USE OF DYE TRACING IN WATERRESOURCES INVESTIGATIONS IN 

WYOMING, 1967-94

By James F. Wilson, Jr. and James G. Rankl

U.S. GEOLOGICAL SURVEY 

Water-Resources Investigations Report 96-4122

Cheyenne, Wyoming 

1996
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

GORDON P. EATON, Director

For additional information 

write to:

Copies of this report can be 

purchased from:

District Chief

U.S. Geological Survey, WRD 

2617 E. Lincolnway, Suite B 

Cheyenne, Wyoming 82001-5662

U.S. Geological Survey 

Branch of Information Services 

Box 25286, Denver Federal Center 

Denver, Colorado 80225
CONTENTS

Page

Abstract...........................................................^ 1

Introduction..............................................................................................._^ 2

Chronology of dye tracing in water-resources investigations in Wyoming.......................................................................... 3

Time of travel and dispersion of solutes in streams.............................................................................................................. 4

Methods....................................................................................................................................................................... 4

Wind/Bighorn River, 1971.......................................................................................................................................... 6

Green River and tributaries, 1975-77.......................................................................................................................... 8

Little Snake River, 1976-77........................................................................................................................................ 10

North Platte River, 1978, 1985.................................................................................................................................... 12

Reaeration coefficients in streams......................................................................................................................................... 14

Methods....................................................................................................................................................................... 14

North Platte River, 1985.............................................................................................................................................. 16

Discharge measurements in streams ..................................................................................................................................... 18

Methods....................................................................................................................................................................... 18

Laramie River under ice, 1967.................................................................................................................................... 20

North and South Brush Creeks, 1967-68 .................................................................................................................... 22

Physical setting ................................................................................................................................................. 22

Data collection.................................................................................................................................................. 24

Results............................................................................................................................................................... 26

South Piney Creek, 1971-78 ....................................................................................................................................... 28

Madison Limestone recharge study, 1975-78 ............................................................................................................. 30

Data collection .................................................................................................................................................. 30

Results............................................................................................................................................................... 32

Other measurements, 1971-82 .................................................................................................................................... 34

Investigations in karst terrane ............................................................................................................................................... 36

Methods...........................................................^ 36

North Fork Powder River below Dullknife Reservoir, 1970...................................................................................... 38

North Fork Crazy Woman Creek, 1974 ...................................................................................................................... 40

Little Tongue River and Tongue River Cave, 1974 .................................................................................................... 42

Middle Popo Agie River in Sinks Canyon State Park, 1983 ...................................................................................... 44

Physical setting ................................................................................................................................................. 44

Data collection .................................................................................................................................................. 46

Results............................................................................................................................................................... 48

Smith Creek below Otter Creek, 1991........................................................................................................................ 50

Other investigations .............................................................................................................................................................. 52

Methods....................................................................................................................................................................... 52

Pass Creek flow tagging, 1967.................................................................................................................................... 53

Old Faithful wastewater lagoon, 1975-76................................................................................................................... 54

Interstate Highway 25 edgedrain test, 1989................................................................................................................ 56

F.E. Warren Air Force Base fire-protection training area, 1990 ................................................................................. 58

Summary and conclusions .................................................................................................................................................... 60

References.........................................................................................................................................................^ 63

Contents iii
FIGURES

Page

1. Typical response curve (concentration-time curve) at a point downstream from slug injection of a

solute, such as a tracer dye................................................................................................................................ 5

2. Example of dye-response curves at several sampling sites for a single injection of dye, Wind/Bighorn

River, March 1971 ............................................................................................................................................ 5

3. Example of graphical relation of time of travel to distance traveled, Wind/Bighorn River, 1971........................ 5

4. Map showing location of streamflow-gaging stations and dye-injection and sampling sites,

Wind/Bighorn River.......................................................................................................................................... 7

5. Graph showing relation of time of travel to water discharge, Wind/Bighorn River.............................................. 7

6. Map showing location of streamflow-gaging stations and dye-injection and sampling sites,

Green River, East Fork River, Big Sandy River, Horse Creek, and Blacks Fork............................................. 9

7. Graph showing relation of mean velocity to water discharge at two streamflow-gaging stations and in

a 70.3-mile reach, Green River downstream from Fontenelle Reservoir......................................................... 9

8. Map showing location of streamflow-gaging stations and dye-injection and sampling sites,

Little Snake River............................................................................................................................................. 11

9. Graph showing relation of time of travel to water discharge at streamflow-gaging station 09257000,

Little Snake River near Dixon, Wyoming......................................................................................................... 11

10. Map showing location of streamflow-gaging stations and dye-injection and sampling sites, North

Platte River........................................................................................................................................................ 13

11-13. Graphs showing:

11. Velocity-discharge relations for leading edge and peak concentration of dye cloud, North Platte

River between Casper and Orin, Wyoming.............................................................................................. 13

12. Relation between passage time of dye cloud and distance downstream from the point of injection,

North Platte River between Casper and Orin, Wyoming......................................................................... 13

13. Relation between unit-peak concentration and time of travel of peak, North Platte River between

Casper and Orin, Wyoming...................................................................................................................... 13

14. Map showing location of dye- and gas-injection sites and sampling sites, and subreaches for which

reaeration coefficients were calculated, North Platte River.............................................................................. 17

15. Dye-response curves in North Platte River at Bryon Stock Trail bridge, October 9, 1985................................... 17

16. Gas-response curve in North Platte River at Bryon Stock Trail bridge, October 9, 1985..................................... 17

17. Dye-response curve for a constant-rate injection of dye....................................................................................... 19

18. Diagram of injection equipment and stream reach for a dye-dilution discharge measurement............................ 19

19. Graphs showing degrees of lateral mixing for dye-dilution discharge measurements.......................................... 19

20. Sketch of the test reach for dye-dilution discharge measurements under ice, Laramie River............................... 21

21. Longitudinal section showing setup for injecting dye through ice, Laramie River............................................... 21

22. Map showing location of streamflow-gaging stations on North and South Brush Creeks.................................... 23

23. Typical cross section of channel of North Brush Creek........................................................................................ 23

24. Typical cross section of channel of South Brush Creek........................................................................................ 23

25. Sketch of dye-injection equipment used for high-flow discharge measurements in North Brush Creek.............. 25

26. Dye-response curve for dye-dilution discharge measurement of October 6, 1967 in North Brush Creek............ 25

27. Dye-response curve for dye-dilution discharge measurement of October 6, 1967 in South Brush Creek............ 25

28. Graph showing stage-discharge relation for streamflow-gaging station 06622700, North Brush Creek

near Saratoga, Wyoming................................................................................................................................... 27

29. Graph showing stage-discharge relation for streamflow-gaging station 06622900, South Brush Creek

near Saratoga, Wyoming................................................................................................................................... 27

30. Map showing location of streamflow-gaging station 06321000, South Piney Creek near Story, Wyoming......... 28

31. Graph showing stage-discharge relation for streamflow-gaging station 06321000, South Piney Creek

near Story, Wyoming ........................................................................................................................................ 29

iv Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
FIGURES Continued

Page

32. Map showing location of streamflow-gaging stations and miscellaneous-measurement sites used for 

the Madison Limestone recharge study and at which dye-dilution discharge measurements were 

made during 1975-78........................................................................................................................................ 31

33. Graph showing stage-discharge relation for streamflow-gaging station 06297480, Tongue River at

Tongue Canyon Campground, near Dayton, Wyoming.................................................................................... 32

34. Map showing location of sites where miscellaneous dye-dilution discharge measurements

were made, 1971-82.......................................................................................................................................... 34

35. Generalized stratigraphic chart of formations of Paleozoic age in parts of Wyoming where dye tests

were conducted in karst terrane ........................................................................................................................ 37

36. Map showing location of dye-injection and sampling sites, North Fork Powder River........................................ 39

37. Hydrographs of flow into sinkholes near Bull Creek and flow from large spring below Johnson Creek,

North Fork Powder River downstream from Dullknife Reservoir, November 4-6, 1970 ................................ 39

38. Dye-response curve in North Fork Powder River at large spring downstream from Dullknife Reservoir,

November 4-6, 1970 ......................................................................................................................................... 39

39. Map showing location of streamflow-gaging stations and dye-injection and sampling sites, North Fork

Crazy Woman Creek......................................................................................................................................... 41

40. Map showing location of streamflow-gaging stations, dye-injection site in the Little Tongue River, and

dye-sampling site in Tongue River Cave.......................................................................................................... 43

41. Dye-response curve in Cave Creek in Tongue River Cave, October 30-November 2, 1974................................ 43

42. Map showing location of the Sinks and the Rise, Sinks Canyon State Park......................................................... 45

43. Flow-duration curve for streamflow-gaging station 06231600, Middle Popo Agie River below the

Sinks, near Lander, Wyoming, water years 1960-68 ........................................................................................ 45

44. Photograph of the Sinks, Sinks Canyon State Park, August 14, 1983................................................................... 47

45. Photograph of the Rise, Sinks Canyon State Park, August 14, 1983 .................................................................... 47

46. Dye-response curves in Middle Popo Agie River at the Rise, Sinks Canyon State Park, August 14, 1983 ......... 49

47. Map showing location of streamflow-gaging stations and dye-injection and sampling sites,

Smith Creek study area..................................................................................................................................... 51

48. Graph showing monthly mean discharge at streamflow-gaging station 06645166, Smith Creek below

Otter Creek, near Casper, Wyoming, water years 1988-91............................................................................... 51

49. Dye-response curve in Smith Creek below Otter Creek, September 19-21, 1991................................................ 51

50. Map showing location of study reach of Pass Creek............................................................................................. 53

51. Map showing location of well OF2 and stream-sampling sites near the Old Faithful wastewater

lagoons, Yellowstone National Park................................................................................................................. 55

52. Dye-response curves in well OF2 and Iron Spring Creek near the Old Faithful wastewater lagoons,

October 1, 1975 through April 25, 1976........................................................................................................... 55

53. Map showing location of the edgedrain-test site on Interstate Highway 25.......................................................... 57

54. Generalized transverse section of northbound lanes of Interstate Highway 25 showing retrofitted

edgedrain and dye-injection hole...................................................................................................................... 57

55. Map showing location of fire-protection training area, F.E. Warren Air Force Base............................................ 58

56. Cross-sectional sketch of retention pond in fire-protection training area.............................................................. 59

57. Dye-response curve for water pumped from leakage-monitoring station at retention pond in fireprotection training area, September 19, 1990................................................................................................... 59

TABLES

1. Time-of-travel measurements, Green River and tributaries, southwestern Wyoming, 1975-77........................... 8

2. Time-of-travel measurements, Little Snake River, southwestern Wyoming, 1976-77.......................................... 10

3. Gas desorption-rate coefficients and reaeration coefficients, North Platte River below Casper,

Wyoming, October 1985................................................................................................................................... 17

Contents v
TABLES-Continued

Page

4. Dye-dilution discharge measurements under ice cover, Laramie River at Laramie,

Wyoming, February 1967 ................................................................................................................................. 21

5. Dye-dilution discharge measurements at streamflow-gaging stations 06622700, North Brush Creek

near Saratoga, Wyoming, and 06622900, South Brush Creek near Saratoga, Wyoming, 1967-68.................. 26

6. Dye-dilution discharge measurements at streamflow-gaging station 06321000, South Piney Creek

near Story, Wyoming, 1971-78......................................................................................................................... 29

7. Dye-dilution discharge measurements at streamflow-gaging stations and miscellaneous-measurement

sites used in the Madison Limestone recharge study, northeastern Wyoming, 1975-78.................................. 33

8. Miscellaneous dye-dilution discharge measurements at streamflow-gaging stations and miscellaneousmeasurement sites in Wyoming, 1971-82......................................................................................................... 35

9. Water temperatures in the Middle Popo Agie River at the Sinks and the Rise and in a spring near the

Rise, Sinks Canyon State Park, Wyoming, August 14, 1983 ........................................................................... 46

CONVERSION FACTORS

Multiply

cubic foot

cubic foot per minute (ft3/min)

cubic foot per second (ft3/s)

foot (ft)

foot per day

foot per second

gallon

gallon

inch

mile

mile per hour

pound

By

0.02832

0.02832

0.02832

0.3048

0.3048

0.3048

3.785

3,785

2.54

1.609

1.609

0.4536

To obtain

cubic meter

cubic meter per minute

cubic meter per second

meter

meter per day

meter per second

liter

milli liter (mL)

centimeter

kilometer

kilometer per hour

kilogram

Temperature can be converted to degrees Fahrenheit (°F) or degrees Celsius (°C) as follows:

°F=9/5 (°C) + 32 

°C=5/9 (°F - 32)

Water year: A water year is the 12-month period, October 1 through September 30. It is designated by the calendar year 

in which it ends.

vi Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Use of Dye Tracing in Water-Resources 

Investigations in Wyoming, 1967-94

By James F. Wilson, Jr. and James G. Rankl

Abstract

The U.S. Geological Survey has used dye tracing during 

many water-resources investigations in Wyoming. When 

mixed with flowing water, fluorescent dye can be traced to 

determine velocity (time of travel), dilution capacity, 

dispersion, and other information. This report describes 

results of all such investigations between 1967 and 1994, 

some of which previously were unpublished.

Time of travel and dispersion were measured in eight 

streams. A 113-mile reach of the Wind/Bighorn River below 

Boysen Dam was measured during 1971. Measurements 

were made during 1975 and 1977 in a 117-mile reach of the 

Green River upstream from Fontenelle Reservoir, in a 

70-mile reach downstream, and in parts of four tributaries: 

East Fork River, Big Sandy River, Horse Creek, and Blacks 

Fork. A 75-mile reach of the Little Snake River along the 

Wyoming-Colorado State line was measured during 1976- 

77. The North Platte River downstream from Casper was 

measured during 1978 (36 miles) and twice during 1985 

(95 and 94 miles).

Reaeration data were collected concurrently with the 

October 1985 time-of-travel measurements in the North 

Platte River. Propane gas and dye were traced through a 

40-mile reach, starting at Casper. Reaeration coefficients, 

used as a measure of the capacity of the river to assimilate 

organic waste, were calculated for three subreaches.

Seventy dye-dilution measurements of stream discharge 

were made at 23 different sites. Five measurements, four 

using various antifreeze additives in the injection solution, 

were made in February 1967 under total ice cover in the 

Laramie River at Laramie as part of research to develop field 

procedures; four of the five were within 2 percent of a 

current-meter measurement made the same day. The 

accuracy of discharge-rating curves for streamflow-gaging 

stations on North and South Brush Creeks near Saratoga 

were verified with a series of 17 measurements during 

1967-68. Similar results were obtained with eight measurements at the station on South Piney Creek near Story during 

1971-78. A total of 25 discharge measurements were made 

during 1975-78 at 11 additional stations at remote sites on 

steep, rough mountain streams crossing outcrops of the 

Madison Limestone of Mississippian age in northeastern

Wyoming. The largest discharge measured by dye tracing 

was 2,300 cubic feet per second at a station on the Tongue 

River. Most of the dye measurements were considered to be 

sufficiently accurate for use in defining the stage-discharge 

relation. Fifteen additional discharge measurements were 

made at eight other sites during 1971-82.

Four losing streams and one sinking stream in karst 

terrane were studied using dye tracing. In November 1970, 

dye injected into a sinkhole in the channel of the North Fork 

Powder River below Dullknife Reservoir was detected 

16 hours later in a spring 5.8 miles downstream from the 

reservoir. In September 1974, dye injected into North Fork 

Crazy Woman Creek above zones of flow loss appeared as 

three separate peaks below springs about 1.3 miles downstream; 73 percent of the amount injected was accounted for 

by sampling. In October 1974,35 percent of the dye injected 

into the Little Tongue River upstream from a losing reach 

was accounted for 2.6 miles to the north, in a stream in 

Tongue River Cave. This water eventually reaches the 

Tongue River, so at least part of the water lost in the Little 

Tongue does not represent recharge to the limestone aquifer. 

A dye test at Sinks Canyon State Park during August 1983 

verified the connection of the Sinks (Sinks of Lander Cave) 

to the Rise, on the Middle Popo Agie River. The entire flow 

disappears into the cave, and surface flow resumes in large 

springs 3,500 feet downstream. The dye arrived 2 hours 

after injection, and 84 percent of the injected dye was 

accounted for by sampling. Dye was used in September 

1991 to evaluate water loss in sinks between two stations on 

Smith Creek near Casper. A weak dye trace appeared at the 

downstream station about 20 hours after injection at the 

upstream station, indicating a hydraulic connection between 

the sinks and flow at the downstream station.

The versatility of dye tracing was demonstrated in four 

other investigations. Dye was used to tag water in Pass 

Creek near Wyoming Highway 130 for current-meter 

measurements at a series of downstream sites; to track flow 

through glacial deposits of Quaternary age in Yellowstone 

National Park; as a passive test for leakage of runoff through 

pavement cracks in Interstate Highway 25 near Wheatland; 

and as an active test for leaks in a retention pond at F.E. 

Warren Air Force Base adjacent to Cheyenne.

Abstract 1
INTRODUCTION

Hydrologists and technicians of the U.S. 

Geological Survey (USGS) have been using modern 

dye-tracing techniques in water-resources investigations in Wyoming since 1967. Modern dye-tracing 

techniques were first reported by Pritchard and 

Carpenter (1960) and were adapted for hydrologic 

investigations by the USGS during the early 1960s. 

Now there are numerous ways to use dye tracing 

because of its most important characteristic 

simplicity of application and detection of the dye.

Dye injected into a stream, lake, well, or artificial 

impoundment mixes readily and moves with the 

flowing water. The amount of dye required, compared 

to the volume of water being tagged, is extremely 

small, because the dye used, rhodamine WT, is strongly 

fluorescent in weak concentrations. Special preparation of the sample is not necessary. In an instrument 

called a fluorometer, the fluorescence of rhodamine 

WT dye is isolated easily from that of other materials 

likely to be present in natural waters. The amount of 

fluorescence varies directly with concentration of dye. 

The photoelectric output of the fluorometer is directly 

proportional to fluorescence, and therefore, to concentration of dye (Wilson and others, 1986).

Dye tracing can be used to help answer a broad 

range of hydrologic questions. As in the earliest 

known experiments with tracer dyes, the simplest uses 

have been for water tagging and path tracing: Is this 

the same water? Where does this water gol What is 

the source of this water? But dye tracing can reveal 

much more information about flowing water. Dye 

tracing can be used to answer these questions: How 

long does water take to travel between site A and site 

B? (or the corollary, How fast does the water travel?), 

and How does material dissolved in the water become 

diluted (dispersed) as it travels with the water? And in 

a variation of the dilution question, accurately measured stream dilution of an injected tracer can be used 

to calculate the stream discharge when conditions are 

unfavorable for current-meter measurements. All of 

these applications of dye tracing have been used in 

Wyoming.

This report serves two purposes. First, it summarizes all dye tracing by the USGS in Wyoming from 

1967 through 1994. Results of some of the investigations have been published previously. Those results are 

described briefly, and the reader is referred to the published reports for details. Second, this report documents all known uses of dye tracing by the USGS in 

Wyoming for which results have not previously been 

published. Those investigations are described in 

greater detail. A chronology of all dye-tracing 

applications in Wyoming is provided on the next page.

The report is organized by major tracing topic: 

time of travel and dispersion of solutes in streams, 

reaeration coefficients in streams, discharge measurements in streams, investigations in karst (limestone) 

terrane, and other investigations. The format consists 

of the combination of text, maps, tables, and graphs for 

each investigation into one or more articles (thematic 

units). Each unit is complete on facing pages.

The first unit under each major topic is a brief 

summary of field and analytical methods for that topic. 

Detailed descriptions of the techniques are available in 

published manuals of the USGS: Kilpatrick (1993); 

Kilpatrick and Cobb (1985); Kilpatrick and Wilson 

(1989); Kilpatrick and others (1989); Wilson and 

others (1986).

The USGS conducted most of the investigations 

described in this report in cooperation with other 

agencies, particularly the Wyoming State Engineer. 

Cooperation for each investigation, if applicable, is 

acknowledged in the text. Also, the field work for 

many of the investigations was accomplished through 

the dedicated effort of many hydrologists and technicians, some of whom are unnamed, but whose assistance is appreciated, nevertheless.

We especially recognize the contributions of 

Hugh W Lowham. He used dye tracing extensively in 

his investigations during the 1970s (Bauer and others, 

1979; Lowham, 1982; Lowham and Wilson, 1971; 

Lowry and others, 1976; the dye tests of North Fork 

Powder River and North Fork Crazy Woman Creek; 

and many dye-dilution discharge measurements).

Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
CHRONOLOGY OF DYE TRACING IN WATER-RESOURCES INVESTIGATIONS IN 

WYOMING

Apr. 1966 Introduction of dye tracing to Wyoming personnel at Rocky Mountain Area [USGS] Conference on 

Fluorometric Techniques at Estes Park, Colo.

FebVl967 Dye-dilution discharge measu^

Sept. 1967- 

Oct. 1968

Dye-dilution discharge measurements of North and South Brush Creeks near Saratoga to verify stagedischarge ratings for these rough mountain streams (p. 22-27). l

test tp>aidrneasurement of g^

Mar. 1969 Time-of+travel measurement in a 90-mile reach of the Laramie River under ice, by the University of 

Wyoming; USGS personnel assisted (Zimmerman, 1970).

Nov. 1970

Mar. 1971; 

June 1971

Time-of-travel measurements in a 113-mile reach of the Wind/Bighorn River between Boysen Dam and 

Greybull (Lowham and Wilson, 1971; Lowry and others, 1976).

d^

fipt §b|| pig Goose Cre^

Sept. 1974 Dye test of water loss in the channel of North Fork Crazy Woman Creek (Boner and others, 1976).

May 1975- 

July 1978

Dye-dilution discharge measurements of selected mountain streams in northeastern Wyoming, mainly for a 

study of recharge to the Madison Limestone of Mississippian age (p. 30-33). 1

Oct. 1975- 

Apr. 1976

Dye test of percolating effluent from a wastewater lagoon through deposits of sand and gravel near Old 

Faithful in Yellowstone National Park (Cox, 1986).

Nov. 1978 Time-of-travel measurement in a 36-mile reach of the North Platte River, Casper to the Dave Johnston Power 

Plant (Armentrout and Larson, 1984).

Aug. 1983 Dye test of connection of the Sinks to the Rise, Middle Popo Agie River, Sinks Canyon State Park

(p. 44-49). 1

Aug. 1989 Dye test of edgedrain on Interstate Highway 25 near Wheatland (Jeffcoat and others, 1992).

Sept. 1991 Dye test of water loss in the channel of Smith Creek below Otter Creek, near Casper (p. 50-51). 1

Results not published previously.

Chronology of Dye Tracing in Wyoming
TIME OF TRAVEL AND DISPERSION OF SOLUTES IN STREAMS

Methods

Dye tracing is well suited for obtaining information about water movement and solute transport in 

stream reaches that typically are many miles long. 

Time-of-travel, velocity, and dilution information is 

readily determined from the data. In most streams, a 

solute becomes evenly distributed (mixed) vertically 

and laterally within a short distance of the injection 

site. Longitudinal (downstream) dispersion, which is 

continuous, is the focus of most time-of-travel measurements (Kilpatrick and Wilson, 1989, p. 1-3).

The USGS has measured time of travel and dispersion in the Wind/Bighorn River, the Green River 

and several tributaries, the Little Snake River (a tributary of the Yampa River in Colorado), and part of the 

North Platte River. Each of those investigations is 

summarized subsequently. The USGS, however, was 

not the first to measure time of travel in Wyoming.

Gerald R. Zimmerman, a University of Wyoming graduate student, measured time of travel and 

dispersion in the Laramie River and in a short reach of 

a small, mountain stream during March, May, and 

November 1969. Ice completely covered the river 

throughout most of the 90-mile study reach in March. 

That is the longest such dye test of an ice-covered 

stream in the United States. For details, see 

Zimmerman (1970).

Data Collection. Typically, a measured 

amount of dye is poured into the stream as a line or at 

several points across the stream a "slug" injection. 

Dye also can be injected continuously by pumping. A 

single-slug or continuous injection can be used to 

simulate a point source of wastewater (see Kilpatrick, 

1993). Diluted by the stream, the dye soon becomes 

invisible.

Water samples are collected at pre-selected sites 

downstream as the dye cloud passes. Bridges are especially useful for sampling and are readily identified on 

topographic maps for determination of distance traveled by the dye. Sampling at a site begins prior to 

arrival of the dye to measure any natural (background) 

fluorometric response to the water, as well as to assure 

sampling of the leading edge of the dye. Sampling at 

one or more points across the stream is continued at 

various time intervals throughout the entire passage 

of the dye cloud, if possible. Because dye may be at

two sampling sites at once and sampling must be done 

around the clock, the completeness of coverage 

depends on the number of people available, distances 

between sites, and ease of access to the sites. Spatial 

sampling sampling an entire dye cloud at many 

points at once generally is not practical in streams.

The samples are tested in a fluorometer in the 

field to determine approximate dye concentrations as a 

guide to sampling, and re-tested later in the laboratory 

or office after the sample temperatures have stabilized 

and any suspended material in the water samples has 

settled. Data-collection procedures are described in 

greater detail by Kilpatrick and Wilson (1989).

Data Analysis. The basic result of sampling at 

a given site is a plot of dye concentration versus 

elapsed time, called a response curve (fig. 1). Time of 

travel of leading edge, peak concentration, and average 

are measured using the response curve for each site. 

The rate of decrease of the peak concentration and the 

increasing passage times (both measures of longitudinal dispersion) are determined from the curves for 

several sites where a single injection of dye was sampled (fig. 2). Spatial information can be extracted from 

the temporal data in a graph of time of travel versus 

distance (fig. 3). For example, 40 hours after injection, 

the March 1971 dye cloud in the Wind/Bighorn River 

was approximately 23 miles long between Worland 

and Manderson (fig. 3).

The amount of dye accounted for by sampling at 

each sampling site is calculated using the stream discharge and the areas under the dye-response curves 

(see investigations in karst terrane, p. 36). As 

described by Kilpatrick (1993), such dye-recovery 

calculations are especially important for simulating 

waste transport from a point source near the stream.

Nearly all time-of-travel investigations include 

dye tests at two or three different stream discharges, so 

that graphs of time of travel versus discharge can be 

prepared. As illustrated in the next unit, the graphs can 

be used to estimate time of travel between any two sites 

at any discharge within the range tested with dye.

Time-of-travel and dispersion characteristics 

without the benefit of dye tracing can be estimated 

using the equations of Boning (1974) or the more 

elaborate procedures of Jobson (1996).

Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
TIME OF TRAVEL, IN HOURS

D)

2.

D)

3 

Q.

D

 a

(D 

O) 5'

(Q

DYE CONCENTRATION, 

IN MICROGRAMS PER LITER

Boysen Dam

Wind River 

Canyon

 - Thermopolis

Lucerne

Winchester

Worland

Manderson

Greybull

Tl

Q.CO'

2 c 

§3

^r1

3 " ,

"

^- CD 

""
TIME OF TRAVEL AND DISPERSION OF SOLUTES IN STREAMS Continued

Wind/Bighorn River, 1971

[Investigation in cooperation with the Wyoming State Engineer]

The USGS first measured time of travel and 

dispersion in Wyoming on the Wind/Bighorn River 

between Boysen Dam and Greybull (fig. 4; the name 

changes from Wind River to Bighorn River at the 

northern end of Wind River Canyon). The study was 

conducted during 1971 as part of an assessment of the 

water resources of the Bighorn basin (Lowry and 

others, 1976). Hugh W. Lowham planned and directed 

the data collection and analyzed the results. Preliminary results were reported by Lowham and Wilson 

(1971). A complete analysis by Lowham is in Lowry 

and others (1976, sheet 2). Lowham's results also were 

summarized by Wilson (1987).

The first of two measurements was made March 

21-24, 1971, when the discharge from Boysen Dam 

was 1,940 ft3/s (cubic feet per second). No water was 

being diverted from the river for irrigation; the discharge increased only 60 ft3/s between the dam and the 

mouth of the Greybull River (fig. 4), which provided 

inflow of about 400 ft3/s. The second measurement 

was made June 29-30, 1971, when the discharge from 

the dam was 8,280 ft3/s. A total of about 800 ft3/s was 

being diverted into irrigation canals between Thermopolis and Worland, and more than 1,000 ft3/s of inflow 

was contributed by the Greybull River.

For both measurements rhodamine WT dye was 

injected as a single slug, just downstream from Boysen 

Dam. In March, 42.5 pounds of dye was injected; in 

June, 40.3 pounds. The passage of the dye was monitored by sampling at seven sites between the dam and 

Greybull, a distance of 112.7 river miles (fig. 4). 

Samples at the first site, Wind River Canyon, were 

collected by throwing a sampler attached to a line into

midstream and retrieving it. At all other sites, samples 

were collected at several points across the river by 

lowering a sampler from a bridge.

In March, the peak concentration of dye reached 

the sampling site near Greybull in 56 hours, and the 

dye cloud took about 12 hours to pass the site (the dyeresponse curves are shown in figure 2, preceding unit). 

The peak concentration was 3.05 micrograms per liter. 

In June, the peak reached Greybull in about 33 hours 

and the dye cloud took about 7 hours to pass. The peak 

concentration was 0.85 microgram per liter.

The data were exceptionally detailed in both the 

number of sampling sites and the completeness of 

sampling, and discharge was nearly steady throughout 

the study reach. Consequently, Nordin and Sabol 

(1974) included the data in their compilation of data 

sets suitable for research of longitudinal dispersion, 

and Nordin and Troutman (1980) used the data to 

evaluate dispersion patterns of solutes in flowing water.

Time of travel between any two sites within the 

study reach can be estimated for a given discharge by 

interpolation of the graph in figure 5 within the range 

of discharges measured. Figure 5 is based on the time 

of travel of the peak concentration, which always is 

slightly less than the average time of travel of the water 

(see fig. 1, preceding unit). The relation of the logarithm of time of travel to the logarithm of stream 

discharge is assumed to be linear (Kilpatrick and 

Wilson, 1989, p. 21). For some streams, however, a 

third measurement is needed to verify the linearity of 

the relation, particularly at very small discharges. 

Because the range in discharge of the two measurements on the Wind/Bighorn River covered most 

releases from Boysen Dam, a third measurement was 

not necessary.

Additional information about the measurements 

is given in Lowry and others (1976, sheet 2). Graphical data include a river profile, longitudinal variation 

in discharge and velocity, and traveltime-distance 

curves for the leading edge, peak concentration, and 

trailing edge of the dye. These graphs help describe the 

solute-transport characteristics of the river.

Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
108°30'

45° MONTANA 108° 

.WYOMING

44°30' -

44° '

43°30'

100

50

m 20

O 

cc 

u.

n 10

O

2 -

1,000

EXAMPLE

For a discharge of 6,000 

cubic feet per second, 

the time of travel of the 

peak concentration from 

Wind River Canyon to Worland 

is approximately 20 minus 1.7, 

or 18.3 hours

2,000 5,000

I I l

10,000

AVERAGE DISCHARGE BETWEEN SITES, 

IN CUBIC FEET PER SECOND

Figure 5. Relation of time of travel to water discharge, 

Wind/Bighorn River (modified from Lowry and others, 

1976, sheet 2). Time of travel between intermediate 

sites is determined by subtraction, as shown in the 

example.

20 KILOMETERS

EXPLANATION

STREAMFLOWGAGING STATION

DYE-INJECTION SITE

^T SAMPLING SITE 

AND NUMBER

Figure 4. Location of streamflow-gaging stations 

and dye-injection and sampling sites, Wind/Bighorn 

River. Site numbers are from Lowry and others 

(1976, sheet 2).

Time of Travel and Dispersion of Solutes in Streams
TIME OF TRAVEL AND DISPERSION OF SOLUTES IN STREAMS Continued

Green River and Tributaries, 1975-77

[Investigation as part of the U.S. Geological Survey Oil-Shale Hydrology Program]

Time of travel and dispersion were measured 

during 1975-77 as part of an investigation of streamflows and hydraulic and solute-transport characteristics 

of streams in the Wyoming part of the Green River 

basin (Lowham, 1982). The information was needed 

by Federal and State agencies responsible for planning 

and development of coal, oil-shale, and other mineral 

resources in southwestern Wyoming.

Equations for estimating channel hydraulic 

characteristics, such as width, depth, slope, and water 

velocity, from stream discharge commonly are used in 

planning and design of water-related projects. Velocities measured at cross sections as a part of streamflow 

measurements may not be representative of velocities 

throughout a stream reach; neither, therefore, are 

equations derived using local velocities. Accurate 

velocities in a reach, however, can be determined by 

dividing reach length by time of travel of dye.

The time-of-travel measurements in the Green 

River and four tributaries that join the Green in Wyoming (fig. 6) are summarized in table 1. Measurements 

in the Little Snake River, which flows into Colorado, 

are described in the next unit.

Details of the measurements and results of data 

analysis are described by Lowham (1982, p. 48-70). 

Lowham's results indicate that at three streamflowgaging stations, the measured cross sections were not 

representative of the study reaches. Lowham also 

notes that for very low flows in some streams, 

velocities calculated from time-of-travel data may be 

too small, because the reach lengths measured on 

topographic maps, which are more representative of 

medium-to-high flows, are shorter than the distances

traveled by the dye. Otherwise, the results indicate 

reasonably small differences between velocities 

measured at selected stations and reach velocities 

measured by dye tracing. An example is shown in 

figure 7. Graphs for the other reaches listed in table 1 

and for the Little Snake River are in the report by 

Lowham (1982, p. 64-66). That report also includes 

graphs for predicting time of travel for a specified 

stream discharge.

Table 1. Time-of-travel measurements, Green River and 

tributaries, southwestern Wyoming, 1975-77

[Source: Lowham (1982, p. 55-59). Site numbers are shown in figure 6]

Date

Reach 

(site Reach length Discharge, start/end 

numbers) (miles) ' (cubic feet per second)

Green River above Fontenelle Reservoir

June 1975

Aug. 1977

1-8

2-5

117.3

47.9

430/2,000

264/268

Green River below Fontenelle Reservoir

June 1975

Aug. 1975

Aug. 1977

Aug. 1977

June 1975

July 1975

July 1976

July 1976

June 1975

June 1975

July 1975

July 1976

July 1976

July 1975

Aug. 1975

July 1975

Aug. 1975

12-15

11-16

12-13

13-16

1-6

1-5

2-4

3-4

3-6

7-10

7-10

1-2

2-3

1-3

1-3

1-3

1-4

61.1

70.3

36.1

30.6

East Fork River

39.3

27.5

8.9

3.0

Big Sandy River

59.1

42.6

42.6

2.3

7.5

Horse Creek

13.8

13.8

Blacks Fork

7.9

14.4

5,760/5,980

1,700/1,730

350/400

420/329

650/916

1,030/860

121/150

146/146

459/440

105/122

350/370

214/214

214/315

250/425

10/16

1,170/1,170

194/169

8 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
EXPLANATION

A STREAMFLOW-GAGING

STATION ON GREEN RIVER

A STREAMFLOW-GAGING

STATION ON TRIBUTARY

DYE-INJECTION 

SITE AND NUMBER

15TT GREEN RIVER SAMPLING 

SITE AND NUMBER

10V TRIBUTARY SAMPLING 

SITE AND NUMBER

WYOMING

UTAH"

10 20 30 40 KILOMETERS

Figure 6. Location of streamflow-gaging stations and dye-injection and sampling sites, Green 

River, East Fork River, Big Sandy River, Horse Creek, and Blacks Fork. Site numbers 

are from Lowham (1982). Sites are numbered independently for each stream.

RELATION USING 

CURRENT-METER MEASUREMENTS

RELATION USING

DYE MEASUREMENTS

Station 09211200 

(site 11)

200 500 1,000 2,000 5,000 7,000

DISCHARGE, IN CUBIC FEET PER SECOND

Figure 7. Relation of mean velocity to water discharge at two streamflow-gaging 

stations and in a 70.3-mile reach, Green River downstream from Fontenelle 

Reservoir (modified from Lowham, 1982, fig. 29).

Time of Travel and Dispersion of Solutes in Streams
TIME OF TRAVEL AND DISPERSION OF SOLUTES IN STREAMS Continued

Little Snake River, 1976-77

[Investigation as part of the U.S. Geological Survey Oil-Shale Hydrology Program 

and the U.S. Geological Survey Yatnpa River Basin Assessment]

Time-of-travel and dispersion data were collected in the Wyoming part of the Little Snake River 

(fig. 8) during 1976 and 1977. The measurements were 

used in a USGS assessment of the water resources of 

the Yampa River basin in Colorado and Wyoming 

(Steele and others, 1979). Because of the substantial 

economic development in the basin, there was an 

immediate need for information for water planning and 

management particularly information about streamflow and waste-transport characteristics of the Yampa 

and its largest tributary, the Little Snake River. The 

Little Snake joins the Yampa in Colorado approximately 77 river miles southwest of site 13 (fig. 8).

The Little Snake time-of-travel measurements, 

directed by Hugh W. Lowham, USGS, Wyoming, were 

coordinated with similar work on the Yampa, conducted by USGS personnel from Colorado. The overall study reach was subdivided into subreaches for dye 

injection and sampling (fig. 8). Time-of-travel and 

longitudinal-dispersion data for three different discharges were collected. The measurements are summarized in table 2.

Results of the dye measurements in both the 

Yampa River and the Little Snake River are described 

in detail by Bauer and others (1979) and by Lowham 

(1982). Bauer and others (1979, p. 25-30 and p. 33-34) 

include graphs that can be used for predicting time of

travel and unit concentration for a given discharge at 

either of the two streamflow-gaging stations in the 

study reach (fig. 8, sites 1 and 8). The graph for site 8 

is shown in figure 9.

As discussed in the preceding unit on the Green 

River and tributaries, the report by Lowham emphasizes mean velocities. Lowham (1982, p. 66) compared mean velocities determined from the dye measurements in the study reach of the Little Snake River 

with mean velocities measured with current meters at 

the two stations. He reported marked differences 

between the velocities measured with dye and velocities measured with a current meter. Lowham (1982, 

p. 54) attributes the differences to the fact that the cross 

sections where current-meter measurements were 

made are not representative of cross sections throughout the study reach.

Table 2. Time-of-travel measurements, Little Snake River, 

southwestern Wyoming, 1976-77

[Source: Bauer and others (1979, p. 13-14). Site numbers are shown in 

figure 8]

Date

June 1976

June 1976

Sept. 1976

Sept. 1976

Sept. 1976

Sept. 1976

Sept. 1976

May 1977

May 1977

May 1977

Reach 

(site 

numbers)

8-13

1-8

11-12

9-10

7-8

4-5

1-2

9-13

4-8

1-6

Reach length 

(miles)

42.9

32.4

3.0

3.5

.9

4.8

3.4

33.3

23.1

17.7

Discharge, start/end 

(cubic feet per second)

1,690/1,690

1,400/2,070

25.0/25.0

32.4/32.4

30.0/30.0

30.0/30.0

20.0/20.0

668/668

711/666

596/711

10 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
108°45' 108°30' 108° 15' 107°

WYOMING ^N^V^ 

COLORADO

EXPLANATION

STREAMFLOWGAGING STATION

DYE-INJECTION 

SITE AND NUMBER

SAMPLING SITE 

AND NUMBER

40°52'

20 MILES 

I

20 KILOMETERS

Figure 8. Location of streamflow-gaging stations and dye-injection and sampling sites, 

Little Snake River. Site numbers are from Bauer and others (1979).

200

100

50

20

10

LL

o

LLJ

I 5

20 50 100 200 500 1,000 2,000 5,000 

DISCHARGE, IN CUBIC FEET PER SECOND

10,000

Figure 9. Relation of time of travel to water discharge at streamflowqaging station 09257000, Little Snake River near Dixon, Wyoming 

(site 8) (modified from Bauer and others, 1979, fig. 12). Numerals 

are site numbers shown in figure 8. Time of travel is from the 

upstream gaging station (site 1) to the indicated site.

Time of Travel and Dispersion of Solutes in Streams 11
TIME OF TRAVEL AND DISPERSION OF SOLUTES IN STREAMS Continued

North Platte River, 1978, 1985

[Investigation in cooperation with the Wyoming Department of Environmental Quality]

Possibilities for hazardous-waste spills into the 

North Platte River between Casper and Orin are numerous. Two railroads and Interstate Highway 25 parallel 

and cross the river. In addition, numerous pipelines 

cross the river, and several cities discharge treated 

wastewater into the river.

To provide information that might be useful in 

the event of a hazardous-waste spill, the USGS measured time of travel and dispersion in the river during 

1978 and 1985. The 1985 work included measurement 

of reaeration coefficients. The Wyoming Department 

of Environmental Quality provided both personnel and 

funding, and co-authored and published the results 

(Rankl and Carnevale, 1989).

From Casper the North Platte River flows eastward along the northern edge of the Laramie Mountains to Orin (fig. 10). The flow is regulated by a series 

of reservoirs upstream from Casper. The river is freeflowing in the study reach except for a low dam at the 

Dave Johnston Power Plant near Glenrock. About 

3 miles downstream from Orin, the North Platte River 

flows into Glendo Reservoir.

Four sets of time-of-travel and dispersion data 

were collected in the North Platte River between 

Casper and Orin. The first measurement was made on 

the upper 36 miles of the reach on November 7-8,1978 

at a discharge of 940 ft3/s (Armentrout and Larson, 

1984). The second measurement was made on the 

entire 95-mile reach on May 14-15,1985 at a discharge 

of 3,100 ft3/s. The third measurement was made in 

conjunction with a reaeration measurement on 40 of 

the first 41 miles of the study reach on October 9-10, 

1985; the discharge was about 800 ft3/s. The fourth

measurement was made on the last 54 miles of the 

study reach on October 10-12, 1985 at a discharge of 

890 ft3/s (Rankl and Carnevale, 1989, p. 8).

For measurements 1, 2, and 4, rhodamine WT 

dye was slug-injected into the river. On November 7, 

1978,19.85 pounds of dye was injected from the center 

of the Bryon Stock Trail Bridge in Casper (site 4, 

fig. 10). For the May 14-15, 1985 measurement, 

24.50 pounds of dye was injected into the center of the 

river from the abandoned U.S. Highway 20-26 bridge 

on the western city limits of Casper (site 1, fig. 10). On 

October 10,1985,9.89 pounds of dye was injected into 

the center of the river from the abandoned U.S. 

Highway 87 bridge downstream from Dave Johnston 

Power Plant (site 17, fig. 10). That injection site was 

the farthest-downstream sampling point for measurements 1 and 3.

Dye and gas tracers were injected concurrently at 

the First Street bridge in Casper (site 2, fig. 10) on 

October 9,1985, to measure both time of travel (measurement 3) and reaeration. Two fluid-metering pumps 

were used to inject 25.29 pounds of 4.76-percent 

solution of rhodamine WT dye at a constant rate for 

2 hours. At the same time, propane gas was injected 

into the water through porous-plate diffusers (the 

reaeration part of the investigation is described on 

p. 16-17 of this report).

Locations of sampling sites used for one or more 

of the measurements are shown in figure 10. For the 

1985 measurements, equations developed by Boning 

(1974) for estimating time of travel were used to plan 

and develop sampling schedules. The equations 

proved quite accurate for the North Platte River.

Graphical relations developed from the data 

include the following: velocity in relation to discharge 

(fig. 11); dye-cloud passage time in relation to distance 

downstream from the injection (fig. 12); and unit-peak 

concentration in relation to time of travel (fig. 13). For 

detailed explanations of these relations and additional 

time-of-travel relations, see Rankl and Carnevale 

(1989).

12 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
106 15' 106 105 45' 105 30' 105 15'

42 52'30"-

42 45'

STREAMFLOWGAGING STATION

DYE-INJECTION 

SITE AND NUMBER

SAMPLING SITE 

AND NUMBER

Figure 10. Location of streamflow-gaging stations and dye-injection and sampling sites, 

North Platte River. Site numbers are from Rankl and Carnevale (1989).

3.0 

DC 2.5

2.0

=! 1.5

1.2

Leading edge,

\

Peak concentration

700 1,000 2,000 3,000 4,000 

DISCHARGE, IN CUBIC FEET PER SECOND

Figure 11. Velocity-discharge relations for leading edge 

and peak concentration of dye cloud, North Platte River 

between Casper and Orin, Wyoming. Break in slope of 

curves indicates change in flow regime (see fig. 13) 

(modified from Rankl and Carnevale, 1989, fig. 9).

20

LU

IwI-DC

7 10 20 50 100 

DISTANCE DOWNSTREAM, IN RIVER MILES

Figure 12. Relation between passage time of dye 

cloud and distance downstream from the point of 

injection, North Platte River between Casper and 

Orin, Wyoming (modified from Rankl and Carnevale 

1989, fig. 10).

ZDC

QUJ 4

0<

UJDC 

0.0

Channel control

Riffle control3 10 50 

TIME OF TRAVEL OF PEAK, IN HOURS

Figure 13. Relation between unit-peak concentration 

and time of travel of peak, North Platte River 

between Casper and Orin, Wyoming (modified from 

Rankl and Carnevale, 1989, fig. 11). Concentrations 

are for an injection of 1 pound of dye and a stream 

discharge of 1,000 cubic feet per second.

Time of Travel and Dispersion of Solutes in Streams 13
REAERATION COEFFICIENTS IN STREAMS

Methods

Biodegradation of organic waste in a stream 

consumes dissolved oxygen. Reaeration is the physical 

process by which dissolved oxygen removed from the 

stream is replaced by oxygen absorbed from the atmosphere. The rate of oxygen absorption is expressed as 

a reaeration coefficient. Mathematical dissolvedoxygen models are used to quantify the amount of 

organic waste that can be discharged to the stream 

without depleting the supply of dissolved oxygen. Use 

of a dissolved-oxygen model to compute an oxygen 

balance requires reaeration coefficients for the reach of 

stream being investigated.

A direct method of measuring reaeration coefficients was developed by Tsivoglou (1967) using 

Krypton-85 radioactive gas for a tracer. The method is 

based upon the concept that tracer gas coming out of 

the water (desorbed) is related inversely to oxygen 

going into the water (absorbed). However, injecting a 

radioactive gas into a stream created safety concerns 

and permitting problems with the regulatory agencies.

A modified tracer technique, using propane or 

ethylene as a tracer, was developed and tested by 

Rathbun and others (1975) and Rathbun and Grant 

(1978). Procedures for applying the modified tracer 

technique are described by Kilpatrick and others 

(1989).

With the modified tracer technique, propane or 

ethylene gas is injected into the stream at a constant 

rate by bubbling the gas through porous-plate diffusers. 

The number of diffusers required depends on the 

discharge (Kilpatrick and others, 1989, table 2, p. 17). 

The gas is supplied from 100-pound tanks equipped 

with pressure regulators and flow meters. At the same 

time the gas is injected into the stream, rhodamine WT 

dye is injected using small, battery-operated fluidmetering pumps. The dye serves as an inexpensive, 

easily monitored guide for collecting samples of the 

gas, and also provides the quantitative measures of 

dilution and dispersion needed to calculate reaeration 

coefficients.

Dye and gas samples are collected at two or more 

sites. The dye samples are analyzed in the field using a

fluorometer. The timing of the gas sampling is controlled by information obtained from the on site evaluation of the dye-response curve. Samples for the 

analysis of gas concentrations are collected at a minimum of three points across the stream using a directdisplacement sampler. The sample bottles are filled 

completely to exclude all air bubbles, injected with a 

small quantity of formalin solution to prevent biological degradation during storage, and tightly sealed. The 

samples are shipped as soon as possible to the laboratory for analysis.

Two methods are available for calculating the 

gas desorption-rate coefficients: the area method and 

the peak method. With the area method, the change of 

mass of the gas tracer over a selected reach is calculated. Mass is equal to the area under the gas-response 

curve multiplied by the stream discharge. The coefficients for the area method are calculated using equation 1. This method requires a large number of gas 

samples to define an entire gas-response curve.

With the peak method, the gas desorption-rate 

coefficients are calculated from the change in gas 

concentration over a selected reach. Gas concentration 

is measured at a characteristic time on the upstream and 

downstream gas-response curves. The characteristic 

time most used is that of the peak concentration of the 

corresponding dye-response curve. The coefficients 

for the peak methods are calculated using equation 2. 

The gas desorption-rate coefficients for both the area 

method and the peak method are adjusted by a ratio, J, 

of the calculated dye recovery at the upstream site to 

that at the downstream site.

Equation 3, developed by Rathbun and others 

(1978), is used to convert gas desorption-rate coefficients to oxygen-absorption coefficients (reaeration 

coefficients). Equation 4 (Kilpatrick and others, 1989, 

p. 8) is used to adjust the reaeration coefficients to

20°C (degrees Celsius).

Reaeration coefficients for unsteady flow in a 

dye-tested reach may be estimated using the numerical 

routing model described by Jobson (1987) calibrated 

with the dye- and gas-tracing data for steady flow.

14 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Gas Desorption-Rate Coefficients

Area Method

With the area method, the gas desorption-rate 

coefficient, A(y, is calculated using the following 

equation (Kilpatrick and others, 1989, eq. 14, p. 9):

Kr = ln

c

where fc is the time of travel of the centroid

(average time of travel) of the dye cloud 

between the selected sections, in hours;

^g is the area under the gas-response curve 

at the upstream (u) and downstream (d) 

sites, in micrograms per liter-hour; and

Q is the stream discharge at the upstream 

(u) and downstream (d) sites, in cubic 

feet per second.

The centroids of the dye cloud and the gas cloud are 

calculated for the upstream and downstream sites 

by taking moments with respect to time of each 

response curve. The areas of the gas-response 

curves, Ag , are calculated by numerical integration 

or by planimetering.

Peak Method

With the peak method, the gas desorption-rate 

coefficient, A(y, is calculated using the following 

equation (Kilpatrick and others, 1989, eq. 13, p. 8):

ACT = -1 (2)

where Cg is the concentration of propane at the 

peak concentration of the dye cloud, 

Cp, at the upstream (u) and downstream 

(d) sites, both in micrograms per liter;

fp is the time of travel of the peak dye 

concentration between the upstream (u) 

and downstream (d) sites, in hours; and

J is the ratio of dye recovery at the 

upstream site to that at the downstream 

site. Calculation of dye recovery is 

described in the methods for 

investigations in karst terrane (p. 36 of 

this report).

Reaeration Coefficients

The following equation developed by Rathbun and others (1978) is used to 

convert the gas desorption-rate coefficient, ACy , determined with either the area 

method or the peak method, to the reaeration coefficient, AC2 :

K2 = 1.39 ACT . (3)

Reaeration coefficients are expressed for a stream temperature of 20°C 

as AC Z20 . The following equation is used to calculate AC Z20 for stream

temperature T in degrees Celsius (Kilpatrick and others, 1989, eq. 8, p. 8):

AC = AC (1.0241) (20-T)

-20 (4)

Reaeration Coefficients in Streams 15
REAERATION COEFFICIENTS IN STREAMS Continued

North Platte River, 1985

[Investigation in cooperation with the Wyoming Department of Environmental Quality]

Discharge of treated wastewater from cities and 

industry into the North Platte River has the potential to 

affect water quality of the river. In 1985 the USGS and 

Wyoming Department of Environmental Quality 

investigated the reaeration capacity of the North Platte 

River downstream from Casper (Rankl and Carnevale, 

1989). The information was needed for applying a 

mathematical dissolved-oxygen model to the reach 

extending from the First Street bridge in Casper to the 

abandoned U.S. Highway 87 bridge downstream from 

Dave Johnston Power Plant near Glenrock (site 2, 

fig. 14).

The North Platte River in the study reach is freeflowing, except for a low-head dam at Dave Johnston 

Power Plant. Inflows to the river are minimal, with the 

largest coming from Deer Creek. Deer Creek has an 

October mean flow of 14 ft3/s (Peterson, 1988, p. 348).

On October 9, 1985 at 11:00 p.m., at a river discharge of 800 ft3/s, rhodamine WT dye and propane 

gas were injected into the North Platte River at the First 

Street bridge in Casper (site 2, fig. 14). Two fluidmetering pumps were used to inject 25.29 pounds of 

4.76-percent solution of rhodamine WT dye at a 

constant rate for 2 hours. Simultaneously, propane gas 

was injected at a rate of 36.0 ft3/min (cubic feet per 

minute). The air temperature at the time of the injection 

of dye and gas was -6°C, and the water temperature 

was 5°C. The cold air temperature caused a loss of 

pressure in the propane tanks, resulting in a flow rate of 

31.2 ft3/min 13 percent less than the design rate. The 

flow rate could not be increased by adjusting the flow 

meters. After the first hour of injection, the propane 

tanks were placed in the river to increase the temperature of the propane. The flow rate returned to the 

design rate almost immediately.

Separate sets of water samples for dye and propane concentration were collected at Bryon Stock Trail 

bridge, 3.0 miles downstream from injection (site 4, 

fig. 14); Mystery bridge, 8.5 miles downstream from 

injection (site 6); Cole Creek Road bridge, 23.6 miles 

downstream from the injection (site 11); and at abandoned U.S. Highway 87 bridge, 40.1 miles downstream from injection (site 17). Dye samples were 

tested in a fluorometer in the field. Dye-response 

curves were prepared in the field and used to guide the 

sampling for propane gas. Because the dye-response 

curves (fig. 15) indicated nearly complete lateral 

mixing at the Bryon Stock Trail bridge, propane 

samples were collected only at the center of flow.

The gas-response curve (fig. 16) is nearly 

identical in shape to that of the dye-response curves 

(fig. 15) except for the secondary plateau resulting 

from the increased gas flow rate described previously. 

Because the peak of the gas-response curve was at or 

near the peak of the dye-response curve, the peak 

method was considered acceptable for calculation of 

the gas desorption-rate coefficients for all three subreaches.

The areas under the gas-response curves were 

determined for the first three sampling sites. However, 

insufficient data and low concentrations prevented 

defining the total mass of gas tracer at the fourth site. 

Therefore, use of the area method to calculate gas 

desorption-rate coefficients was limited to subreaches 1 and 2 (fig. 14).

Reaeration coefficients are listed in table 3. The 

average of the four values for subreaches 1 and 2 

5.38 is considered to be the best estimate of the 

reaeration coefficient for the reach of the North Platte 

River between Casper and the small reservoir at Dave 

Johnston Power Plant. The higher reaeration coefficient for subreach 3 (fig. 14) probably is the result of 

residence time in the reservoir and flow over the dam at 

the power plant. Details of this investigation are 

described by Rankl and Carnevale (1989).

16 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
43

42 52'30'

42 45'

106 15'

Subreach

106 105 45'

Subreach

Dave Johnston

Power Plant 

Platte

River

EXPLANATION

INJECTION SITE 

AND NUMBER

SAMPLING SITE 

AND NUMBER

10 KILOMETERS

Figure 14. Location of dye- and gas-injection sites and sampling sites, and subreaches 

for which reaeration coefficients were calculated, North Platte River. Site numbers 

are from Rankl and Carnevale (1989).

zrr 

 iu

era.

uu:> 

o< 

zee

OO 

GO 1

SAMPLING 

POINTS

a Left 

A Middle 

O Right

1 23456 

TIME AFTER START OF INJECTION, IN HOURS

Figure 15. Dye-response curves in North Platte River 

at Bryon Stock Trail bridge (site 4), October 9, 1985. 

Similarity of curves indicates that lateral dispersion 

is nearly complete (from Rankl and Carnevale, 

1989, fig. 5).

<LU 

DCQ.

LU:> 

o<

ZCC 4 

OO

oo

Cog 2

0123456 

TIME AFTER START OF INJECTION, IN HOURS

Figure 16. Gas-response curve in North Platte 

River at Bryon Stock Trail bridge (site 4), 

October 9, 1985 (previously unpublished).

Table 3. Gas desorption-rate coefficients and reaeration coefficients, North Platte River below Casper, 

Wyoming, October 1985

[Source: Rankl and Carnevale (1989, p. 26). Subreach locations are shown in figure 14. Coefficients are in logarithm base-e units; 

°C, degrees Celsius; , not calculated]

Subreach number

1

Dye-recovery ratio (J) (upstream site to downstream site) 1.14 1.11 1.16

Gas desorption-rate coefficient ( Kj , a ratio of upstream to downstream peak .119 .118 . 1 72 

gas concentration), per hour (peak method)

Gas desorption-rate coefficient ( Kj , a ratio of upstream to downstream total 104 .114 

mass of gas), per hour (area method)

Keaeration coefficient at 2U "(j ^ 

Reaeration coefficient at 20 °C ( ,

A,, ;, per uay {peak metnoa )

Z20

K~ ), per day (area method) Z20

5.55 5.67 6.70 

4.85 5.47

Reaeration Coefficients in Streams 17
DISCHARGE MEASUREMENTS IN STREAMS

Methods

USGS hydrographers have made numerous dyedilution measurements of stream discharge in Wyoming since 1967. Sometimes called dilution gaging, 

the technique is both simple and, if used correctly, 

accurate. A dye-dilution measurement is not a substitute for a current-meter measurement, but is an effective alternative when use of a current meter is either 

impracticable or impossible. The basic principle of 

dilution gaging is that the amount of dilution of an 

injected soluble tracer in a stream is directly proportional to the stream discharge.

There are two methods for dilution gaging. The 

slug-injection method requires extensive sampling and 

might yield less accurate results. Only the constantrate-injection method has been used in Wyoming. Both 

methods are described in detail by Kilpatrick and Cobb 

(1985). The inverse of the slug-injection calculation 

(using known discharge) is used to calculate dye 

recovery in time-of-travel and reaeration measurements and in some dye tests in karst terrane. Calculation of dye recovery is described later in the methods 

for investigations in karst terrane.

Theory. When dye is injected at a constant 

rate into a stream or other conduit in which the discharge is approximately steady, the amount of dye 

passing any cross section in a unit of time is approximately constant. The amount of dye (the dye flux) is 

equal to the discharge in the conduit multiplied by the 

concentration of the dye, whether the conduit is the 

dye-injection tubing or the stream, canal, or pipe 

receiving the dye. As dye injection continues, at some 

point downstream the dye becomes completely mixed 

throughout the cross section of flow, and for some 

additional distance the concentration of dye is approximately the same at any point in the stream. Hydrographers refer to this as the "plateau" concentration 

(fig. 17).

Measurement of dye flux hence, stream 

discharge is practical only at stream cross sections 

where dye injection and the resulting dye concentration 

in the stream are in equilibrium. The equation below 

indicates the relation of dye flux in the stream to dye 

flux in the injection tubing at equilibrium. Stream 

discharge Q can be calculated from measurements of

the other three variables (Kilpatrick and Cobb, 1985, 

p. 5, eq. 2):

Qc = qC,

where Q is the stream discharge,

C is the plateau concentration in the stream,

q is the injection rate, and

C is the concentration of the injection solution

Data Collection. Various apparatus for injecting dye at a constant rate are described by Kilpatrick 

and Cobb (1985, p. 20-23). In Wyoming, a pressurized 

chemical-feed tank was used prior to 1975, and batterydriven fluid-metering pumps thereafter. The injection 

rate q from the pressurized tanks was measured intermittently using a 100-mL (milliliter) graduated cylinder held under the outflow tubing. That method has 

been replaced by timing the cumulative change in 

contents in a 1,000 or 2,000-mL graduated cylinder 

from which the dye solution is pumped directly into the 

stream through 0.25-inch (inside diameter) plastic 

tubing (fig. 18). A sample of the injection solution is 

retained for laboratory determination of injectionsolution concentration C.

The sampling cross section is located where the 

discharge is to be measured. There can be inflow 

between the injection site and sampling site, but there 

should not be outflow. Several sets of samples are 

collected at three or more points across the stream at a 

fixed time interval, such as 5 minutes. The samples are 

retained for determination of plateau concentration c. 

Concentrations may be expressed either in fluorometer 

units or in micrograms per liter.

Data Analysis. Injection rate qis measured as 

described above, and concentrations Cand Care determined fluorometrically. Discharge Q, in cubic feet per 

second, with qin milliliters per minute, is calculated as 

follows:

Q = 5.89 x 10~

c

An acceptable measurement is one with a constant 

injection rate, a well-defined plateau concentration 

(fig. 17), and nearly uniform lateral mixing (fig. 19).

18 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
 WATER SAMPLES 

COLLECTED Plateau concentration

ELAPSED TIME 

Figure 17. Dye-response curve for a constant-rate injection of dye.

Graduated cylinder 

containing injection 

solution of dye of 

concentration, C

^* Plastic tubing. 

Injection rate, q 

(Dye flux = qC)

Dye-injection site

Measurement (sampling) site. 

Discharge, Q, with dye 

concentration, c 

(Dye flux = Qc)

Figure 18. Injection equipment and stream reach for a 

dye-dilution discharge measurement.

Left 

Bank

Right 

Bank

Left 

Bank

Right 

Bank

Left 

Bank

Right 

Bank

B

DISTANCE ACROSS STREAM

Figure 19. Degrees of lateral mixing for dye-dilution discharge measurements. Dots indicate samples. 

A, poor mixing (therefore, poor measurement); B, mixing uncertain because sampling did not extend 

across stream (measurement considered poor); C, excellent mixing (measurement can be used with 

confidence if injection rate was constant, and a plateau was achieved).

Discharge Measurements in Streams 19
DISCHARGE MEASUREMENTS IN STREAMS Continued

Laramie River under Ice, 1967

[Investigation as part of the U.S. Geological Survey Surface-Water Research Program]

The first dye-dilution discharge measurements in 

Wyoming were made as part of USGS research to 

develop procedures for using the technique in streams 

covered with ice. Frederick A. Kilpatrick, USGS, Fort 

Collins, Colo., assisted by James G. Rankl, USGS, 

Cheyenne, Wyo., made five test measurements of 

discharge in the ice-covered Laramie River at Laramie, 

Wyo. (fig. 20) during February 1967. The previous 

year Kilpatrick had made a preliminary measurement 

under ice at a site on the Laramie River near 

Glendevey, Colo. That test had demonstrated that loss 

of dye by sorption on the bottom surface of the ice was 

negligible. The following information is drawn from 

an informal report on the 1967 measurements, prepared 

by Kilpatrick (written commun., 1967) for administrative use within the USGS.

Da fa Collection. Two measurements were 

made on February 17, and three on February 28,1967. 

An injection solution of dye, water, and antifreeze was 

used for each of the first four test measurements. For 

the fifth measurement, only dye and water were used. 

A pressurized chemical-feed tank (fig. 21) was used to 

inject the dye solutions at a constant rate through the 

ice at a point in mid-channel, about 200 feet upstream 

from the gaging station (fig. 20). The plastic feed line 

from the tank was passed through a metal pipe inserted 

through the ice to a point at about two-thirds of the 

depth of the water.

For sampling, 0.5-inch diameter holes were 

drilled with a carpenter's brace. The ice was about 

18 inches thick. Samples were collected at each of five 

points across the stream (fig. 20), 50 minutes after start

of injection. Water was drawn through a plastic tube 

inserted in the holes, then transferred to small bottles 

for fluorometric analysis later.

A current-meter measurement was made each 

day at a section of stream cleared of ice (fig. 20). Also, 

a detailed measurement of the vertical distribution of 

velocity was made February 28. That test verified that 

upstream ice cover did not affect the distribution of 

flow at the measurement site. Mean velocity in the 

vertical-velocity measurement occurred at the standard 

depth (0.6 times total depth) at which the meter usually 

is placed.

Results. The test measurements are summarized in table 4. Kilpatrick noted that because the 

viscosity of each injection solution was different, the 

injection rates for a given setting on the pressurized 

chemical-feed tank were different. For measurements 

2-5, however, injection rates were constant and dye 

losses negligible. The calculated discharge for each of 

the four tests was within 2 percent of the discharge 

measured with a current meter (table 4). In contrast, 

the injection rate for measurement 1 was erratic, and 

dye loss was large; the calculated discharge was 

11 percent greater than that measured with a meter. 

From these tests, Kilpatrick and Cobb (1985, p. 39) 

suggest that commercial antifreezes not be used for 

measurements under ice; laboratory-grade methanol 

works best. Environmental concerns, however, might 

preclude any future use of methanol or antifreeze in 

Wyoming streams.

The main conclusions from the Laramie River 

test measurements are that discharge under ice can be 

measured accurately using dye dilution, and that some 

antifreeze additives can be used in the injection solution without affecting measurement accuracy. The 

chemical-feed injection tank worked well in freezing 

temperatures. The dye-injection and sampling 

methods also worked well. Kilpatrick and Cobb (1985, 

p. 37-40) used the knowledge gained from these tests 

in their manual on dilution gaging.

20 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Streamflow-gaging 

A station

.XmSSwSSv

injection

50-foot section 

cleared of ice 

for current-meter 

measurement

Holes drilled in 

ice for sampling

Stream is composed of alternate 

pools and riffles. Average width, 

25 feet. Mean depth, 1.5 feet. 

Distance from point of injection 

to sampling, approximately 900 

feet.

To Laramie, Wyo. 

1 mile

(NOT TO SCALE)

Figure 20. Sketch of the test reach for dye-dilution 

discharge measurements under ice, Laramie River.

Figure 21. Longitudinal section showing setup 

Tor injecting dye through ice, Laramie River.

Table 4. Dye-dilution discharge measurements under ice cover, Laramie River at Laramie, Wyoming, February 1967

3 [From F.A. Kilpatrick, U.S. Geological Survey, written commun., 1967. ft /s, cubic feet per second]

Stream discharge

Measurement 

number Date

Antifreeze used 

(25 percent of solution 

in measurements 1-4)

Current 

meter 

(ft3/s)

Dye 

dilution 

(ft3/s)

Percent 

difference Remarks

2-17-67 Commercial glycol-base 34.0 

antifreeze with rust inhibitors and magnetic film additives

2-17-67 Laboratory-grade methane 1 34.0

37.7

34.5

3 2-28-67 Commercial methanol-base 32.6 

antifreeze

4 2-28-67 Laboratory-grade glycol 32.6 

solution

2-28-67 None 32.6

32.8

33.0

+11 Substantial dye loss. In a laboratory test, this 

solution coated glassware. Inside of the injection tank also was coated. Additives apparently caused large adsorptive losses under ice 

and adversely affected the injection rate.

+1.5 Initial specific gravity of this solution was less 

than 1, so it tended to float until sufficiently 

diluted by the stream. Best to use under hard 

ice, to minimize possible adsorptive loss, 

although such loss was not apparent in this 

measurement.

+0.6 Same as measurement 2.

+1.2 Initial specific gravity of this solution was

greater than 1, so it tended to sink until sufficiently diluted by the stream. Best to use 

under soft or broken ice. Has low volatility, so 

probably would store well as a stock solution.

33.2 +1.8 Limited to air temperatures above freezing.

Discharge Measurements in Streams 21
DISCHARGE MEASUREMENTS IN STREAMS Continued

North and South Brush Creeks, 1967-68 

Physical Setting

[Investigation in cooperation with the Wyoming State Engineer]

As a result of concerns of USGS hydrographers 

in Wyoming about the accuracy of stage-discharge 

ratings at streamflow-gaging stations on mountain 

streams, an investigation into the use of dye-dilution 

measurements was conducted during 1967-68. Dyetracing equipment and supplies were purchased in 

1967. Eight dye-dilution discharge measurements 

were made at station 06622700, North Brush Creek 

near Saratoga, and nine at station 06622900, South 

Brush Creek near Saratoga (fig. 22). This was the first 

use of modern dye-tracing techniques by personnel of 

the Wyoming District, USGS.

North and South Brush Creeks have similar 

hydrologic and hydraulic characteristics, except that 

the channel of North Brush Creek has a larger widthdepth ratio than the channel of South Brush Creek. 

Therefore, lateral mixing is more difficult to achieve on 

North Brush Creek. Both streams drain an area underlain by a thick sequence of meta-sedimentary rocks of

Precambrian age. During spring snowmelt runoff, both 

streams transport large amounts of coarse sediments 

ranging in size from gravel to boulders.

North Brush Creek has a wide, shallow channel 

consisting mainly of gravel and boulders. The widthdepth ratio of the channel is 50 (fig. 23). A pool-riffle 

flow regime exists to a maximum discharge of about 

25 ft3/s, above which flow becomes increasingly 

channel-controlled. Because of the boulders, shallow 

depth, and high velocities, most current-meter measurements are rated fair to poor for most flows that can 

be waded. Flows larger than 350 ft3/s are measured 

from the bridge with reel and cable. Accurate depths 

are difficult to obtain with a sounding weight because 

of the roughness of the channel. Because of the difficulty of obtaining accurate current-meter measurements, the suitability of dye-dilution measurements 

was investigated.

The channel of South Brush Creek near the 

streamflow-gaging station is incised into coarse 

alluvium. The channel consists mainly of rocks and 

boulders, and has a width-depth ratio of 16.7 (fig. 24), 

in contrast with the ratio of 50 for North Brush Creek 

(fig. 23). The channel has few pools at any stage, 

except for the gage pool. The control for low flows is 

a riffle about 15 feet downstream from the gage. At 

high flows, backwater from a culvert located 100 feet 

downstream from the gage submerges the riffle.

22 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
41°25'

106°30' 106°25'

41°20'

06622700 

North Brush 

Creek near 

Saratoga

06622900 

South Brush 

Creek near 

Saratoga

Park

EXPLANATION

STREAMFLOW-GAGING 

STATION

3 KILOMETERS

Figure 22. Location of streamflow-gaging stations on North and South Brush Creeks. 

Stations are approximately 16 miles southeast of Saratoga, Wyoming.

LEFT 

BANK RIGHT 

BANK

I 

QJUJ2

CO

Discharge = 339 cubic feet

per second

- Area = 79.6 square feet 

Width (W) = 63 feet 

Depth (D) = 1.26 feet 

W/D = 50 .

10 20 30 40 50 60 70 80 

STATIONING, IN FEET

Figure 23. Typical cross section of 

channel of North Brush Creek.

LEFT 

BANK

RIGHT 

BANK

Q-, 

we. Discharge '= 155 cubic feet

per second

Area = 47.1 square feet 

Width (W) = 28 feet 

Depth (D) = 1.68 feet 

W/D,= 16.7, ,

0 10 20 30 40 

STATIONING, IN FEET

Figure 24. Typical cross section of 

channel of South Brush Creek.

Discharge Measurements in Streams 23
DISCHARGE MEASUREMENTS IN STREAMS Continued

North and South Brush Creeks, 1967-68 Continued 

Data Collection

North Brush Creek. A pressurized chemicalfeed tank was used to inject the dye solution at a constant rate. For discharges less than 25 ft3/s, a singlepoint injection was used. A two-point injection system 

was used for discharges between 25 and 100 ft3/s. A 

brass T-fitting was placed in the injection line leading 

from the chemical-feed tank. Two plastic tubes 

connected to the T-fitting were placed over the stream 

at points representing approximately one-half the 

estimated discharge.

For discharges greater than 100 ft3/s, a 20-point 

injection system was designed (fig. 25). Twenty-one 

feet of 3/4-inch steel pipe was suspended above the 

stream at a site about 600 feet upstream from the 

streamflow-gaging station. One-quarter-inch diameter 

holes were drilled into the pipe at 1-foot intervals. One 

end of the pipe was capped and the other was attached 

to the discharge hose from a centrifugal pump. Dye 

was injected into the intake side of the centrifugal 

pump from the pressurized chemical-feed tank through 

a brass fitting. Water was pumped from the stream, 

mixed with dye in the pump, and discharged to the 

stream through the 3/4-inch perforated pipe.

To determine the adequacy of lateral mixing, 

water samples were collected at three points across the 

stream (at the quarter-points of flow). For discharges 

less than 25 ft3/s, mixing was accomplished by 

injecting at a site at least two pool-riffle sequences upstream from the sampling site. For discharges greater 

than 100 ft3/s, mixing was achieved by using the aforementioned dye-injection system (fig. 25). Water 

samples for discharges greater than 100 ft3/s were 

collected from the U.S. Forest Service bridge about 

200 feet upstream from the gage.

The degree of lateral and longitudinal mixing 

was evaluated to determine the adequacy of dyedilution discharge measurements on North Brush 

Creek. Data from a measurement made October 6, 

1967 were used to make the evaluation. A 0.2-percent 

solution of rhodamine WT dye was injected into the 

stream for about 1 hour. The dye-response curve is 

shown in figure 26. Dye concentration on the plateau 

increased, owing to a slight increase in the dyeinjection rate. Because the streamflow was constant, 

averages of the injection rates and the fluorometer 

readings were used to calculate the stream discharge. 

Lateral variation in concentration was about 7 percent, 

and the variation in discharge from four sets of quarterpoint samples was 1.6 percent.

South Brush Creek. A pressurized chemicalfeed tank also was used for dye injections in South 

Brush Creek. For all measurements, dye was injected 

at a single point in mid-stream, about 300 feet upstream from the gage. Water samples for dye concentration were collected at the downstream end of a 

culvert about 150 feet downstream from the gage. 

Row through the culvert facilitated mixing of the dye.

Data from a measurement made October 6,1967 

were used to evaluate the adequacy of dye-dilution 

discharge measurements made on South Brush Creek. 

A 0.2-percent solution of rhodamine WT dye was 

injected into South Brush Creek for about 1 hour. 

Water samples were collected at five points across the 

channel. The dye-response curve for the measurement 

is shown in figure 27. The dye concentrations were 

weighted by the percentage of the estimated discharge 

for each segment. The lateral variation in concentration was 1.4 percent and the spread in discharge 

calculated from two sets of samples was 1.8 percent.

24 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Perforated pipe 

(20 holes)

Chemicalfeed tank

Centrifugal 

pump

Figure 25. Sketch of dye-injection equipment used for high-flow 

discharge measurements in North Brush Creek.

40

03 

b 30

20

LUO

83 10

9:30 10:00 10:30 

TIME

11:00 a.m.

Figure 26. Dye-reponse curve for dye-dilution 

discharge measurement of October 6, 1967 

in North Brush Creek. Dashed line indicates 

approximate shape of curve after dye injection 

ceased (no samples collected).

12:00 1:30 p.m.

Figure 27. Dye-response curve for dye-dilution 

discharge measurement of October 6, 1967 

in South Brush Creek.

Discharge Measurements in Streams 25
DISCHARGE MEASUREMENTS IN STREAMS Continued

North and South Brush Creeks, 1967-68 Continued 

Results

All dye-dilution discharge measurements made 

in North and South Brush Creeks are listed in table 5. 

The use of these measurements in defining stagedischarge relations is described below.

North Brush Creek. A stage-discharge 

relation using all open-water current-meter and dyedilution measurements for water years 1967-69 is 

shown in figure 28. The rating is fairly well defined, 

except for discharges in the transition between the 

pool-riffle flow regime and the channel-flow regime. 

Adequate mixing during the last dye-dilution 

measurement (no. 105, table 5) was not achieved; 

therefore, that measurement was not used in 

developing the stage-discharge relation.

South Brush Creek. All open-water 

measurements made on South Brush Creek near 

Saratoga for water years 1966-68 were used to evaluate

stage-discharge ratings and the results of the dyedilution measurements. The maximum daily discharge 

for water year 1968 was 393 ft3/s, a flow that is 

exceeded less than 1 percent of the time (Peterson, 

1988, p. 286). The high flow caused channel erosion 

and a substantial change in the stage-discharge relation 

(fig. 29). Because hydrologists working the 1968 

record lacked confidence in dye-dilution 

measurements, a new rating based on the dye 

measurements was not developed. However, a new 

rating (rating no. 6, fig. 29) was developed for water 

year 1969, after additional current-meter 

measurements had been obtained. Rating no. 6 was 

nearly identical to a temporary rating (not shown in 

fig. 29) based on the six dye-dilution measurements 

and one current-meter measurement made after the 

1968 flood, thus confirming the accuracy of the dyedilution measurements.

Table 5. Dye-dilution discharge measurements at streamflow-gaging stations 06622700, North Brush Creek near Saratoga, 

Wyoming, and 06622900, South Brush Creek near Saratoga, Wyoming, 1967-68

 y

[ft, feet; ft /s, cubic feet per second]

North Brush Creek

Measurement 

number

93

95

99

101

102

103

104

105

Date

9-11-67

10-6-67

5-23-68

6-13-68

7-17-68

8-12-68

9-13-68

10-4-68

Party

Rankl, Stewart

Rankl, Stewart

Rankl

Rankl, Wilson

Rankl

Rankl

Rankl, McCollam

Stewart

Gage 

height 

(ft)

2.67

2.89

3.66

4.87

3.20

2.90

2.67

2.68

Discharge 

(ft3/s)

12.8

24.6

116

410

56.6

24.8

11.3

9.95

Measurement 

number

93

95

101

103

104

105

106

107

108

Date

9-11-67

10-6-67

5-23-68

6-13-68

6-13-68

7-16-68

8-12-68

9-13-68

10-4-68

South Brush Creek

Party

Rankl, Stewart

Rankl, Stewart

Rankl

Rankl, Wilson

Rankl, Wilson

Rankl

Rankl

Rankl, McCollam

Stewart

Gage 

height 

(ft)

1.86

2.03

2.70

3.53

3.56

2.59

2.08

1.74

1.73

Discharge 

(ft3/s)

8.26

16.1

80.5

314

324

74.1

24.7

8.26

7.27

26 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
s

111

o

o

Transition betwen

pool-riffle control

and channel control

Two points

DYE-DILUTION MEASUREMENT ' 

O CURRENT-METER MEASUREMENT

2.5

8 10 20 50 100 200

DISCHARGE, IN CUBIC FEET PER SECOND

500 1,000

Figure 28. Stage-discharge relation for streamflow-gaging station 06622700, 

North Brush Creek near Saratoga, Wyoming.

3.5

I

HI 

O 

< 

O 

LU

tnHI 

li.

- 2

LU

O

2.5

CO

1.7

0 DYE-DILUTION MEASUREMENT 

v BEFORE 1968 FLOOD

4 DYE-DILUTION MEASUREMENT 

AFTER 1968 FLOOD

O CURRENT-METER MEASUREMENT 

BEFORE 1968 FLOOD

 CURRENT-METER MEASUREMENT 

AFTER 1968 FLOOD

10 20 50 100 

DISCHARGE, IN CUBIC FEET PER SECOND

200 500

Figure 29. Stage-discharge relation for streamflow-gaging station 06622900, 

South Brush Creek near Saratoga, Wyoming.

Discharge Measurements in Streams 27
DISCHARGE MEASUREMENTS IN STREAMS Continued

South Piney Creek, 1971-78

[Investigation in cooperation with the Wyoming State Engineer and the Old West Regional Commission]

The successful application of dye-dilution procedures for measuring discharge in North and South 

Brush Creeks led to use of the technique in South Piney 

Creek. At streamflow-gaging station 06321000, South 

Piney Creek near Story, Wyo. (fig. 30), the channel is 

steep, and the stream bed is composed mainly of boulders. High flows are swift and turbulent, commonly 

moving boulders along the streambed beneath the 

cableway. High-water measurements with a current 

meter are extremely difficult; as is typical of such 

conditions, measurement accuracy is a concern.

The dye-dilution discharge measurements are 

listed in table 6. The first four were made by Hugh W. 

Lowham, USGS, Worland, with assistance from other

USGS or State Engineer personnel. The last four 

measurements were made by personnel of the USGS 

Casper and Buffalo offices as part of the Madison 

Limestone recharge study, described subsequently (this 

station is site 22 in Glass and Sultz, 1992).

A pressurized chemical-feed tank was used for 

the constant-rate injection for the four measurements 

prior to 1975, and a small battery-operated fluidmetering pump was used thereafter. For all measurements, dye was injected 0.25 mile upstream from the 

gage, and samples were collected from the cableway 

200 feet downstream from the gage. Lateral mixing for 

most measurements was excellent.

All eight dye-dilution measurements and all 

current-meter measurements greater than 100 ft3/s 

made between June 1971 and July 1978 are plotted in 

figure 31. The stage-discharge curve in use for most of 

the period covered by the dye-dilution measurements 

also is plotted on the graph. Because the channel 

changed noticeably during high flows, much of the 

scatter of data points in figure 31 likely is the result of 

movement of boulders (H.W. Lowham, USGS, written 

commun., 1995).

107° 106°55' 106°50'

44°35'

44°32'

SHERIDAN CO 

JOHNSON CO

3 KILOMETERS

Figure 30. Location of streamflow-gaging station 06321000, South Piney Creek near Story, Wyoming.

28 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Table 6. Dye-dilution discharge measurements at streamflow-gaging station 06321000, South Piney Creek near Story, 

Wyoming, 1971-78

[ft, feet; ft /s, cubic feet per second]

Measurement 

number Date Party

Gage

height

(ft)

Discharge 

(ftVs) Remarks

289 6-15-71 Lowham, Smalley 3.54 567

295 7-1-72 Lowham, Kawulok 3.01 185

299 6-13-73 Lowham, Leavitt 3.73 696

308 6-19-74 Lowham, Englert 3.40 576

324 7-1-75 Glass 3.40 456

325 7-7-75 Glass 3.48 720

350 6-14-77 Polinoski 2.95 208

363 7-7-78 Polinoski, Pedersen 3.36 323

Injection rate constant; lateral mixing excellent; plateau welldefined.

Injection rate constant; lateral mixing excellent; plateau fairly 

well-defined.

Injection rate decreased during sampling; lateral mixing 

excellent. Average of two sets of injection measurements and 

samples used to calculate discharge.

Chemical-feed tank operating poorly; dye-injection rate 

decreased during measurement.

Injection rate constant; lateral mixing uneven; plateau fairly 

well-defined.

Very turbulent flow. Injection rate constant; lateral mixing and 

plateau not verified (only two sets of samples at only two points 

in cross section).

Injection rate constant; lateral mixing fair to poor; plateau welldefined.

Injection rate decreased approximately 3 percent during 

sampling. Lateral mixing excellent; plateau well-defined.

LLJ

CD < 

cs

LU§ 3

CD

DYE-DILUTION MEASUREMENT 

O CURRENT-METER MEASUREMENT

100 200 500

DISCHARGE, IN CUBIC FEET PER SECOND

Figure 31. Stage-discharge relation for streamflow-gaging station 06321000, 

South Piney Creek near Story, Wyoming. All measurements greater than 

100 cubic feet per second during water years 1971-78 are plotted.

1,000

Discharge Measurements in Streams 29
DISCHARGE MEASUREMENTS IN STREAMS Continued

Madison Limestone Recharge Study, 1975-78 

Data Collection

[Investigation in cooperation with the Wyoming State Engineer and the Old West Regional Commission]

In 1975 USGS hydrographers in Wyoming were 

faced with the problem of making high-water discharge 

measurements at several new streamflow-gaging 

stations having no cableways or bridges. Stations had 

been installed in pairs on streams crossing outcrops of 

rocks of Paleozoic age mainly the Madison Limestone of Mississippian age in northeastern Wyoming 

(Boner and others, 1976). The purpose of the study 

was to obtain data for estimating streamflow recharge 

of the aquifer. Results are summarized by Glass and 

Sultz (1992). Most of the stations were at remote sites 

on mountain streams where access is difficult.

During 1975-78 dye-dilution techniques were 

used to measure discharge too high for a current-meter 

measurement by wading. Equipment and samples had 

to be compact and lightweight for backpacking to and 

from these remote sites. Procedures had to be simple 

and accurate. The location of sites at which one or 

more dye-dilution measurements were made is shown 

in figure 32.

Field Procedures. The injection solution was 

prepared at the site by mixing a pre-measured amount 

of rhodamine WT dye with water from the stream. The 

amounts of dye and water to mix for the estimated 

stream discharge were determined onsite using guidelines prepared specifically for these measurements. A 

sample of the injection solution was retained for 

accurate determination of concentration later. A 

typical injection solution was 1 part dye (20 percent by 

weight) to 5 parts final solution, or a concentration of 

4 percent dye by weight, or 0.04.

Constant-rate injection of dye was achieved with 

a battery-operated fluid-metering pump. The injection 

rate, set for the estimated stream discharge, was spotmeasured using a stopwatch and a small graduated 

cylinder held under the outflow tubing. Air bubbles 

entrained in the 3/8-inch injection tubing used through 

1978 sometimes affected the injection rate. The 

problem was eliminated for measurements after 1978 

by using 1/4-inch tubing.

Samples were collected at three points across the 

stream, where possible, to assess lateral mixing. Four 

or five sets of samples collected 5 minutes apart were 

deemed sufficient to determine whether the plateau 

concentration had been established. Because the dye 

concentrations intentionally were well below visible 

levels, neither the status of lateral mixing nor the 

existence of a plateau concentration at the sampling 

site could be ascertained in the field. If the fluorometric 

results later indicated that lateral mixing was poor or 

that the plateau had not been achieved, the distance 

between the injection and sampling sites and (or) the 

time between start of injection and start of sampling 

were increased for the next measurement.

If a stream were too wide to sample across the 

entire width, complete lateral mixing could not be 

verified. Measurement accuracy was downgraded for 

such measurements, a few of which could not be used.

Laboratory Procedures. An indirect calibration of the fluorometer was made for each discharge 

measurement to minimize work in the field. All 

samples were sent to the laboratory in Cheyenne, 

where the injection solution was diluted by a factor of 

10 7 . The diluted solution and all stream samples were 

tested in a fluorometer after they had been stored for at 

least 1 day. Plateau concentrations generally were 

between 0.5 and 3 micrograms per liter. Concentrations in fluorometer units were used to calculate the 

stream discharge. The reading for the diluted injection 

solution was multiplied by the dilution factor, 10 7, for 

the calculation.

30 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
106°45'

44°45' -

44°30' -

20 KILOMETERS

EXPLANATION 

STREAMFLOW-GAGING STATION AND SITE NUMBER

MISCELLANEOUS STREAMFLOW-MEASUREMENT SITE 

AND NUMBER

Figure 32. Location of streamflow-gaging stations and miscellaneous-measurement sites 

used for the Madison Limestone recharge study and at which dye-dilution discharge 

measurements were made during 1975-78. Site numbers are from Glass and Sultz (1992).

Discharge Measurements in Streams 31
DISCHARGE MEASUREMENTS IN STREAMS Continued

Madison Limestone Recharge Study, 1975-78 Continued 

Results

Results of 29 dye-dilution discharge measurements made for the Madison Limestone recharge study 

are listed in table 7. Unless otherwise noted under 

remarks, the injection rate was constant and the plateau 

concentration well-defined.

Most of the listed measurements were used to 

define the stage-discharge relation (rating curve) for 

the station or site. A few that otherwise appeared to be 

acceptable were not used because, in the judgement of 

the hydrographer analyzing the records, they were not 

consistent with other measurements. For some stations, however, the dye-dilution measurements were 

essential for developing the high-flow part of the 

curves and hence, the high-flow records for the station.

Four dye-dilution discharge measurements had 

been made previously at one station, South Piney 

Creek near Story (site 22 in Glass and Sultz, 1992; 

location shown on fig. 32). All dye measurements are 

listed in table 6 (p. 29); only the dye measurements 

made for the Madison Limestone recharge study are 

repeated in table 7. The rating curve (fig. 31, p. 29) 

provides a comparison of dye-dilution measurements 

with current-meter measurements at this site.

The stage-discharge relation for Tongue River at 

Tongue Canyon Campground, near Dayton, Wyo. 

(site 2, fig. 32), shown in fig. 33, also provides evidence of the accuracy of the dye-dilution method.

Current-meter measurements were made from a 

National Forest footbridge; water samples for some of 

the dye measurements also were collected from that 

bridge. Sampling from the bridge assured accurate 

determination of lateral mixing, which essentially was 

complete for every measurement. The two largest 

discharges ever measured by dye dilution in Wyoming 

were at this station (measurements 15 and 52, table 7).

Hydrographers occasionally had difficulty in 

obtaining consistent spot-measurements of the injection rate. Also, the outlet tubing was too large for the 

small injection rates, so air bubbles in the tubing 

affected the measurement of the injection rate. Since 

the completion of the Madison Limestone recharge 

study, the procedure has been changed to time the 

cumulative volume of dye pumped from a 1- or 2-liter 

graduated cylinder during the cumulative injection 

time. Using plastic tubing with a smaller diameter 

solved the air-entrainment problem.

Incomplete lateral mixing at the sampling site 

was evident in a few measurements. Procedures have 

been modified to include injecting the dye closer to 

midstream and sampling farther downstream from the 

injection site. Sampling techniques also have been 

modified to assure collection of samples near the opposite streambank for better assessment of the extent of 

lateral mixing.

UJ 

(5

< o

(5 3 

UJ

SCO 

< 2

InUJ

Rating No. 1

Top of large boulder 

in mid-channel 4 DYE-DILUTION MEASUREMENT 

O CURRENT-METER MEASUREMENT

100 200 500 1,000 

DISCHARGE, IN CUBIC FEET PER SECOND

3,000

Figure 33. Stage-discharge relation for streamflow-gaging station 06297480, Tongue River 

at Tongue Canyon Campground, near Dayton, Wyoming (site 2, fig. 32 and table 7). All 

measurements greater than 100 cubic feet per second during 1975-79 are plotted.

32 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Table 7. Dye-dilution discharge measurements at streamflow-gaging stations and miscellaneous-measurement sites used in 

the Madison Limestone recharge study, northeastern Wyoming, 1975-78

[Site numbers from Glass and Sultz (1992); locations shown in figure 32. ft3/s, cubic feet per second]

Measurement 

number

12 

13 

15 

52

14

12 

13 

14 

15

11 

12 

13 

14

71

138

13

13

324 

325 

350 

363

11 

12 

22 

23 

47 

48

438

Date

5-22-75 

6-4-75 

6-24-75 

6-15-78

6-19-75

6-5-75 

6-19-75 

6-24-75 

7-1-75

6-3-75 

6-5-75 

6-19-75 

7-1-75

6-14-78

6-14-78

6-24-75

6-27-75

7-1-75 

7-7-75 

6-14-77 

7-7-78

7-1-75 

7-7-75 

6-10-76 

6-10-76 

6-13-78 

7-7-78

9-24-75

9-24-75

Discharge 

(ft3/s) Party Remarks

Site 2 06297480 Tongue River at Tongue Canyon Campground, near Dayton, Wyo.

359 Druse Mixing excellent. 

913 Druse Injection rate increased slightly during sampling; mixing excellent. 

1,750 Muench, Druse Injection rate increased slightly during sampling; mixing excellent. 

2,300 Polinoski, Pedersen Injection rate decreased slightly during sampling; mixing very good.

Site 5 06298480 Little Tongue River at Steamboat Point, near Dayton, Wyo.

159 Druse Mixing poor to fair.

Site 7 06299480 Wolf Creek below Alden Creek, near Wolf, Wyo.

218 Druse Mixing good. 

271 Druse Mixing fair to good; plateau fluctuated. 

468 Muench Mixing excellent. 

217 Druse Mixing good.

Site 8 06299490 Wolf Creek above Red Canyon Creek, near Wolf, Wyo.

156 Druse Injection rate and plateau definition erratic; mixing good. 

195 Druse Injection rate and plateau decreased slightly during sampling. 

265 Druse Mixing good. 

235 Druse Mixing good.

Site 16 06313950 North Fork Crazy Woman Creek below Pole Creek, near Buffalo, Wyo.

219 Polinoski, Pedersen Mixing fair to good.

Site 17 06314000 North Fork Crazy Woman Creek near Buffalo, Wyo.

216 Pedersen, Polinoski Mixing good.

Site 20 06319470 South Rock Creek afforest boundary, near Buffalo, Wyo.

245 Glass, Ragsdale, Peterson Rising stage. Mixing good.

Site 21 06319480 South Rock Creek above Red Canyon, near Buffalo, Wyo.

241 Ragsdale, Peterson Mixing poor. Not used for rating.

Site 22 06321000 South Piney Creek near Story, Wyo.

456 Glass Lateral mixing uneven. 

720 Glass Very turbulent flow. Lateral mixing, plateau not verified. 

208 Polinoski Lateral mixing fair to poor. 

323 Polinoski, Pedersen Injection rate decreased during sampling; lateral mixing excellent.

Site 25 06321100 South Piney Creek below Mead-Coffeen Ditch, near Story, Wyo.

414 Glass Mixing excellent; plateau slightly erratic. 

735 Glass Only two sets of samples at two points. 

708 Muench Mixing poor; plateau decreased and was erratic. 

529 Muench Mixing poor. 

368 Polinoski Mixing poor; plateau erratic. 

346 Polinoski, Pedersen Injection rate decreased during sampling; mixing and plateau erratic.

Site 38 Little Goose Creek (upper site; see Glass and Sultz, 1992, p. 73)

59.7 Muench, Englert Mixing excellent; plateau increased.

Site 39 06303500 Little Goose Creek in canyon, near Big Horn, Wyo.

56.2 Muench, Englert Mixing excellent.

Discharge Measurements in Streams 33
DISCHARGE MEASUREMENTS IN STREAMS Continued

Other Measurements, 1971-82

In addition to the dye-dilution discharge measurements on South Piney Creek and for the Madison 

Limestone recharge study, USGS hydrographers made 

measurements during 1971,1975-78, and 1982 at eight 

other streamflow-gaging stations and miscellaneous 

sites, most in cooperation with the Wyoming State 

Engineer. The site locations for these measurements 

are shown in figure 34; the measurements are listed in 

table 8.

At least two dye-dilution measurements were 

made in East Fork Big Goose Creek immediately 

below the Park Reservoir dam (site 3, fig. 34) 

August 2, 1971 for use in rating the outlet (Myron E. 

Smalley, U.S. Geological Survey, oral commun., 

1995). Current-meter measurements are extremely 

difficult at that site because of the rocky channel and 

swift current. Results of those measurements could not 

be located.

Training measurements were made during 1975 

on the No wood River (site 1) and Deer Creek (site 8), 

in preparation for the Madison Limestone recharge 

study. A measurement of Deer Creek in 1977 also was 

for training. The discharge measured by dye-dilution

in 1975 was 5 percent less than the discharge measured 

with a current meter; the dye measurement in 1977 was 

5 percent greater than the current-meter measurement.

Five high-water discharge measurements using 

dye were made during 1975-78 at a station on Middle 

Fork Powder River near Barnum (site 7). Some results 

were poor, because of dye-injection problems or difficulty in verifying lateral mixing (table 8).

On August 5, 1977, dye-dilution measurements 

were made at three sites on East Fork Big Goose Creek 

downstream from Park Reservoir (sites 4-6), in an 

attempt to verify an apparent loss of about 8 ft3/s in a 

2-mile reach downstream from Park Reservoir (Donald 

D. Englert, Wyoming State Engineer's Office, oral 

commun., 1995). The results listed in table 8 indicate 

a decrease of about 2 ft3/s between sites 4 and 5.

The streamflow-gaging station on Middle Creek 

at East Entrance, Yellowstone National Park (site 2) 

was operated for 3 years in cooperation with the 

National Park Service. The two dye-dilution discharge 

measurements listed in table 8 were higher than any 

current-meter measurements made at this station.

EXPLANATION

8A STREAMFLOW-GAGING 

STATION AND SITE

3,4,5,6 NUMBER 

A MISCELLANEOUS 

STREAMFLOWMEASUREMENT 

SITE AND NUMBER

50 100 KILOMETERS

Figure 34. Location of sites where miscellaneous dye-dilution discharge measurements were made, 1971-82. 

34 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Table 8. Miscellaneous dye-dilution discharge measurements at streamflow-gaging stations and miscellaneousmeasurement sites in Wyoming, 1971-82

[Site locations shown in figure 34. ft3/s, cubic feet per second; (?), information missing]

Date

5-28-75

6-21-82 

6-28-82

8-2-71

8-5-77

8-5-77

8-5-77

6-6-75

5-18-76

4-30-77

5-23-77 

5-24-78

5-8-75 

5-10-77

Discharge 

(ft3/s) Party Remarks

846

Site 1 06270000 Nowood River near Ten Sleep, Wyo.

Druse, McCollam, Muench Training measurement. High sediment content may have affected

dye loss in samples. Mixing excellent. Calculated discharge 

considered inconsistent with current-meter measurements of 

similar magnitude.

478

742

Site 2 06279850 Middle Creek at East Entrance, Yellowstone National Park, Wyo.

Muench, Smalley Mixing fair.

Muench, Smalley Highest measurement made at station; stage-discharge relation

drawn to this measurement.

Site 3 East Fork Big Goose Creek immediately below Park Reservoir, near Beckton, Wyo.

(?) Lowham, Smalley, (?) At least two measurements made; results not found.

Site 4 East Fork Big Goose Creek 0.5 mile below Park Reservoir, near Beckton, Wyo.

61.5 Ragsdale, Pedersen, Englert, Mixing good. 

Moore

Site 5 East Fork Big Goose Creek 0.5 mile above Beaver Ditch diversion, near Beckton, Wyo.

59.3 Ragsdale, Pedersen, Englert, Mixing good; plateau not well-defined. 

Moore

83.1

674

256

631

140

800

173

251

Site 6 East Fork Big Goose Creek at Beaver Ditch diversion, near Beckton, Wyo.

Ragsdale, Pedersen, Englert, 

Moore

Mixing good; plateau definition erratic. 

Current-meter measurement = 64.7 ft3/s.

Site 7 06309200 Middle Fork Powder River near Barnum, Wyo.

Glass Injection rate constant before sampling; not measured after

Glass, Pedersen 

Glass

Glass 

Glass

sampling. Mixing not verified (all samples taken within nearest

one-third of channel width). 

Rising stage. Mixing good. 

Mixing not verified past midstream. Measurement not used for

stage-discharge relation.

Mixing excellent. Current-meter measurement =134 ft /s. 

Poor measurement, mainly due to erratic and declining injection rate

during sampling. Mixing very good.

Site 8 06646600 Deer Creek below Millar wasteway, at Glenrock, Wyo.

Casper and Worland field

personnel 

Casper and Cheyenne field Training measurement. Good lateral mixing. Current-meter

personnel measurement = 239 ft3/s.

Training measurement. Poor lateral mixing. Current-meter 

measurement = 182 ft3/s.

Discharge Measurements in Streams 35
INVESTIGATIONS IN KARST TERRANE

Methods

The availability of water in carbonate rocks and 

the relation of streamflow across outcrop areas to water 

in the underlying carbonate aquifers in Wyoming have 

been the subject of several hydrologic investigations. 

Losing or gaining streams, sink holes, caves, and 

sinking streams (streams that disappear into caves) are 

typical features that define the surface and subsurface 

topography called karst terrane. Karst features develop 

as a result of dissolution of carbonate rocks mainly 

limestone and dolomite as ground water passes 

through fractures in the rocks. Most exposed karst 

features in Wyoming are in moderately to steeply 

dipping carbonate rocks on the flanks of major 

mountain ranges and other uplifts (Hill and others, 

1976, p. 12, fig. 1). Additional information on karst 

processes and features is given by Hill and others 

(1976, p. 11-18) and Mull and others (1988, p. 6-20).

Dye tests can provide information that water 

managers can use to understand streamflow losses or 

gains as to destination or source when allocating the 

affected water resources. Dye tests have been made in 

four losing streams in northeastern Wyoming: North 

Fork Powder River, North Fork Crazy Woman Creek, 

Little Tongue River, and Smith Creek; and in a sinking 

stream in west-central Wyoming: Middle Popo Agie 

River. The tests of the Little Tongue and Middle Popo 

Agie Rivers also involved caves. Each of the five dye 

tests is described in a subsequent unit. The stratigraphic position of the formations of Paleozoic age mentioned in these units is shown in figure 35.

Procedures. Path tracing in caves may be the 

oldest application of dye tracing. Dye is injected at 

known or suspected inflow points and detected visually 

or with an ultraviolet ("black") light at known or 

suspected resurgence points. The configuration and 

dimensions of the intervening conduits usually are 

unknown. Mull and others (1988, p. 22) refer to this 

technique as qualitative tracing. Fluorescein, a fluorescent yellow-green dye, commonly is used.

Rhodamine WT, a fluorescent red dye accurately 

detectable in sub-visible concentrations with a modern 

fluorometer, is the dye of choice for most quantitative 

tracing. Rhodamine WT was used in all Wyoming dye 

tests, most of which had primary qualitative objectives 

and secondary quantitative objectives.

For each test in Wyoming, dye was injected into 

the stream, and samples were collected at springs or 

other points of resurgence, usually throughout the 

entire passage of the dye. The samples were tested in a 

fluorometer. For some of the tests, dye recovery was 

calculated as described below. More complicated 

hydrologic systems require more elaborate procedures, 

as described in a manual prepared by the USGS in 

Kentucky (Mull and others, 1988).

Dye-Recovery Calculation. The term "dye 

recovery" is used to indicate the amount of dye 

accounted for by sampling. Dye recovery is calculated 

for tests in karst terrane to evaluate how much water 

entering the system at the injection site emerges at the 

sampled site(s) of resurgence. The tendency of the dye 

to adhere to the rocks, sand, and gravel through which 

the water passes, however, may affect the amount 

accounted for at the sampling sites. In karst terrane, 

there usually is no way to determine how much of the 

dye unaccounted for is lost to sorption and how much 

is lost to underground storage or diversion.

Dye recovery is calculated either by using dye 

concentrations determined from direct calibration of 

the fluorometer, or indirectly using concentrations 

expressed in fluorometer units. For the indirect method 

of calibration, the amount of dye recovered is calculated using the following equation, modified from 

Kilpatrick (1993, p. 4, eq. 2):

R = 28,320 x

QA

where /? is the amount of rhodamine WT dye solution 

(20 percent strength) recovered, in milliliters,

Q is stream discharge, in cubic feet per second,

A is the area under the dye-response curve, in 

fluorometer units times seconds,

F is the fluorescence of a precisely diluted 

sample of the injection solution, in 

fluorometer units multiplied by the amount of 

dilution (ratio of dye to water plus dye), and

28,320 is milliliters per cubic foot.

Percent recovery is the amount of dye accounted for by 

sampling divided by the amount of dye injected, 

multiplied by 100.

36 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
ERA SYSTEM Wind River Range Bighorn Mountains Laramie Mountains

Oo ^n ni

Mesozoic rocks Mesozoic rocks Mesozoic rocks

PERMIAN

Phosphoria 

Formation

and 

related rocks

Phosphoria 

Formation <

and 

related rock^-

Goose

Egg

Formation

Forelle 

Limestone

Satanka 

Shale

Snowy Range 

Formation

Gros Ventre 

Formation

PRECAMBRIAN Precambrian rocks Precambrian rocks Precambrian rocks

EXPLANATION

HIATUS-Some minor 

formations not shown

Abbreviations: Fm, Formation; Ss, Sandstone

Figure 35. Generalized stratigraphic chart of formations of Paleozoic age in parts of Wyoming where 

dye tests were conducted in karst terrane (modified from Love and others, 1993). Names in bold 

letters are mentioned in text.

Investigations in Karst Terrane 37
INVESTIGATIONS IN KARST TERRANE Continued

North Fork Powder River below Dullknife Reservoir, 1970

[Investigation in cooperation with the Wyoming State Engineer]

Downstream from Dullknife Reservoir the North 

Fork Powder River flows across sinkholes near the 

mouth of Bull Creek and across another losing reach 

upstream from the mouth of Johnson Creek (fig. 36). 

Water discharges from a large spring downstream from 

Johnson Creek. A dye test was conducted during 1970 

to assist the Wyoming State Engineer in evaluating loss 

of water released from the reservoir for irrigation. 

Supplementary geologic information was obtained 

during 1971.

Study Reach. On September 16, 1971 

Warren G. Hodson and Marlin E. Lowry, USGS, 

accompanied by Paul Kawulok, State Engineer's 

Office, examined the geology along the 3.7-mile reach 

between the sinkholes near Bull Creek and the spring, 

which is about 0.7 mile downstream from Johnson 

Creek (fig. 36). Their observations are described in 

Boner and others (1976, p. 30-31). The sinkholes are 

about 2.1 miles downstream from the reservoir. For 

some distance downstream from Bull Creek, the North 

Fork Powder River flows along an extensive fault zone, 

where the Tensleep Sandstone of Pennsylvanian age is 

adjacent to the Flathead Sandstone of Cambrian age. 

Displacement is as much as 1,400 feet. Several hundred feet of carbonate rocks underlie the Tensleep.

At the time of the geologic reconnaissance, some 

one had placed straw over the sinkholes near Bull 

Creek, partly plugging them. Flow passing the sinkholes was about 20 ft3/s. For the next 2.1 miles, the 

stream flows across the Tensleep Sandstone or the 

Amsden Formation of Pennsylvanian and Mississippian age, with no apparent changes in flow. Over the 

next 0.6 mile, however, where the stream flows over 

the Madison Limestone of Mississippian age, the entire

flow disappeared below the stream bed. Flow in the 

channel resumed at the large spring below Johnson 

Creek.

Dye Test. The test was made November 4-6, 

1970 by Hugh W. Lowham, USGS, assisted by Paul 

Kawulok, to assess the hydraulic connection between 

the sinkholes near Bull Creek and the spring below 

Johnson Creek. Prior to the test, no water was being 

released from the dam, but seepage was about 0.5 ft3/s. 

Stream discharge was about 1.5 ft3/s just upstream 

from the sinkholes, about 5 ft3/s at the spring, and 

20 ft3/s at the streamflow-gaging station about 16 miles 

downstream from the dam (station 06311500, North 

Fork Powder River near Mayoworth, Wyo.). On 

November 4 Kawulok opened the reservoir outlet to 

release a constant flow of 22 ft3/s for the next 49 hours. 

The leading edge of the released water reached the 

sinkhole area near Bull Creek in about 2 hours.

After the flow at the sinkholes had stabilized, the 

investigators poured 2 liters of rhodamine WT dye into 

the river just upstream from the sinkholes. The stream 

discharge was measured as 23.4 ft3/s upstream from 

the sinkholes and 3.29 ft3/s downstream. Thus, about 

20.1 ft3/s was entering the sinkholes (fig. 37).

Water samples were collected at the large spring 

below Johnson Creek, about 3.7 miles downstream 

from the dye-injection site. The dye-response curve 

(fig. 38) indicates that at least some water entering the 

sinkholes discharges from the spring. However, only 

about 6 percent of the dye injected was accounted for 

by sampling.

Although flow from the reservoir was steady 

throughout the dye test, discharge from the spring first 

increased to about 16 ft3/s, then rapidly decreased 

(fig. 37), indicating a possible underground siphon. 

Also, roughly 60 percent of the volume of water that 

entered the sinkholes during the dye test was not 

accounted for at the gaging station. Additional dye 

tests might help determine: (1) why the flow from the 

spring decreased during steady release from the reservoir, (2) the connection of the second losing reach to 

the spring, and (3) the fate of water lost in the streambed but not accounted for at the gaging station.

38 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
107° 106°57'

EXPLANATION

DYE-INJECTION SITE 

(SINKHOLES)

SAMPLING SITE 

(SPRING)

43°58' 2 KILOMETERS

Figure 36. Location of dye-injection and sampling sites, North Fork Powder River. 

Study reach is approximately 28 miles southwest of Buffalo, Wyoming.

23

Q 

Z on 0 ^

0

_,LU

 CO

uftt 15

|S

IS 1 °

g

CO 5

^)

O

n

I I 1 I I I I I I

.Computed flow into sinkholes

f*'

1

/

,...-X .....

 * - " ^^ f &'

Flow from spring v /' 

(pattern estimated) N. /

O DISCHARGE MEASUREMENT

._--.-. -.Q- ...... ..-' x DISCHARGE ESTIMATED FROM

STAGE READING

i i i i i i i i i

\~

_

-5 5 10 15 20 25 30 35 

ELAPSED TIME AFTER INJECTION OF DYE, IN HOURS

40 45

Figure 37. Hydrographs of flow into sinkholes near Bull Creek and flow from 

large spring below Johnson Creek, North Fork Powder River downstream 

from Dullknife Reservoir, November 4-6, 1970.

50

CO 40

r^tr 30

20

10

OCC 

ZO 

O=>

OrH

n r

Dye 

injected

-5 5 10 15 20 25 30 35 

ELAPSED TIME AFTER INJECTION OF DYE, IN HOURS

40 45

Figure 38. Dye-response curve in North Fork Powder River at large spring 

downstream from Dullknife Reservoir, November 4-6, 1970. Curve is 

dashed where estimated (no samples).

Investigations in Karst Terrane 39
INVESTIGATIONS IN KARST TERRANE Continued

North Fork Crazy Woman Creek, 1974

[Investigation in cooperation with the Wyoming State Engineer and the Old West Regional Commission]

During the summer of 1974 a geohydrologic 

field reconnaissance was made of 55 perennial streams 

where they cross rocks of Paleozoic age particularly 

the Madison Limestone of Mississippian age in 

northeastern Wyoming (Boner and others, 1976). 

Subsequently, 32 streamflow-gaging stations were 

installed at selected sites to determine streamflow loss 

or gain in the reaches across the outcrops of the 

Madison. The objective was to provide data for 

estimating recharge to the Madison Limestone, a 

potential major source of water for the rapidly 

increasing development of the vast coal deposits in 

northeastern Wyoming. As a part of the reconnaissance, dye tests were made in two losing streams with 

known or suspected sites of resurgence: North Fork 

Crazy Woman Creek (fig. 39) and Little Tongue River 

(discussed in the next unit).

Study Reach. A geologic traverse of the 

study reach (site 16 to site 17, fig. 39) is described by 

Boner and others (1976, p. 27). In that reach, North 

Fork Crazy Woman Creek flows eastward across 

successively younger Paleozoic rocks. The upstream 

end of the reach is in rocks of Cambrian age, near the 

base of the Bighorn Dolomite of Ordovician age. The 

downstream end is near the top of the Tensleep Sandstone of Pennsylvanian age. In the 1.3-mile reach, the 

stream also crosses the Madison Limestone.

Between the two sites (fig. 39) three zones of 

streamflow loss were particularly noticeable during 

low flow. The two primary zones were about 0.7 mile 

and 0.9 mile downstream from the upper measuring

site. Loss of about equal amounts at these sites nearly 

depleted the flow. A small amount remained, but was 

lost a few hundred feet farther downstream. Flow 

resumed a short distance upstream from the lower site, 

issuing from springs near the top of the Madison 

Limestone.

Streamflow-gaging stations were operated at 

both sites during 1974-84. The records were analyzed 

by Glass and Sultz (1992, p. 49-53) for monthly and 

annual gains and losses. Annual net losses were 

recorded during 7 years, and net gains during 4 years. 

The annual differences typically were 2 to 4 percent of 

the flow at the upper site.

Dye Test On September 25,1974 Hugh W 

Lowham and Marlin E. Lowry, USGS, Cheyenne, 

Wyo., injected a measured quantity of rhodamine WT 

dye as a single slug into the stream at the site of the 

upstream station (site 16, fig. 39). A brief description 

of the test is given in Boner and others (1976, p. 27).

Samples were collected at the site of the 

downstream station (site 17, fig. 39), approximately 

1.3 miles from the injection site. The dye arrived as 

three separate peaks. The first peak arrived in the small 

streamflow that bypasses the two major zones of loss 

3.50 hours after injection. The other peaks arrived 6.75 

and 9.50 hours after injection, indicating multiple 

underground conduits. The relation of these two peaks 

to other sinks and springs was not observed.

Sampling accounted for about 73 percent of the 

dye injected. Sorptive loss might account for some or 

all of the remaining 27 percent. In addition to sorptive 

loss, however, part of the water passing the upstream 

site may have discharged elsewhere. In any case, 

ground water from another source had entered the 

stream between the two measuring sites. Discharge 

measured at the downstream site was 9.81 ft3/s, about 

9 percent greater than the discharge measured at the 

upstream site, 8.98 ft3/s (Glass and Sultz, 1992, p. 49).

40 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
44°13' 106°55' 106°50'

44°10'-

3 KILOMETERS

EXPLANATION

STREAMFLOW-GAGING STATION 

AND SITE NUMBER

DYE-INJECTION SITE 

SAMPLING SITE

Figure 39. Location of streamflow-gaging stations and dye-injection and sampling sites, 

North Fork Crazy Woman Creek. Study reach is approximately 13 miles southwest of 

Buffalo, Wyoming (see map on p. 31). Site numbers are from Glass and Sultz (1992).

Investigations in Karst Terrane 41
INVESTIGATIONS IN KARST TERRANE Continued

Little Tongue River and Tongue River Cave, 1974

[Investigation in cooperation with the Wyoming State Engineer and the Old West Regional Commission]

.k 

TV J,

, \WYGMiMNG

The 1974 geohydrologic reconnaissance of 

streams flowing across rocks of Paleozoic age in northeastern Wyoming (Boner and others, 1976), described 

in the preceding unit, included the Tongue and Little 

Tongue Rivers (fig. 40). The main objective of the 

investigation was to provide data for estimating recharge to the Madison Limestone of Mississippian age. 

A dye test was made in the Little Tongue River, a losing 

stream. Some of the water lost from the Little Tongue 

is known to resurge in Tongue River Cave, and subsequently, the Tongue River.

Study Reach. -The upstream site on the Little 

Tongue River (site 5, fig. 40) is along the strike of the 

Gallatin Limestone of Cambrian and Ordovician age 

and the Gros Ventre Formation of Cambrian age, and 

near the base of the Bighorn Dolomite of Ordovician 

age (Boner and others, 1976, p. 20). All of the flow is 

lost beneath the stream bed within about 300 feet 

downstream from site 5. Annual flow at the downstream site (site 6, fig. 40) was 8.9 percent less than at 

the upstream site in 1975 and 18.6 percent less during 

1976 (Glass and Sultz, 1992, p. 28-30). How much, if 

any, of the water at the upstream site reaches the downstream site is not known.

Lowry and Cummings (1966, p. 29) made a 

qualitative dye test in about 1960 using fluorescein dye 

and visual detection. That test confirmed that at least 

part of the water lost from the Little Tongue River 

undergoes subterranean diversion northward to Tongue 

River Cave in the Bighorn Dolomite. Some of the dyetagged water appeared in the underground stream 

called Cave Creek, which flows through the rear part of 

the cave (see Hill and others, 1976, p. 123-125 and map 

sheet 3). The cave entrance is near the Tongue River

(fig. 40), approximately 2.6 miles north of the losing 

reach of the Little Tongue River and 2,500 feet lower in 

elevation. The stream enters the cave approximately 

1,600 feet south-southeast of the cave entrance and 

exits the mapped part of the cave approximately 

1,300 feet north of where it enters. It discharges into 

the Tongue River (Lowry and Cummings, 1966, p. 29).

Dye Test. A quantitative dye test was made 

for the recharge study, to determine how much of the 

water lost in the stream channel reappears in the cave. 

On October 29, 1974 at 4:30 p.m., 389 mL of rhodamine WT dye was injected into the Little Tongue River 

about 300 feet downstream from the upper measurement site (site 5, fig. 40) and 200 feet upstream from 

where water was last visible on the stream bed. Estimated discharge was 2 ft3/s at the upper measurement 

site and 0.5 ft3/s at the dye-injection site. Sampling of 

Cave Creek commenced at 7:50 p.m., October 30, 

1974, and continued for about 3 days. The water 

samples were tested in a fluorometer onsite to guide 

sampling and were retested later under laboratory 

conditions. A single peak concentration arrived 

34 hours after injection (fig. 41), indicating the dye 

probably followed a single underground conduit to the 

sampling site. The stream was not sampled at site 6 

(fig. 40).

The average of three measurements of discharge 

in Cave Creek, 1.76 ft3/s, was used to calculate dye 

recovery. Only 35 percent of the dye injected into the 

river was accounted for by sampling. Therefore, only 

part of the water lost from the Little Tongue River 

reaches Cave Creek.

The part of the water lost in the channel of the 

Little Tongue River that passes through the cave and 

resurges in the Tongue River does not represent 

recharge to the Madison Limestone. When reporting 

on the dye test, D.T. Hoxie (U.S. Geological Survey, 

written commun., 1974) stated: "The possibility that 

[subterranean diversion between surface drainages] 

occurs elsewhere in the [Bighorn Mountains] must be 

taken into account in any analysis of recharge to the 

carbonate aquifers using streamflow data * * *."

42 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
107°20' 107°15'

44°52' -

44°47'

EXPLANATION

->- STRAIGHT-LINE PATH 

OF DYE

L STREAMFLOW-GAGING 

STATION AND SITE 

NUMBER

DYE-INJECTION SITE

SAMPLING SITE IN 

TONGUE RIVER CAVE

3 KILOMETERS

Figure 40. Location of streamflow-gaging stations, dye-injection site in the Little Tongue River, and 

dye-sampling site in Tongue River Cave. Site 5 is about 19 miles west of Sheridan, Wyoming. 

Site numbers are from Glass and Sultz (1992).

cc

LU 

DL

w

CD 

O DC

O 

H

LU 

O

I

20 30 40 50 60 70 80 90 

ELAPSED TIME AFTER INJECTION, IN HOURS

Figure 41. Dye-response curve in Cave Creek in Tongue 

River Cave, October 30-November 2, 1974 (modified 

from D.T. Hoxie, U.S. Geological Survey, written commun. 

1974). Graph not previously published.

Investigations in Karst Terrane 43
INVESTIGATIONS IN KARST TERRANE Continued

Middle Popo Agie River in Sinks Canyon State Park, 1983 

Physical Setting

[Investigation in cooperation with the Wyoming Recreation Commission*]

In 1983 the USGS assisted the Wyoming Recreation Commission l in conducting a dye test of the 

Middle Popo Agie River in Sinks Canyon State Park. 

The river disappears into Sinks of Lander Cave ("the 

Sinks"), and surface flow resumes at "the Rise," about 

0.6 mile northeast of the Sinks (fig. 42). The intervening surface channel is dry, except during large 

floods when some flow bypasses the cave entrance. 

Prior to 1983 the hydraulic connection of the Rise to 

the Sinks had not been proven. Hill and others (1976, 

p. 129) state: "there has been speculation that the rise 

* * * is not the resurgence of this cave's waters. * * * 

Although not yet dye tested, the sink and rise appear to 

have a normal karst relationship."

The primary objective of the 1983 dye test was to 

verify the connection of the Rise to the Sinks. A few 

years earlier, Orren Bower, then Lander City Engineer, 

had tried unsuccessfully to verify the connection using 

fluorescein dye and a black light (Tom King, Wyoming 

State Engineer's Office, oral commun., 1983).

The River and the Cave. Flow in the Middle 

Popo Agie River is sustained by the melting of highmountain snowpack and by ground-water discharge. 

The river begins in an area of igneous and metamorphic 

rocks of Precambrian age, then flows northeastward 

across a sequence of rocks of Paleozoic age to the 

Sinks, where it turns sharply southward to enter the 

cave. The rocks dip approximately 15 degrees to the

^inks Canyon State Park now (1996) is administered by the 

Division of State Parks & Historic Sites, Wyoming Department of 

Commerce.

northeast (Roberts, 1987, p. 62), the same general 

direction in which the river flows. Downstream from 

the Rise, the river flows across rocks of Mesozoic age.

Sinks of Lander Cave is a dissolution feature in 

the Madison Limestone of Mississippian age (Hill and 

others, 1976, p. 129). At the farthest point mapped 

(about 200 feet from the entrance) the water moves in 

the opposite direction to that of the surface channel. 

The distance between that point and the Rise is about 

3,500 feet. About 90 feet of the 210-foot difference in 

surface elevation between the Sinks and the Rise 

occurs within the mapped part of the cave (Hill and 

others, 1976, p. 129 and map sheet 2).

The Rise is a large pool in what may be a 

dissolution-collapse feature (J.S. McLean, 

U.S. Geological Survey, oral commun., 1984). Springs 

flow upward through the sand-and-gravel bed of the 

poel. Springs and seeps flow from the limestone headwalls at the Rise and from the canyon walls for some 

distance downstream. Records for the streamflowgaging station about 0.5 mile downstream (fig. 42) 

indicate that the flow is sustained by ground-water 

discharge throughout the year (fig. 43).

Acknowledgments. Gary Stephenson, 

Wyoming Recreation Commission, initiated the study 

and made the necessary arrangements. Ronald 

Livesay, Superintendent of Sinks Canyon State Park, 

was instrumental in planning the test. Ronald Fuller, 

Park Attendant, coordinated the field work. Park 

Naturalist Donald Higgins assisted in the field work 

and contributed to the assessment of the hydrologic 

system. Park Attendant Jennifer Crook and Recreation 

Commission photographer Kerry Kelley assisted in the 

collection of water samples. Philip McCollam, USGS, 

measured the stream discharge and assisted in sample 

collection. The staff of station KCWC-TV, Riverton, 

Wyo., produced an excellent video of the field work. 

Park personnel developed exhibits and a folder 

(Wyoming Department of Commerce, 1993) 

describing the dye test.

44 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
108°49' 108°48'

42°45'30"

42°45'

42°44'30"

EXPLANATION

STREAMFLOW-GAGING 

STATION 06231600

0.5 1 MILE

0.5 1 KILOMETER

Figure 42. Location of the Sinks and the Rise, Sinks Canyon State Park. 

Study reach is approximately 7 miles southwest of Lander, Wyoming.

1,000

LUQ

08 

CC LU 

<CO

occ

100

10

10 20 30 40 50 60 70 80 90 95

PERCENT OF TIME INDICATED DISCHARGE 

WAS EQUALLED OR EXCEEDED

Figure 43. Flow-duration curve for streamflow-gaging 

station 06231600, Middle Popo Agie River below the 

Sinks, near Lander, Wyoming, water years 1960-68.

Investigations in Karst Terrane 45
INVESTIGATIONS IN KARST TERRANE Continued

Middle Popo Agie River in Sinks Canyon State Park, 1983 Continued 

Data Collection

Dye Injection and Sampling. At 1:00 p.m. 

on August 14, 1983 a mixture of 40 mL of rhodamine 

WT dye and approximately 2 gallons of water from the 

stream was injected into the river approximately 

200 feet upstream from the mouth of the cave (figs. 42 

and 44). The amount of dye was estimated by the 

method for surface streams (Kilpatrick and Wilson, 

1989, p. 14-15). A small sample of the injection 

solution was retained for indirect calibration of the 

fluorometer later.

Water samples for fluorometric analysis were 

collected at three points in the large pool at the Rise 

(figs. 42 and 45) starting at about 1:10 p.m. on 

August 14, 1983: (1) At a visible spring within the 

pool at the right side, beneath the overlook platform 

near the head of the pool (site A, fig. 45); (2) a few feet 

from the right bank at the old power plant (site B); and 

(3) at a sand bar at the left bank near the downstream 

end of the pool (site C).

The presence or absence of dye in the water 

samples was determined onsite by testing the water in 

a fluorometer. A 5-minute sampling interval was 

maintained until the peak concentration of dye had 

passed, after which the interval was increased 

periodically. By 6:30 p.m. the concentration of dye 

had decreased almost to the detection limit. Two 

samples collected the following morning (August 15) 

contained no detectable dye. All samples containing 

dye and a few background samples collected before the 

dye arrived were retained in glass bottles. The samples 

were retested later at the USGS laboratory in 

Cheyenne.

Stream Discharge. On the day of the dye test, 

the change in discharge between the cave and the Rise 

was determined. The discharge at a small diversion 

dam approximately 0.25 mile upstream from the mouth 

of the cave was 80.8 ft3/s, as measured with a current 

meter. The discharge at the streamflow-gaging station 

0.5 mile downstream from the Rise was determined

from the station rating curve to be 136 ft3/s, somewhat 

larger than the average daily discharge during 1959-68 

(123 ft3/s). During the period of record, daily mean 

discharge at the station exceeded 136 ft3/s about 

20 percent of the time (fig. 43, p. 45). Discharge at the 

outlet of the pool at the Rise is assumed to be 

approximately the same as the discharge at the station.

The two values of discharge indicate a net gain of 

approximately 55 ft3/s between the Sinks and the 

gaging station on the day of the dye test. The gain is 

unlikely to have been caused by variation in discharge 

entering the cave; the recorder trace at the station 

indicated that the discharge had been nearly constant 

for several days.

Water Temperature. Water temperatures 

were measured at several places in the study reach on 

the day of the dye test (table 9). The increase of about 

8°C (about 14°F (degrees Fahrenheit)) between the 

Sinks and the Rise indicates the possibility that some 

geothermal water is being discharged to the stream. A 

simple mass-balance calculation indicates that the 

temperature of the additional water would be about 

26°C (79°F).

Table 9. Water temperatures in the Middle Popo Agie River 

at the Sinks and the Rise and in a spring near the Rise, 

Sinks Canyon State Park, Wyoming, August 14, 1983

Location

Middle Popo Agie River at Sinks

Spring in left headwall at Rise

Spring in pool (right side) at Rise

Flowing water in pool (right side) at 

Rise

Time 

(p.m.)

1:00

1:10

1:10

3:55

1:10 

3:55

Temperature

(degrees 

Celsius)

6.5

14.0

14.5 

15.0

14.0 

15.0

46 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Figure 44. The Sinks, Sinks Canyon State Park, August 14,1983. Flow is from 

right to left. Dye was injected about 100 feet upstream from point of photograph. 

Photograph by Kerry Kelley, Wyoming Recreation Commission.

Figure 45. The Rise, Sinks Canyon State Park, August 14, 1983. View is downstream. 

Dye-sampling sites: A, Spring in pool at right side near upstream end of pool; B, Near 

right bank at old power plant; C, At sand bar at left bank near downstream 

end of pool. Photograph by Kerry Kelley, Wyoming Recreation Commission.

Investigations in Karst Terrane 47
INVESTIGATIONS IN KARST TERRANE Continued

Middle Popo Agie River in Sinks Canyon State Park, 1983 Continued 

Results

Time of Travel and Dispersion. The primary 

result of the dye-tracer test is that the dye appeared at 

the Rise, proving the direct connection of the Rise to 

the Sinks. However, time-of-travel and dispersion 

information also was determined from the dyeresponse curves (fig. 46).

Time of travel of the dye between the injection 

site at the Sinks and the sampling site at the head of the 

pool at the Rise (a straight-line distance of about 

3,500 feet) from figure 46, is as follows:

 Leading edge of dye 2 hours

 Peak concentration of dye 2 hours, 40 minutes

 Trailing edge of dye 8 hours (approximate)

The passage time, or time for the dye to clear the 

pool after first appearance, was about 6 hours. Similar 

information for the other two sampling sites at the Rise 

may be determined from figure 46.

The dye-response curves (fig. 46) depict the 

amount of dispersion that occurred between the injection and sampling sites. The curve for the upstream site 

is smooth because the samples were collected from a 

single spring. The unevenness of the curves at the two 

downstream sites may indicate the effect of uneven 

mixing of water from several points in the pool. The 

unusually long tails of the response curves are indicators of some sort of temporary storage in the underground part of the flow path (or paths).

Dye Recovery. The amount of dye accounted 

for by sampling is an approximation of how much 

water entering the Sinks emerges directly at the Rise. 

For this test, dye recovery was calculated using 

136 ft3/s, the discharge at the gaging station downstream from the Rise. Actual discharge at the Rise 

probably was slightly smaller. The areas under the 

dye-response curves in figure 46 were measured using 

a digitizer; the average for the three curves is 2,800 

fluorometer units times seconds. The fluorescence of 

the diluted injection solution is 32 x 10 7 fluorometer 

units. The amount of dye accounted for is calculated to 

be 33.7 mL, or 84 percent of the 40 mL injected.

Evaluation of the recovery data for the three 

sampling sites indicates the following:

 The dye was well mixed with the water flowing 

through the pool.

 The dye was well mixed in the water entering 

through springs in the bed of the pool.

 The amount of untagged water added by other 

springs near the pool must have been only a small 

part of the total flow of the pool.

Peak Concentration. The value of the peak 

concentration of dye observed at the Rise was calculated. USGS requires that the peak concentration in 

any dye study be less than 10 micrograms per liter 

(10 parts per billion) at the downstream end of any 

study reach or at any intermediate site where water is 

withdrawn for use by humans (Wilson and others, 

1986, p. 8).

Because the relations of fluorescence to concentration and fluorometer output to fluorescence both are 

linear for dilute solutions, peak concentration C is 

calculated using the simple proportion:

Hence,

C =

C

F'

Cf

where C is the peak concentration,

f is the fluorescence of the peak concentration

(0.76 fluorometer unit in this test), 

C is the concentration of the injection solution

(0.24 kilogram per liter when adjusted for

specific gravity, 1.2), and 

F is the fluorescence of the injected solution

(32 x 10 7 fluorometer units in this test).

The calculated value of C is 5.7 x 10 " 10, or 

0.57 microgram per liter well below the limit of 

10 micrograms per liter. This procedure amounts to a 

single-sample, direct calibration of the fluorometer.

48 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Discussion. The dye test was successful 

because it proved the connection of the Rise to the 

Sinks. The conduit, or system of conduits, between the 

Sinks and the Rise may be very circuitous, both 

laterally and vertically, which could account for the 

long traveltime. Other conditions that could account 

for long traveltimes are a small hydraulic gradient and 

(or) temporary storage of dye in pools in the 

underground conduits. Future tests might be done to 

determine traveltimes and dilution during low and very 

high flows, or to determine the source of the additional 

water observed downstream from the Rise. In any test, 

measurement of the discharge of the river at the Rise 

would be useful for calculating dye recovery.

Possible sources of additional water include 

discharge from the Madison Limestone and discharge 

captured from an adjacent stream, Sawmill Creek 

(fig. 42), through an underground conduit. The 

increase in water temperature between the Sinks and 

the Rise is one indication of possible additional 

ground-water inflow. A systematic survey of water 

temperatures in the stream, pool, sidewall springs, and 

any local wells completed in the Madison Limestone, 

might be useful for interpreting the flow system. If 

most of the water entering the cave re-appears directly 

at the Rise, the dye and water not recovered could be 

accounted for by storage in the underground part of the 

flow system or by underground flow away from the 

study area.

SPRING IN POOL 

RIGHT EDGE OF POOL

 . LEFT EDGE OF POOL

34567 

ELAPSED TIME AFTER INJECTION OF DYE, IN HOURS

Figure 46. Dye-response curves in Middle Popo Agie River at the Rise, 

Sinks Canyon State Park, August 14, 1983.

Investigations in Karst Terrane 49
INVESTIGATIONS IN KARST TERRANE Continued

Smith Creek below Otter Creek, 1991

[Investigation in cooperation with the Wyoming State Engineer]

Base flow at the streamflow-gaging station on 

Smith Creek below Otter Creek (site 4, fig. 47) is 

sustained by discharge from limestone formations. A 

declining base flow during water years 1989-90 

(fig. 48) raised concerns that water lost in the sinks in 

limestone downstream from the station above Otter 

Creek (site 1, fig. 47) did not return to the channel at 

the station below Otter Creek. To better understand the 

karst flow system in the vicinity of Smith and Otter 

Creeks, a dye test was done during 1991.

Streamflow records for water years 1988-91 

were analyzed for stations 06645150, Smith Creek 

above Otter Creek, near Casper (site 1, fig. 47); 

06645164, Otter Creek at mouth, near Casper (site 3); 

and 06645166, Smith Creek below Otter Creek, near 

Casper (site 4). Average flows for the 4 years indicate 

a 13-percent loss in water at Smith Creek below Otter 

Creek when the flows were compared to the combined 

flow of the two upstream stations. However, the 1990 

records indicate a flow loss of 25 percent between the 

stations. A drought had occurred during that year.

Study Reach. A geologic reconnaissance of 

the reach was made in 1974 (Boner and others, 1976, 

p. 15-16). The station upstream from Otter Creek 

(site 1, fig. 47; site 85 in Glass and Sultz, 1992) is near 

the contact of the Madison Limestone of Mississippian 

age and the underlying granite of Precambrian age. 

Smith Creek flows across, and nearly parallel to the 

strike of, the steeply dipping Madison for nearly

1 mile. At a point about 0.2 mile upstream from Otter 

Creek, the stream crosses the contact with the Casper 

Formation of Pennsylvanian and Permian age. The 

upstream station and a station at the Madison and 

Casper contact, 1.4 miles upstream from the station 

below Otter Creek (site 86 in Glass and Sultz, 1992; 

location not shown on fig. 47), were operated during 

1975-79. Records indicate annual net flow losses 

ranging from 8 to 36 percent of the flow at the upstream 

station (Glass and Sultz, 1992, p. 105-108).

Dye Test. Smith Creek at site 1 was sluginjected with 100 mL of a 20-percent solution of 

rhodamine WT dye on September 19, 1991. The dye 

was observed to arrive 2.9 hours later at the sinks 

(site 2, fig. 47) about 0.8 mile downstream from site 1. 

Some flow was lost between the point of injection and 

the main sinks.

Sampling was started at site 4, about 2.8 miles 

downstream from site 1, about 3.5 hours after injection. 

Two bottles of water per sample were collected at 

30-minute intervals until dye was detected and less 

frequently thereafter.

One set of samples was analyzed onsite using a 

fluorometer. Under field conditions, with very low dye 

concentrations and varying light and temperature, the 

presence of dye in the samples could not be ascertained. The second set of samples was analyzed later 

in the laboratory under controlled light and temperature 

conditions. After background response was blanked 

out, a very weak dye response could be detected. Dye 

was detected in samples starting about 20 hours after 

injection and continuing for about 13 hours (fig. 49).

Calculation of the amount of injected dye 

recovered at Smith Creek below Otter Creek (site 4) 

was not possible because of the low concentrations, nor 

was it possible to determine what percentage of the 

water entering the sinks was recovered. The tracer 

study confirms a hydraulic connection between the 

sinks and the downstream station.

50 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
106° 15' 106°10'

42°40' -

42°37'

EXPLANATION

STREAMFLOW-GAGING

STATION AND SITE NUMBER

DYE-INJECTION SITE 

, SAMPLING SITE AND NUMBER

3 KILOMETERS

Figure 47. Location of streamflow-gaging stations and dye-injection and sampling sites, Smith Creek 

study area. Study reach is approximately 17 miles southeast of Casper, Wyoming.

0.10

1988 1989 1990 1991

WATER YEAR

Figure 48. Monthly mean discharge at streamflow-gaging station 06645166, Smith Creek 

below Otter Creek, near Casper, Wyoming (site 4), water years 1988-91.

.CO

E2

uiO°£ zO

0.05

10 20 30 40

ELAPSED TIME AFTER INJECTION OF DYE, IN HOURS

Figure 49. Dye-response curve in Smith Creek below Otter Creek (site 4), September 19-21, 1991.

Investigations in Karst Terrane 51
OTHER INVESTIGATIONS

Methods

The miscellaneous applications of dye tracing in 

the four units that follow do not fit into any of the previously discussed groups. Each dye test was unique; the 

investigator applied a general knowledge of dye tracing 

and some degree of ingenuity. Dye-injection and sampling procedures were adapted as necessary. The one 

feature all applications of dye tracing have in common, 

however, is the capability to detect the dye in extremely 

small concentrations (less than 0.5 microgram per liter) 

quickly and accurately.

Four dye tests are described in this group. In the 

Pass Creek test, a tracer dye was used to tag moving

water for some other kind of measurement or sampling. 

The test in glacial deposits in Yellowstone National 

Park, discussed in the next unit, is the only groundwater application of dye tracing by the USGS in Wyoming to date that was not done in karst terrane. In the 

highway edgedrain test and the fire-protection training 

facility test, described in subsequent units, dye was 

used to detect leakage. For the highway test, dye was 

buried to detect storm runoff that might seep through 

the pavement, whereas the training-facility test was a 

direct check for a leak.

52 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
OTHER INVESTIGATIONS Continued

Pass Creek Flow Tagging, 1967

[Investigation in cooperation with the Wyoming State Engineer]

' 'v,-

I 'i-^ V_{

7' \WYORiN3

A dye test was made in Pass Creek at a site 

between Wyoming Highway 130 and the North Platte 

River (fig. 50) November 14,1967, as part of an investigation of ground-water resources of a large area in 

south-central Wyoming. Marlin E. Lowry, USGS, 

Cheyenne, Wyo., was project chief.

The purpose of the dye test was to obtain information about the ground-water component of low 

flows. Stream discharge was measured with a current 

meter at several cross sections along a reach approximately 2 miles long, where the stream passes Stage 

Station Springs (fig. 50).

Because gains in streamflow from ground-water 

discharge between successive measurement sites were

expected to be small, it was necessary to avoid discharge fluctuations from other causes, such as diurnal 

freezing and thawing of water in the stream. That can 

be done if the same water, together with any gains or 

losses, is measured at every site. Therefore, the water 

at the upstream site was tagged by injecting dye. The 

presence of the dye was monitored at downstream measurement sites by sampling and immediately testing the 

samples in a fluorometer. The current-meter measurements were timed to coincide with the passage of the 

dye cloud.

Although the data could not be found for inclusion in this report, the test indicated how dye tracing 

can be used as a tag for collecting other kinds of data, 

such as current-meter measurements. A similar use of 

dye tagging is in reaeration measurements. As previously described, dye and gas tracers are injected simultaneously. Timing of collection of water samples for 

analysis for dissolved propane is based on the presence 

of dye in the stream at the sampling site.

41°44'

106°55' 106°50'

41°40'

3 KILOMETERS

Figure 50. Location of study reach of Pass Creek. Study reach is 

approximately 17 miles north of Saratoga, Wyoming.

Other Investigations 53
OTHER INVESTIGATIONS Continued

Old Faithful Wastewater Lagoon, 1975-76

[Investigation in cooperation with the National Park Service]

In 1974 the USGS began a hydrologic investigation at four wastewater treatment and disposal plants in 

Yellowstone National Park. Evaporation-percolation 

lagoons are used at the plants, which serve major 

visitor areas. Shallow nonthermal ground water and, in 

some places, discharging thermal water may move 

percolating effluents from the lagoons toward nearby 

streams and lakes. The purpose of the investigation 

was to determine the effects, if any, of the percolation 

on chemical quality of the surface waters. The results 

are reported by Cox (1986).

The investigation included a dye test at the Old 

Faithful wastewater treatment and disposal plant, 

which is built on a sand-and-gravel terrace about 

40 feet higher than Iron Spring Creek (fig. 51). Waterlevel contours indicated that water in glacial deposits 

of Quaternary age beneath the terrace moved toward 

the stream (Cox, 1986, p. 54-55). Cox concluded that 

effluent percolating from the wastewater lagoons also 

moved toward Iron Spring Creek. The purpose of the 

dye test was to verify the direction of movement and 

estimate the rate of movement of the effluent. Most of 

the following discussion of the dye test is from Cox 

(1986, p. 60-61).

Rhodamine WT dye was injected in the southeasternmost lagoon on October 1,1975. Water samples 

were collected about weekly from October 1, 1975 

through April 25,1976 from well OF 2, which is about 

130 feet from the lagoon, and at the two sampling sites 

on Iron Spring Creek (fig. 51).

The leading edge of the dye plume arrived at well 

OF 2 on about October 15, and the peak concentration 

arrived on November 26, 1975 (fig. 52). The dye concentration, as indicated by fluorometer units, had 

decreased to the natural, or background level of fluorometer response by about April 20, 1976. The average time of travel of the dye is calculated as the 

concentration-weighted average (the time of the centroid of the response curve, fig. 52). Therefore, the 

average traveltime for the dye between the lagoon and 

the well was about 65 days, and the velocity of the dye 

is estimated to be about 2 feet per day.

The sampling data for Iron Spring Creek are 

inconclusive. Cox (1986, p. 60) states that the dye 

probably reached Iron Spring Creek (at least 400 feet 

from the lagoon) between the two sampling sites, but in 

very diluted concentrations, only slightly above background levels (fig. 52). Given a velocity of about 2 feet 

per day, the main part of the dye plume possibly had not 

reached the stream when sampling was discontinued. 

The small increases in fluorometer readings at the site 

downstream from the lagoons could indicate fluorescence of dye, but they also could have been caused by 

turbidity of the samples. False-positive readings for 

dye can occur in a fluorometer when light is scattered 

by suspended materials (Wilson and others, 1986, 

p. 19). Turbidity of the water could have been caused 

by precipitates of iron compounds (described by Cox, 

1986, p. 62) or other constituents from the wastewater 

effluent mixed with the ground water. Cox used 

chloride concentrations and specific conductances of 

water in wells and the stream to verify the discharge of 

effluent into Iron Spring Creek between the two 

stream-sampling sites (Cox, 1986, p. 56-59). Chloride 

probably is a more conservative tracer than rhodamine 

WT dye, which sorbs to sediments, especially clays.

54 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
OF2

EXPLANATION

GLACIAL DEPOSITS-Mainly 

sand and gravel

STEEP HILLS AND 

BLUFFS

WELL AND NUMBER

DYE-INJECTION SITE 

STREAM-SAMPLING SITE

1000 FEET

I I I

300 METERS

44°27'10"

Figure 51. Location of well OF2 and stream-sampling sites near the Old Faithful 

wastewater lagoons, Yellowstone National Park (modified from Cox, 1986, p. 57).

0.4 

0.2 

0

1 1

1 1

1 1 1 

Iron Spring Creek upstream from the lagoons

A A :

1 1 1

i i i 

Iron Spring Creek downstream from the lagoons

Well OF2

/Centroid of curve 

(See text)

OCT. NOV. 

1975

DEC. JAN. FEB. MAR. 

1976

APR.

Figure 52. Dye-response curves in well OF2 and Iron Spring Creek near the 

Old Faithful wastewater lagoons, October 1, 1975 through April 25, 1976 

(modified from Cox, 1986, fig. 54).

Other Investigations 55
OTHER INVESTIGATIONS Continued

Interstate Highway 25 Edgedrain Test, 1989

[Investigation in cooperation with the Federal Highway Administration]

This test was part of a national evaluation of 

retrofitted edgedrains on Federal highways by the 

USGS (Jeffcoat and others, 1992). Retrofitted edgedrains are entrenched longitudinal drains placed along 

pavement margins some years after construction of the 

highway. As a highway ages, seepage of water from 

precipitation through joints and cracks in the pavement 

increases, leading to accelerated deterioration of a 

highway. Edgedrains have been retrofitted on many 

highways to help drain the underside of the pavements.

Sites in 10 States, including a site on Interstate 

Highway 25 near Wheatland, Wyo. (fig. 53) were 

instrumented to monitor rainfall, edgedrain runoff, 

piezometric water levels, and subbase moisture, as a 

means of evaluating the effectiveness of retrofitted 

edgedrains in removing water from the highway surface and subsurface. Kent D. Becher, USGS, Casper, 

Wyo., was coordinator for the work near Wheatland.

A dye test was a minor part of the investigation 

at each site. A 1-inch diameter hole was drilled 

through the pavement and into the subbase (fig. 54). 

During the second week of August 1989, approximately 50 mL of rhodamine WT dye was poured into 

the hole, and the hole was sealed. During periodic 

visits to the site, samples of water discharging from the 

edgedrain were obtained for fluorometric analysis.

At the test sites in 9 of the 10 States, including 

the Wyoming site, results were negative: there was no 

evidence of dye in the discharge water. At the North 

Carolina site, however, dye appeared shortly after 

emplacement, but the dye hole was known to have 

intercepted voids in the subgrade material beneath an 

aggregate subbase. Jeffcoat and others (1992, p. 75) 

concluded that, because no obvious voids or channels 

in the subbase or subgrade were intercepted by the drill 

holes at the other nine sites, the lack of permeability in 

the subbases (confirmed by laboratory tests) inhibited 

water movement. Water discharged through the edgedrain was from direct runoff and seepage through 

pavement joints and cracks. This "negative" result 

may be useful for future design of highways, as it is one 

indicator of poor drainage of subsurface water in tight, 

low-permeability subbase or subgrade materials 

(Jeffcoat and others, 1992, p. 78).

56 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
105° 

42°05'

42°

104°55'

Wheatland

^Edged rain-test 

site

3 MILES

3 KILOMETERS

Figure 53. Location of the edgedrain-test site on 

Interstate Highway 25.

Portland cement . . .. . concrete roadway Longitudinal Permeable 

Longitudinal backfill

Asphalt concrete 

shoulder

(Not to scale)

Edged rain Outlet pipe

Figure 54. Generalized transverse section of northbound lanes of Interstate Highway 25 showing 

retrofitted edgedrain and dye-injection hole (modified from Jeffcoat and others, 1992, fig. 32). 

Arrows indicate direction of flow.

Other Investigations 57
OTHER INVESTIGATIONS Continued

F.E. Warren Air Force Base Fire-Protection Training Area, 1990

[Investigation in cooperation with the U.S. Air Force]

A brief but successful dye test at one of the fireprotection training areas at F.E. Warren Air Force Base 

during 1990 illustrates the versatility of dye tracing. 

The base is located adjacent to Cheyenne (fig. 55). 

Since 1985 the USGS has been conducting an extensive hydrologic investigation to determine the nature 

and extent of hazardous materials in the soil and water 

at the base. The dye test, not related to the hydrologic 

investigation, was coordinated by L. Rodney Larson, 

USGS, Cheyenne, in response to a request from Air 

Force engineers.

The fire-protection training area in use during 

1990 was an outdoor facility where firefighters practice 

extinguishing fires, mainly using aqueous film-forming 

foam (AFFF). The runoff of water and AFFF is collected in a double-lined retention pond (fig. 56). Air 

Force engineers suspected a leak in the inner (upper) 

liner. USGS personnel concluded that a dye test might 

verify the existence of a leak.

Water in the retention pond, which is shaped like 

an inverted truncated square pyramid, was about 4 feet 

deep when the dye test was performed. The volume of 

water in the pit was estimated to be about 7,200 cubic 

feet, or about 200,000 liters. It was decided to inject 

0.2 liter of rhodamine WT dye; if that amount were 

completely mixed with the water in the pit, the concentration in the pit would be about 1 milligram per liter 

(part per million). That concentration would be easily 

detected in water pumped from the space between the 

two liners.

The dye was poured into the retention pond 

September 18,1990. First, the dye was mixed with 

about 3 liters of pond water in a plastic bucket. Then 

the bucket was attached to ropes, and with a person on

each side of the pit holding a rope, the dye was spread 

across the water surface. By the following morning, 

the dye appeared to be evenly dispersed throughout the 

pond.

On September 19, Air Force personnel began 

pumping water from the leakage-monitoring station 

(fig. 56), a 10-inch cased piezometer well connected 

horizontally to the space between the two liners. A 

water sample was collected from the well prior to 

pumping. Nine samples were collected from the well 

at varying time intervals during 5 hours of pumping. 

As shown in figure 57, there was a strong presence of 

dye in the water pumped from the space between the 

liners, proving the existence of a leak and providing the 

Air Force with the information needed to arrange for 

repair under the contract warranty.

104°54' 104°50'

41°08'

Ife. Warren 

Air Force Base

3 KILOMETERS

Figure 55. Location of fire-protection training 

area, F.E. Warren Air Force Base.

58 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
Leakagemonitoring 

station

Scale (approximate): 1 inch = 15 feet

Figure 56. Cross-sectional sketch of retention pond in fire-protection training area 

(from drawings provided by U.S. Air Force).

w 1,000

z 3

oc

HI

I 

O 

oc 

O

O

!*

HI 

O

O 

O

800

600

. 400

200

Note: Dye concentration in 

sample of pond water: 

2,150 fluorometer units

10:00 a.m. 12:00 p.m. 2:00 p.m. 4:00 p.m.

Figure 57. Dye-response curve for water pumped from 

leakage-monitoring station at retention pond in 

fire-protection training area, September 19, 1990.

Other Investigations 59
SUMMARY AND CONCLUSIONS

For nearly three decades, U.S. Geological 

Survey hydrologists and technicians, in cooperation 

with State and other Federal agencies, have been using 

small quantities of rhodamine WT dye to trace flowing 

water in Wyoming. Each of the many applications of 

dye tracing in Wyoming during 1967-94 is described in 

this report. Previously published investigations are 

summarized, and previously unpublished investigations are described in greater detail. The applications 

of dye tracing range from measurements of time of 

travel and dispersion in stream reaches more than 

100 miles long, to measurements of the discharge of 

small mountain streams when the flow was too swift 

and turbulent to measure by traditional methods. In 

some investigations the objective was to determine the 

destination of surface water lost to the subsurface. 

Collectively, this series of articles illustrates the versatility and simplicity of dye tracing in water-resources 

investigations.

Time of Travel and Dispersion of Solutes in 

Streams. Measurements of time of travel and dispersion in long reaches have been conducted for the 

Wind/Bighorn River between Boysen Dam and the 

town of Greybull, most of the Green River and four of 

its tributaries upstream from Flaming Gorge Reservoir, 

the Little Snake River along the Wyoming-Colorado 

State line, and the North Platte River between the city 

of Casper and Glendo Reservoir. The measurements 

provided information that water managers can use in 

response to accidental spills of harmful materials along 

highways, railroads, or pipelines adjacent to the 

streams or their tributaries particularly the Wind/ 

Bighorn and North Platte Rivers. In addition, the information can be used to calculate water velocities that are 

more representative of long reaches than velocities 

measured only at stream cross sections, an objective of 

the measurements of the Green River and tributaries 

and the Little Snake River. The data from the measurements of the Wind/Bighorn River also were used in 

research studies of dispersion of solutes in flowing 

water. Previously published regression equations calculated using data from streams throughout the United 

States accurately predicted time of travel of the dye 

injected into the North Platte River in 1985.

Additional interpretation of the time-of-travel 

and dispersion data previously collected is possible. 

Dispersion information for unsteady flow or highly 

variable reach hydraulics can be determined accurately 

from the tracing data by applying numerical routing 

procedures. Published techniques also are available for 

simulating soluble-waste transport from a known or 

planned point source near any of the dye-tested 

streams.

Reaeration coefficients in Streams. 

Reaeration coefficients have been determined only for 

a 40-mile reach of the North Platte River, starting at the 

city of Casper. The reaeration coefficients calculated 

from dye- and gas-tracer data for steady flow were used 

by the Wyoming Department of Environmental Quality to assess the capacity of the river to assimilate 

municipal organic waste without depleting the supply 

of dissolved oxygen. Reaeration coefficients for 

unsteady flow in the study reach of the North Platte 

River may be estimated using a numerical routing 

model calibrated with the previously collected dye- and 

gas-tracing data.

Dye-Dilution Discharge Measurements. 

Seventy dye-dilution discharge measurements were 

made during 1967-82. Dye-dilution discharge measurements are useful where current-meter measurements of stream discharge are difficult or impossible, 

or independent verification of such measurements is 

needed. As a part of USGS national research to 

develop methods, five test measurements were made in 

the Laramie River during February 1967 to test the 

method in a stream covered by ice. Four of the five 

measurements under ice were within 2 percent of the 

discharge measured by current meter in an ice-free 

reach. Next, an investigation of the methods was 

conducted at streamflow-gaging stations on North and 

South Brush Creeks during 1967-68. Seventeen dyedilution discharge measurements were made, confirming the stage-discharge rating curves previously 

developed using current-meter measurements. Four 

dye-dilution measurements were made at a 

streamflow-gaging station on South Piney Creek 

during 1971-74, with similar success. With confidence 

in the dye-dilution method thus established, hydrographers proceeded to use the method at other sites.

60 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
In 1975, USGS hydrographers in Wyoming were 

faced with the problem of measuring discharge at 

streamflow-gaging stations on the east flank of the 

Bighorn Mountains during spring runoff, where there 

were no cableways or bridges from which to suspend a 

current meter. The stations were operated to estimate 

streamflow recharge to the Madison Limestone of 

Mississippian age. Equipment and water samples had 

to be compact and lightweight for backpacking to and 

from the remote sites.

Twenty-nine dye-dilution measurements were 

made for the Madison study during 1975-78, including 

four additional measurements at the station on South 

Piney Creek, with results of varying accuracy. Most 

were used to define the stage-discharge rating curves 

for the stations, but a few were judged to be inconsistent with previous current-meter measurements at the 

site and were not used. At some stations the dye 

measurements were essential for developing the highflow part of the ratings and, therefore, the high-flow 

records for the station. The stage-discharge relation for 

Tongue River at Tongue Canyon Campground, near 

Dayton, where current-meter measurements could be 

made from a footbridge, was verified by four dyedilution discharge measurements, two of which were 

the largest to date (early 1996). The largest was 

2,300 ft3/s.

At a few sites the accuracy of the dye-dilution 

measurement was downgraded, either because the dyeinjection rate was unsteady, or because lateral mixing 

was not uniform or could not be ascertained from the 

stream samples. Consequently, sampling procedures 

have been changed to assure collection of samples near 

the opposite streambank for better assessment of lateral 

mixing. After 1978 only two dye-dilution measurements were made, both to define the high end of the 

stage-discharge rating at a streamflow-gaging station 

on Middle Creek at East Entrance, Yellowstone 

National Park.

Investigations in Karst Terrane. USGS 

hydrologists conducted dye tests in five streams in 

karst terrane during 1970-91. Streams on the flanks of 

mountain ranges in Wyoming commonly cross limestones and dolomites of Paleozoic age. Karst terrane, 

including sinkholes, caves, and springs, has developed 

in many places where dissolution of the carbonate rock 

has occurred. Some streams lose water into sinkholes 

or caves, or gain water from springs. Dye tests can

provide information that water managers can use to 

understand the loss or gain as to its destination or 

source when allocating the affected water resources. 

Each of the five dye tests in karst terrane was successful, but each also raised questions that might be 

resolved with additional dye tests.

Dye was injected upstream from sinkholes in the 

North Fork Powder River below Dullknife Reservoir 

during 1970 to evaluate losses of water released for 

irrigation. Only about 6 percent of the injected dye was 

accounted for by sampling flow from a large spring 

about 3.7 miles downstream from the injection site. 

During the test, flow at the spring increased in response 

to the reservoir release, then decreased. About 

86 percent of the flow entered the sinkholes. Results of 

the dye test do not explain: (1) the decrease in flow 

from the spring, (2) the connection of a second losing 

reach to the spring, and (3) the fate of most of the dyetagged water lost into the streambed.

Losing reaches of North Fork Crazy Woman 

Creek and the Little Tongue River were dye-tested 

during 1974 as part of the study of streamflow recharge 

to the Madison Limestone. In the 1.3-mile reach 

between two streamflow-gaging stations on North Fork 

Crazy Woman Creek there were three zones of streamflow loss. Dye arrived at the downstream station in 

separate peaks 3.50, 6.75, and 9.50 hours after injection at the upstream station. About 73 percent of the 

dye was accounted for by sampling, indicating that 

some water may have bypassed the sampling site. 

Discharge increased 9 percent, however, indicating an 

additional source of ground-water discharge to the 

stream.

The test of the Little Tongue River was conducted to determine how much of the water lost into the 

streambed resurges in Tongue River Cave (and eventually the Tongue River), some 2.6 miles north of and 

2,500 feet lower than the losing reach. A single peak 

concentration of dye arrived in the stream in the cave 

34 hours after injection, but only 35 percent of the dye 

was accounted for, indicating that only part of the water 

lost into the streambed reaches the cave. There is a 

2-mile gap between the point where the stream loses all 

flow and the point where flow resumes in the Little 

Tongue River, a site not sampled for the presence of 

dye. The upstream losing reach might be the source of 

this water. For the study of recharge to the Madison 

Limestone, the results of the dye test serve as a 

reminder that streamflow losses do not always 

represent recharge.

Summary and Conclusions 61
A 1983 dye test in the Middle Popo Agie River 

in Sinks Canyon State Park confirmed the direct connection of the Sinks (the cave where the river disappears) to the Rise (springs about 3,500 feet downstream where flow in the river resumes). The leading 

edge of dye injected upstream from the Sinks appeared 

at the Rise after 2 hours; the dye cloud had cleared the 

Rise after an additional 6 hours. Between the Sinks 

and the Rise discharge increased from about 81 ft3/s to 

136 ft3/s, and water temperature increased about 8°C, 

indicating an additional source of ground-water discharge. About 84 percent of the dye was accounted for, 

indicating possible diversion of some water in the subterranean part of the flow system. An adjacent stream, 

Sawmill Creek, might be the source of some of the 

water gained.

Dye was used in 1991 to help evaluate water 

losses to sinks between two streamflow-gaging stations 

on Smith Creek near Casper. A very weak trace 

appeared at the downstream station about 20 hours 

after injection of dye at the upstream station, indicating 

a hydraulic connection between the sinks and flow at 

the downstream station. Because a dye-recovery calculation could not be made, the amount of water lost to 

the sinks and regained at the downstream station could 

not be estimated.

Other Investigations. four applications of 

dye tracing do not fit into any of the previously discussed groups. These investigations illustrate the 

potential for using dye tracing creatively when opportunities occur.

One of the earliest uses of dye tracing in Wyoming was in 1967 in Pass Creek near its mouth at the 

North Platte River. Dye was used as a tag, so as to 

make current-meter measurements of the same water at 

successive cross sections. Thus, small gains in stream

discharge from ground water would not be obscured by 

other variations in streamflow. Water tagging with dye 

also can be used to assure correctly timed collection of 

water samples for other purposes, such as gas-tracer 

samples for reaeration measurements.

Dye was used in Yellowstone National Park 

during 1975-76 to measure the direction and rate of 

movement of effluent percolating from the Old Faithful 

wastewater-treatment facility through sand and gravel 

deposits toward a nearby stream. The average velocity 

of the dye plume between the wastewater lagoon 

injected with dye and a shallow well about 130 feet 

away was about 2 feet per day. Dye was detected in the 

well for nearly 7 months. The dye probably reached 

Iron Spring Creek, about 400 feet from the lagoon, but 

fluorometric responses in samples from the stream 

were only slightly above background levels. If the dye 

plume traveled at 2 feet per day, it may not have 

reached the stream when sampling was discontinued.

As part of a national study of the effectiveness of 

retrofitted highway edgedrains, in 1989 dye was placed 

in a sealed hole in the pavement of Interstate Highway 

25 near Wheatland. The purpose was to detect runoff 

water seeping through the roadway subgrade. The dye 

was not detected in the discharge from the edgedrain, 

however, probably because of the lack of voids in the 

low-permeability subgrade.

In 1990 an active test for leakage was conducted 

at a fire-protection training facility at F.E. Warren Air 

Force Base near Cheyenne. The Air Force suspected a 

leak in the upper liner of a double-lined pond used to 

retain fire-fighting foam. Dye injected into the pond 

was detected in water pumped from a piezometer well 

connected to the space between the two liners, confirming the leak.

62 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94
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64 Use of Dye Tracing in Water-Resources Investigations in Wyoming, 1967-94