) 

south of the New Mexico border. The precipitation varies 

widely throughout the study area depending on elevation. 

The higher elevations of the study area near Sacramento Peak 

receive 33 inches annually, 35 percent of which occurs during 

the winter months, likely in the form of snow. Snowmelt in the 

southern Sacramento Mountains sustains perennial streamflow 

in the Sacramento River at or near the mountain front. The 

lower elevations near the western base of the Guadalupe 

Mountains at the New Mexico-Texas border receive less 

than 9 inches of precipitation annually, most of which occurs 

as rainfall (PRISM Climate Group, 2009). The analysis 

conducted in this study focuses primarily on four main 

subbasins in the northern and eastern parts of the Salt Basin 

in New Mexico, three of which are considered mountain-front 

drainages (Piñon Creek, Sacramento River, and Big Dog 

Canyon). 

Acknowledgments

Several people from the USGS New Mexico Water 

Science Center assisted in preparation of this report. Peter 

Bennett assisted with collection of field data. Roger Durall 

compiled geographic information system (GIS) data. Scott 

Waltemeyer provided guidance and advice on application of 

the method. Jack Veenhuis assisted with the precipitation-data 

analysis. Chuck Parrett of the USGS California Water Science 

Center provided a colleague review.

Steve Finch of John Shomaker and Associates also 

provided a colleague review.
Introduction 3

Shiloh Draw

Surveyors Canyon

New Tank Draw

Cornucopia Draw

Jernigan Wash

Salt Basin

Big Dog Canyon

Box Canyon

Wildcat Draw

104 ̊50’W 105 ̊0’W 105 ̊10’W 105 ̊20’W 105 ̊30’W 105 ̊40’W 105 ̊50’W

32 ̊40’N32 ̊30’N32 ̊20’N

32 ̊10’N

32 ̊0’N

LincolnNationalForest

Guadalupe Mountains

Big DogCanyonsubbasin

Cornucopia Draw subbasin

ChatfieldCanyon Seventeen

Canyon

SacramentoRiversubbasin

Sacramento Mountains

Sacramento River

Chaves CountyOtero County

Eddy County

Piñon Creek subbasin

GeorgeCanyon

CrookedCanyonsubbasin

Base from U.S. Geological Survey National Hydrography Dataset, 2002, 1:24,000 andHydrologic Unit Code modified, 2009, 1:24,000

CornudasMountainssubbasins NEW MEXICO

TEXAS

LincolnNationalForest

WildcatDraw

Fort Bliss MilitaryReservation

Study area

0 2.5 5 10 MILES

0 2.5 5 10 KILOMETERS

Otero Mesa

Chatfield Draw

Piñon Creek

Piñon Creek Tributary

Piñon Creek

Fleming Draw

EXPLANATION

Subbasins measured

Salt Basin boundaryForest boundaryMilitary boundary

Timberon

SacramentoPeak

Figure 1. Salt Basin study area in southeastern New Mexico showing location of surface-water subbasins measured for this study.
4 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Methods Used To Estimate 

Mean-Annual Streamflow

For this study, mean-annual streamflow was estimated 

at various locations on ephemeral channels in the Salt Basin 

by using multiple methods, each of which was initially 

established for estimating mean-annual streamflow specifically 

for channels in New Mexico. Two of the methods are based 

on channel geometry, specifically active-channel width, and 

one method is based on the basin characteristics of area and 

precipitation. The active-channel-width methods used include 

a relation for estimation of mean-annual streamflow developed 

by Waltemeyer (1993) for mountain-front channels in southern 

New Mexico and a relation for estimation of mean-annual 

streamflow developed by Kunkler and Scott1 (Waltemeyer, 

1993) for channels throughout the State of New Mexico. 

Waltemeyer used active-channel width (W) in feet to 

estimate mean-annual streamflow (Qa) in cubic feet per second 

as follows:

Qa = 0.04 W1.59 (1)

The Kunkler and Scott channel-geometry method 

(Waltemeyer, 1993) varies considerably in the weight assigned 

to the active-channel-width variable as follows:

Qa = 1.59 W0.58 (2)

The basin-characteristics method used also was 

developed by Waltemeyer (1993) and is specific to mountainfront channels in southern New Mexico:

Qa = 1.7 x10-4 A1.35 P1.65 (3)

where A = drainage area, in square miles, and

 P = mean-annual precipitation, in inches.

For this study, the channel-geometry annual-flow 

regression developed by Waltemeyer (1993) was selected 

to estimate flow. Waltemeyer’s (1993) channel-geometry 

equation was selected because the regression equation was 

established by using mountain-front channels in southern 

New Mexico and also because, at 29 percent, the standard 

error of estimate for the regression equation is much lower 

than standard error of estimate for both the Kunkler and 

Scott (1976) equation (82 percent) and the regression 

equation developed for mountain-front basin characteristics 

(46 percent) (Waltemeyer, 1993). 

1

 The original Kunkler and Scott report could not be located and may never 

have been published; however, the Kunkler and Scott mean annual flow 

regression equation is fully explained in Waltemeyer (1993).

Active-Channel Width

Many investigations of streamflow based on channel 

geometry have been conducted in the Western United States. 

Some of the more comprehensive investigations include 

Moore (1974), Hedman and Osterkamp (1982), Omang 

and others (1983), and Parrett and others (1987). Studies 

specific to New Mexico include Scott and Kunkler (1976), 

Hejl (1980), and Waltemeyer (1993, 2001). Summaries of 

the accuracy of channel-geometry measurements and the 

evolution of the channel-geometry method were published 

by Wahl (1977, 1984). Most of the previous studies were 

conducted to estimate flood-frequency discharges rather than 

mean-annual streamflows. No channel-geometry studies have 

been conducted in the Salt Basin.

Channel-width equations may provide more reliable 

estimates of mean-annual streamflow than do basincharacteristics equations in arid and semiarid regions where 

flow characteristics are often only poorly related to basin 

measurements (Hedman and Osterkamp, 1982; Wahl, 1984; 

Waltemeyer, 1993). Channel width generally reflects the 

prevailing streamflow and sediment-transport conditions at a 

site, regardless of the climatic conditions. 

The channel-geometry method described in detail by 

Hedman and Osterkamp (1982) and used by Waltemeyer 

(1993) requires field measurement of active-channel width 

and characterization of channel-bed material to estimate 

mean-annual runoff. The technique requires selection of 

appropriate reaches and proper identification of the active 

channels in the field. In general, reaches selected need to be 

the following: at least three times the cross-section width 

in length, 100 percent natural, nonregulated, and formed 

entirely in alluvium (no bedrock exposed). Reaches with 

incoming tributaries, large pools or steep inclines, unusually 

shaped channel cross sections, and braided channels need 

to be avoided because such channel inconsistencies would 

invalidate the method. Because of these criteria, reaches that 

contained bedrock in the bed or banks, which were entirely 

vegetated (such as grassy draws), and braided-channel 

sections were eliminated. Additionally, the method is 

applicable only where channel morphologies are well defined. 

Geomorphic and ecologic indicators are used to identify 

active-channel width. The most prominent indicators are a 

break in slope between the steep slope of the channel bank 

and the gently sloping flood plain, ideally coinciding with the 

lower limit of permanent vegetation.

Site Selection

Specific locations for applying the channel-geometry 

method were selected during field reconnaissance and by 

analyzing aerial photographs prior to field work. Sites were 

selected on the basis of the specific criteria previously 

described and whether or not they were easily accessible. 

Multiple measurements were made down the length of each 

major channel, in addition to selected tributary channels, to 
Methods Used To Estimate Mean-Annual Streamflow 5

provide information about where runoff accumulates and 

where channel losses occur. 

Selection of reaches was challenging because of the 

prominence of braided-stream morphology in many of the 

channels and the grassy swales and draws in the southwestern 

part of the study area, neither of which are applicable to the 

channel-geometry method. It also was not possible to use the 

active-channel-width method in the most downstream reaches 

of all channels in the Salt Basin, because all of the channels 

tended toward braiding and bifurcation as they reached 

the flatter terrain in the lower elevations of the internally 

drained basin. Lack of appropriate channel conditions in the 

southwestern and south-central parts of the basin resulted 

in most measurement sites being located within four main 

subbasins: Sacramento River, Piñon Creek, and Big Dog 

Canyon, located in the mountain-front areas of the Sacramento 

and Guadalupe Mountains, and Cornucopia Draw, located 

in the limestone uplands just below the mountain-front 

areas (fig. 1). 

Although selection of active-channel width in the field 

requires practice, identification of active-channel width in 

channels in the Salt Basin was fairly straightforward in most 

cases. The active-channel width was frequently defined by 

the lowest extent of permanent vegetation, which usually 

coincided with a change in slope from a steep one below the 

vegetation line to a shallower one above. Additionally, the 

clean gravel and cobbles in the channel beds provided a sharp 

visual contrast to the soil-rich overbank materials (fig. 2). 

Each site was labeled according to (1) the subbasin name, 

(2) relative position as the sites were established downstream, 

and (3) whether the site was located on the main-stem 

channel or a tributary. Each site label begins with a four-letter 

abbreviation for the subbasin name followed by a two-digit 

number that increases in downstream order followed by 

another two-digit number to represent a tributary of the named 

subbasin or zeros to represent main-stem sites. For example 

a site on the main stem of Big Dog Canyon would be labeled 

BDOG-20.00. A tributary in the vicinity of that main-stem 

site would be labeled BDOG-20.05. The two-digit numbers 

generally increase by fives to allow room for the later addition 

of sites in between two previously measured sites. 

Collection and Compilation of Data

Channel surveys were made at 10 sites in the Sacramento 

River subbasin, 8 in the Piñon Creek subbasin, 9 in the 

Big Dog Canyon subbasin, and 15 in the Cornucopia Draw 

subbasin, in addition to 10 in six other small subbasins (see 

appendix). Three measurements of active-channel width 

were made, one stream width apart, at all but two sites, 

where the reach length was not adequate. At each of three 

sites, one measurement was discarded after initial analysis 

because it was substantially different from the remaining 

two measurements at each of those sites. The two or three 

measurements made at each site were then averaged. Because 

the individual measurements at each site varied somewhat 

depending on natural channel-width variability, the precision 

of the average value was considered to be about two 

significant figures. For example, an average width of 9.86 ft 

was reported as 9.9 ft, and an average width of 20.36 ft was 

reported as 20 ft. The average active-channel-width value at 

each site was used in flow calculations. Photographs were 

taken facing upstream and downstream and of the substrate 

material at each site. A hand-held Global Positioning System 

(GPS) unit was used to record the coordinates of each 

measurement point. 

After the general channel substrate and morphologies 

were established through field visits, making additional 

channel-geometry measurements remotely by using aerial 

photographs also was tested. The location of each field 

measurement was plotted on Google Earth 

(Google Earth, 2009), and channels were again 

measured by using the remote measuring tool 

provided on Google Earth (Google Earth, 2009). 

Remote measurements of active-channel width 

were compared with the field measurements.

Basin Characteristics

The basin-characteristics regression 

equation requires the input variables of basin 

area and mean-annual precipitation for each 

site. A geographic information systems (GIS) 

database was used to calculate these variables 

at each measurement site for active-channel 

width. The 1971–2000 mean-annual precipitation 

coverage created by the PRISM Climate Group 

(2009) data was used to calculate the weighted 

mean-annual precipitation for each basin. Figure 2. Typical channel cross section in the northern Salt Basin, N. Mex. 

(SACR-25.00 central cross section, facing downstream).
6 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Analysis of Data

Mean-annual streamflow was estimated at each 

measurement location by using the two active-channel-width 

methods and one basin-characteristics method discussed. 

Field Observations

Substrate materials of the ephemeral channels varied 

throughout the Salt Basin and consisted almost exclusively of 

clean, subangular to well-rounded gravel and cobbles at most 

of the sites measured (fig. 3). Grain size, rounding, and sorting 

of the material varied with downstream distance. Sand and (or) 

clay occasionally would be present in the channel beds but 

only in small percentages compared to the gravel and cobbles. 

The only exception to this observation was one site in the 

Cornudas Mountain area, where the channel bed is dominated 

by sand.

Because of the limestone source rock in the northern Salt 

Basin, the alluvial-channel beds tend to exhibit early stages of 

carbonate cementation. Carbonate cementation results in banks 

that are more resistant to horizontal weathering and, perhaps, 

more prone to incision or entrenchment than they might be 

in the absence of the carbonate. At some measurement sites, 

vertical-channel banks were as much as 3 ft high. Generally, 

sites with deeply entrenched channels were avoided.

Measurements from Aerial Photography

Remote measurements of active-channel width 

determined from aerial photographs were poorly 

correlated with the field measurements and were 

determined to be an unsuitable substitute for field-data 

collection of active-channel width. From aerial photographs, 

it is not possible to see important channel features such as 

channel bars, channel braiding, and bedrock exposures that are 

Figure 3. Typical substrate material of ephemeral 

channels in the northern Salt Basin, N. Mex. 

(SACR.25.00 downstream cross section).

critical to establishing the active-channel width. Additionally, 

riparian vegetation frequently obscures the channel banks from 

view in the aerial photographs. The error of aerial photograph 

measurements from field measurements of active-channel 

width ranged from -125 percent to +75 percent (fig. 4). Only 

13 of 52 aerial-photograph measurements of active-channel 

width agreed within 10 percent of the field measurement. The 

aerial-photograph measurements with the lowest percent errors 

did not correspond to any particular magnitude of channel 

width. Of the 13 measurements with less than 10 percent error, 

the active-channel widths, measured in the field, 

ranged from 7.4 to 83 ft.

Limitations of the Equations

Regression equations may not provide reliable results 

when the variables are outside the range of values used to 

develop the equations. The established range of active-channel 

widths for the Waltemeyer (1993) channel-geometry method 

is 15–55 ft. Eight channels measured, mostly including small 

tributaries and two channels in Big Dog Canyon, have activechannel widths less than 15 ft. The three most downstream 

channel sections measured on Piñon Creek and one section 

measured on Sacramento River have active-channel widths 

greater than 55 ft. 

The established range of basin areas for the basincharacteristics method is 20.7–184 mi2

. Twenty-five sites 

including several of the smaller tributaries on Cornucopia 

Draw and Sacramento River and some of the miscellaneous 

channels measured have basin areas less than 20.7 mi2. The 

effect of this loss of sensitivity in the smaller basins generally 

results in low estimates of mean-annual streamflow and is 

evident in the plots of annual-flow estimates developed by 

the basin-characteristics method. The two most downstream 

sites on both Cornucopia Draw and Piñon Creek have basin 

areas larger than 184 mi2. Annual precipitation values for the 
Estimates of Mean-Annual Streamflow and Flow Loss 7

entire basin were within the range specified for the basincharacteristics equation.

Estimates of Mean-Annual Streamflow 

and Flow Loss

Initial analyses validate Wahl’s (1984) observation that 

basin area is only poorly related to flow characteristics for 

channels in arid regions. Basin areas compared to activechannel widths for 52 sites measured in this study are 

presented in a log-log scatter plot in figure 5.

Because the basin-characteristics equation relies 

on drainage area (A) and mean-annual precipitation 

(P), and because precipitation does not vary greatly 

across these basins, the basin-characteristics 

regression-equation estimates always indicate 

increasing annual flow with increasing basin area 

(and consequently, downstream distance) in the 

Salt Basin. In contrast to the trend of increasing 

flow with downstream distance, the maximum 

active-channel width did not occur at the most 

downstream sections measured in any of the main 

subbasins studied. The maximum active-channel 

widths in each basin are located at an intermediate 

location some distance upstream from the farthest 

downstream section measured. In three of the 

four main subbasins studied, the measurements of 

active-channel width follow a pattern of increasing 

downstream from the headwaters to some 

maximum value and then decreasing again towards 

the most downstream channel reach measured. The 

results of the active-channel-width measurements 

and mean-annual streamflow estimates for the 

individual subbasins follow.

0.1

1

10

100

1,000

1 10 100

ACTIVE-CHANNEL WIDTH, IN FEET

BASIN AREA, IN SQUARE MILES

All Salt Basin data

0

2

4

6

8

10

12

14

16

-130 -110 -90 -70 -50 -30 -10 10 30 50 70 More

FREQUENCY

PERCENT ERROR

Figure 4. Histogram of percent error in

aerial-photograph channel-geometry 

measurements for 52 sites in the Salt Basin, 

N. Mex. Results are presented in groups of 

20 percent starting at -130. For example, the 

percent error of -125 percent falls in the 

lowest group, -130 to -110.

Figure 5. Log-log scatter plot comparing basin area to active-channel 

width for all 52 sites measured in the Salt Basin, N. Mex.

Sacramento River Subbasin

The active-channel width was measured at five locations 

on the Sacramento River (fig. 6) and at four sites on the 

tributary Surveyors Canyon and two other small tributaries. 

Initial analysis indicated that the measurement made at site 

SACR-20.00 was anomalously high. Further inspection of 

field notes and photographs indicated that site SACR-20.00 

was less than ideal because of divided flow and insufficient 

length of reach; thus, the measurement was discarded. The 

active-channel widths and annual-flow estimates for the 

Sacramento River subbasin sites are shown in table 1. 
8 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Figure 6. A, Estimates of mean-annual streamflow for each Sacramento River, N. Mex., subbasin site displayed categorically by 

increasing basin area (ACW, active-channel width). B, Sacramento River subbasin (see fig. 1). C, Trends of mean-annual streamflow 

estimates compared to basin area for the two methods used at the study sites in the Sacramento River, N. Mex., subbasin.

B

SACR-05.00

SACR-15.05

SURV-05.05

SURV-05.00

SURV-10.00

SURV-15.00

SACR-40.00

SACR-25.00

SACR-20.00

SACR-15.00

Flow

0.0

10.0

20.0

0 20 40 60 80 100 120 140

ANNUAL FLOW, IN CUBIC FEET PER SECOND

30.0

C

BASIN AREA, IN SQUARE MILES

ACW Method (Waltemeyer, 1993)

Basin-Characteristics Method (Waltemeyer, 1993)

0.0

10.0

20.0

30.0

ANNUAL FLOW, IN CUBIC FEET PER SECOND

SURV-05-05SACR-15-05SURV-05-00SURV-10-00SURV-15-00SACR-05-00SACR-15-00SACR-25-00SACR-40-00

Basin Characteristics (Waltemeyer, 1993)

ACW (Waltemeyer, 1993)

A
Estimates of Mean-Annual Streamflow and Flow Loss 9

The maximum active-channel-width measurement was at 

site SACR-15.00 on the main stem of the Sacramento River, 

16 stream miles upstream from the most downstream channel 

section measured. The active-channel width at SACR-15.00 

was 41 ft, which corresponds to a mean-annual streamflow 

of 15 ft3

/s or 10,866 acre-ft/yr (fig. 6). This mean-annual 

streamflow is 81 percent higher than mean-annual streamflow 

calculated at the most downstream measurement site for 

the active-channel-width method, SACR-40.00. The activechannel width at SACR-40.00 is 29 ft, which corresponds to a 

mean-annual streamflow of 8.3 ft3

/s or 6,013 acre-ft/yr.

Cornucopia Draw Subbasin

The active-channel width was measured at eight locations 

on Cornucopia Draw (fig. 7), two locations on the Fleming 

Draw tributary, one location on the New Tank Draw tributary, 

and four other locations on tributaries of Cornucopia Draw 

(fig. 7). The active-channel widths and annual-flow estimates 

for Cornucopia Draw subbasin are presented in table 2. The 

maximum active-channel width occurred at site COPA40.00, which is 26.4 stream miles upstream from the most 

downstream section measured (COPA-70.00). 

The maximum active-channel width at COPA-40.00 

was 51 ft, which corresponds to a mean-annual streamflow of 

21 ft3

/s or 15,212 acre-ft/yr. This annual flow is 126 percent 

higher than the annual flow calculated at the most downstream 

channel section measured (see fig. 7, COPA-70.00), which had 

an active-channel width of 31 ft corresponding to a meanannual streamflow of 9.3 ft3

/s or 6,737 acre-ft/yr.

Piñon Creek Subbasin

In the Piñon Creek subbasin (fig. 8), the active-channel 

width was measured at six locations on the main stem of the 

channel and at two additional tributaries. The active-channel 

widths and mean-annual streamflow estimates for the Piñon 

Creek subbasin are presented in table 3. The maximum 

active-channel width occurred at site PINO-60.00, which is 

15 stream miles upstream from the most downstream section 

measured (PINO-70.00). 

The maximum active-channel width at PINO-60.00 was 

78 ft, which corresponds to a mean-annual streamflow of 

41 ft3/s or 29,700 acre-ft/yr. This annual flow is 37 percent 

higher than the annual flow calculated at the most downstream 

channel section measured (PINO-70.00) (see fig. 8), which 

had an active-channel width of 64 ft corresponding to an 

annual flow of 30 ft3

/s or 21,732 acre-ft/yr.

Big Dog Canyon Subbasin

In Big Dog Canyon (fig. 1), the active-channel width 

was measured at seven locations on the main stem of the 

channel and at two additional sites in Box Canyon adjacent 

to the area north of Big Dog Canyon. As with the other three 

basins previously discussed, considerable effort was taken in 

the field to find suitable locations for active-channel-width 

measurements in Big Dog Canyon. There were, however, 

two specific challenges to distinguishing the active-channel 

widths in this subbasin (fig. 9). First, the channel beds were 

rarely flat and were usually sloping to one side. Second, 

sparse or moderate vegetation often covered the entire width 

of the channel. 

Table 1. Sacramento River, N. Mex., active-channel widths and mean-annual streamflow estimates.

[ACW, active-channel width; ft3/s, cubic feet per second]

Site (see fig. 6) ACW, in feet

Annual flow in ft3

/s, 

Waltemeyer (1993) ACW 

method (standard error: 

29 percent)

Annual flow in ft3

/s, Kunkler 

and Scott ACW method (in 

Waltemeyer, 1993) (standard 

error: 82 percent)

Annual flow in ft3

/s, 

Waltemeyer (1993) 

basin-characteristics 

method (standard error: 

46 percent)

SURV-05.05 26 7.2 10 1

0.02

SACR-15.05 26 7.3 10 1

0.07

SURV-05.00 22 5.3 9.4 1

0.42

SURV-10.00 14 2

2.7 7.4 10.52

SURV-15.00 20 4.5 8.9 1

0.67

SACR-05.00 16 3.3 7.9 8.9

SACR-15.00 41 15 14 11

SACR-25.00 34 11 12 22

SACR-40.00 29 8.3 11 22

1

 Basin area is outside the range for which the equation was developed.

2

 Active-channel width is outside the range for which the equation was developed.
10 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

COPA-45.00

COPA-45.05

COPA-50.00

COPA-50.05

COPA-55.00

COPA-60.00 COPA-65.00

COPA-70.00

FLEM-20.05

COPA-10.00

NEWT-25.05 FLEM-20.15

COPA-65.05

COPA-65.10

COPA-40.00

Fleming Draw

Cornucopia Draw

Jernigan Wash

Flow

Flow

B

0

10

20

30

0 20 40 60 80 100 120 140 160 180 200

ANNUAL FLOW, IN CUBIC FEET PER SECOND

BASIN AREA, IN SQUARE MILES

Basin-Characteristics Method (Waltemeyer, 1993)

ACW Method (Waltemeyer, 1993)

C

0

10

20

30

COPA-50-05NEWT-25-05COPA-45-05COPA-65-05FLEM-20-05COPA-10-00COPA-65-10FLEM-20-15COPA-40-00COPA-45-00COPA-50-00COPA-55-00COPA-60-00COPA-65-00COPA-70-00

ANNUAL FLOW, IN CUBIC FEET PER SECOND

Basin-Characteristics Method (Waltemeyer, 1993)

ACW Method (Waltemeyer, 1993)

A

Figure 7. A, Estimates of mean-annual streamflow for each Cornucopia Draw, N. Mex., subbasin site displayed categorically by 

increasing basin area (ACW, active-channel width). B, Cornucopia Draw subbasin (see fig. 1). C, Trends of mean-annual streamflow 

estimates compared to basin area for the two methods used at the study sites in the Cornucopia Draw, N. Mex., subbasin.
Estimates of Mean-Annual Streamflow and Flow Loss 11

PINO-10.00

PINO-15.00

PINO-20.05

PINO-20.15

PINO-50.00

PINO-60.00

PINO-05.00

PINO-70.00

Flow

Piñon Creek

B

0.00

10.00

20.00

30.00

40.00

50.00

PINO-20-05PINO-05-00PINO-10-00PINO-20-15PINO-15-00PINO-50-00PINO-60-00PINO-70-00

ANNUAL FLOW, IN CUBIC FEET PER SECOND

Basin-Characteristics Method (Waltemeyer, 1993)

ACW Method (Waltemeyer, 1993)

A

0.0

10.0

20.0

30.0

40.0

50.0

0 50 100 150 200 250 300

ANNUAL FLOW, IN CUBIC FEET PER SECOND

BASIN AREA, IN SQUARE MILES

ACW Method (Waltemeyer, 1993)

Basin-Characteristics Method (Waltemeyer, 1993)

C

Figure 8. A, Estimates of mean-annual streamflow for each Piñon Creek, N. Mex., subbasin site displayed categorically by increasing 

basin area (ACW, active-channel width). B, Piñon Creek subbasin (see fig. 1). C, Trends of mean-annual streamflow estimates compared 

to basin area for the two methods used at the study sites in the Piñon Creek, N. Mex., subbasin.
12 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Table 2. Cornucopia Draw, N. Mex., active-channel widths and mean-annual streamflow estimates.

[ACW, active-channel width; ft3/s, cubic feet per second]

Site (see fig. 7) ACW, in feet

Annual flow in ft3

/s, 

Waltemeyer (1993) ACW 

method (standard error: 

29 percent)

Annual flow in ft3

/s, 

Kunkler and Scott ACW 

method (in Waltemeyer, 

1993) (standard error:

82 percent)

Annual flow in ft3

/s, 

Waltemeyer (1993) 

basin-characteristics 

method (standard error: 

46 percent)

COPA-50.05 12 1

2.2 6.8 20.02

COPA-65.05 31 9.6 12 2

0.22

COPA-45.05 25 6.7 10 2

0.11

NEWT-25.05 18 4.0 8.5 2

0.10

COPA-10.00 24 6.2 9.9 2

0.32

COPA-65.10 30 8.8 11 2

0.41

FLEM-20.05 37 12 13 2

0.38

FLEM-20.15 45 17 15 0.91

COPA-40.00 51 21 16 6.0

COPA-45.00 41 15 14 11

COPA-50.00 35 11 12 13

COPA-55.00 40 14 14 14

COPA-60.00 33 11 12 15

COPA-65.00 33 10 12 21

COPA-70.00 31 9.3 12 21

1

Active-channel width is outside the range for which the equation was developed.

2

 Basin area is outside the range for which the equation was developed.

Table 3. Piñon Creek, N. Mex., active-channel widths and mean-annual streamflow estimates.

[ACW, active-channel width; ft3/s, cubic feet per second]

Site (see fig. 8) ACW, in feet

Annual flow in ft3

/s, 

Waltemeyer (1993) ACW 

method (standard error: 

29 percent)

Annual flow in ft3

/s, 

Kunkler and Scott ACW 

method (in Waltemeyer, 

1993) (standard error: 

82 percent)

Annual flow in ft3

/s, 

Waltemeyer (1993) 

basin-characteristics 

method (standard error: 

46 percent)

PINO-20.05 28 8.0 11 1

0.37

PINO-05.00 21 5.2 9.3 2.5

PINO-10.00 23 6.0 9.8 2.8

PINO-20.15 24 6.1 9.9 3.5

PINO-15.00 44 16 14 4.7

PINO-50.00 62 2

28 17 21

PINO-60.00 78 2

41 20 31

PINO-70.00 64 2

30 18 37

1

 Basin area is outside the range for which the equation was developed.

2

 Active-channel width is outside the range for which the equation was developed.
Estimates of Mean-Annual Streamflow and Flow Loss 13

Proceeding in a downstream direction, the active-channel 

widths in Big Dog Canyon do not exhibit the trend of the other 

three subbasins where the active-channel widths increased 

gradually to a maximum value and then decreased towards 

the most downstream sections. The active-channel widths 

for Big Dog Canyon varied unpredictably with distance 

downstream. The difficulties in differentiating and measuring 

the active-channel widths in Big Dog Canyon account for the 

unpredictable variations in the active-channel widths with 

distance downstream. The active-channel widths and meanannual streamflow estimates for the Big Dog Canyon subbasin 

are presented in table 4. 

The active-channel-width measurements made with 

the most confidence (because of the more classic channel 

geometry) are the tributary site in Box Canyon BDOG-50.02 

and the main-stem sites BDOG-30.00 and BDOG-40.00. 

BDOG-40.00 has the maximum dependable active-channelwidth measurement in the Big Dog Canyon subbasin. 

The active-channel width at BDOG-40.00 is 24 ft, which 

corresponds to a mean-annual streamflow of 6.4 ft3

/s or 

4,636 acre-ft. 

Outlier Measurements

Active-channel widths were measured in the field at 

several smaller tributaries unrelated to, or downstream from, 

the four main subbasins previously discussed. The activechannel widths and mean-annual streamflow estimates 

for the outlying subbasins are presented in table 5. Three 

measurements were made on Chatfield Draw in Chatfield 

Canyon (fig. 1). Here again, the largest active-channel width 

of the three Chatfield Canyon sites measured was not the most 

downstream measurement but the middle measurement. The 

most downstream measurement (CHAT-15.00) had a stream 

length of 6.08 mi, and the site with the largest active-channel 

width (CHAT-10.00) had a stream length of 4.44 mi. The 

annual flow calculated for the maximum active-channel width 

in Chatfield Canyon is 9.2 ft3

/s or 6,664 acre-ft. 

Other outlier basins measured included three small 

basins on the western slopes of the Cornudas Mountains 

(CNDS), one measurement in a small (0.3 mi2

) basin near 

Big Dog Canyon called Crooked Canyon (CCAN), and 

one measurement in the northwestern part of the basin 

called Wildcat Draw (WILD) (fig. 1 and table 5). Two other 

downstream tributaries of the Sacramento River also were 

measured, but both canyons had irregular channels due 

to incision and bedrock outcrops, so these measurements 

were discarded. The measurements made in the Cornudas 

Mountains, Wildcat Draw, and Crooked Canyon subbasins 

were intended to expand the reach of the methods across the 

Salt Basin. Unfortunately, the active-channel widths and basin 

areas are too small in the Cornudas Mountains and Crooked 

Canyon subbasins to give reliable results with either the 

channel-geometry method or the basin-characteristics method. 

The measurement and subsequent calculations for Wildcat 

Draw are reliable, but because only one measurement was 

made in the entire draw, no information is available about the 

location of maximum flow or possible flow losses.

The USGS has continuously operated a peak-flow 

streamgage in the Fleming Draw tributary to Cornucopia 

Draw since 1959 (National Water Information System, 2009). 

This gage is designed to record only the peak gage height of 

floods and does not have a record applicable to calculating 

annual flow; however, the peak-flow record at the Fleming 

Draw streamgage does provide information on the timing of 

large rainfall events. There have been only 5 years with no 

flow at Fleming Draw since 1959. For the period 1959–2009, 

the gage recorded annual peak flows that were less than a 

Figure 9. Typical Big Dog Canyon, N. Mex., 

channel section (BDOG-20.00 central cross section, 

facing upstream). 
14 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Table 4. Big Dog Canyon, N. Mex., active-channel widths and mean-annual streamflow estimates.

[ACW, active-channel width; ft3/s, cubic feet per second]

Site ACW, in feet

Annual flow in ft3

/s, 

Waltemeyer (1993) ACW 

method (standard error: 

29 percent)

Annual flow in ft3

/s, 

Kunkler and Scott ACW 

method (in Waltemeyer, 

1993) (standard error:

82 percent)

Annual flow in ft3

/s, 

Waltemeyer (1993) basincharacteristics method 

(standard error:

46 percent)

BDOG-50.02 14 1

2.6 7.3 20.05

BDOG-50.05 22 5.6 9.6 2.1

BDOG-20.00 16 3.3 7.9 1.5

BDOG-25.00 12 1

2.0 6.6 3.3

BDOG-27.00 26 7.1 11 3.4

BDOG-30.00 17 3.7 8.3 3.6

BDOG-35.00 12 1

2.0 6.6 7.6

BDOG-40.00 24 6.4 10 8.1

BDOG-45.00 18 4.1 8.6 10

1

 Active-channel width is outside the range for which the equation was developed.

2

 Basin area is outside the range for which the equation was developed.

Table 5. Southeastern New Mexico outlier active-channel widths and mean-annual streamflow estimates.

[ACW, active-channel width; ft3/s, cubic feet per second]

Site ACW, in feet

Annual flow in ft3

/s, 

Waltemeyer (1993) ACW 

method (standard error: 

29 percent)

Annual flow in ft3

/s, 

Kunkler and Scott ACW 

method (in Waltemeyer, 

1993) (standard error:

82 percent)

Annual flow in ft3

/s, 

Waltemeyer (1993) basincharacteristics method 

(standard error:

46 percent)

CHAT-05.00 18 4.0 8.5 1

0.08

CHAT-10.00 42 15 14 1

0.71

CHAT-15.00 31 9.2 11 1

0.84

CNDS-05.00 16 3.1 7.7 1

0.07

CNDS-05.05 11 2

1.8 6.3 10.01

CNDS-05.10 12 2

2.0 6.6 10.03

CCAN-20.05 7.4 2

0.97 5.1 10.003

WILD-20.00 29 8.5 11 0.36

1

 Basin area is outside the range for which the equation was developed.

2

 Active-channel width is outside the range for which the equation was developed.
Comparison of Annual-Flow and Flow-Loss Estimates 15

small base level of flow during 12 years and recorded flood 

peaks during 28 years. Of the 28 years with flood peaks, the 

actual dates of the peaks were estimated by using Carlsbad, N. 

Mex., precipitation records 23 times. The dates of the 23 peak 

flows indicate a clear link to summer monsoonal precipitation 

patterns because 17 of the 23 recorded dates occurred in June, 

July, or August. The flow associated with the highest flood 

peak was 9,900 ft3/s, and it occurred in July 2006.

Comparison of Annual-Flow 

and Flow-Loss Estimates

In all four of the main subbasins studied, active-channel 

widths achieved a maximum value some distance upstream 

of the most downstream section measured. Selected basin 

characteristics associated with the location of the maximum 

active-channel-width measurement in the four main subbasins 

measured are listed in table 6.

Results from the Waltemeyer (1993) channel-geometry 

method, using the maximum active-channel-width values for 

each of the four main subbasins, indicate that, on average, 

an estimated 60,414 acre-ft of flow is generated annually 

among the four main subbasins, three of which are mountainfront subbasins, in the New Mexico part of the Salt Basin. 

These basins represent most of the mountain-front regions 

in the study area and 30 percent of the total Salt Basin area 

in New Mexico. The sum of the annual flows from the four 

basins evaluated could be considered a reasonable estimate of 

recharge for the New Mexico part of the Salt Basin, although 

subbasin areas not evaluated could contribute additional 

recharge to the Salt Basin, particularly in areas with karst (sink 

holes) and fractured rock. The standard error for this estimate 

is 29 percent. Results from the basin-characteristics method 

indicate a mean-annual streamflow of 65,196 acre-ft (standard 

error of estimate of 46 percent), which is comparable to the 

channel-geometry method. The important distinction between 

the basin-characteristics and channel-geometry estimates is 

not so much the volume but the location of the maximumflow estimates. The location of the maximum flow estimated 

from the basin-characteristics method is always calculated at 

the most downstream section measured, whereas the channelgeometry method indicated that the maximum flow occurs 

upstream from the most downstream section measured.

Active-channel width measurements indicate that each of 

the four main subbasin channels studied loses between 27 and 

56 percent of annual flow from the point of maximum activechannel width to the most downstream measurable section 

in the channel. The flow losses are occurring over distances 

of 6.1–16.4 stream miles. The flow losses and associated 

distances for each of the four main subbasins studied are 

summarized in table 7. The basin-characteristics method is not 

useful in terms of identifying, quantifying, or locating flow 

losses along the length of a channel.

The active-channel-width method for estimating meanannual streamflow has traditionally been used at single 

locations on channels where estimates for annual flow are 

desired. The results of this study indicate that the activechannel-width method also has applications for estimating 

locations and quantities of flow losses when applied down the 

length of a channel. Each of the measurements for a channel 

was spaced several miles apart down the length of the stream. 

More detailed information on locations and amounts of flow 

accumulations and losses could possibly be obtained from 

closer spacing of sites down the length of a channel, but users 

are cautioned that measurements of channel width are subject 

to error and that the flow estimates also have considerable 

error as indicated by the standard errors of the regressions. 

More precisely, determining flow losses and their locations 

probably requires more accurate methods, such as gain-loss 

flow measurements, which can be challenging to acquire in 

these flashy systems.

Table 6. Basin characteristics associated with location of maximum active-channel width in each of the main subbasins measured in 

southeastern New Mexico.

[ACW, active-channel width; NAVD 88, North American Vertical Datum of 1988]

Subbasin (see fig. 1) Maximum ACW,

in feet

Stream length,

in miles

Basin area,

in square miles

Elevation, in feet 

above NAVD 88

Mean basin 

elevation, in feet

Sacramento River 41 22.4 66.1 6,318 7,888

Cornucopia Draw 51 13.2 70.1 4,955 5,819

Piñon Creek 78 38.1 229 4,696 6,149

Big Dog Canyon 24 25.2 79.6 4,552 5,741
16 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Summary

As much as 57 million acre-feet (acre-ft) of groundwater 

may be stored in the subsurface of the New Mexico part of the 

Salt Basin in southern Otero County, N. Mex. Recharge to a 

system such as the Salt Basin aquifer can result largely from 

focused recharge of surface water in channels and at mountain 

fronts. The Salt Basin is a closed basin that covers about 

2,400 square miles (mi2

) of southeastern New Mexico and 

extends across the State line into Texas. A graben underlies 

the east-central valley, which is buried by hundreds of feet of 

alluvial deposits. Bedrock that underlies the alluvial deposits 

and forms the surrounding plateaus is composed primarily 

of carbonate and mixed carbonate/evaporate units that can 

be karst forming in places. Karst and fractured-rock features 

in the downstream parts of some areas of the Salt Basin also 

may provide opportunities for substantial recharge. Annual 

recharge to an aquifer such as the Salt Basin aquifer is 

commonly estimated in groundwater models by mean-annual 

streamflow. 

Mean-annual streamflow was estimated for four main 

subbasins, including three mountain-front subbasins, in the 

internally drained Salt Basin in southeastern New Mexico. 

These four main subbasins account for 30 percent of the 

Salt Basin area in New Mexico. Estimates of mean-annual 

streamflow were generated at multiple sites down the length 

of each basin by using two regional regression equations 

based on channel geometry and one based on the basin 

characteristics of area and precipitation. The channel-geometry 

method requires field measurements of active-channel width at 

carefully selected channel reaches. The possibility of making 

channel-geometry measurements remotely, by using aerial 

photographs to increase measurement density and project 

efficiency, was tested. Remote measurements of activechannel width correlated poorly with field measurements and 

were determined to be an unsuitable substitute for field data 

collection of active-channel widths.

Estimates of streamflow derived by the two methods 

were compared for the four main subbasins. Results from 

the channel-geometry method indicate that, on average, an 

estimated 60,414 acre-ft of flow, assumed to be available for 

potential recharge to the basin, is generated annually among 

the four main subbasins, including the three main mountainfront subbasins, in the New Mexico part of the Salt Basin. 

The standard error for this estimate is 29 percent. Results 

from the basin-characteristics method indicate a mean-annual 

streamflow of 65,196 acre-ft (standard error of estimate of 

46 percent), which is comparable to the channel-geometry 

method. 

The use of the channel-geometry method at multiple 

locations down the length of each channel also provided 

information on the locations of flow accumulation and losses. 

The important distinction between the basin-characteristics 

and channel-geometry estimates is not so much the volume 

but the location of the maximum-flow estimates. The location 

of the maximum flow estimated from the basin-characteristics 

method is always calculated at the most downstream section 

measured, whereas the channel-geometry method indicated 

that the maximum flow occurs upstream from the most 

downstream section measured. Channels measured achieved 

maximum active-channel widths from 6 to 16 stream miles 

upstream from the locations in which channels bifurcate and 

lose shape altogether in the lowlands of the internally drained 

basin. Active-channel-width measurements indicate that each 

of the four main subbasin channels studied loses between 27 

and 56 percent of annual flow from the point of maximum 

active-channel width to the most downstream measurable 

section in the channel.

References

Anderholm, S.K., 2000, Mountain-front recharge along 

the eastern side of the middle Rio Grande Basin, central 

New Mexico: U.S. Geological Survey Water-Resources 

Investigations Report 00–4010, 36 p.

Table 7. Flow losses and associated distances for the four main subbasins studied in southeastern New Mexico.

Subbasin

(see fig. 1)

Maximum

annual-flow 

estimate,

in acre-feet

Most downstream 

annual-flow 

estimate,

in acre-feet

Difference between 

maximum annual 

flow and 

downstream annual 

flow, in acre-feet

Flow loss,

in percent

Stream miles over 

which losses occur

Sacramento River 10,866 6,013 4,853 45 16.0

Cornucopia Draw 15,212 6,737 8,475 56 16.4

Piñon Creek 29,700 21,723 7,977 27 9.2

Big Dog Canyon 4,636 2,970 1,666 36 6.1
 References 17

Google Earth, 2009, Source measurements, accessed 

November 2009, at http://earth.google.com/.

Hedman, E.R., and Osterkamp, W.R., 1982, Streamflow 

characteristics related to channel geometry of streams 

in Western United States: U.S. Geological Survey 

Water-Supply Paper 2193, 17 p.

Hejl, H.R., 1980, Preliminary appraisal of ephemeralstreamflow characteristics as related to drainage area, 

active-channel width, and soils in northwestern New 

Mexico: U.S. Geological Survey Open-File Report 81–64, 

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 19

Appendix. Data Collected in the Salt Basin, N. Mex.

Table. Data collected in the Salt Basin, N. Mex.

[ACW, active-channel width; NAVD 88, North American Vertical Datum of 1988]

Subbasin

(see fig. 1) Site name

Average 

ACW, in 

feet

Basin area, 

in square 

miles

Annual 

precipitation for 

basin, in inches

Upstream 

stream 

length, in 

miles

Elevation 

at site, in 

feet above 

NAVD 88

Average basin 

elevation, in 

feet above 

NAVD 88

Big Dog Canyon BDOG-20.00 35 26.3 21.0 14.56 5,223 6,174

BDOG-25.00 1

12 37.1 20.6 17.17 5,058 6,059

BDOG-27.00 26 38.6 20.5 18.34 4,981 6,039

BDOG-30.00 17 40.1 20.4 19.45 4,898 6,018

BDOG-35.00 1

12 74.8 19.3 23.67 4,641 5,550

BDOG-40.00 24 79.6 19.1 25.17 4,552 5,741

BDOG-45.00 18 97.0 18.3 31.26 4,156 5,602

BDOG-50.02 1

14 22.35 15.7 3.67 4,372 4,890

BDOG-50.05 22 29.8 15.2 4.67 4,190 4,838

Crooked Canyon CCAN-20.05 1

7.4 20.3 17.0 0.91 5,281 5,473

Chatfield Canyon CHAT-05.00 18 2

2.3 21.4 2.57 6,016 6,409

CHAT-10.00 42 2

10.6 22.6 4.44 5,797 6,247

CHAT-15.00 31 2

12.1 22.7 6.08 5,647 6,218

Cornudas Mountains CNDS-05.00 16 2

3.77 13.0 1.96 4,679 5,211

CNDS-05.05 1

11 20.71 13.0 4.01 4,884 5,391

CNDS-05.10 1

12 21.97 13.0 1.54 4,764 5,460

Cornucopia Draw COPA-10.00 24 2

8.4 17.0 5.07 5,499 5,902

COPA-40.00 51 70.1 17.6 13.17 4,955 5,819

COPA-45.00 41 112.5 17.2 16.15 4,743 5,656

COPA-45.05 25 2

4.69 14.4 3.54 4,573 4,982

COPA-50.00 35 134.6 16.8 20.14 4,512 5,543

COPA-50.05 1

12 21.38 13.4 2.58 4,604 4,856

COPA-55.00 40 141.7 16.6 22.20 4,414 5,499

COPA-60.00 33 153.4 16.3 26.66 4,243 5,427

COPA-65.00 33 2

190.0 16.6 28.16 4,160 5,279

COPA-65.05 31 2

7.05 15.5 3.40 5,026 5,372

COPA-65.10 30 2

11.5 15.3 6.45 4,751 5,244

COPA-70.00 31 2

190.7 16.6 29.59 4,122 5,276

Fleming Draw FLEM-20.05 37 2

8.1 19.4 6.60 5,880 6,362

FLEM-20.15 45 2

16.6 18.2 11.61 5,427 6,114
20 Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, 2009

Subbasin

(see fig. 1) Site name

Average 

ACW, in 

feet

Basin area, 

in square 

miles

Annual 

precipitation for 

basin, in inches

Upstream 

stream 

length, in 

miles

Elevation 

at site, in 

feet above 

NAVD 88

Average basin 

elevation, in 

feet above 

NAVD 88

George Canyon 3

GEOR-05.00 51 22.57 18.4 2.77 4,794 5,473

New Tank Draw NEWT-25.05 18 2

3.38 18.0 4.69 5,621 6,029

Piñon Creek PINO-05.00 21 27.7 22.2 10.46 6,509 7,252

PINO-10.00 23 30.7 22.0 12.15 6,367 7,195

PINO-15.00 44 45.5 21.7 15.97 6,087 7,109

PINO-20.05 28 2

7.25 20.7 5.32 6,181 6,610

PINO-20.15 24 42.3 19.2 13.34 5,715 6,389

PINO-50.00 1

62 164.8 18.9 30.27 5,160 6,368

PINO-60.00 1

78 2228.8 18.2 38.11 4,696 6,149

PINO-70.00 1

64 2265.6 17.7 47.29 4,141 5,987

Sacramento River SACR-05.00 16 54.3 27.5 18.24 0 8,082

SACR-15.00 41 66.1 27.1 22.39 6,318 7,888

SACR-15.05 26 2

1.67 25.0 2.11 6,321 6,859

3

SACR-20.00 183 79.7 26.7 25.85 6,013 7,741

SACR-25.00 34 115.2 25.5 32.01 5,472 7,313

SACR-40.00 29 119.0 25.2 38.38 4,959 7,252

Seventeen Canyon 3

SEVN-05.00 29 21.57 21.0 2.13 5,290 5,894

Surveyors Canyon SURV-05.00 22 2

7.3 22.4 4.49 6,248 6,734

SURV-05.05 26 2

0.77 23.0 1.35 6,281 6,716

SURV-10.00 1

14 28.47 22.5 5.21 6,147 6,718

SURV-15.00 20 2

10.2 22.6 5.80 6,070 6,674

Wildcat Draw WILD-20.00 29 2

7.32 20.5 6.84 5,094 5,788

1

 Active-channel width is outside the range for which the equation was developed.

2

 Basin area is outside the range for which the equation was developed.

3

 Measurement is unreliable and excluded from analysis.

Prepared by the USGS Lafayette Publishing Service Center

Table. Data collected in the Salt Basin, N. Mex.—Continued

[ACW, active-channel width; NAVD 88, North American Vertical Datum of 1988]
ISBN 978-1-4113-3155-6

9 7 81411 331556

Printed on recycled paper

Tillery—Estimates of Mean-Annual Streamflow and Flow Loss for Ephemeral Channels in the Salt Basin, Southeastern New Mexico, 2009—SIR 2011–5062