WATER-RESOURCES APPRAISAL OF 

THE WET MOUNTAIN VALLEY, IN 

PARTS OF CUSTER AND FREMONT 

COUNTIES, COLORADO

U. S. GEOLOGICAL SURVEY

Water-Resources Investigations 78-1

Water

Prepared in cooperation with the 

Southeastern Colorado Wat^rOLOHAp 

Conservancy District

\

U.S.G

WRD,
\N
UNITED STATES

DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

WATER-RESOURCES APPRAISAL OF THE WET MOUNTAIN VALLEY, 

IN PARTS OF CUSTER AND FREMONT COUNTIES, COLORADO 

By Clark J. Londquist and Russell K. Livingston

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations 78-1

Prepared in cooperation with the

Southeastern Colorado Water Conservancy District

Water Resources

Library

Open-File Report 

February 1978
UNITED STATES DEPARTMENT OF THE INTERIOR 

CECIL D. ANDRUS, Secretary

GEOLOGICAL SURVEY 

W. A. Radlinski, Acting Director

Open-File Report

For additional information write to:

District Chief 

U.S. Geological Survey 

Box 25046, Mail Stop 415 

Denver Federal Center 

Denver, Colo. 80225
CONTENTS

Page

Metric conversion ............................ IV

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

Introduction. .............................. 2

Geohydrologic setting .......................... 2

Ground-water occurrence ......................... 6

Mountainous area .......................... 6

Valley-floor area. ......................... 8

Ground-water movement .......................... 12

Surface water .............................. 13

Streamflow ............................. 13

Runoff analysis. .......................... 21

Magnitude and frequency of floods. ................. 21

Generalized water budget. ........................ 23

Precipitation. ........................... 26

Surface-water inflow and outflow .................. 26

Ground-water underflow ....................... 26

Evapotranspirat ion ......................... 29

Change in storage. ......................... 29

Water quality .............................. 29

Ground water ............................ 29

Surface water. ........................... 34

Suitability of water for irrigation. ................ 34

Summary ................................. 37

References. ............................... 39

Supplemental information. ........................ 41

System of numbering water-quality sampling sites .......... 41

System of numbering wells. ..................... 41

System of numbering surface-water stations ............. 41

Geologic log of test hole SC 23-J2- 6AAAB1 ............. 45

Records of selected wells. ..................... 48

Specific conductance and temperature of water data from selected

surface-water stations ...................... 54

ILLUSTRATIONS

Plate 1. Map showing location of wells, surface-water gaging

stations and potentiometric surface of the basin-fill

aquifer, Wet Mountain Valley, parts of Custer and

Fremont Counties, Colorado. ........... In pocket

Figures 1-4. Maps showing:

1. Location of study area. ............... 3

2. Generalized geology ................. 4

3. Distribution of average annual precipitation, 1931~60 5

4. Availability of ground water. ............ 7

5. Diagram showing electrical resistivity section near

Westcliffe. ....................... 9

6. Map showing depth to water in the basin-fill aquifer. ... 10

I I I
CONTENTS

Page

Figure 7- Hydrographs from selected wells in the basin-fill aquifer. . . 11 

8. Hydrograph of mean monthly discharge of Grape Creek near

Westcliffe, 1927 to 1975 water years ............ 16

9- Hydrograph of annual runoff of Grape Creek near Westcliffe,

1925 to 1975 water years .................. 20

10. Map showing locations of water-budget tributary areas and

area of basin-fill material in the Grape Creek basin .... 28

11. Diagram for the classification of irrigation water ...... 36

12. Diagram showing U.S. Geological Survey's system of numbering

water-quality sampling sites ................ k2

13. Diagram showing system of numbering wells. .......... ^3

TABLES

Table 1. Surface-water diversion rights prior to 1880 along Grape and

Texas Creeks ........................ 1 k

2. Principal lakes and reservoirs in the Wet Mountain Valley

and vicinity ........................ 17

3. Stream-gaging stations in the Wet Mountain Valley and vicinity 18

4. Annual runoff in the Wet Mountain Valley ........... 22

5. Flood characteristics for selected gaging stations in the

Wet Mountain Valley. .................... 2k

6. Generalized annual water budgets for two areas in the Wet

Mountain Valley, calendar years 1931 through 1960. ..... 27

7. Chemical analyses of water from selected wells ........ 30

8. Recommended limits of selected substances in water supplies. . 33

9. Chemical analyses of water from selected surface-water sites . 35 

10. Salinity and sodium classification for irrigation water. ... 38

METRIC CONVERSION

Customary units used in this report may be expressed as metric units by 

use of the following conversion factors:

Multiply customary units

inch (in.) 

foot (ft)

foot per mile (ft/mi) 

mile (mi) 

square mile (mi 2 ) 

acre

acre-foot (acre-ft) 

gallon per minute (gal/min) 

cubic foot per second (ft 3 /s) 

cubic foot per second per square 

mile [(ft 3 /s)/mi 2 ]

By

25.40 

.3048 

.189^ 

1.609 

2.590

1.233xlO~ 3 

.06309 

.02832 

.01093

To obtain metric units

mi 1 1 imeters 

meter

meter per kilometer 

kilometers 

square kilometers 

hectare

cubic hectometers 

liter per second 

cubic meter per second 

cubic meter per second per 

square ki lometer

IV
WATER-RESOURCES APPRAISAL OF THE WET MOUNTAIN VALLEY, 

IN PARTS OF CUSTER AND FREMONT COUNTIES, COLORADO

By Clark J. Londquist and Russell K. Livingston

ABSTRACT

The Wet Mountain Valley is an intermontane trough filled to a depth of at 

least 6,700 feet with unconsolidated deposits. Ground water occurs under both 

artesian and water-table conditions within the basin-fill aquifer and groundwater movement is toward Grape and Texas Creeks. The depth to the water table 

is less than 10 feet in an area of about 40 square miles along the central 

part of the valley and is less than 100 feet in most of the remainder of the 

valley. Ground water stored in the upper 100 feet of saturated basin-fill 

sediments is estimated to total 1.5 million acre-feet.

Yields greater than 50 gallons per minute generally can be expected from 

wells in the central part of the basin-fill aquifer, and yields less than 50 

gallons per minute are generally reported from wells around the edge of the 

basin-fill aquifer. Yields of wells in the mountainous areas are generally 

less than 10 gallons per minute.

The 540-square-mile study area is drained by two principal streams, Grape 

Creek and Texas Creek. Most streamflow occurs as a result of snowmelt runoff 

during June and July. In addition to a stream-gaging station on Grape Creek 

near Westcliffe, which has operated since 1924, there are two continuousrecord and four partial-record stations in the study area that were 

established in 1974. The long-term annual runoff at these seven stations 

ranges from an estimated 0.02 cubic foot per second per square mile to an 

estimated 1.17 cubic feet per second per square mile, generally increasing 

with station altitude.

DeWeese Reservoir, just outside of the study area, has a design storage 

capacity of 1,772 acre-feet. All other reservoirs in the area have a combined 

design storage capacity of about 215 acre-feet.

Generalized annual water budgets for two areas in the Wet Mountain Valley 

indicate that surface-water outflow is only 7 to 11 percent of the total water 

supply from precipitation and other sources. The remaining water is lost to 

the atmosphere by evapotranspiration. Ground-water underflow and changes in 

ground-water storage are considered insignificant in both water budgets.

The quality of both the surface and ground water is generally within the 

recommended limits for drinking water set by the U.S. Public Health Service. 

The hardness, as calcium carbonate, of the ground water is generally greater 

than 100 milligrams per liter.

1
INTRODUCTION

The Southeastern Colorado Water Conservancy District entered into a 

cooperative agreement with the U.S. Geological Survey in 1970 to conduct a 

water-resources investigation of the Wet Mountain Valley (fig. 1) The 

purpose of this investigation was to determine the quantity and quality of 

both the surface and the ground water within the valley. This information 

will be used in the management of the water resources of the area.

Westcliffe and Silver Cliff are the only towns with centralized 

populations in the area, each with a population of less than 400 people. The 

economy of the region is based primarily on agriculture. Irrigation plays a 

major role in crop production throughout the valley, particularly in the 

valley floor north and south of Westcliffe.

The scope of this investigation included the determination of the quality 

of water in the area, the amount of recoverable water stored in the first 

100 ft of saturated alluvial material, expected yields from properly 

constructed wells, depths to water in the alluvial aquifer, estimates of 

surface-water flow from small ungaged drainage basins, and a water budget for 

the Grape Creek drainage area. Streamflow was measured at 7 sites, water 

samples for chemical analysis were collected from 20 wells and at 2 surfacewater sites, and a network of 31 wells was measured bimonthly during 1970-75 

(pl. 1).

The authors wish to acknowledge the cooperation and assistance provided 

by the many landowners in the area, particularly those who permitted access to 

their wells and property for the many measurements and tests necessary for the 

successful completion of this investigation.

GEOHYDROLOGIC SETTING

The Wet Mountain Valley is an intermontane trough filled with unconsolidated deposits of Cenozoic age, bordered by mountain ranges composed of volcanic rocks of Tertiary age and igneous, metamorphic, and sedimentary rocks of 

pre-Tertiary age (MacNish, 1966). The approximate location and extent of the 

various geologic units within the study area are shown on figure 2.

The study area includes about 540 mi2 and is primarily drained by two 

north-flowing tributaries of the Arkansas River. Grape Creek, the principal 

stream, drains the southern 320 mi 2 of the study area. Texas Creek, the other 

large stream in the study area, drains an area of 144 mi2 . The remainder of 

the area is drained by several small streams that flow directly into the 

Arkansas River west of Texas Creek.

Precipitation generally increases with land-surface altitude in the Wet

Mountain Valley. Based on the areal distribution of the average annual

precipitation from 1931 to 1940 (fig. 3) (U.S. Weather Bureau, 1967),
106C 105°

10I 15 I 20 25 MILES _i____I I I I I I I

0 5 10 15 20 25 KILOMETERS

Figure 1. Location of study area.
Texas 

Creek

EXPLANATION

CENOZOIC BASIN- FILL MATERIAL 

TERTIARY VOLCANIC ROCKS

PRE-TERTIARY, IGNEOUS, METAMORPHIC, AND SEDIMENTARY ROCKS

38° 15

Base from U.S. Geological Survey 

Pueblo 1:250 000, 1954 

Trinidad 1:250 000, 1954

Geology modified from 

Scott and Taylor (1975)

10 MILES

\ 

10 KILOMETERS

Figure 2. Generalized geologic map.
Texas

105

EXPLANATION

LINE OF EQUAL AVERAGE 

ANNUAL PRECIPITATION - 

Interval, in inches, is variable

38° 15

10 15 MILES

I I 

10 15 KILOMETERS

Figure 3. Distribution of average annual precipitation 1931 60 

(from U.S. Weather Bureau, 1967).

COLORADO WATER 

SOURCES LIBRARY
precipitation ranges from less than 16 in. per year on the valley floor 

(altitude about 8,000 ft) to more than 40 in. per year (altitude about 

13,000 ft) along the Sangre de Cristo Range. About 37 percent of the total 

annual precipitation in the area occurs in the form of snow.

GROUND-WATER OCCURRENCE

Ground water occurs in two different hydrologic environments within the 

study area the mountainous area, which is composed chiefly of consolidated 

rocks, and the valley-floor area, which is underlain by unconsolidated basinfill material. The availability of ground water in the Wet Mountain Valley is 

summarized in figure 4.

Mountainous Area

The Sangre de Cristo Range, on the west side of the valley, consists of 

igneous, metamorphic, and complexly folded and faulted sedimentary rocks of 

pre-Tertiary age. The Wet Mountains, on the east side of the valley, are 

composed of igneous and metamorphic rocks of pre-Tertiary age which are 

overlain by Tertiary volcanic rocks at some localities.

In the mountainous area, ground water is chiefly contained in the 

fractured and weathered zones of the consolidated rocks or in minor, isolated 

pockets of overlying glacial and alluvial material. The weathered zones of 

the consolidated rocks are generally limited to the upper few tens-of-feet of 

the rock and the fractures generally become tighter and, hence, contain less 

water with depth. Yields from wells completed in consolidated rock are 

unpredictable due to the uncertain distribution of fractures and thickness of 

the weathered zones but, generally, are less than 10 gal/min (fig. 4). Yields 

greater than 10 gal/min might be obtained where the fractures or weathered 

zones are in direct hydraulic connection with the water in nearby streams.

The glacial and alluvial material in the mountainous area is generally 

restricted to the canyons and is not widespread. Where these materials occur 

above the water level of nearby streams, they are generally well drained and 

can be expected to yield less than 10 gal/min. In areas where the 

unconsolidated materials are in direct hydraulic connection with the water in 

nearby streams, well yields greater than 10 gal/min may be obtained.

In the volcanic rocks along the eastern margin of the valley, reported 

well yields vary considerably. In areas where the volcanic rocks are 

tuffaceous and of low permeability, the reported well yields are relatively 

small. Several wells have reportedly been drilled to depths ranging from 200 

to 300 ft and have yields of less than 2 gal/min . Locally, where rhyolitic 

rock is encountered, well yields of as much as 30 gal/min have been reported 

from wells of less than 50 ft deep.
Texas 

Creek

38°15

EXPLANATION

WELL YIHLDS GENFKA1.LY LESS THAN 

10 GALLONS PER MINUTE EXCEPT 

LOCALLY WHERE HIGHER YIELDS 

MIGHT BE INDUCED EROM NEARBY 

STREAMS

WELL YIELDS GENERALLY LESS THAN 

50 GALLONS PER MINUTE OR ARE

UNKNOWN

WELL YIELDS GENERALLY GREATER 

THAN 50 GALLONS PER MINUTE

38°00

Base from U.S. Geological Survey V 

Pueblo 1:250 000, 1954 ' V 

Trinidad 1:250000, 1954

10 MILES

O 5 10 KILOMETERS

Figure 4. Availability of ground water.

7
Valley-Floor Area

The basin-fill deposits in the valley-floor area cover an area of 

approximately 233 mi2 and are the principal source of ground water in the 

study area. The basin-fill material is composed primarily of alluvial 

material derived during Tertiary time from the mountains surrounding the 

valley. Glaciation of the Sangre de Cristo Range has formed glacial moraine 

and outwash deposits which are superimposed on the Tertiary basin-fill 

material in some localities. Since the disappearance of the glaciers from the 

area, the trough has continued to slowly fill with alluvial material derived 

from the surrounding mountains.

An electrical resistivity survey was made from west to east across the 

valley about 3 mi south of Westcliffe (pi. 1). The resistivity section 

(fig. 5) indicates that the thickness of the basin-fill material ranges from 

about 1,000 ft at the east end of the section to about 6,700 ft at the west 

end (Zohdy and others, 1971). A test hole, SC 23-72- 6AAB1 (the system of 

numbering wells is explained in the Supplemental Information section of this 

report), was drilled along the line of the section, about 0.5 mi west of Grape 

Creek, to a depth of 1,200 ft. The geologic log of this test hole is included 

as Supplemental Information in this report. The log indicates that the upper 

1,200 ft of the basin-fill material, in this area, is composed primarily of 

sand and gravel with interbedded and intergranular clay. The resistivity 

section indicates that the basin-fill material contains increasing amounts of 

clay with depth, or that the water in the basin-fill material contains 

increasing amounts of dissolved solids with depth.

Ground water occurs under both artesian and water-table conditions within 

the basin-fill aquifer. Artesian conditions are created by interbedded and 

intergranular clays confining the water beneath them. These confining layers 

probably are not continuous or completely impermeable and there is most likely 

a considerable amount of leakage between the confined and unconfined parts of 

the aquifer. The artesian conditions exist, to some extent, throughout most 

of the area of the basin fill. Along the central part of the valley, there 

are several flowing wells (pi. 1).

The depth to the water table is less than 10 ft in an area of about 

46 mi2 along the central part of the valley, as shown on figure 6. The depth 

to the water table is less than 100 ft in most of the remainder of the valley 

except for the extreme southern and southeastern parts of the valley, where it 

is generally greater than 100 ft.

There is an estimated 1.5 million acre-ft of recoverable ground water 

stored in the upper 100 ft of saturated basin-fill material. Hydrographs from 

selected wells are shown in figure 7. The hydrographs indicate that for the 

observed period of record, 1970-75, the water levels are undergoing only 

seasonal fluctuations and that no changes in the amount of ground water in 

storage are taking place.
FEET A 

9000-

8000- 

7000 - 

6000 - 5000 - 

4000- 3000 - 

2000

EXPLANATION

RESISTIVITY, IN OHM-METERS

165-250

100-135

60-80

20-30

10

OS

QU

U5, oS oS 

c < o oZ CQ c/3g 

< ~ 5g uw > oS

OS < £X j U J PJ 

OJ U Q

APPROXIMATE BOUNDARY BETWEEN 

RESISTIVITY UNITS - Dashed where questionable

Igneous or metamorphic rocks

A' FEET 

-9000

8000

-7000-6000- 5000^4000

-3000

2000

o i 3 MILES

i i r n

0123 KILOMETERS

VERTICAL EXAGGERATION X 2.6 

DATUM IS MEAN SEA LEVEL

Figure 5.-Electrical resistivity section near Westcliffe. Modified from Zohdy and others, (1971).
Texas 

Creek EXPLANATION

DEPTH TO WATER GENERALLY LESS 

THAN 10 FEET

DEPTH TO WATER 10 TO 100 FEET 

EXCEPT LOCALLY ALONG SOME OF 

THE GULCHES AND STREAM CHANNELS 

WHERE IT MAY BE LESS THAN 10 FEET 

AND ON SOME OF THE HILLTOPS WHERE 

IT MAY BE GREATER THAN 100 FEET

DEPTH TO WATER GENERALLY GREATER 

THAN 100 FEET EXCEPT LOCALLY 

ALONG SOME OF THE GULCHES AND 

STREAM CHANNELS WHERE IT MAY BE 

LESS THAN 100 FEET

APPROXIMATE BOUNDARY OF BASINFILL AQUIFER

Base from U.S. Geological Survey 

Pueblo 1:250 000, 1954, 

Trinidad 1:250 000, 1954

10 MILES

0 5 10 KILOMETERS

Figure 6. Depth to water in the basin fill aquifer.

10
O (71 O O (71 O 

1970

1972

1974 <Tl 

oo" c

1976 ,-J i - j ; 

- 

~ ~ X

S

1970 2. 

COO

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1972 ^ 

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1974 0 

1976 i - ^^J 

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-^ ____1 1

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COX1ro

CO>

0 O

SC

a.

i-t o

00

I-t

o en o o CTI o ^ 

cr

1970 

!-*> 

I-t 03

1972 3 

rfT* O

1974 5S 

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1976 3 

"~ r /\ \

\- - _ ^ 

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1970 2. 

CO

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ro

1972 i 

ro1

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1974 § 

1976 1 \ i 1 S

cp_

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4,

ro1>j OOo

cr

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cr

t/a

oo oo to S° ft £ ¥ O (71 O (71 O (71 I - - | !-*> 

1970 S: c^ t 

1972 2 '

1974

1976 i

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i; 1 

1970

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COO

10

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1972 i 

N) Lj^

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1974 0 

1976 1

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005
The basin-fill area has been divided into two areas on the basis of 

reported well yields (fig. 4). In the central part of the valley, wells of 

adequate depth, diameter, and screen length can be expected to have sustained 

yields of at least 50 gal/min. Several wells in this area have reported 

yields greater than 300 gal/min. (See Records of Selected Wells in the 

Supplemental Information section of this report.)

GROUND-WATER MOVEMENT

Water enters the aquifers in the mountainous area as infiltration from 

precipitation or streams. The water then moves downgradient where it is 

discharged by springs to the numerous small streams, lost to evapotranspiration, or discharged into the basin-fill aquifer as underflow.

Extensive faults have been mapped along both the east and west sides of 

the basin between the basin-fill material and the consolidated rock (Scott and 

Taylor, 1975). The low permeability fault gouge associated with these faults 

probably serves as at least a partial barrier to water movement between the 

consolidated rock and the basin-fill material. This barrier and the general 

low permeability of the consolidated rock limit the direct discharge of water 

from the consolidated rock to the basin-fill material to very small amounts. 

Water enters the basin-fill aquifer as infiltration from precipitation falling 

directly on the aquifer or as rim inflow from the surrounding mountainous 

area.

The basin-fill material is surrounded, except for the southern end, by 

bedrock of low permeability. The volcanic rocks in the basin (fig. 2) are not 

continuous and do not serve as a conduit for transporting water out of the 

basin. Once the water enters the basin-fill aquifer, it moves toward the 

center of the basin and does not flow out of the basin to the south under 

Promontory Divide. Very little, if any, water leaves the basin-fill aquifer 

as underflow. The direction of ground-water flow in the basin-fill aquifer is 

shown on plate 1. Ground water moves from higher to lower potentiometric 

levels. As illustrated by the potentiometric map (pi. 1), ground water moves 

from the boundaries of the basin-fill aquifer toward Grape and Texas Creeks.

Water leaves the aquifer in several ways. Direct evapotranspiration from 

the water table occurs in the area where the depth to water is less than 10 ft 

(fig. 6). Water is discharged from the aquifer into Grape Creek along the 

reach from just south of Westcliffe to the edge of the basin fill and to Texas 

Creek in the reach just before it leaves the basin-fill material. Some water 

also is lost to small streams that cross the northern end of the valley-fill 

material and then discharge directly into the Arkansas River. Water is 

discharged through wells either by pumping or by artesian flow. Part of the 

water discharged from wells infiltrates the land surface and percolates back 

down to the water-table aquifer, while the remainder is consumed, lost to 

evapotranspiration, or runs off into the streams.

12
SURFACE WATER

The surface-water resources of the Wet Mountain Valley are vital to the 

agricultural economy of the area. Most of the water for irrigation is 

obtained by diversion of surface water rather than pumping of ground water. A 

tabulation of water rights on Grape Creek and Texas Creek is presented in 

table 1.

Observed streamflow consists of runoff from precipitation, return flow 

from irrigation, seepage from ground water, and (or) water released from 

reservoir storage. A hydrograph of mean monthly discharges (1925-75) of Grape 

Creek near Westcliffe (station 07095000; the station numbering system is 

explained in the Supplemental Information section of this report) is shown in 

figure 8. Runoff from melting snow dominates the hydrograph during May, June, 

and July. Streamflow during the low-flow or base-flow period in fall and 

winter is due largely to irrigation return flows and ground-water discharge.

The streamflow hydrograph shown in figure 8 does not indicate the effects 

of significant surface-water storage in the watershed. A tabulation of lakes 

and reservoirs in the study area and their location, design surface area, and 

design storage capacity is given in table 2. DeWeese Reservoir, the largest 

reservoir in the vicinity of the study area, is located about 0.5 mi 

downstream from station 07095000. The water-storage capacity of this 

reservoir is 1,772 acre-ft. The remaining five reservoirs in the study area 

have a combined water-storage capacity of about 215 acre-ft.

Streamflow

The Wet Mountain Valley has large year-to-year variations in streamflow. 

A hydrograph of annual runoff recorded by the Grape Creek near Westcliffe gage 

(07095000) is shown in figure 9. From 1924 to 1975, annual recorded runoff 

ranged between 5,120 acre-ft in 1963 and 78,850 acre-ft in 1942. As 

previously stated, the study area has only about 215 acre-ft of available 

water storage in surface-water reservoirs.

Other than at the Grape Creek near Westcliffe (07095000) gaging station 

that was established in 1924, very few records of streamflow have been 

collected in the study area. The streamflow-gaging station on Grape Creek 

near Canon City (07095500) was operated during 1907-09 and the station on 

Texas Creek at Texas Creek (07094000) was operated during 1923. Unpublished 

records of streamflow exist for Dry Creek near Westcliffe during the late 

1960's and for Texas Creek at Texas Creek since September 1970.

In order to improve areal coverage of streamflow information, two 

continuous-record and four partial-record gaging stations were installed in 

August 1974 as part of this study. These stations are listed in table 3 and 

located on plate 1. Data obtained from these six additional stations were 

useful in evaluating the streamflow characteristics of the many smaller 

streams draining the perimeter of the study area.

COLORADO WATER 

RESOURCES LIBRARY 

U.S. GEOLOGICAL SURVEY 13 WRD, DENVER *UttVfcY
Table 1 . --Surface-water diversion rights prior to 1880 

along Grape and Texas Creeks*-

Name of diversion

Location 2

Township Range Section

Amount of 

decree,

in cubic Date of decree 

feet per 

second

GRAPE CREEK

Aldrich No. 2 

Voris Bros. No. 1- ---------

DeWeese Dye Ma in-------------

Voris Bros. No. 1-- ---- --

Pinto ---- --- __-__

Sou them ---------------------

Voris Bros. No. 1------ - -

DeWeese Dye Main ---- -----

Voris Bros. No. 1 ------------

Difz 

Rifster No. 2----- -

C B H 

Pinto----- ---- 

Gordon W. Smith No. 1--------

Elze No. 3 

Elze No. 5 

Voris Jarvis No. 1-----------

Risser and Locke-------------

Hulmuth----------------------

R B 

Chetelate No. 2 ------ -

Schulz No. 3 

C B H 

Col fax-- ---------------------

Voris Bros. No. 2- 

DeWeese Dye Ma in-------------

Voris Bros. No. 2 - 

Schoolfield No. 4------------

Schulz No. 5-----------------

Voris Bros. No. 1, 2d Enl----

DeWeese Dye Ma in-------------

Voris Bros. No. 1, 2d EnlTotal---- -------------

22S

21S

19S

21S

23S

23S

21S

19S

21S

23S

23S

23S

23S

22S

24S

24S

22S

23S

23S

23S

23S

24S

46N

23S

22S

19S

22S

22S

24S

21S

19S

21S

072W

073W

07 OW

073W

072W

07 2W

072W

070W

072W

072W

072W

072W

072W

072W

072W

072W

073W

072W

072W

072W

072W

072W

012E

072W

073W

070W

073W

072W

072W

073W

07 OW

073W

32

25

06

25

21

27

25

06

25

27

3^

34

21

19

04

03

01

05

16

20

20

03

13

04

01

06

01

05

03

25

06

25

0.34

2.34

2.34

2.34

.50

1.38

 95

.95

.95

.83

.88

.50

2.50

3.00

.69

.16

2.61

5.11

2.50

.89

.33

.66

1.30

2.33

1.33

1.33

1.33

.56

.33

1.09

1.09

1 .09

-- 44.53

04-15-1870

07-31-1871

07-31-1871

07-31-1871

05-01-1872

06-12-1873

10-31-1873

10-31-1873

10-31-1873

06-15-1874

10-10-1874

10-10-1874

03-03-1875

05-15-1875

05-31-1875

05-31-1875

05-31-1875

06-01-1875

10-05-1875

05-05-1876

06-01-1876

06-01-1876

06-05-1876

06-10-1876

06-30-1877

06-30-1877

06-30-1877

04-01-1878

05-15-1878

10-31-1879

10-31-1879

10-31-1879

14
Table ].--Surface-water diversion rights prior to 1880 

along Grape and Texas Creeks 1 --Cont inued

Locat ion 2

Name of diversion Townshi p

Range Section

Amount of 

decree,

in cubic Date of decree 

feet per 

second

TEXAS CREEK

Hill No. 1-- ---- 47N

Fitter No. 1 21S

Likely & McCormi ck----------- 47N

[IL*l^V-MIIIIL*rs. H / IN

M ; | i | i |_________________________ _________________________ ____

Ritter No. 2 21S

Duckett No. 1 ---------------- 4yN

Belknap & Hendr ickson-------- 47N

Duckett No. 1--- ---- - 47N

Belknap & Howard------------- 46N 

Dissmore No. 2 McC 1 urkens---- 21S

McClurken No. 1 -------------- 21S

Hugg No. 3 21S

Hugg No. 4 --- ---------- 21S

Duckett No. 2-------- ----- 4yN

Hill Ditch No. 2 47N

Myers 21 S

J. M. Duckett --- ------- ^yN

Burgman No. 2---------------- 47N

Hill No. 1 -- -- 47N

Belknap & Hendr i ckson-------- 47N

TC-I+- ±b 1 ---_____-____

012E 

012E 

073W 

012E 

01 2E

073W 

012E 

012E 

012E

012E 

073W 

073W 

073W 

073W

012E 

012E 

073W 

012E 

012E

012E 

01 2E 

012E

12 

12 

29

13

29 

26 

35 

26

31 

31 

32 

32

26 

12 

16

33

12 

12 

35

1.05 

1.05 

1.00 

1.32 

1.00

1 .00 

1.00 

1 .00 

1 .00 

1 .00

2.76 

1 .00 

1.00 

1 .06 

1 .00

1.32 

1.05 

1.00 

3.50 

1.00

1.05 

1 .60 

1.58

,

9.3

08-31-1869 

08-31-1869 

04-30-1871 

06-01-1871 

06-01-1871

09-01-1871 

05-01-1872 

05-10-1872 

05-10-1872 

05-10-1872

05-31-1872 

07-24-1872

f\~I O f\ 1 Q ~7O 0/-3U- I o/Z

11-30-1872 

11-30-1872

05-15-1873

01-17-1874 

05-01-1874 

05-31-1874

04-30-1875

04-14-1876 

03-06-1877

05-31-1878

Source: Colorado Division of Water Resources, Office of the State 

Eng i neer.

2 Refers to location of point of diversion.

15
100

0s*

OCT. NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. 

Figure 8. Mean monthly discharge of Grape Creek near Westcliffe (station number 0

1927 to 1975 water years.
Table 2. --Principal lakes and TeseTVoiTs in tine Wet Mountain Valley

and vicinity 1

Locat ion 2

Name Town - _, _

, . Range Sect ion ship y

Owner

Design Design

surface capacity,

area, in

in acres acre-feet

Balman Reservoir 46N 12E

Hook Reservoir 46N 12E

DeWeese Reservoir- 21S 72W

Lake of the Clouds

Reservoir No. 1- 45N 12E

Lake of the Clouds

Reservoir No. 2- 45N 12E

Lake of the Clouds

Reservoir No. 3- 45N 12E

6 U.S. Forest Service 

2 Thomas Hook

20 DeWeese Dye Ditch

and Reservoir Co.

3.6 50.9

2.0 35.0

148 1,772

(21) U.S. Forest Service 15.0

(21)

(21)

 do-

 do15.0

(15)

48.0

36.0

(45)

Source: Colorado Division of Water Resources, Office of the State 

Engineer.

2 Refers to location of dam or outlet.

17
Table 3 .--Stream-gaging stations in

r U.S. Geolog- Location Stream , ^

ical Survey rj_ . . _ site . Station name Operatinq aqency

, i station . ... , . . . ,. number 1 , Latitude Longitude number

1 07093980 Lake Creek near

Hillside, Colo- U.S. Geological 38°15 l/*9" 105 0 39'^1" 

Survey

2 0709^000 Texas Creek at

Texas Creek 

(near Cotapaxi), Colo Office of the 38°2V30" 105 0 35'00" 

Colorado State 

Eng ineer

3 0709^530 Grape Creek near

Bradford, Colo- U.S. Geological 37 0 57'03" 105 0 27'03" 

Survey

k 0709^600 South Colony

Creek near 

Westcliffe, 

Colo do 37°59 I 57" 105 0 29'25"

5 0709^700 Antelope Creek

near Rosita, 

Colo do 38°0ri8" 105°21 I 43"

6 0709^800 Venable Creek

near Westcl iffe, Colo do 38 0 05'02" 105 0 33'52"

7 0709^900 Middle Taylor

Creek near 

Westcliffe, 

Colo do 38 0 06'30" 105°36 I 03"

8 07095000 Grape Creek near

Westcli ffe, 

Colo Office of the 38°11 I 10" 105 0 28'59"

Colorado State

Engi neer

Defers to sites shown on figure 2.

2 Refers to available record from which flow characteristics were

18
fhe Wet Mountain Valley and vicinity

Drainage 

area 

(mi 2 )

Mean Maximum Minimum

Period of annual observed observed

record 2 discharge discharge discharge

(ftVs) (ftVs) (ftVs)

Remarks

9.07 June 1974- 20 

September 1976

44 April-November - - 2,800 

1923

6.72 June 197**- 19 

September 1976

6.03 October 1974- 6.65 47 

September 1976

35-3 June 197*1- 9.** 

September 1976

2.55 June 1974- 17 

September 1976

1.6

.20

Partial-record station, discharge 

measurements only,

Records only for 

1923 are published

Partial-record station, discharge 

measurements only.

.04

Do,

Do.

3.19 October 1974- 4.10 

September 1976

38 .40

320 October 1924-

September 1961; 

October 1962- 

September 1976

32.3 7,460 .01

determined; records may exist for other periods.

19
OQ 

C 

1-1

CD

>o ro 

CD Wi 

o

ACRE-FEET THOUSAND IN RUNOFF. ANNUAL 

>J O) Ol A W M -» 

o o o o o o o 

T I ^ ,J. I "1~ I ~\ 

«-> CD 

O y, 

£T 1-1 

 "S

c 

3 

cr

CD 1-1

O 

-4

O

O

o 

o
Runoff Analysis

The results of an analysis of runoff in the study area are summarized in 

table 4. The 1975-76 annual runoff for the four partial-record stations was 

determined by correlation techniques using the two continuous-record stations 

and is expected to be within 10 percent of the actual runoff (Riggs, 1969). 

Observed annual runoff in the study area was generally greatest during the 

1975 water year.

Long-term annual runoff (1931-60), also given in table 4, was estimated 

for the six short-term gaging stations based on the 1975-76 average annual 

runoff, channel-geometry techniques (Hedman and others, 1972), and regression 

analysis of basin characteristics (Livingston, 1970). Equations for predicting the long-term mean annual runoff using channel-geometry measurements have 

a standard error of estimate of 19 percent; those for basin characteristics, 

47 percent. (The standard error of estimate is the percentage above or below 

calculated values within which about two-thirds of the actual values are 

expected to fall.) The recorded 1975-76 average annual runoff for Grape Creek 

near Westcliffe is in close agreement with the long-term (1931-60) runoff. 

Consequently, the 1975-76 average annual runoff for the six short-term gaging 

stations, along with the determinations made using channel-geometry and 

regression methods, were averaged to estimate the long-term (1931-60) mean 

annual runoff at these stations. These data were used in the water-budget 

analysis which is discussed in a later section of this report.

Annual runoff expressed as a function of drainage area, in cubic feet per 

second per square mile, generally increases with altitude in the Wet Mountain 

Valley, as shown in table 4. Values of estimated mean annual runoff for 1931 

through 1960 range from about 0.02 (ft 3 /s)/mi2 for Antelope Creek (altitude 

8,290 ft) to about 1.17 ft 3 /s)/mi2 for Middle Taylor Creek(altitude 9,960 ft). 

Such data can be used to give an estimate of annual runoff at ungaged sites 

in the study area. For example, the data shown in table 4 indicate that the 

annual runoff for a stream with a 5-mi2 drainage area at an altitude of 

9,000 ft is about 5 ft 3 /s or 1.0 (ft 3 /s)/mi2 .

Magnitude and Frequency of Floods

Occasional flooding in the Wet Mountain Valley results from either 

intensive rainstoms or unusual snowmelt-runoff conditions. Information on the 

magnitude and frequency of floods can be used by planners and designers to 

minimize damages and hazards in areas subject to flooding.

Where adequate records of flood discharge are available, a relation can 

be developed between flood magnitude and frequency of occurrence. The logPearson Type III distribution has been established as the method for uniform 

flood-frequency analyses by all Federal agencies (U.S. Water Resources 

Council, 1976). In order to reduce the effects of possible time-sampling 

errors associated with such analyses, a weighting procedure can be used 

(Sauer, 1974; McCain and Jarrett, 1976). For example, the 100-year flood 

discharge for Grape Creek at Westcliffe (07095000) is 4,900 ft 3 /s by log21

COLORADO WATER

^ 

SUft
Table k,.--Annual runoff in the

Dra inage 

Station name area, in 

(station number) square 

mi les

Lake Creek near 

Hillside (07093980) k --

Grape Creek near 

Bradford (07094530) k 

South Colony Creek near 

Westcliffe (07094600)-

Antelope Creek near 

Rosita (07094700) 4 

Venable Creek near 

Westcl iffe (07094800) 4

Middle Taylor Creek near 

Westcl iffe (07094900)-

Grape Creek near 

Westcl iffe (07095000)-

9.07

6.72

6.03

35.3

2.55

3.19

320

Altitude, 

i n 

feet

8,300

8,690

8,940

8,290

9,020

9,960

7,790

Observed annual runoff, in

1975 

Water year

3,590

3,330

5,060

780

2,160

3,700

33,710

1976 

Water year

3,610

2,960

4,570

50

1 ,510

2,240

14,780

acre-feet

1975-76 

Average

3,600

3,140

4,820

420

1 ,840

2,970

24,240

1 Hedman, Moore, and Livingston, 1970. 

2 Livingston, 1970.

3 Figures in parentheses were determined as the mean of the 

regression methods (see text). 

^Partial-record station. 

5 Value not used in determining mean annual runoff.

observed

Pearson Type III analysis and 9,370 ft 3 /s by the weighting procedure. A 

complete summary of the flood characteristics for Grape Creek at Westcliffe 

(07095000), including the equations and parameter values used in their 

determination, is given in table 5.

For natural-flow streams where adequate records of flood discharge are 

not available, the flood characteristics can be estimated using regional 

relations given in a manual developed by McCain and Jarrett (1976). The 

method presented in the manual involves the use of basin characteristics and 

regionalized regression equations. A summary showing the use of this method 

to determine the flood characteristics at two partial-record stations, 

Antelope Creek near Rosita (07094700) and Venable Creek near Westcliffe 

(07094500) is given in table 5.

22
Wet Mountain Valley

Estimated annual runoff,

Channel -geometry 

method 1

3,560

5 1 ,120

2,920

380

1,830

2,260

in acre-feet

Regression 

method 2

5 5,170

2,880

5,930

_____

1,930

2,850

Mean 

(1931-60

Acre-feet

(3,600)

(3,000)

(4,500)

(400)

(1,900)

(2,700)

22,460

annual runoff 

calendar years) 3

Cubic feet per second 

per square mile

(0.55)

(.62)

(1.03)

(.02)

(1.03)

(1.17)

.10

1975-76 average runoff and the estimated runoff by channel-geometry and

GENERALIZED WATER BUDGET

The movement of water in a particular area may be expressed as a water 

budget in which an accounting is made of all water entering or leaving the 

area. The water budget can be expressed in equation form as:

Water in = Water out ± change in storage,

where "water in" includes precipitation and surface- and ground-water inflow, 

"water out" includes evapotranspiration and surface- and ground-water outflow, 

and "change in storage" includes both surface- and ground-water storage and is 

positive for a net increase in storage.

23
Table 5. --Flood characteristics for selected

Station name 

and number Basin type Required parameters

Antelope Creek 

near Rosita 

(0709^700) Ungaged site-- 

mixed population (plains/ 

mountain) region

0=discharge for recurrence interval, T, 

D =depth for recurrence interval, T, 

A= 35.3 rni 2 (drainage area) 

(9.^5 mi 2 , plains region; 

25.8 mi 2 , mountain region), 

P=18 in. 

=mean annual precipitation

(mountain region only), 

S =114 ft/mi (basin slope)

D

S = 64 ft/mi (streambed slope)

R=0.70 (reduction factor for site 

elevation).

Venable Creek 

near Westcli ffe 

(07094900) Ungaged site-- A=>2.55 mi 2 (drainage area),

mountain region P=28 in. (mean annual precipitation)

Grape Creek near 

Westcliffe 

(07095000) Gaged site mixed 

populat ion 

(plains/mountain) region

Q / x=weighted discharge for recurrence interval , T,

Q_, v=station value of the flood for 

recurrence interval, T 1 ,

Q_/ R v=regression value of the flood

for recurrence interval, T, 

N=46 (number of years of station 

data used to compute Q_/~v),

E=10 (equivalent years of record 

for Qj/ R \)»

A= 320 mi 2 (drainage area) 

(220 mi 2 , plains region;

100 mi 2 , mountain region), 

P=19 in., 

S =47 ft/mi,

S $ =29 ft/mi.

Method of determination as described by McCain and Jarrett,1976. 

Standard error of estimate is the percentage above or below calculated 

3 Highest flood characteristic obtained by the two methods used; in this

24
gag-ing stations in the Wet Mountain Valley^-

Regress ion 

equat ion

Standard error 

of estimate2 

(percent)

Resultant flood characteristic

Plains region:

Q, n = 1/t/t A° ' 528 S ° * 33G

Q50 = 891 A 0 ' 482 S B 0 ' 154 

(1100=1,770 A 0 - 463 S B 0 ' 086 

0-500=5,770 A°- 432 

Dioo=59.3 S s ' 0 - 517

Mountain region:

Q 10 =0.12 A 0 ' 815 pl-592

Q50 =0.91 A 0 - 795 P 1 - 110

(1100=1-88 A 0 ' 787 P°- 932

Q50Q =8.70 A 0 - 766 pO.560

D 100 =i./t4 A 0 ' 187 p0.059

31 

2k 

28

45

21

39

37

38

45

28

3 Q 10 = 1,620 ft 3 /s. 

3 Q50 = 3,820 ft 3 /s. 

3 Q 100 = 5,270 ft 3 /s. 

3 Q 500 =10,660 ft 3 /s. 

3 D 100 =6.9 ft.

(Equations given above) Q 10 = 52 ft 3 /s.

0.50 = 77 ft 3 /s.

88 ft 3 /s.

115 ft 3 /s.

D loo =2.1 ft.

T(W) N+E

(Equations for 0,T /- R \ and 

D 10 o given above)

3 Qio (w) 

3 0_50 (w)

= 2,780 ft 3 /s 

= 6,740 ft 3 /s 

= 9,370 ft 3 /s 

ft 3 /s

values within which about two-thirds of the actual values are expected to fal 

instance, the characteristics from the plains-region determination are used.

25
Generalized annual water budgets are given in table 6 for the Grape Creek 

drainage basin above the Grape Creek near Westcliffe gaging station 

(07095000), and for that part of this drainage basin consisting of basin-fill 

material (fig. 10). The area of basin-fill drained by Grape Creek represents 

167 mi2 of the 320-mi2 drainage basin. The budgets are based on calendar 

years 1931 through 1960.

Precipitation

The average annual precipitation falling on the water-budget areas was 

determined by use of the distribution of mean annual precipitation for 1931-60 

shown on figure 3. The isohyetal method of analysis resulted in a 331,000- 

acre-ft average for the entire drainage area and a 151,000-acre-ft average for 

the basin-fill area.

Surface-Water Inflow and Outflow

There is no surface-water inflow across the Grape Creek drainage divide, 

such as transmountain diversions. Surface-water inflow to the basin-fill area 

consists of runoff from the mountainous regions along the perimeter of the 

area. For purposes of the water budget, the 153 mi2 that contribute inflow 

were separated into the two tributary areas shown on figure 10. Tributary 

area A (72 mi2 ), which extends from the Sangre de Cristo Range divide to the 

basin-fill boundary, receives the most precipitation within the study area 

(fig. 3) and is consequently heavily vegetated. Tributary area B (81 mi 2 ), on 

the other hand, generally extends from the Wet Mountain divide to the basinfill boundary and is characteristically dry and sparsely vegetated except at 

higher altitudes. Runoff from the two tributary areas was determined using 

the estimated 1931-60 mean annual runoff for the six gaging stations 

(table 4), with consideration given to the relative characteristics of these 

basins and the ungaged area. Runoff data from several other hydrologically 

similar gaged basins outside the Wet Mountain Valley also were considered. 

The average annual yield during 1931-60 was estimated to be 50,000 acre-ft 

from tributary area A and 4,000 acre-ft from tributary area B.

Surface-water outflow from both the entire drainage basin and the basinfill part of the basin was measured by the Grape Creek near Westcliffe gaging 

station (07095000). During the 1931 through 1960 calendar years, the flow 

past this gage averaged about 22,000 acre-ft annually.

Ground-Water Underflow

Ground-water underflows into or out of both water-budget areas are 

assumed negligible because low-permeable pre-Tertiary rocks are located along 

most of the perimeter of the basin. The potentiometric map (pi. 1) indicates 

that ground-water does not flow across the Grape Creek-Texas Creek drainage 

divide or the Promontory Divide (Custer-Huerfano County line). Consequently, 

there are no significant ground-water underflows out of the water-budget areas,

26
Table £>.--Generalized annual water budgets for two areas in the Wet Mount

calendar years 1931 through 1960

Hi a |JL* Lrl L*L*rx

budget area 

3 Source

Ent i re drainage 

area 1 --------- Precipi tat ion 2 ---

Surface water---- 

Ground-water 

underf low4 -----

Totals

Basin-f i 1 1

area --------- Precipitation 

Surface water 

(tributary

a i ca r\ /

Surface-water

(tri butary 

-ii-^-> c^6_______ area \j) ------- 

Ground-water

Totals

Water in

Acre-feet

331 ,000 

0

331,000

151 ,000 

50,000

MOO

0

205,000

Inches

19-4 

0

0

19-4

17-0 

5.6

0.4 

0

23.0

Percenttage

100 

0

0

100

74 

24

2 

0

100

Source

Evapotranspi rat ion 3 -- 

Surface water2 -------

Ground-water 

underflow4 - ------

Change in storage4 ---

Totals

Evapotranspi rat ion 3 -- 

Surface water2 -------

Ground-water 

underf low4 ---------

Change in storage4 ---

Totals

Drainage basin above Grape Creek near Westcliffe (07095000), location shown on fig

320 mi 2 .

2 Based on recorded data.

Estimated as all water otherwise unaccounted for in the budget.

^Assumed negligible.

5 That part of the Grape Creek near Westcliffe (07095000) drainage composed of 

figure 11). This is an area of 167 mi 2 .

Estimated (see text).
to

00

105-30' AGa9'n9 Nation 

 -^10530 A Q709500

EXPLANATION

AREA OF BASIN-FILL 

TRIBUTARY AREA A 

TRIBUTARY AREA B 

AREA BOUNDARY 

DRAINAGE DIVIDE

38C00'

10 MILES

0 5 10 KILOMETERS

Figure 10. Locations of water budget tributary areas and area of basin fill material in the Grape 
Evapotranspiration

The evapotranspiration component of the water budgets was estimated to be 

all water unaccounted for in the budget. The result of this determination is 

309,000 acre-ft or 18.1 in. for the entire drainage basin, and 183,000 acreft or 20.5 in. for the basin-fill area. These estimates are in close agreement with the results of several detailed studies conducted elsewhere in 

Colorado. Wymore (1974) estimated that the average annual evapotranspiration 

from the 142-mi2 upper Piceance Creek basin is 18.47 in. Kruse and Haise 

(1974) measured 23.2 to 24.5 in. of evpotranspiration from high mountain 

meadows in the South Park area, and 23.5 to 27.8 in. in the Gunnison area.

Change in Storage

Because there are no large surface-water reservoirs in the water-budget 

area and ground-water levels measured in wells during the 24-month period were 

relatively stable, this component of the budgets was assumed to be zero.

WATER QUALITY 

Ground Water

Water samples were collected and analyzed from 20 wells within the basin 

(pi. 1). The results of these analyses are shown in table 7. (The system of 

numbering water-quality sampling sites is explained in the Supplemental 

Information section of this report.) The analyses indicate that, except for 

four wells discussed below, the constituents found in ground water in the 

basin are within the recommended limits for drinking water (table 8) set by 

the U.S. Public Health Service (1962) and the U.S. Environmental Protection 

Agency (1972).

The concentrations of dissolved solids, 703 mg/L (milligrams per liter), 

and dissolved nitrite plus nitrate, 16 mg/L, exceeded the recommended limits 

of 10 mg/L in water from well SC 22-72-31ADB. As this well is a 15-ft deep 

stock well, located in a feed lot, the water chemistry is not typical of the 

water from the major part of the valley. Dissolved solids greater than 

500 mg/L may impart a bitter taste to the water. Dissolved nitrite plus 

nitrate greater than 10 mg/L is generally indicative of pollution of the water 

from animal wastes and (or) fertilizers and may cause methemoglobinemia (bluebaby disease) in infants (less than 6 months of age) who drink the water or 

who are breast-fed by mothers who drink the water.

The main significance of the above sampled well shows the relative ease 

with which surface and near-surface sources may pollute a normally potable 

domestic water supply. Therefore, it is important that proper consideration 

be given in the future to waste-disposal practices and their consequent 

effects upon the ground-water supply, especially in the 46-mi2 area in which 

the depth to water is less than 10 ft.

29
u> 

o

Table ~].--Chemioal analyses of water from selected wells

[Major aquifer codes: 02, Basin fill; E7, Dry Union Formation; E8, Santa Fe Fo

E9, Tertiary igneous, undivided]

Site 

number 1

1

10

16

19

22

26

32

34

37

46

66

74

101

108

112

114

118

127

144

153

Local wel 1 

number

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

SC

NA

NA

21-73- 8BDD

21-73-28BDC

21-73-34DBB

21-73-35CDB

22-72-14CDA

22-72-17CAC

22-72-31ADB

22-72-32AAB

22-73- 6ACB

22-73-12DDC

22-73-36DCC

23-72- 6AAB

23-72-20CBC

23-72-23DDD

23-72-24DBC

23-72-26CBB

23-73- 4CAC

24-71- 6BAA

45-12- 2DAA

46-12-12DBC

Station number

381438105335900

381155105330500

381059105314600

381042105305800

380752105241500

380805105273800

380608105282300

380605105271000

381017105350800

380847105292500

380519105294600

380513105281400

380201105280600

380142105235000

380155105231500

380114105245800

380443105332200

385947105222500

381039105362400

381548105355800

Date of 

sample

72-08-22

72-08-18

72-08-18

72-08-22

72-08-16

72-08-16

72-08-18

72-08-16

72-08-22

72-08-18

72-08-16

72-08-18

72-08-16

72-08-16

72-08-16

72-08-16

72-08-18

72-08-16

72-08-22

72-08-22

Depth 

of 

wel 1 

(ft)

66

117

202

124

50

120

15

89

46

45

103

1 ,200

23

180

96

60

95

29

110

184

Major 

aqui - 

fer

E8

E8

E8

E8

02

E9

02

E8

02

02

E8

E8

02

02

02

02

02

E7

--

E8

Dissol ved 

si 1 ica 

(Si0 2 ) 

(mg/L)

24

18

17

20

29

29

21

27

15

22

11

25

14

31

29

22

15

41

19

17

Dissol ved 

aluminum 

(Al) 

(yg/L)

10

0

10

10

10

10

20

10

10

10

0

10

0

0

10

0

10

10

0

10

D

so

i 

(

(y

6,

4,
Table ~l.--Chemical analyses of water from selected wells--Cor\t in

Site 

number 1

1

10

16

19

22

26

32

34

37

46

66

74

101

108

112

114

118

127

144

153

Dissol ved 

magnes ium 

(Mg) 

(mg/L)

14

7-2

7.9

10

17

8.6

14

13

5.2

7.3

4.7

2.5

8.6

8.3

6.5

4.9

5.8

12

17

2.9

Dissol ved 

sod i urn 

(Na) 

(mg/L)

21

7.5

5.6

8.0

12

17

39

16

7.9

9.4

3.8

15

9.0

12

13

6.5

4.7

14

14

4.6

Dissolved 

potass i urn 

(K) 

(mg/L)

2.1

1.4

1 .1

-9

2.8

2.6

200

4.8

.4

1.4

1 .0

1 .1

1.4

3.7

3-5

1 .2

.9

6.1

2.3

.7

Bicarbonate 

(HC0 3 ) 

(mg/L)

263

151

113

149

192

183

359

333

136

145

85

125

198

225

191

123

170

261

226

106

Carbonate 

(C0 3 ) 

(mg/L)

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Alka1 ini ty 

as 

CaC0 3 

(mg/L)

220

124

93

122

157

150

294

273

112

119

70

103

163

185

157

101

139

214

185

87

Dissol ved 

sulfate

(soO

(mg/L)

82

9.5

22

21

48

21

63

13

8.5

11

8.5

4.3

7.2

12

11

7.4

4.7

35

23

2.6

Dissolved 

chloride 

(Cl) 

(mg/L)

7.1

2.3

1 .0

.9

25

8.2

69

6.8

.9

1 .2

.9

1.6

1 .2

3.6

3.8

3.3

.9

31

2.0

.9

Dissolve

fluo

r ide 

(F) 

(mg/L

0.5

.2

.2

.2

.6

.6

-5

.4

.2

.2

.1

.2

.2

.3

.6

.3

.1

.3

1.8

.1
Table 1.--Chemical analyses of water from selected wells--Cont inu

U) 

N3

Site 

number 1

1

10

16

19

22

26

32

3k

37

46

66

7^

101

108

112

114

118

127

144

153

Dissolved 

orthophosphate 

(POO 

(mg/L)

0.06

.03

.03

.03

.06

.09

1.7

 03

.00

.03

.00

.03

.06

.06

.21

.09

.06

1.1

.03

.03

Dissolved 

sol ids 

(sum of 

const i tuents) 

(mg/L)

367

157

139

169

305

225

703

328

138

155

94

138

188

238

207

138

157

431

238

107

Dissolved 

sol ids 

(tons 

per 

acre-f t)

0.50

.21

.19

.23

.41

.31

.96

.45

.19

.21

.13

.19

.26

.32

.28

.19

.21

.59

.32

.15

Hardness 

as 

CaC0 3 

(Ca,Mg) 

(mg/L)

260

110

100

130

220

140

170

250

100

110

74

75

150

170

140

95

130

300

180

77

Noncarbonate 

hardness 

(mg/L)

43

0

7

4

62

0

0

0

0

0

5

0

0

0

0

0

0

85

0

0

Percent 

sort i urn

15

12

11

12

10

20

16

12

14

16

10

30

11

13

17

13

7

9

14

11

Sod i umadsorpt ion 

rat io 

(SAR)

0.6

.3

.2

.3

.4

.6

1.3

.4

.3

.4

.2

.8

 3

.4

.5

.3

.2

.4

.5

.2

Speci - 

fie conductance 

(ymhos/cm 

at 25°C)

590

262

226

273

493

357

1 ,110

543

230

247

154

206

324

382

329

217

266

678

397

170

p

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

7

1 See figure 2.
Table 8 .- -Recommended limits of selected substances in water supplies

[Adapted from U.S. Public Health Service, 1962. The following chemical substances should not be present in a water supply in excess of the listed concentrations where, in the judgment of the reporting agency and the certifying authority, other more suitable supplies are or can be made available]

Concentration, in

Substance

Chloride (Cl) 

Dissolved sol ids-----------------------

Fluor ide (F) 1 

1 ron (Fe) - ---- -------- -_-_____.

Manganese (Mn )------------------------- 

Nitrite-plus-nitrate as elemental 

n i trogen (N) 2 ----- -----------------

Sulfate (SO^)--- ---- - 

Mill igrams 

per 1 i ter

250

500

1.3

.30

.05

10

250

Micrograms 

per 1 i ter

300 

50

 'The recommended control limit for fluoride concentrations is variable 

and dependent upon the annual average of maximum daily air temperature.

2 ln areas in which the nitrate concentration of water is known to be in 

excess of the listed concentration, the public should be warned of the potential danger of using the water for infant feeding.

The concentration of dissolved iron, 6,000 yg/L (micrograms per liter), 

exceeded the recommended limit in water from well SC 22-72-32AAB. Dissolved 

iron greater than 300 yg/L imparts a bitter taste to beverages, such as coffee 

and tea made using the water, and stains laundry and porcelain fixtures.

The concentration of dissolved nitrite plus nitrate of 14 mg/L exceeds 

the recommended limit in water from well SC 24-71-06BAA,a 29-ft deep windmill.

The concentrations of dissolved iron, 4,200 yg/L; manganese, 230 yg/L; 

and fluoride, 1.8 mg/L, exceeded recommended limits in water from well NA 45- 

12-02DAA. Dissolved manganese greater than 50 yg/L causes the same effects as 

dissolved iron greater than 300 yg/L. Dissolved fluoride greater than 

1.3 mg/L can cause mottling of children's teeth.

Ground water in the basin is generally hard (as defined by Hem, 1970, 

p. 225). The hardness, expressed as calcium carbonate (table 7), in the 

samples analyzed ranged from 74 to 300 mg/L. All but four of the samples have 

a hardness of 100 mg/L or greater. According to Hem (1970), the hardness of 

water to be used for domestic purposes becomes objectionable when the 

concentration is about 100 mg/L.

33
According to J. M. Klein, P. A. Emery, L. A. Hershey, and R. D. Penley 

(written commun., 1977), there are two different water-quality zones in the 

basin-fill aquifer. Generally, east of the axis of the valley the concentration of dissolved silica is greater than 25 mg/L and the concentrations of 

dissolved solids are greater than 200 mg/L, while in the western part of the 

basin these constituents are generally less than these concentrations. The 

difference in water quality between these two zones is probably due to the 

different sources of the sediments in the two areas. The source of the 

sediments in the western one-half of the valley is the Sangre de Cristo Range 

and the source for the east side of the basin is the Wet Mountains.

Dissolved silica in ground water originates from dissolution of various 

silicate minerals or volcanic glass which the ground water contacts. Large 

areas of the Wet Mountains are covered with layers of volcanic rocks (fig. 2) 

that contain substantial proportions of readily dissolved silica. Sediments 

derived from these volcanic rocks are the probable source of the larger silica 

concentrations on the east side of the valley.

Surface Water

Two surface-water samples were collected for water-quality analyses from 

a site along lower Grape Creek (pi. 1). The results of these analyses are 

listed in table 9 and indicate that, at the time the samples were collected, 

the substances analyzed for were within the recommended limits for drinking 

water set by the U.S. Public Health Service (1962) (table 8). Wentz (1974) 

lists temperature, pH, and specific-conductance data for several surface-water 

sites in the study area.

Suitability of Water for Irrigation

The suitability of water for irrigation is dependent on several 

variables, the most important of which are the quality of the water, the type 

of soil and crops to be irrigated, and the irrigation practices used. A 

concentration of dissolved solids greater than 1,000 mg/L (Robinove and 

others, 1958) may affect crop growth indirectly through the effect on the 

physical condition of the soil, and directly by increasing the osmotic pressure of the soil solution and by an accumulation of toxic quantities of various ions within the plant. Thus, the ability of a plant to use water is 

diminished and a reduced crop yield results (Reeve, 1957, p. 175). Sodium 

buildup in the soil may reduce soil permeability, which limits air penetration 

to the root zone, leads to waterlogging, and reduces plant growth (Klein and 

Bingham, 1975).

A diagram used for classification of irrigation water, based on the 

sodium-adsorption ratio (SAR) and the specific conductance, is shown on 

figure 11. This diagram is a useful tool in predicting potential sodium and 

salinity hazards involved in the use of water for irrigation. The diagram has 

16 different categories for classifying irrigation water. These categories 

range from low salinity (Cl), low sodium (SI), which is water that can be

34
Table 9- --Chemical analyses of water from selected surface-water s

Site

num- Station name 

ber 1

c*. ^ u Date of 

Station number , 

sample

Discharge

Dissolved

s i 1 ica 

(Si0 2 ) 

(mg/L)

Dissolved

a 1 umi - 

num 

(Al) 

(yg/L)

Di

sol

i r

(F

(yg

U) 

Ln

Grape Creek at 

Hermit Lake 

Road--------- 380752105262000 72-08-18 H.O 22 2

Grape Creek at 

Hermit Lake

i\uau--------- jou/pi i upzozuuu / z- 1 i-^u lu zi -- p

Site 

number 1

1

1

Site 

number 1

1

1

Dissolved 

magnes ium 

(Mg) 

(mg/L)

7.7

8.0

Dissolved 

orthophosphate 

(PO^) 

(mg/L)

0.01

.06

Dissolved 

sod ium 

(Na) 

(mg/L)

lo

9-5

Dissol ved 

sol ids 

(sum of 

const! tuents) 

(mg/L)

182

187

Dis " Alkasolved Bicar- Car- ,. 

u *. u *. 1 i ni ty potas- bonate bonate

slum (HC0 3 ) (C0 3 ) r asr 

(K) (mg/L) (mg/L) ( m /L)

2.2

1.6

Dissolved 

sol ids 

(tons 

per 

acre-f t)

0.25

.25

176

182

Hardness 

as 

CaC0 3 

(Ca,Mg) 

(mg/L)

130

140

0 1 44

0 149

Noncar- Perbonate cent 

hard- soness d i urn 

(mg/L)

0 14

0 13

solved solved solved 

sul- chlo- fluofate ride ride 

(SOiJ (Cl) (F) 

(mg/L) (mg/L) (mg/L)

8.0

12

Sod i umadsorpt ion 

rat io 

(SAR)

0.4

4

3.3 0.4

3.1 -3

Speci - 

fie conductance 

(ymhos/cm 

at 25°C)

291 7

286 7

 ' See figure 2.
O)

I

O) 

I

100 500

30

28

24

O 20

16

12

ii

 .*! ''''I 1 '*! "I I I I

1000

Ground water 

Surface water

5000

30

28

24

20

16

12

I___I

100 250 750 2250

SPECIFIC CONDUCTANCE, IN MICROMHOS PER CENTIMETER AT 25° C

C1

Low

C2

Medium

C3

High

C4

Very high

SALINITY HAZARD

Figure 11. Classification of irrigation water.

36
applied to nearly all types of soils and crops with little danger of harmful 

effects, to very high salinity (C4) , very high sodium (S4) , which is water 

suitable for irrigation use only under very limited conditions (table 10).

All of the water samples analyzed during the course of this study plot 

within the SI sodium-hazard category and all but one plot within either the Cl 

or C2 salinity-hazard categories (fig. 11). This would indicate that both the 

surface and ground water have low-sodium hazard and low- to medium-salinity 

hazard. Within the study area, surface and ground water are generally safe to 

use for irrigation under most conditions.

SUMMARY

The Wet Mountain Valley is an intermontane trough filled with 

unconsolidated deposits of Cenozoic age, and bordered by mountain ranges 

composed of volcanic rocks of Tertiary age and igneous, metamorphic, and 

sedimentary rocks of pre-Tertiary age. The valley includes an area of 540 mi2 

and is primarily drained by Grape Creek and Texas Creek. Average annual 

precipitation ranges from less than 16 in. to more than 40 in., generally 

increasing with land-surface altitude.

Ground water occurs in two different hydrologic areas within the study 

area the mountainous area, which is composed chiefly of consolidated rock; 

and the valley-floor area, which is underlain by unconsolidated basin-fill 

sediments. In the mountainous area, well yields are highly unpredictable but 

are generally less than 10 gal/min. In the basin-fill aquifer, yields of 

greater than 50 gal/min can generally be expected from wells located near the 

central part of the valley. In areas around the edge of the basin-fill 

aquifer, well yields of less than 50 gal/min are generally reported.

The basin-fill deposits cover an area of about 233 mi2 and are the 

principal source of ground water in the study area. South of Westcliffe, this 

material is at least 6,700 ft thick and the upper 1,200 ft is composed of sand 

and gravel with interbedded and intergranular clay. There is an estimated 1.5 

million acre-ft of ground water stored in the upper 100 ft of saturated basinfill sediments although considerably less than this amount could be developed 

from wells. Hydrographs of selected wells indicate that the volume of water 

stored in the basin-fill material is not changing.

Ground water occurs under both artesian and water-table conditions within 

the basin-fill aquifer. Artesian conditions exist, to some extent, throughout 

most of the basin-fill area and there are several flowing wells. The depth to 

the water table is less than 10 ft in an area of about 46 mi2 along the central part of the valley and is less than 100 ft in most of the remainder of 

the valley.

Ground-water movement in the basin-fill aquifer is generally toward Grape 

and Texas Creeks. Ground water leaves the aquifer either by discharge to 

streams, discharge by wells, or as direct evapotranspiration from the water 

table. Underflow out of the basin is considered negligible.

COLORADO WATER
Table 10. --Salinity and sodium classification for irrigation water 

[Adapted from U.S. Salinity Laboratory Staff (195*0]

SALINITY

Class

Specific conductance, 

in micromhos per 

centimeter at 25°C

Comments

C1 (low) Less than 250

C2 (medium) 250-750

C3 (high) 750-2,250

(very high)- Greater than 2,250

May be used for any crop on nearly all 

soi1s.

May be used if a moderate amount of 

leaching occurs.

Should be used only on soils with better than adequate drainage and for 

plants with good salt tolerance.

Not suitable for irrigation under ordinary conditions, but may be used on 

permeable soil with adequate drainage 

if water is applied in excess to provide considerable leaching. Very 

salt-tolerant plants should be selected.

SODIUM

Class Comments

51 (low) 

52 (medium)----

S3 (high) - 

Sk (very high)

May be used for any crop on nearly all soils.

May be used on coarse-textured (sandy) soils with good permeability; may present a moderate sodium problem in finetextured (clay) soils unless gypsum is present.

May present sodium problems in most soil types.

Not suitable for irrigation of any crops in any soil, except 

under special conditions.

Sodium-adsorption-ratio range for each class is dependent on 

specific conductance.

38
Streamflow in the area is typical of a high mountain valley with most 

runoff occurring in June and July as the result of snowmelt. Observed 

streamflow consists of runoff from precipitation, return flow from irrigation, 

discharge of ground water, and water released from reservoir storage. 

Continuous records of streamflow have been collected since 1924 at the Grape 

Creek near Westcliffe gaging station. Additionally, two continuous-record and 

four partial-record stations have been operated in the study area since August 

1974. Analysis of the streamflow data for water years 1975 and 1976 shows 

that the average annual runoff for 1975-76 at the seven stations ranged from 

about 420 to 24,240 acre-ft per year. Long-term annual runoff (1931-60) at 

these stations ranges from an estimated 0.02 (ft 3 /s)/mi2 to an estimated 

1.17 (ft 3 /s)/mi2 , generally increasing with station altitude. Using the data 

at two partial-record stations where natural-flow conditions prevailed, the 

magnitude, frequency, and depth of floods were estimated using basin 

characteristics and regionalized regression equations.

DeWeese Reservoir, located near the study area, has a storage capacity of 

1,772 acre-ft. All of the other reservoirs within the study area have a 

combined storage capacity of about 215 acre-ft.

Generalized annual water budgets for two areas in the Wet Mountain Valley 

indicate that surface-water outflow is only 7 to 11 percent of the total water 

supply from precipitation and other sources. The remaining water is lost to 

the atmosphere by evapotranspiration. Ground-water underflow and changes in 

ground-water storage are considered insignificant in both water budgets.

The quality of both the surface and ground water is generally within the 

recommended limits for drinking water set by the U.S. Public Health Service 

(1962). The hardness of the ground water is generally greater than 100 mg/L 

as calcium carbonate. There are two different water-quality zones in the 

basin-fill aquifer. East of the axis of the valley, the concentration of 

dissolved silica is greater than 25 mg/L and the concentration of dissolved 

solids is greater than 200 mg/L. In the western part of the valley, these 

constituents are generally less than these concentrations.

Both the surface and ground water are generally safe to use for 

irrigation. None of the samples analyzed indicated a potential sodium hazard 

and most indicated only a low- to medium-potential salinity hazard.

REFERENCES

Hedman, E. R., Moore, D. 0., and Livingston, R. K., 1972, Selected streamflow

characteristics as related to channel geometry of perennial streams in

Colorado: U.S. Geol. Survey open-file report, 14 p. 

Hem, J. D., 1970, Study and interpretation of the chemical characteristics of

natural water: U.S. Geol. Survey Water-Supply Paper 1473, 2d ed., 363 p. 

Klein, J. M., and Bingham, D. L., 1975, Water quality, Fountain and Jimmy Camp

Valleys, Colorado, 1973: Colorado Water Conserv. Board Water-Resources

Circ. 26, 27 p.

39
Kruse, E. G., and Raise, H. R., 1974, Water use by native grasses in high

altitude Colorado meadows: U.S. Dept. Agriculture, Agr. Research

Service ARS-W-6, 59 p. 

Livingston, R. K., 1970, Evaluation of the streamflow data program in

Colorado: U.S. Geol. Survey open-file report, 72 p. 

MacNish, R. D., 1966, The Cenozoic history of the Wet Mountain Valley: Ann

Arbor, Michigan Univ., unpub. Ph. D. dissertation, 120 p. 

McCain, J. F., and Jarrett, R. D., 1976, Manual for estimating flood

characteristics of natural-flow streams in Colorado: Colorado Water

Conserv. Board Tech. Manual No. 1, 68 p. 

Reeve, R. C., 1957, The relation of salinity to irrigation and drainage

requirements: Internat. Comm. Irrig. and Drainage, 3d Gong., p. 175-187. 

Riggs, H. C., 1969, Mean streamflows from discharge measurements: Internat.

Assoc. Sci. Hydrology, Bull. 14, no. 4, p. 95-110.

Robinove, C. J., Langford, R. H., and Brookhart, J. W., 1958, Saline-water resources of North Dakota: U.S. Geol. Survey Water-Supply Paper 1428, 72 p. 

Sauer, V. B., 1974, Flood characteristics of Oklahoma streams: U.S. Geol.

Survey Water-Resources Inv. 52-73, 298 p. 

Scott, G. R., and Taylor, R. B., 1975, Post-Paleocene Tertiary rocks and

Quaternary volcanic ash of the Wet Mountain Valley, Colorado: U.S. Geol.

Survey Prof. Paper 868, 15 p. 

U.S. Environmental Protection Agency, Environmental Studies Board, 1972, Water

Quality Criteria, 1972 A report of the committee on water quality

criteria: Washington, U.S. Govt. Printing Office, 694 p. 

U.S. Public Health Service, 1962, Drinking water standards, 1962: U.S.

Public Health Service Pub. 956, 61 p. 

U.S. Salinity Laboratory Staff, 1954, Diagnosis and improvement of saline and

alkali soils: U.S. Dept. Agriculture Handb. 60, 160 p.

U.S. Water Resources Council, 1976, Guidelines for determining flood frequency: Washington, D.C., U.S. Water Resources Council Bull. 17., 26 p. 

U.S. Weather Bureau, 1967, Normal annual precipitation, normal May-September

precipitation, 1931-1960, Colorado: Denver, Colorado Water Conserv.

Board map. 

Wentz, D. A., 1974, Effect of mine drainage on the quality of streams in

Colorado, 1971-1972: Colorado Water Conserv. Board Water-Resources

Circ. 21, 117 p. 

Wymore, I. F., 1974, Estimated average annual water balance for Piceance and

Yellow Creek watersheds: Colorado State Univ., Environmental Resources

Center Tech. Rept. No. 2, 60 p. 

Zohdy, A. A. R., Hershey, L. A., Emery, P. A., and Stanley, W. D., 1971,

Resistivity sections, upper Arkansas River basin, Colorado: U.S. Geol.

Survey Open-File Rept. 71002, 16 p.

40
SUPPLEMENTAL INFORMATION 

System of Numbering Water-Quality Sampling Sites

The system of numbering water-quality sampling sites is based on the grid 

system of latitude and longitude. The system provides the geographic location 

of the site and a unique number for each site. The number consists of 

15 digits. The first six digits denote the degrees, minutes, and seconds of 

latitude; the next seven digits denote degrees, minutes, and seconds of 

longitude; and the last two digits are a sequential number for sites within a 

1-second grid. (In the event that the latitude-longitude coordinates for two 

or more sites are the same, sequential numbers "01," "02," and so forth are 

assigned. See figure 12.)

System of Numbering Wells

The well locations in this report are given numbers based on the U.S. 

Bureau of Land Management system of land subdivision, and show the location of 

the wells by quadrant, township, range, section, and position within the 

section. A graphic illustration of this method of well location is shown in 

figure 13. The first letter of the location number indicates which principal 

meridian governs the area in which the well is located; S indicates the sixth 

principal meridian and N indicates the New Mexico principal meridian. The 

second letter indicates the quadrant in which the well is located. Four 

quadrants are formed by the intersection of the base line and the principal 

meridian; A indicates the northeast quadrant, B the northwest, C the 

southwest, and D the southeast. The first number indicates the township; the 

second, the range; and the third, the section in which the well is located. 

The letters following the section number indicate the location of the well 

within the section. The first letter denotes the quarter section; the second, 

the quarter-quarter section; and the third, the quarter-quarter-quarter 

section. The letters are assigned within the section in a counterclockwise 

direction, beginning with A in the northeast quarter. Letters are assigned 

within each quarter section and within each quarter-quarter section in the 

same manner. Where two or more locations are within the smallest subdivision, 

consecutive numbers, beginning with 1, are added in the order in which the 

wells are inventoried. For example, SC23-72-15DAA indicates a well in the 

E^ sec. 15, T. 23 S., R. 72 W.

System of Numbering Surface-Water Stations

Surface-water station numbers are assigned in downstream direction along 

the main stream. Station numbers on tributaries are assigned between station 

numbers on the main stream in the order in which those tributaries enter the 

main stream. Downstream-order station numbers are not assigned to 

miscellaneous sites where water-quality samples are collected or discharge 

measurements are made intermittently.

41
38°12'45"

44"

43'

42'

41'

38°12'40'

Coordinates for site A 381241105373101 

B 381241105373102 

C 381244105373301

Figure 12. U.S. Geological Survey's system of numbering 

water quality sampling sites.

42
23-72-15DAA

Figure 13. System of numbering wells,

43
Geologic Log of Test Hole SC 23-72- 6AAB1

_,. . Depth Thick- , "7

SC 23-72- 6AAB1 ness, * 

(Altitude 7,930 feet above mean sea level) in ,. feet sur ac^ 

______________________________________________________in feet

Soil, brown; contains scattered 1-inch rounded gravel------- -- 3 3

Gravel, clayey; contains rounded cobbles as large as 6 inches--- 3 6

Gravel, very fine, to very coarse sand; contains some medium

gravel------ ------------ - ______ ______ __ _ ___ 4 IQ

Sand, very coarse, silty; contains some medium gravel---------- 10 20

Sand, very coarse, arkosic; contains some reddish-brown clay--- 10 30

Clay, reddish-brown----- ------------------------- __________ 5 35

Gravel, fine to very fine, clayey------------------------------ 10 45

Clay, reddish-brown---------------------------------------- -- 5 50

Gravel, fine to very fine, clayey-------- -- -- - ----- 5 55

Gravel, fine, well-sorted, clayey -- ------ ----------- _-- 5 $Q

Sand, very coarse, clayey, grading to well-sorted fine gravel-- 10 70

Clay, reddish-brown, sandy, grading to clay; contains thin

yellowish-gray, hard, platy bentonite(?) stringers- -- -- 10 80

Gravel, very fine, to coarse sand, clayey; contains cemented

beds in bottom 10 feet----- -- --- --------- 25 105

Gravel, very fine, to sand, very coarse, clayey----- - -- -- 15 120 

Gravel, very fine to fine, clayey-------- ------- __----____- 49 160

Gravel, grading from coarse to very coarse sand; contains clay

streaks and some intergranular clay------ -------- ---- 20 180

Gravel, very fine to fine, and sand, clayey; contains some

clean beds - --------- - ______________ 30 210

Clay, grayish-yellow, and interbedded sand and gravel -------- 20 230

Sand and very fine gravel, some clayey------------------------- 20 250

Sand, very coarse, to gravel, very fine, clayey; contains

cemented zone from 255 to 260 feet----- --- --- ---- 20 270

Sand, very coarse to coarse, grading to fine gravel-- ---- -- 10 280

Gravel, very fine to fine, and sand grading to very fine,

silty gravel---- -- ---- ________ ______ _____ __ 20 300

Sand, silty, poorly sorted- - --------- -- ---- - 25 325

Gravel and sand, clayey---------------------------------- ---- 10 335

45
Geologic Log of Test Hole SC 23-72- 6AAB1 Continued

SC 23-72- 6AAB1 

(Altitude 7,930 feet above mean sea level)

Thickness ,

in 

feet

Depth

below

land

surface, 

in feet

Sand, coarse to medium, clayey; contains cemented(?) sand and

gravel-- - -- --- --- -- ----- -- ZjQ 375

Sand, medium, to very fine gravel, clayey; clean(?) from

375 to 380 feet 20 395

Sand, very clayey, grading to clay, sandy--------- ----------- 20 415

Sand and interbedded clay--- - - --------------------- ---- 20 435

Clay, sandy; contains some very fine gravel-------------------- 20 455

Sand, coarse, clayey, grading to clay, containing very fine

gravel-- ------ --- ------ -- - __ -- 20 475

Sand, very coarse, grading to sandy clay----------------------- 20 495

Sand, medium, to very fine gravel, grading to sandy clay-- --- 20 515

Sand, medium to coarse, grading to sandy clay------------ ---- 20 535

Clay, sandy, and interbedded clay----------------------- --- 20 555

Sand, medium to coarse; contains clay streaks------------------ 20 575

Sand, poorly sorted, some clayey and reddish-brown clay

streaks; some caliche bottom 5 feet- - -- --- ------- -- ZjQ 615

Sand, medium to very coarse, and very fine gravel; contains

clay streaks---- -- --------------- ------------ ________ 20 635

Sand, medium to coarse, clayey; contains beds of yellowishgray bentoni tic(?) clay------------- _ _ ______ ---- 20 655

Sand, very coarse, clean, grading to poorly sorted clayey sand- 20 675 

Sand, coarse, to very fine gravel, clayey------------------ -- 50 725

Sand, silty to clayey, cemented(?); small amount of reddishbrown clay and yellowish-gray, bentonitic(?) clay--- ------- 10 735

Sand, silty to clayey, loosely cemented, grading to reddishbrown clay ---------- ----------- _____________ _________ 15 750

Clay, reddish-brown to greenish-yellow------------------- -- 10 760

Clay, sandy, greenish-yellow to pink; contains some caliche---- 15 775

Clay, reddish-brown, sandy, grading to varicolored clays--- 20 795

Sand and very fine gravel, clay-filled------------------------- 20 815

Sand, medium to coarse, clayey, grading to sandy clay-------- 20 835

46
Geologic Log of Test Hole SC 23-72- 6AAB1 Continued

SC 23-72- 6AAB1 

(Altitude 7,930 feet above mean sea level)

Thickness ,

in 

feet

Depth

below

land

surface, 

in feet

Sand, fine to medium; contains some clay grading to very fine

gravel and coarse sand--------------------------------------- 20 855

Sand, fine, clayey, grading to clean coarse sand---- - -- 20 875

Sand, medium to coarse, grading to clayey sand and some

tightly cemented conglomerate-------------------------------- 20 895

Sand and gravel, conglomeratic; some interbedded clay- ----- 20 915 

Sand to very fine gravel; contains loosely cemented stringers-- 20 935

Sand, clayey; contains some tightly cemented sand and gravel

beds ----- _____ __________ ________ 20 955

Sand, poorly sorted to clayey-------------------- ------------ 20 975

Sand, medium to very coarse, less clayey than above- ---- --- 20 995

Sand, very coarse, grading to very fine, clayey gravel- 20 1,015

Sand and fine gravel grading to sand and medium gravel;

contains clay stringers---------- - -- ---- ---- -- - 20 1,035

Sand and very fine gravel grading to tightly cemented gravel--- 20 1,055

Sand, fine to very coarse; contains some reddish-brown clay

and cemented beds------ - ----- -- ------ ____________ 20 1,075

Gravel, very fine to medium; contains cemented beds and sandy

clay 40 1,115

Gravel, fine to very fine, and sand, and interbedded caliche,

brown clay, and sandstone----- ------------------- -------- 20 1,135

Sand, fine to very coarse, si1ty and clayey - - - --- --- 20 1,155

Sand and interbedded reddish-brown clay----- - -- -------- 25 1,180

Sand, silty to clayey--- - --- -- --- --- 20 1,200

47
Records of Selected Wells

[Depth to water: F, Flowing. 

Major aquifer codes: 02, Basin f } 11 ; E7, Dry Union Formation; E8, Santa Fe Forma

Group; E9, Tertiary, igneous, undivided; FT, Precambrian, undifferentiated. 

Type lift: C, Centrifugal; J, Jet; N, None; P, Piston; S, Submersible; T, Turbine

Power: E, Electric; G, Gas, diesel, natural or LP gas engine; H, Hand; N, None; W

Use of water: H, Domestic; I, Irrigation; P, Public supply; S, Stock; U, Unused]

Site 

number

on 

figure 2

Local 

wel1 number

Year 

drilled

Altitude 

of land 

surface 

(ft)

Well

depth

(ft)

Depth

to

water 

(ft)

Date 

water 

level 

measured 

(M-Y)

Major Yield Drawaqui- (gal/ down

fer min) (ft)

Ca

d

e

(

-Pco

1 SC 21-73- 8BDD 1971

2 SC 21-73-18DBC 

3 SC 21-73-21CDC 1955

4 SC 21-73-21CDD -

5 SC 21-73-26CCC -

6 SC 21-73-27CBC 

7 SC 21-73-27CDC -

8 SC 21-73-27DCC -

9 SC 21-73-27DDD 1953

10 SC 21-73-28BDC -

11 SC 21-73-28DAA -

12 SC 21-73-34AAA -

13 SC 21-73-34BAA 1947

14 SC 21-73-34BBB 19^7

15 SC 21-73-34BBC 1974

16 SC 21-73-34DBB 1947

17 SC 21-73-34DBD 

18 SC 21-73-35CCB 1947

19 SC 21-73-35CDB 1946

20 SC 22-72- 7CCA 

21 SC 22-72-14BCD 

22 SC 22-72-14CDA -

23 SC 22-72-16BDD -

24 SC 22-72-17CAC1 1920

25 SC 22-72-17CAC2 -

7,615

7,960

7,820

7,880

7,841

7,882

7,891

7,880

7,850

7,928

,896

,840

,878

,890

,885

,868

,859

,821

,805

7,775

8,195

8,260

7,980

7,890

7,890

66

183

120

174

25

110

62

70

30

117

110

202

128

220

92

202

284

197

124

11

43

50

119

120

120

87

9

52

12

5-71 

10-70 

10-70

4-71

E8 

02 

Z8 

E8 

E8

350

350

24 8-72 02 -

17 10-70 E8 -

19 10-70 E8 -

7 10-70 E8 -

72 10-70 E8 -

19 10-70 E8 -

F 10-70 E8 -

9 10-70 E8 602

14 10-70 E8 1,203

16 5-75 02 

F 10-70 E8 -

F 10-70 E8 -

F 10-70 E8 

F 10-70 E8 -

8 7-71 02 

25 8-71 F1 -

35 11-70 02 -

5 11-70 E9 

69 10-70 E9 300

	 E9 350
JS

^ C m °

*°oOo

O m C JD

'ADO WATER RC ES UBRARV 

OLOGlCAtSURVE

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53 

54 

55

56 

57 

58 

59 

60

SC 22-72-17CAC3 

SC 22-72-22DAD 

SC 22-72-29ADD 

SC 22-72-29BCB 

SC 22-72-29CCA

SC 22-72-30BBC 

SC 22-72-31ADB 

SC 22-72-31DDA 

SC 22-72-32AAB 

SC 22-72-32DDA

SC 22-72-35CBD 

SC 22-73- 6ACB 

SC 22-73- 8DCA 

SC 22-73- 9AAC 

SC 22-73-10ACC

SC 22-73-1OACO

SC 22-73-11CDD

SC 22-73-12BCA

SC 22-73-12CBA

SC 22-73-12CDC

SC 22-73-12DDC 

SC 22-73-13CDC 

SC 22-73-14BDD 

SC 22-73-15BCB 

SC 22-73-21BDC

SC 22-73-21 DAB 

SC 22-73-23ACB 

SC 22-73-23ACC 

SC 22-73-23BBC 

SC 22-73-25ABD

SC 22-73-25BDD 

SC 22-73-25CDD 

SC 22-73-26ABB 

SC 22-73-26BBA 

SC 22-73-26BCC

1920

1916

1966

1960

1960

1947

1946

1946 

1963

1959

1963 

1963

1934

7,890 8

0 1 n

7 972 / > J I *-

7,850

7,870 

7,866

7,895

7,905

7,950

7,955

8,196

8,430

8,301 8 AO O ,032

7 915 / , .> i j

7,908

7,850 7

-7 Q r ,7°5

7,800

7,790

7,778 

7,830

7,870 

8,060

8,240 8

1 O A

7,883

7,900 

7,920 7

QQA ,OOU

7,910

/ , jt-v 

1 940 / , j~v

7,990 

8,015

120 

 jp 3o

130

19

13 

81

15

10

89 

60

204

46

75

49

70

160

93

350

50

63

45 

94

100 

95

72

99 

39

403 

217

14 

65

 jO 30

50

74 

141

nQ

93 

144597

/TO

52

Dry

15339951

5 5

9 664

3 12F22

3 F

11-70

11-70

12-70

11-70 

8-71

11-70

11-70

10-70

10-70

4-71

10-70

10-70

11-70

11-70

11-70

10-70

11-70

11-70

11-70

11-70 

4-71

10-70 

10-70

11-70

11-70 

10-70

10-70 

10-71

10-70 

10-70

11-70

11-70

11-70 

11-70

E9 300

cQ

eft

02 

02 

E8 24

02 

02 

r-Q

r-Q

02 

02 

02 

02 

02 

02 

02 

02 

02 

02 

02 

02 

02 5

02 

02 

02 10

eft

02 160

02 

02 

02 

r\*) _ _ __

02 8

14

_ _ _

83

---
Records of Selected Wells Continued

Site 

number 

on 

figure 2

61 

62

63 

6k

65

66 

67 

68 

69 

70

71 

72 

73 

74 

75

76 

77 

78 

79 

80

81 

82 

83 

84 

85

86

87 

88 

89 

90

Local 

well number

SC 22-73-27BAD 

SC 22-73-28BBC 

SC 22-73-28BDD 

SC 22-73-35CDB 

SC 22-73-36DAA

SC 22-73-36DCC 

SC 23-71- 4DCC 

SC 23-71- 9ABC 

SC 23-71- 9DBB 

SC 23-72- 1AAB

SC 23-72- 4CDB 

SC 23-72- 5AAB1 

SC 23-72- 5ABB2 

SC 23-72- 6AAB1 

SC 23-72- 6AAB2

SC 23-72- 6BDD 

SC 23-72- 6CBD 

SC 23-72- 7ADA1 

SC 23-72- 7ADA2 

SC 23-72- 7BCC1

SC 23-72- 7BCC2 

SC 23-72- 7CBB1 

SC 23-72- 7CBB2 

SC 23-72- 7CCC1 

SC 23-72- 7CCC2

sc 23-72- 8ccc

SC 23-72-10BBA 

SC 23-72-10BDD 

SC 23-72-1 ODDD 

SC 23-72-14BBD

Year 

drilled

1964 

1953

1861 

1971

1953

1958 

1870

1971 

1974

1962 

1960 

1952

Altitude 

of land 

surface 

(ft)

8,040 

8,238 

8,240 

8,182 

7,990

8,020 

8,635 

8,650 

8,660 

8,400

7,975 

7,905 

7,895 

7,930 

7,930

7,995 

8,043 

8,000 

7,995 

8,130

8,132 

8,142 

8,142 

8,180 

8,175

8,035 

8,070 

8,000 

8,020 

8,060

Well 

depth 

(ft)

128

89 

82 

13 

26

103 

18 

110 

300 

13

30 

16 

12 

1,200 

92

34 

40 

16 

25 

180

22 

28

115 

120 

30

60 

115 

44 

54 

52

Depth 

to 

water 

(ft)

12

12 

4 

4

3 

5 

70 

71 

9

3 

13 

4 

F 

16

1 

4 

4 

3 

10

3 

1 

1 

2 

1

3

85 

12 

10 

44

Date 

water 

level 

measured 

(M-Y)

12-64

8-71 

4-71 

11-70

11-70 

4-71 

4-71 

4-71 

4-71

11-70 

11-70 

11-70 

7-71 

5-74

11-70 

11-70 

11-70 

11-70 

10-70

8-71 

10-70 

10-70 

10-70 

11-70

11-70 

12-70 

12-70 

10-70 

12-70

Major Yield Drawaqui- (gal/ down 

fer min) (ft)

02 30 

02 

02 

02 

E8 - 

E8 - 

02 

F1 2

F1 .5 

02 

02 

02 

02 

E8 - 

02 

02 

02 

02 

02 

r-fl

02 

02 

02 

rfl

02 

E8 10

r-Q

02 

r-O

02 

Cas

d i

et

(i

1

1

6

4

6

6

1

1

1

1

4
91 SC 23-72-14CAA 8,048

92 SC 23-72-15BBB 8,005

93 SC 23-72-16ABA 7,995

94 SC 23-72-16CAC 8,025

95 SC 23-72-17BBC 1963 8,050

96 SC 23-72-18AAD 1974 8,059

97 SC 23-72-18ABB 8,082

98 SC 23-72-19AAD 8,165

99 SC 23-72-19BCC 1961 8,375

100 SC 23-72-20BBC 8,154

101 SC 23-72-20CBC1 8,200

102 SC 23-72-20CBC2 8,7.00

103 SC 23-72-20CBC3 1947 8,198

104 SC 23-72-21BCB 8,078

105 SC 23-72-21DCC 1951 8,105

106 SC 23-72-22BAC 1960 8,061

107 SC 23-72-23BCB 8,073

108 SC 23-72-23DDD 1940 8,125

109 SC 23-72-24ABB 1960 8,215

110 SC 23-72-24CCC 8,130

111 SC 23-72-24CDB 8,135

112 SC 23-72-24DBC 8,181

113 SC 23-72-24DDA I960 8,185

114 SC 23-72-26CBB 8,151

115 SC 23-72-33DAA1 8,200

116 SC 23-72-33DAA2 1964 8,215

117 SC 23-72-36ADB 8,182

118 SC 23-73- 4CAC 1970 8,800

119 SC 23-73-13ACC 8,300

120 SC 23-73-15AAB 1966 8,806

121 SC 23-73-15ACD 8,895

122 SC 23-73-15ADB 8,865

123 SC 23-73-23ADC 1970 8,760

124 SC 23-73-24ABB 8,405

125 SC 24-71- 4CAD 8,455

35

45

30

66

245

75

22

28

83

13

23

76

900

65

40

51

50

180

100

23

160

96

82

60

16

100

100

957

52

113

70

57

9 12-70 02 

7 11-70 02 

3 11-70 02 

2 11-70 E8 

32 10-70 02 450 213 

9 5-74 02 

3 10-70 02 

9 11-70 02 

11 11-70 E8 15 10 

6 11-70 02 

2 11-70 02 

4 11-70 02 

11 7-71 02 

5 11-7° 02 50 

6 11-70 02 

12 11-70 E8 

4 12-70 02 

F 11-70 02 16 

63 12-70 E8 25 8 

15 11-70 02 

5 11-70 E8 

33 11-70 02 

25 11-70 02 20 

21 9-70 02 

3 11-70 02 

2 11-70 E8 20 

F 11-70 E8 

22 4-71 02 10 35 

2 11-70 02 

22 8-71 02 

67 9-70 02 

68 9-70 E8 

34 8-71 02 14 

2 11-70 02 

187 12-70 02 
Records of Selected Wells Continued

Ln 

ho

Site

number 

on 

figure 2

126 

127 

128 

129 

130

131 

132 

133

134 

135

136 

137 

138

1.39 

140

141 

142 

143 

144 

145

146 

147 

148 

149 

150

151 

152 

153 

154 

155

Local 

well number

SC 24-71- 5BCA 

SC 24-71- 6BAA 

SC 24-71- 7ACD 

SC 24-71-14DCA 

SC 24-71-15BCC

SC 24-71-17ABA 

SC 24-71-17CBA 

SC 24-71-18DAA 

SC 24-71-19BDD 

SC 24-71-22BBC

SC 24-71 -25CBA 

SC 24-71-35BAB 

SC 24-72- 4DBB 

SC 24-72- 5ABB 

SC 24-72-1 OCCC

SC 24-72-1 5AAD 

SC 24-72-26BAC 

SC 24-72-28CAA 

NA 45-12- 2DAA 

NA 46-12- 3DDD

NA 46-1 2-1 OBDD 

NA 46-12-10DCB 

NA 46-12-1 1ACC 

NA 46-12-1 1CDA 

NA 46-12-12DAC

NA 46-12-12DBB1 

NA 46-12-12DBB2 

NA 46-12-12DBC 

NA 46-12-12DBD1 

NA 46-12-12DBD2

Year 

drilled

1965

1931

1966

1964 

1964 

1969

1959 

1954

Altitude 

of land 

surface 

(ft)

8,320 

8,240 

8,358 

8,721 

8,480

8,438 

8,485 

8,465 

8,571 

8,585

9,038 

8,875 

8,320 

8,545 

8,440

8,495 

8,755 

8,170 

8,835 

7,650

7,860 

7,880 

7,620 

7,749 

7,620

7,630 

7,640 

7,650 

7,600 

7,615

Well 

depth 

(ft)

99 

29 

142 

70 

228

240 

332

400

142 

150 

220

310 

387 

12 

110 

150

145 

130 

196 

104

161 

159 

184 

89 

121

Depth 

to 

water 

(ft)

90 

25 

138 

24 

219

258

320 

309

165

4 

92 

180

295 

Dry 

5

F

143 

133 

51 

24 

F

F 

F 

F 

F 

F

Date 

water 

level 

measured 

(M-Y)

12-70 

4-71 

4-71 

10-70 

4-71

4-71

4-71 

4-71

6-66

11-70 

11-70 

7-69

12-59 

4-71 

11-70

10-70

5-74 

5-74 

10-70 

10-70 

10-70

11-70 

10-70 

10-70 

10-70 

10-70

Major 

aquifer

E8 

E7 

E7 

E7 

E8

E7 

E7 

E7 

E7 

E8

E8 

02 

02

E8 

E8

02 

E8 

02

E8

02 

02 

E8 

E8 

E8

E8 

E8 

E8 

E8 

E8

Yield Draw- 

(gal/ down 

min) (ft)

10 5

2 135

20 0

10 10 

5 2

-------

20

2 

40 

40 

9

Cas

di

et

(i

3

3

1

1
156

157

158

159

160

161

162

NA 46-12-12DDB 

NA 46-12-13ACB 

NA 46-12-14BBD 

NA 46-12-15AAC 

NA 46-12-15ABC 

NA 46-12-22DDA 

NA 46-12-27ADB 

7,625

7,740

7,879

7,910

7,935

8,330

8,465

131

53

108

163

---

60

70

F

8

24

23

86

35

63

10-70

4-71

10-70

10-70

5-74

5-74

5-74

E8

02

E8

02

02

02

02

18

---- 

 

_______ ___

c ___

10

6

--

6

6

6

6

Ln
Specific Conductance and Temperature of Water Data from

Selected Surface-Water Stations

Site U.S. Geological .. ^ r 

, c 3 Cj_ ^. Date of number on Survey Station name , £ o *. 4. u sample figure 2 station number

1 07093980 Lake Creek 7-31-74

near 8-19-74

Hillside, 9-16-74

Colo. 10-16-74

11-15-74

12-18-74

4-18-75

5-21-75

6-13-75

8- 6-75

9- 9-75

10- 7-75

11-11-75

12-23-75

2- 3-76

4- 8-76

5- 5-76

8-13-76

9-17-76

2 07094530 Grape Creek 7-31-74

near 8-19-74

Bradford, 10-16-74

Colo. 11-15-74

12-18-74

5-20-75

6-13-75

7-10-75

8- 6-75

9- 9-75

10- 7-75

11-11-75

12-23-75

2- 3-76

4- 8-76

5- 5-76

6-30-76

8-13-76

9-17-76

Temperature 

(degrees 

Celsius)

11.5

12.5

9

7

3

0

2

11.5

10

10.5

10

8

1.5

1.5

2.5

7

9.5

10.5

9.5

19

12.5

3

0

0

9

6.5

9.5

11.5

5.5

9.5

0

0.5

0.5

2.5

5.5

14

12.5

20

Specific 

conductance 

(ymho/cm 

at 25°C)

150

119

130

123

122

127

120

125

101

155

132

101

115

139

115
Specific Conductance and Temperature of Water Data from

Selected Surface-Water Stations Continued

Site U.S. Geological _. r Temperature 

, c c Date of / , number on Survey Station name . (degrees

figure 2 station number sample Celsius)

4 07094600 South Colony 8- 1-74

Creek near 8-19-74

Westcl iffe, 9-16-74

Colo. 10-16-7^

11-15-74

4-17-75

5-20-75

6-13-75

7-10-75

8- 6-75

9- 9-75

10- 7-75

11-11-75

12-23-75

2- 3-76

4- 8-76

5- 5-76

6-11-76

7-12-76

8-13-76

9-17-76

5 07094700 Antelope 7-31-74

Creek near 4-17-75

Rosita, 5-20-75

Colo. 6-13-75

7-10-75

8- 6-75

9- 9-75

11-11-75

2- 3-76

4- 8-76

5- 5-76

6-30-76

14

10.5

6.5

3

0

0.5

4.5

6.5

7.5

9

9

6.5

0

0

0.5

2

3.5

8

13.5

8.5

10.5

30.5

10.5

9

12

14.5

16

12

0

0

9.5

10

23

Specific 

conductance 

(ymho/cm 

at 25°C)

140

95

100

122

116

91

70

70

90

105

310

360

362

370

370

55
Sp ecific Conductance and Temperature of Water Data from

Selected Surf ace-Water Stations Continued

Site U.S. Geological _. £ Temperature 

u r r ^- Date of / , r number on Survey Station name . (degrees 

r . 0 ^ , sample ^ i \ figure 2 station number Celsius)

6 07094800 Venable Creek 7~31~74

near 8-19-74

Westcliffe, 9-16-74

Colo. 10-16-74

5-21-75

6-13-75

7-10-75

8- 6-75

9- 9-75

10- 7-75

11-11-75

12-23-75

2- 3-76

4- 8-76

5- 5-76

6-11-76

6-30-76

8-13-76

9-17-76

7 0709^900 Middle Taylor 8- 1-74

Creek near 8-19~7^

Westcl iffe, 9-16-7^

Colo. 10-16-7^

11-26-74

1-29-75

6-13-75

8- 6-75

9- 9-75

10- 7-75

10-16-75

12-23-75

2- 3-76

4- 8-76

5- 5-76

5-11-76

6-11-76

6-30-76

7-12-76

8-13-76

9-17-76

10.5

9.5

5.5

3-5

6

8

9

10

9

6

0

0

0

1

6

7

11

9.5

9

16

15.5

7.5

9

0

0

13

17.5

13.5

10.0

7

0

0

0.5

6

7.5

10.5

17

12

13

10

Speci fie 

conductance 

(ymho/cm 

at 25°C)

138

70

170

74

110

120

140

160

240

197

215

218

220

215

150

125

105

155

50

185

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56 GPO 844 - 958
UNITED STATES DEPARTMENT OF THE INTERIOR 

GEOLOGICAL SURVEY

Prepared in cooperation with the 

SOUTHEASTERN COLORADO WATER CONSERVANCY DISTRICT

WATER-RESOURCES INVESTIGATIONS 78-1

PLATE 1

R.11 E. 105*45' R.12E.

T.48N.

T.47N.

R.73W. 30'

Creek \

-otopaxi

i

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38° 15' 

T.46N

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Peak \

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\

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R.11 E. 105M5' V

Base from U.S. Forest Service ^ / 

San Isabel National Forest V 

(South Half) 1967 \

S

T.45N.

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T.19S.

T.20S.

. ____/_ FREMQNT CO

*. CUSTER CO R.72W.

38° 15'

.155

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Reservoir

T.21S.

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37^'

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Lake of th 

Reservoir

T.44N.

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42

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46

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101,102,

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106

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R.12E. Mt. 

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38°

T.24S.

115.

112

11 r

ir

139

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\

140

Crestone 

Peak

t

\

141

\

142

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T.25S

8 MILES

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k

/ 

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127

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133^ 132

later fieeouroes Division 

Colorado District library

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-790OEXPLANATION

WELL Number corresponds to number in records of 

selected wells

FLOWING WELL Number corresponds to number in 

records of selected wells

OBSERVATION WELL - Number corresponds to number 

in records of selected wells

WELL FROM WHICH WATER SAMPLE WAS COLLECTED 

FOR ANALYSIS Number corresponds to number in 

table 7 and in records of selected wells

UNDERLINED NUMBERS INDICATE THOSE WELLS USED 

TO DRAW POTENTIOMETRIC CONTOURS

SURFACE-WATER CONTINUOUS-RECORD GAGING 

STATION Number corresponds to number in table 3

SURFACE-WATER PARTIAL-RECORD GAGING STATION -

Number corresponds to number in table 3

DISCONTINUED SURFACE-WATER GAGING STATION

Number corresponds to number in table 3

SURFACE-WATER SITE WHERE WATER QUALITY 

SAMPLE WAS COLLECTED - Number corresponds to 

number in table 9

PRECIPITATION GAGE

LOCATION OF RESISTIVITY SECTION - Section shown 

on figure 6

APPROXIMATE POTENTIOMETRIC CONTOUR - Shows 

altitude at which water level would have stood in tightly 

cased wells, 1973. Contour interval 100 feet. Datum is 

mean sea level

GENERAL DIRECTION OF GROUND-WATER FLOW 

APPROXIMATE BOUNDARY OF BASIN-FILL AQUIFER 

DRAINAGE DIVIDE

R 71 W

T.22S.

-Rosita

105°15'

R.70W

\

V \

Lar

Sheep.

Creek

3

T.23S.

38°00'

3?*-

131

130

O O

J34

137

\

Bradford

A)

T.24S.

T.25S.

R.72W. R.71 W.

OPEN-FILE REPORT

MAP SHOWING LOCATION OF WELLS, SURFACE-WATER GAGING STATIONS, AND POTENTIOMETRIC SURFACE OF THE 

BASIN-FILL AQUIFER, WET MOUNTAIN VALLEY, PARTS OF CUSTER AND FREMONT COUNTIES, COLORADO