The Channels and~ Waters of the 

Upper Salin on River Area, Idaho 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 870-A 

• THE CHANNELS AND WATERS OF THE 

UPPER SALMON RIVER AREA, IDAHO 
Imagery of study area observed at an altitude of 570 miles from the ERTS-1 earth-orbiting satellite. 
The Channels and Waters of the 

Upper Salmon River Area, Idaho 

By WILLIAM W. EMMETT 

HYDROLOGIC EVALUATION 

OF THE UPPER SALMON RIVER AREA, IDAHO 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 870-A 

UNITED STATES GOVERNMENT PRINTING OFFICE,WASHINGTON: 1975 
U.S. DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, Jr., Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

Any use of trade, product, or firm names in this publication is for 

descriptive purposes only and does not imply endorsement by the 

U.S. Government 

First printing 1975 

Second printing 1992 

Library of Congress Cataloging in Publication Data 

Emmett, William W. 

The channels and waters of the Upper Salmon River area, Idaho. (Hydrologic evaluation of the Upper Salmon River area, 

Idaho) 

(Geological Survey Professional Paper 870-A) 

Bibliography: p. 95-96. 

Includes index. 

Supt. of Docs. No.: I 19.16:870-A 

1. Stream measurements-Idaho-Salmon River watershed. 2. Salmon River watershed, Idaho. 3. Water-Composition. 

I. Title. II. Series. Ill. Series: United States. Geological Survey. Professional Paper 87 0-A. 

GB1227.S22E45 551.4'83'0979672 75-619068 

For sale by Book and Open-File Report Sales, U.S. Geological Survey, 

Federal Center, Box 25425, Denver, CO 80225 
CONTENTS 

Page 

Symbols -------------------------------------------------- VII 

Metric conversion table ------------------------------------VIII 

1\bstract -------------------------------------------------- 1\1 

Introduction ---------------------------------------------- 1 

1\cknowledgrnents ____ _ ___ ____ __ __ _ _ __ _ _ __ _ _ _ __ _ _ _ _ _ _ _ 2 

Description of the problem ---------------------------- 2 

Scope of the investigation ------------------------------ 3 

Units of measurements -------------------------------- 4 

Description of the study area ------------------------------ 4 

General location -------------------------------------- 4 

Topography ------------------------------------------ 4 

Geology ---------------------------------------------- 5 

Climate ---------------------------------------------- 8 

Vegetation ____ _ _ __ _ _ __ _ __ _ _ ___ _ _ __ _ _ __ _ _ __ __ _ _ __ _ _ __ _ _ 9 

Land use______________________________________________ 11 

Stream channel network ---------------------------------- 13 

General description------------------------------------ 13 

Water-data stations____________________________________ 13 

f.lorton analysis -------------------------------------- 14 

Drainage areas tributary to East Fork Salmon River 15 

Main-stern East Fork Salmon River ________________ 22 

Summary discussion of drainage net____________________ 24 

Collection and analysis of streamflow data ------------------ 25 

Stream-gaging measurements -------------------------- 26 

Streamflow runoff ------------------------------------ 27 

f.lydraulic geometry------------------------------------ 28 

1\t-a-station hydraulic characteristics ______________ 28 

Downstream hydraulic characteristics ______________ 31 

Channel geometry ------------------------------------ 34 

Field surveys and observations ____________________ 35 

Determination of bankfull discharge________________ 36 

Dimensionless rating curve ------------------------ 37 

Collection and analysis of streamflow data-Continued Page 

Frequency of flows ------------------------------------1\38 

Flow duration ---------------------------------------- 39 

Other streamflow characteristics________________________ 42 

Dimensionless high-flow characteristics ____________ 43 

Dimensionless low-flow characteristics ______________ 44 

Summary discussion of streamflow data ---------------- 45 

Collection and analysis of water-quality data---------------- 51 

1\ basis for comparison and interpretation of water quality 53 

Stream-water temperature ---------------------------- 54 

Standard chemical analyses ---------------------------- 56 

pf.l and specific conductance------------------------ 56 

Dependency of ionic concentration on solubility of rock 

and magnitude of discharge ______________________ 57 

Content of major ions------------------------------ 61 

Silica -------------------------------------------- 62 

Nutrients ____ _ _ __ __ __ _ _ ____ _ _ __ _ _ __ _ _ __ _ _ ___ _ ____ 65 

1\lkalinity and hardness -------------------------- 68 

1\real composition of stream water---------------------- 69 

Trace-element analyses -------------------------------- 73 

Stream biota _ __ _ __ _ _ __ _ _ __ _ _ __ _ _ __ _ __ ___ ____ _ ___ _ ___ _ _ 77 

Other biological observations -------------------------- 78 

Suspended sediment ---------------------------------- 80 

Turbidity -------------------------------------------- 83 

Bedload transport ------------------------------------ 85 

1\nnual runoff of solids -------------------------------- 86 

Synoptic approach to water quality -------------------- 88 

Summary discussion of water-quality data ______________ 89 

Summary of findings -------------------------------------- 92 

Selected references ---------------------------------------- 95 

Summary of data------------------------------------------ 97 

Index ---------------------------------------------------- 115 

ILLUSTRATIONS 

FRONTISPIECE. Imagery of study area observed at an altitude of 570 miles from the ERTS-1 earth-orbiting satellite. 

Page 

FIGURE 1. Map showing location of primary water-data stations ----------------------------------------------------------- 1\5 

2. Photographs ofpristine character and rugged topography in the White Cloud Peaks area___________________________ 6 

3. Photographs of selected rivers in the study area ----------------------------------------------------------------- 7 

4. Photographs of developments within the study area ------------------------------------------------------------- 9 

5. Map of study area showing generalized topography ------------------------------------------------------------- 10 

6. Map of study area showing generalized geology ----------------------------------------------------------------- 11 

7-16. Graphs showing: 

7. Relation of number of streams to stream order ----------------------------------------------------------- 18 

8. Relation of length of streams to stream order------------------------------------------------------------- 18 

9. Relation of drainage area to stream order --------------------------------------------------------------- 19 

10. Relation of watershed relief to stream order ------------------------------------------------------------- 19 

11. Relation of channel drop to stream order----------------------------------------------------------------- 19 

12. Relation of channel slope to stream order --------------------------------------------------------------- 20 

13. Relation of drainage area to stream length---------------------------------------------- _________________ 21 

14. Percentage of streams as a function of size of drainage area----------------------------------------------- 22 

v 
VI CONTENTS 

FIGURES 7-16.-Graphs showing-Continued Page 

15. Altitude and drainage area as a function of downstream distance _________________________________________ A24 

16. Stream length as a function of drainage area for the main-stem East Fork Salmon River __ _________________ 25 

17-21. Streamflow hydrographs for: 

17. Valley Creek at Stanley, Idaho ____________________________________________________________ ---- ____ ____ _ 27 

18. Salmon River below Yankee Fork, Idaho----------------------------------------------------------------- 28 

19. Bruno Creek near Clayton, Idaho ----------------------------------------------------------------------- 28 

20. Little Boulder Creek near Clayton, Idaho --------------------------------------------------------------- 29 

21. Salmon River near Challis, Idaho ----------------------------------------------------------------------- 29 

22-50. Graphs showing: 

22. At-a-station curves of hydraulic geometry, Salmon River near Challis, Idaho ------------------------------- 30 

23. Bankfull surface width as a function ofbankfull discharge ----------------------------------------------- 33 

24. Bankfull mean depth as a function of bankfull discharge ------------------------------------------------- 33 

25. Bankfull mean velocity as a function ofbankfull discharge ----------------------------------------------- 34 

26. Bankfull flow area as a function of bankfull discharge_____________________________________________________ 35 

27. Dimensionless rating curves of depth and flow area as functions of discharge ------------------------------- 37 

28. Flow-frequency curves for selected stream-gaging stations in the upper Salmon River area ----------------- 39 

29. Dimensionless flow-frequency curve for streamflow in the upper Salmon River area ------------------------- 40 

30. Flow-duration curves for selected stream-gaging stations in the upper Salmon River area____________________ 41 

31. Dimensionless flow-duration curve for streamflow in the upper Salmon River area ------------------------- 43 

32. High- and low-flow characteristics, Salmon River near Challis, Idaho_______________________________________ 45 

33. High-flow characteristics for upper Salmon River area --------------------------------------------------- 47 

34. Low-flow characteristics for upper Salmon River area ----------------------------------------------------- 47 

35. Bankfull discharge as a function of drainage area_________________________________________________________ 48 

36. Bankfull runoff as a function of drainage area ----------------------------------------------------------- 49 

37. Bankfull surface width as a function of drainage area----------------------------------------------------- 50 

38. Bankfull mean depth as a function of drainage area_______________________________________________________ 51 

39. Bankfull mean velocity as a function of drainage area_____________________________________________________ 51 

40. Bankfull flow area as a function of drainage area----------------------------------------_________________ 52 

41. Stream-water temperature, 197~ 72, Little Boulder Creek near Clayton, Idaho ____________ _________________ 55 

42. Specific conductance as a function of discharge ratio ------------------------------------ _________________ 59 

43. Calcium concentration as a function of discharge ratio ---------------------------------------------------- 62 

44. Sodium concentration as a function of discharge ratio----------------------------------------------------- 63 

45. Magnesium concentration as a function of discharge ratio -------------------------------- _________________ 64 

46. Bicarbonate concentration as a function of discharge ratio------------------------------------------------- 65 

47. Sulfate concentration as a function of discharge ratio -------~---------------------------- _________________ 66 

48. Chloride concentration as a function of discharge ratio --------------------------------------------------- 67 

49. Dissolved solids as a function of discharge ratio ___________________________________________________________ 68 

50. Silica concentration as a function of discharge ratio--------------------------------------_________________ 69 

51-56. Maps showing areal concentration of: 

51. Calcium in streams at mean annual discharge ------------------------------------------------------------ 70 

52. Sodium in streams at mean annual discharge ____________________________________________ ------------------ 71 

53. Bicarbonate in streams at mean annual discharge -------------------------------------------------------- 72 

54. Sulfate in streams at mean annual discharge-------------------------------------------------------------- 73 

55. Silica in streams at mean annual discharge -------------------------------------------------------------- 74 

56. Dissolved solids in streams at mean annual discharge------------------------------------------------------ 75 

57-64. Graphs showing: 

57. Suspended-sediment concentration as a function of discharge ratio _________________________________________ 82 

58. Suspended-sediment load as a function of discharge ratio -------------------------------- _________________ 84 

59. Measurements of bedload transport and concurrent hydraulic and channel data, Slate Creek near Clayton, Idaho ________________________________________________________________________________________________ 87 

60. Particle-size distribution of bedload material ___ __ _ _ __ _ _ __ _ __ _ _ _ __ _ __ _ _ __ ____ ___ _ __ _ _ ___ _ __ _ _ _ ___ _ __ _ __ _ _ _ 88 

61. Discharge of suspended sediment as a function of percentage of time _______________________________________ 90 

62. Percentage of annual discharge of suspended sediment as a function of percentage of time ___________________ 90 

63. Discharge of dissolved solids as a function of percentage of time -------------------------- _________________ 92 

64. Percentage of annual discharge of dissolved solids as a function of percentage of time _______________________ 93 

65. Map showing values of synoptic observations of specific conductance and temperature on June 28, 1972----------------- 94 

TABLES 

Page 

TABLE 1. Mean monthly temperatures for two weather-station locations within study area --------------------------------A12 

2. Mean monthly precipitation for two weather-station locations within study area -------------------------------- 12 
TABLE 

A 

D 

G 

L 

Q 

R 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

16. 

17. 

18. 

19. 

20. 

21. 

22. 

23. 

24. 

25. 

26. 

27. 

28. 

29. 

30. 

31. 

32. 

33. 

34. 

35. 

36. 

37. 

38. 

39. 

40. 

41. 

42. 

43. 

44. 

CONTENTS VII 

Page 

Station number and name of primary data sites --------------------------------------------------------------- A13 

Drainage basin number and name of areas included in Horton analysis, East Fork Salmon River ----------------- 15 

Characteristics of Horton analysis compiled by individual drainage basins, East Fork Salmon River----------------- 16 

Summary of Horton analysis data, East Fork Salmon River ----------------------------------------------------- 17 

Characteristics of Horton analysis compiled by size of drainage area, East Fork Salmon River _____________________ 20 

Characteristics of Horton analysis accumulated downstream along East Fork Salmon River _______________________ 23 

Summary of water-data station information ______________________________________________________________ ---- _ 26 

Water-data stations with records available for streamflow frequency and duration analyses _______________________ 26 

Exponents of hydraulic-geometry equations for width, depth, and velocity --------------------------------------- 31 

Summary of bankfull-stage data from channel-geometry surveys------------------------------------------------- 32 

Summary of channel-material particle-size analyses _________________________________________________________ ---- 36 

Flow-frequency data: value of discharge at various recurrence intervals for water-data stations with adequate 

records___________________________________________________________________________________________________ 38 

Flow-frequency data: value of discharge ratio, QIQB, at various recurrence intervals for water-data stations with more 

than 10 years of record and channel survey available ------------------------------------------------------- 40 

Flow-duration data: discharge that is equaled or exceeded during percentage of time indicated, for water-data stations 

with adequate records _____________________________________________________________________________________ 40 

Flow-duration data: discharge ratio, QIQB, that is equaled or exceeded during percentage of time indicated, for waterdata stations with more than 10 years of record and channel survey available ______________ ------------------ 42 

High- and low-flow characteristics: value of discharge for given number of consecutive days at various recurrence intervals ___________________________________________________________________________________________________ 44 

High-and low-flow characteristics: value of discharge ratio, QIQB, for given number of consecutive days 

at various recurrence intervals _ _ __ _ _ __ _ _ __ _ _ ___ _ __ _ _ __ _ _ ____ _ __ _ _ _ __ _ _ ____ _ _ _ ___ _ _ __ _ _ _ __ ___ _ _ ___ _ _ __ _ __ _ _ 46 

High-flow characteristics: mean value of discharge ratio, QIQB, for given number of consecutive days at various recurrence 

intervals for water-data stations with more than 10 years ofrecord and channel survey available ----------------'- 46 

Low-flow characteristics: mean value of discharge ratio, QIQB, for given number of consecutive days at various recurrence 

intervals for water-data stations with more than 10 years of record and channel survey available _________________ 46 

Water-data stations for biological studies and for which water-quality data ex'ist in addition to data for stations given in 

table 3--------------------------------------------------------------------------------------------------- 53 

Average composition in percentage by weight of various oxides in the earth's crust ------------------------------- 54 

Weight percentages of the earth's crust for those elements analyzed in stream waters of this study----------------- 54 

Mean monthly temperatures for Little Boulder Creek near Clayton --------------------------------------------- 56 

Summary of log-transformed regression data of specific conductance as a function of discharge--------------------- 58 

Summary of streambed lithology ______________________________________________________________ --------------___ 60 

Summary of log-transformed regression data of silica as a function of discharge __________________ ----------------- 64 

Frequency of reported occurrence of trace elements ------------------------------------------------------------- 76 

Trace-element concentration at selected percentiles of samples analyzed ----------------------------------------- 77 

Summary oflog-transformed regression data for iron concentration as a function of discharge _____________________ 77 

Summary of log-transformed regression data for strontium concentration as a function of discharge ----------------- 77 

Summary of microbiological, dissolved-oxygen, and organic carbon parameters for five water-data stations ----------- _-- 79 

Summary oflog-transformed regression equation data for suspended-sediment concentration as a function of discharge--- 81 

Summary oflog-transformed regression equation data for suspended-sediment load as a function of discharge_----------- 83 

Particle-size distribution of suspended sediment --------------------------------------------------------------- 85 

Summary of bedload-transport measurements obtained with Helley-Smith bedload sampler ----------------------- 89 

Computations of annual suspended-sediment yield, Salmon River near Challis ----------------------------------- 91 

Computations of annual dissolved load, Salmon River near Challis----------------------------------------------- 98 

Summary of selected water-quality characteristics and concentrations of major ions at water-data stations ------------- 104 

Summary of concentrations of dissolved trace elements at water-data stations ----------------------------------- 106 

Summary of suspended sediment and turbidity data _____________________________________________________________ 110 

Summary ofregression equation data-significant major ion concentration as a function of discharge ----------------- 110 

Summary ofregression equation data-miscellaneous water-quality parameters as a function of discharge ____________ 112 

SYMBOLS 

Flow area of stream, in square feet ( = W xD) S Stream slope, in feet per foot 

Flow depth in stream, in feet T 

Suspended-sediment discharge, in tons per day 

Stream length, in miles V 

Water discharge of stream, in cubic feet per second W 

Unit runoff of streamflow, in cubic feet per second per square DA 

mile DS 

Temperature, in degrees Fahrenheit (°F) or degrees Celsius 

(oC) 

Flow velocity in stream, in feet per second 

Flow width in stream, in feet 

Drainage area, in square miles 

Dissolved solids, in milligrams per litre 
VIII 

RI 

sc 

a 

b 

c 

d 

k 

Recurrence interval, in years 

Specific conductance, in micromhos 

Coefficient of width in hydraulic geometry 

Coefficient of specific conductance 

Coefficient of depth in hydraulic geometry 

Particle diameter, in millimetres 

Coefficient of velocity in hydraulic geometry 

CONTENTS 

B 

T 

c 

m 

s 

With reference to bankfull 

With reference to total 

With reference to concentration 

With reference to map values 

With reference to field survey 

r Correlation coefficient, may be either negative or positive 

Turbidity, in Jackson Turbidity Units (JTU) 

b 

f 

j 

Superscripts 

Exponent of width in hydraulic geometry 

Exponent of depth in hydraulic geometry 

Exponent of suspended sediment in hydraulic geometry 

Exp<>nent of velocity in hydraulic geometry 

A 

Subscripts 

With reference to average 

m 

s Exponent of specific conductance 

CONVERSION FACTORS 

[Multiply English units by factor given to obtain metric units; divide metric units by factor to obtain English units] 

Length Volume 

inches (in.) 25.4 millimetres (mm) cubic feet (ft3) 28.32 cubic decimetres (dm3) 

.0254 metres (m) .02832 cubic metres (m3 ) 

feet (ft) .3048 metres (m) Flow 

miles (mi) 1.609 kilometres (km) cubic feet per 

Area second (ft3/s) 28.32 litres per second {l/s} 

square feet (ft2) .0929 square metres (m2) 28.32 cubic decimetres per second (dm3/s) 

acres 4047 square metres (m2) .02832 cubic metres per second (m3/s) 

.4047 hectares (ha) Mass 

.4047 square hectometre (hm2) pound (lb) 454 grams (g) 

.004047 square kilometres (km2) .454 kilograms (kg) 

square ton (short) .9072 tonne (t) 

miles (mi2) 2.590 square kilometres (km2) 
HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

THE CHANNELS AND WATERS OF THE UPPER 

SALMON RIVER AREA, IDAHO 

By WILLIAM w. EMMETT 

ABSTRACT 

The upper 1,800 square miles of the Salmon River drainage basin in 

south-central Idaho is an area of great scenic beauty and littledisturbed natural environment. Proper development and use of this 

land and its natural resources are contingent on a multifaceted and 

detailed environmental study. The report series emphasizes the 

complex interaction of hydr~logical, biological, geological, and 

chemical parameters. This particular report concentrates on the 

hydraulics and geometry of streamflow and the composition of stream 

water. 

Stream runoff at bankfull stage varies with size of drainage area 

according to the approximate relation RB =28.3 DA - 0·

31, but this 

relation is locally variable, as precipitation is locally greater or less 

than the mean for the area. More exacting than size of drainage area, 

the size of stream channel is everywhere related to the magnitude of 

bankfull discharge, QB, by the approximate relations W B = 1.37 QB 0.54 

andDB=0.25 QB0.34. Bankfulldischarge has a recurrence interval of 

about 1.5 years, and flows proportional to bankfull discharge tend to 

have a common frequency of occurrence among streams. Mean annual 

discharge is approximately 25 percent ofbankfull discharge, and flows 

equal to or greater than mean annual discharge occur about 25 

percent of the time. Magnitude of high- and low-flow stream 

characteristics are presented in terms of the ratio of discharge to 

bankfull discharge, QIQB, and the frequency and duration characteristl.cs of these flows are approximately the same for all streams in 

the area. 

Stream-water composition is primarily of the calcium bicarbonate 

type, and mineral concentrations generally are low. Typified by data 

from the main stream at the exit from the study area, major cations 

in the weight ratio Ca:N a:Mg:K are present in the amounts 

1.0:0.22:0.12:0.04; major anions in the weight ratio HC03:S04:Cl:Fl 

are present in the amounts of 1.0:0.06:0.01:0.005. Dissolved solids, 

DS, vary with discharge approximately asDS ex (Q!QB)-0.20. Values of 

the concentration of dissolved solids at a given value ofthe discharge 

ratio are locally variable depending on solubility of upstream rock 

types and magnitude of runoff. At the exit from the study area, the 

main stream has a concentration of dissolved solids of78 milligrams 

per litre at bankfull stage and 101 milligrams per litre at mean 

annual discharge. The concentration of individual major ions follows 

the trend of dissolved solids. Ions present in trace concentrations are 

more erratic in respect to both temporal and spatial occurrence. The 

frequency of occurrence of the true trace elements generally is related 

to their relative abundance in the average composition of the earth's 

crust as modified by mineral solubilities. Taking an average of the 

whole of 2,304 analyses for 21 different trace elements, a trace 

element was detected in 56 percent of the samples analyzed and 

occurred, at one time or another, at 96 percent of the locations 

sampled. 

Suspended sediment varies with discharge approximately as 

Goc (Q/QB)2·

5. Values of the concentration of suspended sediment at a 

given value ofthe discharge ratio are locally variable depending on 

erodibility of upstream rock types, artificially induced impacts, and 

the competence of the stream to transport its imposed sediment load. 

At the exit from the study area, the concentration of suspended 

sediment in the main stream is 80 milligrams per litre at bankfull 

discharge and 5 milligrams per litre at mean annual discharge. 

On the basis of average duration of flows of various frequency, the 

average annual discharge of suspended and dissolved solids is about 

200,000 tons. The ratio of weight of dissolved solids to weight of 

suspended solids is about 1.75:1.0. 

Continued monitoring of all aspects of the study for detection and 

documentation of changes provides data to determine variations in 

initial or baseline relations, relations discussed here and those yet to 

be made such as between biological parameters and total sediment 

yield. The data presented in this report should help decisionmakers in 

the judicious use of the resources of the area so that any changes in 

baseline characteristics ·will not be degrading to the quality of the 

environment. 

INTRODUCTION 

Relatively few studies of the quality of the nation's 

rivers have been directed toward determining changes 

in specific parameters over long periods of time. As 

detailed by Wolman (1971), this lack of direction is due 

to a number of reasons. First, hydrologic records in the 

United States are sufficiently short that a knowledge of 

the background or baseline characteristics as well as 

temporal variations are not available. Second, techniques of observation and of analysis have changed. 

Third, changes in location or frequency of observations 

distort the record. Fourth, adequate correlation of 

specific water-quality parameters to hydrologic behavior has not been made. And fifth, a knowledge of the 

cultural or land-use background is as necessary in 

explaining changes in water-quality parameters as is a 

description of the natural resources background. This 

report attempts, albeit for a small area, to alleviate 

some of the mentioned shortcomings. 

A1 

' 
A2 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

The upper drainage basin of the Salmon River in 

south-central Idaho consists of a river net of pristine, or 

nearly so, waters where the impact of man's influence is 

either negligible or may be described simply. Waterquality samples and associated channel-hydraulics 

data were systematically collected at a network of 

water-data stations; water-quality analyses were conducted by standardized U.S. Geological Survey techniques. The relations of hydrologic behavior to channel 

geometry allow extrapolation of flow characteristics to 

ungaged areas, and the interrelation of streamflow, 

water quality, geology, topography, and land use allow 

interpretation of data for the entire area as a river 

system rather than isolated observations of river 

quality. Although only a short-term record of waterquality data exists, the present report materially adds 

to a description of the hydrologic environment of the 

area. With the present work being undertaken before 

the natural environment of the area is greatly 

disturbed, the short length of the record may be 

overlooked, for future data collection will complete the 

record and not just add length to a partially complete 

record. 

The author's work with overland flow on hillslopes 

(Emmett, 1970) has shown that considerable erosive 

work or modification to the landscape is done by water 

before it becomes confined to a tributary channel, and 

thus the dissolved and suspended load of the main river, 

and moreover its entire geomorphic character, is in 

large measure a function of the geologic, biologic, and 

meteorologic conditions within the entire watershed. 

The analyses of the present report specifically emphasize this complex interaction of the hydrological, 

geological, biological, and chemical parameters. 

Few studies over the years have attempted to 

interrelate the many environmental factors of a given 

area. Other than the present study, the author knows 

only of the work reported by Miller, Troxell, and 

Leopold (1971) on the hydrology of two small watersheds in Pennsylvania before urbanization. One reason 

why these interrelations are seldom expressed for wide 

areas is that they require special types of graphs, and for 

this reason the author has developed some new tools. 

Also, this report shows the consistency of streamflow 

characteristics among the various channels by dimensionless curves valid for the region of study. Chemical 

quality of water is particularly difficult to regionalize, 

but the present report includes one attempt to do this. 

Moreover, an averaging of regional data provides a 

factor against which to judge individual rivers or 

stations. 

ACKNOWLEDGMENTS 

The primary effort in this study was initiated in the 

spring of 1971, and fieldwork was conducted through 

the remainder of that year and all of 1972. Prior to this 

primary effort, in 1970, five water-data stations were 

established in the Little Boulder Creek and Big Boulder 

Creek drainage areas by the Idaho District, U.S. 

Geological Survey. Throughout this study, these stations provided important data for those areas. 

Many of the streamflow measurements and sample 

collections for wate:f..quality analysis were made by 

personnel of the Idaho District under the direction of 

Hal K. Hall, District Chief. Especially notable was the 

work performed by Robert W. Luscombe. Summer field 

assistant for both years was Michael W. VanLiew, who 

also assisted in the compilation of data. The help of 

these and other Idaho District personnel is gratefully 

acknowledged. 

The biological data-collection program is still underway and is being conducted in collaboration with Keith 

V. Slack and Larry J. Tilley, U.S. Geological Survey, 

Menlo Park, Calif. 

Many persons provided stimulating discussions, both 

in the field and in the office, which materially aided the 

success of the study. These include Luna B. Leopold, 

Lawrence E. Newcomb, Paul C. Benedict, Don M. 

Culbertson, and Robert R. Curry. Most also assisted in 

review of the manuscript. For their review, comments, 

and suggestions regarding the manuscript, the author 

is indebted also to Thomas Dunne, L. Edward Perry, 

Vance C. Kennedy, Garnett P. Williams, Howard F. 

Matthai, John H. Feth, Willis L. Burnham, Alfred H. 

Harder, Kenneth L. Dyer, and Cecil A. Thomas. 

DESCRIPTION OF THE PROBLEM 

In the center of the study area are the White Cloud 

Peaks, renowned for their scenic vistas and primitive 

character. The area's 250 mountain peaks average close 

to 10,000 feet in height and cover an area of 80 square 

miles. Within a 5-mile radius of Castle Peak, the 

highest of the White Cloud Peaks, are more than 50 

alpine lakes providing extraordinary fishing for cutthroat, rainbow, and golden trout. The Salmon River 

and its tributaries are important spawning grounds for 

salmon and steelhead. Big game in the area includes 

deer, elk, bighorn sheep, mountain goats, and black 

bear. The alpine soil supports lush meadows and their 

profusion of wildflowers. Even within recent years, the 

region has been lightly used, and man's activities have 

had. little impact on the environment of the area. 

Because of its remoteness and ruggedness, the American public has, in the past, paid little attention to this 

area of great natural beauty. 

The area is highly mineralized and contains economic 

deposits of numerous mineable ores. Indeed, the first 

settlers were miners, and many abandoned mine shafts, 
CHANNELS AND WATERS A3 

mill buildings, and access roads are still present. Even 

today, mining accounts for an appreciable amount of the 

area's economy. Still, these mineral exploitations have 

had little major impact on the natural environment. 

And, many believe these relics of the pick and shovel 

era of mining are esthetically appealing as part of the 

area's heritage rather than derogatory to the beauty of 

the landscape. 

In the 1960's, the discovery of extensive deposits of 

molybdenum ore in the White Cloud Peaks area of the 

upper Salmon River country resulted in mineral claims, 

exploration activities, and proposals for open-pit mining of ore. One large open-pit mine was proposed at the 

base of Castle Peak and included an extensive tailings 

pond in the Little Boulder Creek drainage. The area of 

the proposed mine is, perhaps, the scenic highlight in an 

overall area of great scenic beauty; this fact, combined 

with the increasing concern of the American public 

toward conservation of the natural resources and 

maintenance of environmental quality, led to requests 

to the Federal Government, as proprietor of the land 

involved, to evaluate all aspects of the environment in 

determining the most judicious uses of the area's 

resources. This report series describes one aspect of the 

evaluation, an assessment of the hydrologic environment. The present report is confined to a description of 

the stream channels and an analysis of the streamflow 

and water-quality characteristics of the area. 

Since the initiation of the present study, the Congress 

of the United States enacted a law in 1972 to establish 

the Sawtooth National Recreation Area. Included 

within its boundaries are the Sawtooth Mountains, 

White Cloud Peaks, and Boulder Mountains; these 

areas and the adjacent valley lands compose about half 

the present study area. The language of the bill 

establishing the recreation area is directed toward 

preservation of the existing environment and precludes 

the initiation of new mining activity within the 

boundaries of the recreation area. Although the 

prospects of large-scale mining in the White Cloud area 

are no longer highly probable, the data of this report 

assume new importance in planning and management 

decisions of the land and resources in their new 

classification status. Even more importantly, the data 

begin to satisfy the environmental needs detailed by 

Wolman (1971). 

SCOPE OF THE INVESTIGATION 

The study area comprises 1,800 square miles upstream from the U.S. Geological Survey gaging station 

on the Salmon River near Challis. About one-third of 

the area comprises the White Cloud Peaks drainage 

area, which includes the headwaters of streams 

draining westward to the Salmon River from its origin 

to the town of Stanley, northward to the Salmon River 

from Stanley to Clayton, and eastward to the East Fork 

Salmon River. 

Prior to 1970, the study area contained three 

recording gaging stations, each with lengths of record 

exceeding 40 years. Three crest-stage gages were 

located on small tributaries, and these installations had 

8 years of record. Also, five discontinued recording 

gaging stations had data records varying from several 

to 30 years. Records from all these stations were for 

streamflow characteristics only; few water-quality data 

were available prior to 1970. These data, although 

sparse, provided invaluable information on magnitude, 

frequency, and duration of streamflow in the area. 

In 1970, one recording gaging station and four 

miscellaneous water-data stations were established in 

the Little Boulder Creek and Big Boulder Creek 

drainage basins. Water-quality data collection was 

initiated by quarterly samplings at these stations. 

Intensive data collection began in 1971 with the 

establishment of additional water-data stations that 

brought the total to 39 stations. Measurements at these 

stations included streamflow, chemical quality including trace metals at selected stations, and sediment 

quality. Channel-geometry surveys at all stations 

related streamflow characteristics to channel size and 

shape and provided a basis for extrapolation of data to 

ungaged areas. 

Data collection in 1972 confirmed the data trends 

established the previous year and opened new areas of 

investigation. Verification measurements and sampling were conducted at all previously established 

stations. Determination of trace-metal concentrations 

was extended to several additional locations. In 

addition, synoptic runs which included observations of 

discharge, temperature, and specific conductance were 

made at scores of intermediate locations; these runs 

increase the transfer value of the chemical-quality data 

to unsampled areas. At several key stations, collection 

of sediment samples was greatly expanded. Sediment 

data included both suspended-sediment data and 

bedload-transport data. Aspects of the bedloadsampling program are being expanded, and these will 

be reported in more detail in a later publication. A 

program ofbiological observation in stream water of the 

area was also initiated in 1972; qualitative interpretation of these observations are included in this report, 

and quantitative results will be detailed in a later 

report. 

In summary, data collection thus far has provided a 

basis for the definition of the hydrologic environment of 

the area. The characteristics of stream channels and 

their water are the most important components of the 

hydrology of the area; thus the geometry and flow 
A4 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

characteristics of stream channels are discussed. A map 

folio (Emmett, 1972b) has summarized some of the 

water-quality data, and the present report details the 

composition of stream water. 

UNITS OF MEASUREMENTS 

Data used in this report and requiring units of 

dimension or definition are generally expressed in the 

customary English units of feet, pounds, and seconds. 

~hus, for example, water discharge is expressed as cubic 

feet per second and has a nominal unit weight of 62.4 

pounds per cubic foot. In line with the increasing trend 

to present water-quality data in metric units, temperatures are expressed in degrees Celsius and concentrations of suspended and dissolved matter in water are 

expressed as milligrams per litre. For values of 

concentration used in this report, milligrams per litre 

are equivalent to parts per million by weight. Trace 

concentrations are expressed in micrograms per litre 

and are equivalent to parts per billion. However, values 

of suspended or dissolved load are expressed in the more 

usual units of tons per day. A list of conversion factors is 

provided in the ucontents" section of the report. 

Symbols are defined where they first appear in the 

text; for symbols which are recurring throughout the 

text, a list is provided in the !!Contents" section of the 

report. 

DESCRIPTION OF THE STUDY AREA 

The description of some of the physiographic characteristics of the study area are necessarily brief because 

the remoteness and ruggedness of the area generally 

have precluded detailed descriptions of the area. For 

example, within the boundaries of the study area, there 

are no current long-term reporting weather stations. 

Because of the high interest in ore deposits in the area, 

however, geological studies are an exception to the 

paucity of data, and several excellent descriptions are 

available for the geology. Especially notable are the 

geological studies by Ross (1937). The U.S. Forest 

Service has completed an ecological evaluation of part of 

the lands included in the study area which are within 

forest boundaries. However, this report (U.S. Forest 

Service, 1972) is largely a qualitative description 

related to resource management rather than a quantitative description of resource investigation. 

GENERAL LOCATION 

The region of study lies in the upper drainage basin of 

·the Salmon River in south-central Idaho (fig. 1). It is 

mostly in southwestern Custer County but includes a 

small area in the northwestern part of Blaine County. 

The area comprises 1,800 square miles and extends 

from the headwater divide of the Salmon River 

downstream to the U.S. Geological Survey gaging 

station near Challis, Idaho. It lies in the southern part of 

the Northern Rocky Mountain Province (Fenneman, 

1931). 

The extremely rugged mountains west of Stanley 

Basin and defining the western divide of the area 

constitute the Sawtooth Range, so named because of 

their serrate appearance. In the area east of Stanley 

Basin and south of the Salmon River, a group of 

unnamed mountains is considered by many to form the 

most easterly part of the Sawtooth Mountains, which 

also include the Sawtooth Range. The highest part of 

this unnamed unit consists of the White Cloud Peaks. 

East of the White Cloud Peaks, the country has the 

appearance of a greatly dissected plateau with flat 

summits. These eastern foothills differ greatly from the 

central mountains, for they have a much drier climate 

and are not forested except for a few pockets of timber on 

some north-facing slopes. South of the White Cloud 

Peaks, the altitudes increase to the peaks of the Boulder 

Mountains. All the mountainous areas have been 

shaped and modified by intense alpine glaciation. 

Cirques and glacier-scoured rocky ridges are common. 

Lands at the midaltitudes are dominated by U-shaped 

valleys formed by the glaciers. Lands in the lower, 

nonglaciated areas were shaped by folding and faulting 

and have been further modified by fluvial and colluvial 

processes resulting in long, dissected hillslopes. 

The area was visited by early fur trappers, but 

general settlement awaited the last quarter of the 19th 

century. These early settlements were confined to 

mining camps and towns, most of which enjoyed boom 

days but are now relics. Today, the area is sparsely 

populated and has an economy based on mining, 

ranching, timbering, and catering to the recreational 

activities of visitors. 

Figures 2--4 illustrate typical views of the study area. 

Figure 2 emphasizes the ruggedness of the country and 

its general pristine character. Figure 3 shows views 

along the main-stem Salmon River and several representative tributaries. Figure 4 shows examples of 

developments within the area. 

TOPOGRAPHY 

High mountain country exceeding 10,000 feet in 

altitude occupies about 3 percent of the area, uplands 

ranging from 8,000 to 10,000 feet in altitude occupy 

about 35 percent, foothills ranging from 6,000 to 8,000 

feet in altitude occupy about 59 percent, and river 

lowlands at altitudes less than 6,000 feet occupy about 3 

percent. The mean altitude of the drainage area above 
CHANNELS AND WATERS A5 

', I 

EXPLANATION 

.22 

Water-data station 

Number relates station 

to table 3 

Drainage boundary 

0 

0 5 

5 10 15 MILES 

10 15 20 KILOMETRES 

FIGURE 1.-~ocation of primary water-data stations. 

the water-data station near Challis is about 7,820 feet. 

Castle Peak, the highest of the White Cloud Peaks, 

has an altitude of 11,815 feet above mean sea level, and 

a number of other peaks in this group, as well as in the 

Boulder Mountains to the southeast, are well above 

10,000 feet. At the exit from the study area, the gaging 

station Salmon River near Challis, Idaho, is at an 

altitude of about 5,165 feet. Figure 5 is a generalized 

topographic map of the upper Salmon River area. 

GEOLOGY 

The region is underlain by a thick sequence of 

Paleozoic sedimentary rocks intruded on the west by the 

Idaho batholith and in large part overlain to the east by 
A6 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

FIGURE 2.-Photographs showing pristine character and rugged topography in the White Cloud Peaks area. A, Quiet Lake on Little Boulder 

Creek. B, Cirque basin of Quiet Lake. C, Cross-valley view in Little Boulder Creek drainage. D, Down valley view in Little Boulder 

Creek drainage. 

Tertiary volcanic strata and associated sedimentary 

rocks. Figure 6 is a generalized geologic map of the 

studied area (Ross, 1937; Ross and Forrester, 1947). 

The Idaho batholith underlies a major part of the 

study area, particularly the central and western parts. 

The batholith is composed of granitelike rock, primarily 

granodiorite, quartz diorite, and quartz monzonite. It is 

believed to be of Late Jurassic or Early Cretaceous age. 

Ross (1937) stated that this rock type is 20-40 percent 

quartz, 40-80 percent feldspar, and 5-15 percent biotite 

mica. 

The volcanic rocks are designated the Challis 

Volcanics and crop out widely in the east half of the 

area, generally but not entirely at altitudes considerably below the high peaks and ridges. They are of 

Tertiary age, younger than the granitic rocks of the 

Idaho batholith, yet of sufficient age that considerable 

erosion and physical alteration has occurred. They are 

composed chiefly of volcanic flows with some interbedded flow breccias, mostly of andesitic and rhyolitic 

composition. A moderately consolidated tuff member of 

the Challis Volcanics is widespread and is shown 

separately in figure 6. The various members are highly 

variable in composition. Ross (1937) reported for the 
CHANNELS AND WATERS A7 

most extensive member, a latite-andesite, a composition of 63.5 percent silica, 3.1 percent lime, 4.0 percent 

soda, and 3.4 percent potash. 

The Paleozoic rocks appear in two north-south 

trending bands. One band, through the center of the 

White Cloud Peaks area, is approximately 25 miles long 

and as much as 8 miles wide. A smaller band extends 

north and south from the town of Clayton. In both areas 

the sedimentary rocks run through high and low 

altitudes. These sedimentary exposures may be regarded as erosional remnants or islands perched on the 

massive intrusions of the granitic rocks and perhaps 

buried in places by the volcanic rocks. The band through 

the White Cloud Peaks area is mapped as about half 

Wood River Formation (impure quartzite, argillaceous 

and calcareous, and some limestone) and about half 

Milligen Formation (argillite and argillaceous 

quartzite with impure dolomite beds; most of the 

formation is characterized by much carbonaceous 

matter). The Clayton band consists primarily of the 

FIGURE 3.-Photographs of selected rivers in the study area. A, Salmon River upstream of Valley Creek and showing flood plain and low 

terrace levels in Stanley Basin. B , Salmon River downstream of Yankee Fork River at gaging-station location. C, Salmon River at gaging 

station nt)ar Challis, Idaho. D , Beaver Creek tributary to Salmon River at crest-stage gage location. E, Valley Creek at gaging station 

near Stanley, Idaho. F , Little Boulder Creek at headwater reach in White Cloud Peaks area. G, Little Boulder Creek below Boulder 

Chain Lakes; Castle Peak is in the left background. H, Wickiup Creek tributary to East Fork Salmon River. Figure continued on next 

page. 
AS HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

FIGURE 3.-Continued. 

Kinnikinic Quartzite and Ramshorn Slate. 

A few surficial deposits of Quaternary age are 

present in the area. Large glacial deposits occur in the 

:aig Boulder Creek and Little Boulder Creek drainage 

basins. These deposits are mainly till and coarse gravel 

of glacial origin and are of Pleistocene age. The largest 

extent of alluvial deposits occurs in the Stanley Basin. 

These deposits range in age from the Pleistocene 

alluvium on the upper terraces hundreds of feet above 

the present stream channel through the more recent 

terrace alluvium on the lower terraces to the Holocene 

terrace and flood plain alluvium. 

CLIMATE 

Although some 500 miles from the Pacific Ocean, the 

upper Salmon River area is, nevertheless, influenced by 

maritime air borne eastward on the prevailing westerly 

winds. In the winter months, the Aleutian low 

dominates the weather and produces cloudiness and 

abundant precipitation. During the summer months, 

the Pacific high dominates with fair weather, except 

when moisture-laden air from the Gulf of Mexico and 

Caribbean areas is brought in from the south at high 

levels to produce thundershowers, especially in the 

eastern fringes of the area. 
CHANNELS AND WATERS A9 

FIGURE 4.-Photographs showing development within study area. A , Scars associated with exploration for mineral deposits on Railroad 

Ridge in the White Cloud Peaks area. B, Summer home construction near Obsidian, Idaho, in Stanley Basin. 

Only one weather station, at Stanley, is currently 

operated within the boundaries of the study area. The 

records of a former weather station, at Obsidian, and of 

a station just outside the downstream perimeter of the 

area, at Challis, can be combined with the Stanley records to infer some of the climatic characteristics of the 

area. 

Tables 1 and 2 give values of mean monthly temperature and precipitation for the year 1971 at the Stanley and Challis stations (National Oceanic and Atmospheric Administration, 1971a). The records at Challis 

are of sufficient length to determine long-term normals, 

and these values are included in tables 1 and 2 (National Oceanic and Atmospheric Administration, 

1971b). The mean annual precipitation ranges from less 

than 10 inches to more than 60 inches depending on 

altitude and location, but the major part of the area 

receives about 30 inches. The effects of altitude are seen 

in the low amounts of precipitation recorded at Stanley 

and Challis, both of which are along the main stem of 

the Salmon River. The effect oflocation is illustrated by 

the Challis station, which is located at the northeastern 

fringe ofthe area on the leeward side ofthe mountains. 

On the basis of available records, the station at Challis 

has the lowest average annual precipitation in the State~ 

with a long-term average of7 inches. These amounts of 

precipitation may be compared with an average annual 

tunoff from the area of about 12 inches. 

The mean annual temperature ranges from about -4° 

to 7°C1 depending on location but averages about 2°C. 

Obsidian, at an altitude of6,870 feet, is the only station 

1

Degrees Fahrenheit=(T,degrees Celsius)+32. 

within the area with sufficient length of record to compute a mean annual temperature. With a mean annual 

temperature of 1.7°C, it has the lowest annual average 

of any reporting station in the State. Very cold winters 

alternate with cool summer months when temperatures 

rarely exceed 30°C. In January the mean minimum 

temperature is about -20°C, and the mean maximum is 

about 0°C. Frost can occur in any month of the year, and 

the continuous days of killing frost generally extend 

from September through May. 

VEGETATION 

The area contains numerous forested areas. The 

principal tree species include Douglas fir, subalpine fir, 

lodgepole pine, white bark pine, and Engelmann spruce. 

Several hundred species of plant life are present. Grass, 

sedge, figwort, and composite families make up the 

larger number of herbaceous species. Sagebrush is often 

found on south-facing slopes and in patchwork with 

forested areas. 

On strongly glaciated lands, generally at altitudes 

above 10,000 feet, large areas are open and sparsely 

vegetated. On the deeper soils of the cirque basins, 

subalpine fir may be found. On rocky dry soils, 

whitebark pine predominates. In many areas, 

whitebark pine has been attacked by mountain pine 

beetle leaving statuesque snags. The lower glaciated 

lands have a heavy conifer cover on north-facing slopes, 

but sagebrush covers many ridgetops and south-facing 

slopes. At the higher altitudes, whitebark pine is associated with subalpine fir. Below altitudes of about 
AlO 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

EXPLANATION 

ALT ITU DE. IN FEET 

ABOVE M EA N 

SEA LEVEL 

D 

Less than 6,000 

t22lill 

~ 

6,000 to 8,000 

8,000 to 10,000 

More 

-

than 10,000 

--··-- Drainage boundary 

T 14 N 

I 

0 5 10 15 MILES 

0 10 15 20 KILOMETRES 

FIGURE 5.-Generalized topography. 

8,200 feet, Douglas fir occurs on north-facing slopes, and 

below altitudes of about 7,800 feet, Douglas fir occurs in 

all areas. Seral stands of lodgepole pine occur and are 

quick to replace the firs after a fire or other agent has 

destroyed the original stand. 

Unglaciated mountain lands provide for an open and 

closed stand of conifers with sagebrush-grass openings. 

Timber occupies about two-thirds of these lands with 

Douglas fir predominant. At the higher altitudes some 

subalpine fir occurs. Lodgepole pine is the dominant 

sere and is invading the areas offir. Pockets of quaking 

aspe:n occur, especially at the lower altitudes. On the 

still lower hillslope lands, Douglas fir grows on the 

north- and east-facing slopes where available moisture ' 

and other environmental factors permit. A sagebrushgrass cover occupies the rest ofhillslope lands except for 

scattered aspen stands along streams and at seeps. 

Depositional lands, as contrasted to the erosional 
CHANNELS AND WATERS All 

EXPLANATION 

Alluvium and glacial deposits 

Tuff 

Moderately consolidated 

D 

Challis Volcanics 

Idaho batholith 

Paleozoic rocks, 

undifferentiated 

Contact 

Drainage boundary 

Geology adapted from Ross and Forrester, 1947 

0 5 10 15 MILES 

0 5 10 15 20 KI LOMETRES 

FIGURE 6.- Generalized geology. 

surfaces discussed, are almost entirely covered with 

sagebrush-grass except for scattered groups of conifers 

and meadow species in moist areas. 

The harshness of climate on growth and survival of 

trees, combined with the remoteness and ruggedness of 

the country, make commercial timbering of little 

importance. A reasonable estimate would classify less 

than 10 percent of the forest land as commercial. Areas 

of commercial timber occur most often in the lower 

unglaciated mountain and hillslope areas. 

LAND USE 

The land is sparsely populated, and the pressures of 

land use on the area are minimal. In 1970, the 

population within the area was estimated at about 600 

persons (U.S. Bureau of Census, 1970), or a population 
A12 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 1.-Mean monthly temperatures, in degrees Celsius, for two 

weather-station locations within study area 

Mont h 

[M = missing] 

Stanley 

1971 

Chall is 

1971 Average 1 

January ------------------ -6.2 - 3.8 -7.6 

February------------------ -7.1 -1.4 - 3.9 

March -------------------- - 4.8 .5 1.2 

April__ __ ____ _____ __ __ __ __ _ 1.2 5.7 7. 1 

May -- --------- -- ---- -- 6.3 11.3 11.6 

June ---------------------- 9.6 15.0 15.4 

July ---------------------- 13.9 20.2 20.1 

August -------------------- 15.2 21.8 18.8 

September ---------------- 6.8 12.0 14.2 

October---- ---------------- 3.3 7.3 8.4 

November ---------------- M .6 .2 

December------------------ M -7.3 5.0 ------------------------- Average _____ _________ 6.8 6.7 

'1921- 71 period of record. 

density of about 1 person per 2,000 acres. Land 

ownership helps explain the low population density. 

The Federal Government owns about 96 percent of the 

land with about 75 percent administered by the Forest 

Service and 21 percent by the Bureau of Land 

Management. An additional 2 percent is owned by the 

State Government. The remaining 2 percent of land, 

which is privately owned, is mostly in the Stanley Basin 

and at other scattered locations along the Salmon River 

and East Fork Salmon River. 

Ranching and farming account for the livelihood of 

most of the inhabitants. Although in recent years the 

number of persons engaged in farming has decreased, 

the total acreage of land utilized is nearly constant. 

Cattle and sheep are the primary products. In former 

years overgrazing created serious erosion and forage 

problems. However, the numbers of stock, especially 

sheep, have been reduced until the balance of stock and 

forage is about in equilibrium. It is estimated that the 

number of sheep in the area is now only 10 percent of 

that number in the peak years of 1905-10. Only in 

isolated areas are examples of past or present overgrazing still evident; these areas are centered around 

Challis and in the valley of the East Fork Salmon River. 

Ranching activity is expected to remain stationary for 

at least the next several years. 

Because of the high mineralization of the area, 

mining and mineral exploration are causes of considerable activity and interest. Past mining provided even 

more activity than today, and present-day ghost towns 

like Custer and Bonanza on the Yankee Fork Salmon 

River had populations in the thousands during the late 

1800's. Relics of these past exploitations are scattered 

mine shafts, mill structures, and a maze of roads 

seemingly abandoned at midslope locations. Better 

preserved of the relics is the large hydraulic dredge on 

the Yankee Fork and the miles of mounds from dredging 

that it left. 

TABL E 2.-Mean monthly precipitation, in inches, for two weatherstation locations within study area 

Month 

January ------------------

February ------------------ March -------------------- April ---------------------- May ----------------------

June ---------------------- July ---------------------- August ___________ ________ _ 

September _______________ _ October ____________ _______ _ 

November ---------------- December __ ____ __ __ __ _____ _ 

Stanley 

1971 

2.20 

.82 

1.84 

.25 

.72 

2.48 

.44 

.38 

.97 

1.05 

1.73 

2.09 

Total ________________ 14.97 

'19 16-7 1 period of record. 

Challis 

1971 Average 1 

0.85 0.48 .26 .33 .56 .35 .66 .53 

1.05 1.11 

.99 1.18 .35 .58 

.23 .53 

.28 .60 .52 .46 

.45 .31 

1.31 .47 

7.51 6.93 

Today, several mines are still in operation and 

exploration continues, most notably in the Thompson 

Creek drainage basin. However, the establishment of 

the Sawtooth National Recreation Area in 1972 has 

imposed considerable restraint on future mineral 

exploration and mining activity within the boundaries 

of the recreation area. 

Timber in the area has been logged in the past and 

will undoubtedly continue to be in the future . Because 

only a small percentage of the total land supports 

commercial timber, lumbering is not expected to 

present seriously degrading impacts. Good timbering 

practices and care in locating and constructing logging 

roads can minimize environmental impact due to this 

use. However, any use which includes road construction 

means additional country is opened by easy access, and 

increased use caused by ·accessibility can create other 

imbalances such as the ratio of hunters to game 

animals. 

Residential use poses no serious threat to environmental stability because of the small number of 

residents. However, the high quality of the area for 

recreational uses has in the last decade resulted in the 

construction of many recreational and seasonal homes, 

especially in the Stanley Basin. If this trend continues 

uncontrolled, irreparable damage to the environmental 

quality could occur. 

Recreational use of the area has dramatically 

increased since the early 1950's and in recent years has 

increased at about 10 percent annually. Primary 

recreational uses include fishing, hunting, and 

backpacking. Generally, the area has borne well the 

impact of recreational use, but some controls clearly 

will have to be placed on some mechanized traffic, especially off-road vehicles. Management of a large part 

of the area as a National Recreation Area will by law 

place some restraints on indiscriminate use of the 

area. 
CHANNELS AND WATERS A13 

STREAM CHANNEL NETWORK 

The 1,800 square miles of the study area are drained 

by the main stem of the Salmon River and a principal 

tributary, the East Fork Salmon River, which has a 

drainage area of about 540 square miles. The entire 

drainage area of the Salmon River, about 14,000 square 

miles, is tributary to the Snake River, thence to the 

Columbia River, and into the Pacific Ocean. 

GENERAL DESCRIPTION 

The main Salmon River flows first north, then east, 

then north again diagonally across the region. Above its 

junction with Valley Creek near the town of Stanley, it 

flows in the wide alluvium-floored depression of Stanley 

Basin. At Stanley it turns eastward and flows in a 

steep-sided valley that widens somewhat downstream. 

Near its junction with the East Fork Salmon River, the 

river swings northward, and its valley widens further. 

West of Stanley Basin several of the numerous short 

tributaries of the Salmon River have lakes in their 

lower reaches. Elsewhere in the study area, lakes are 

more commonly found in alpine locations. Valley Creek 

is the largest tributary from the west or northwest. 

Below Stanley, the Yankee Fork is by far the largest 

tributary from the north. On the opposite side of the 

Salmon River is one of the larger tributaries, Warm 

Springs Creek, which enters at Robinson Bar, formerly 

a placer-mining camp and now a year-round resort. The 

East Fork Salmon River joins the Salmon River from 

the south 22 miles below Robinson Bar. Through much 

of its length, the East Fork Salmon River flows through 

country of only moderate relief. In the northeast 

quadrant of the drainage area of the East Fork Salmon 

River, streamflow runoff decreases noticeably because 

of the more arid environment. All streams entering the 

Salmon River from the east below the East Fork Salmon 

River and within the study area are ephemeral and flow 

only in response to snowmelt and thunderstorm 

activity. 

WATER-DATA STATIONS 

Thirty-nine locations were chosen as principal points 

of data collection. These stations along with other 

station descriptions are given in table 3 and are shown 

on the area map (fig. 1). Primary station identification is 

the eight-digit U.S. Geological Survey station number. 

The first two digits of this number refer to the major 

drainage basin involved. In this study, all stations have 

the prefix 13 in reference to the Snake River basin. The 

last six digits refer to individual station location with 

increasing numbers referring to locations progressively 

farther downstream. The last two digits are offset with a 

decimal to facilitate reading. 

TABLE 3.--Station number and name of primary data sites 

Figure 

plotting No. (fig. 1) 

U.S. Geological 

Survey 

station No. 

1 

2 

- - - - - - - 13-2922.00 

3 -

4 - - - - - - -

5 

6 - --- - - --- 7 

8 - --- - - - 9 --- ---------

10 

11 

12 - - - - - - 13 

14 

15 

16 --- 17 

18 - 19 ------ ------- 20 

21 

22 -- ----------- 23 

24 

25 --- ----- - 26 

27 

28 ------------ -- 29 

30 -- 31 ------- ------ 32 

33 

34 ------------- 35 

36 -------------- 37 

38 ----- ----- 39 

2924.00 

2932.00 

2934.00 

2950.00 

2956.50 

2960.00 

2965.00 

2970.00 

2971.00 

2972.50 

2973.00 

2973.10 

2973.20 

2973.30 

2973.40 

2973.50 

2973.60 

2973.80 

2973.84 

2973.88 

2973.96 

2974.00 

2974.04 

2974.18 

2974.25 

2974.40 

2974.45 

2974.50 

2974.80 

2974.85 

2975.00 

2975.30 

2976.00 

2976.70 

2976.80 

2977.00 

2980.00 

2985.00 

Station name 

Salmon River near Galena Summit. Beaver Creek near mouth. Champion Creek near mouth. Fourth of July Creek near mouth. Valley Creek near mouth. Basin Creek near mouth. Yankee Fork near mouth. Salmon River below Yankee Fork. Warm Springs Creek near mouth. Peach Creek near mouth. Slate Creek near mouth. Holman Creek near mouth. Thompson Creek above Pat Hughes Creek. Pat Hughes Creek near mouth. Thompson Creek near mouth. Squaw Creek above Bruno Creek. 

Bruno Creek near mouth. Squaw Creek near mouth. Salmon River above East Fork Salmon River. South Fork East Fork Salmon River near mouth. West Fork East Fork Salmon River near mouth. 

West Pass Creek near mouth. East Fork Salmon River below West Pass Creek. Germania Creek near mouth. Wickiup Creek near mouth. East Fork Salmon River below Wickiup Creek. Little Boulder Creek above Baker Lake. Little Boulder Creek below Boulder Chain Lakes. Little Boulder Creek near mouth. Big Boulder Creek above Jim Creek. 

Jim Creek near mouth. Big Boulder Creek near mouth. Big Lake Creek near mouth. Herd Creek near mouth. Road Creek above Horse Basin Creek. Horse Basin Creek near mouth. Road Creek near mouth. East Fork Salmon River near mouth. Salmon River near Challis. 

Station locations were selected on the basis of several 

criteria and primarily to assure continuity in interpretation of data among stations. Such continuity provides 

the difference between the collection of data at isolated 

locations and the evaluation of a river system. To this 

end, 19 stations were chosen along the main stem of the 

Salmon River upstream from the confluence with the 

East Fork Salmon River, 19 stations were chosen along 

the drainage of the East Fork Salmon River, and 1 

station was located below the confluence of the two 

rivers. 

To fully utilize available data, all existing data 

stations were incorporated into this net. These include 

three recording gaging stations, three crest-stage gage 

stations, and the five water-data stations established in 

1970 on the east flank of the White Cloud Peaks. In 

addition, three locations were chosen at sites of 

previously existing gaging stations. 

In general, a tributary approach was used in selecting 

station locations. That is, stations were located on 

tributary streams near their confluence with the 

main-stem rivers. These tributaries were selected to 

include all principal contributing streams and streams 

draining representative interfluve areas between major 

streams. To further define tributary characteristics, five 

trib:utary systems have two additional stations located 

in headwater reaches. In total, the station locations 

included 10 sites in headwater reaches of tributary 

streams, 22 sites at the mouths of principal or 

representative tributaries, 3 sites each along the main 
A14 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

stems of the East Fork Salmon River and the Salmon 

River upstream of the East Fork, and 1 site on the 

Salmon River below the confluence of the East Fork and 

at the exit from the study area. Five of the sites included 

installations of the continuous-record type. 

Primary data collection at each of the 39 sites 

included measurements of streamflow, collection of 

water samples for sediment and chemical-quality 

analysis, and surveys of channel geometry. In addition 

to the 39 primary water-data stations, other locations 

were chosen at which particular observations were 

made to further define characteristics of selected areas 

and to allow more reasonable extrapolation of data from 

primary locations. For example, detailed chemicalquality analyses are available for 55 locations, and 

during near-synoptic samplings for representative 

values of specific conductance, more than 75 locations 

were visited. Miscellaneous data, for example measurements of bedload transport, were collected at some 

of the sites. These data, some repetitive and others 

one-of-a-kind, add to the interpretation of primary data 

and will be discussed later. 

The frequency of sampling or data observation was 

variable among stations and during the period of study. 

During 1971, the first full year of the study, 8 of the 39 

primary water-data stations were selected for monthly 

observations during the period of late spring to early 

fall, generally from May to October. These eight 

locations include the five continuous-record water-data 

stations. No winter observations other than streamflow 

measurements were made. Because of long and severe 

winters in the area, data collection at many locations 

would have been difficult if not impossible. Further, 

during the winter period of November to April, many 

operable processes in the area probably remain at such a 

constant rate that the fall and spring observations 

adequately define winter characteristics. At the other 

31 primary locations, three samplings were conducted 

in 1971 during the high-, medium-, and low-water 

periods. 

All primary data observations in 1971 included 

measurements of streamflow and temperature and 

retention of water samples for analysis of suspendedsediment concentration and standard chemical-quality 

determinations. In addition, at the 8 monthly stations 

and 4 other locations, the stations on the headwater 

reaches of Little Boulder Creek and Big Boulder Creek, 

water samples were collected for analysis of 21 trace 

elements. The frequency of miscellaneous observations 

was variable. 

In 1972 all primary water-data stations were visited 

at least once, and data collection was as previously 

described. Several stations were sampled monthly. The 

trace-metal analysis was extended to five additional 

stations with at least one sampling at these new 

locations. The concentration of suspended sediment is 

one of the most variable of the water-quality parameters. For better definition of this parameter, additional 

determinations of discharge and suspended-sediment 

concentration were made for a number of the stations. 

HORTON ANALYSIS 

A drainage area, defined as that area which contributes water to a given network of stream channels, 

provides a convenient geomorphic unit to divide a larger 

area and to isolate or present on a detailed scale those 

components of hydrologic processes which contribute to 

the hydrology of the larger area. It has already been 

stated that isolation of the characteristics of individual 

or small drainage areas by data observations near the 

mouths of tributaries was the primary approach to an 

evaluation of the hydrology in the present study. The 

drainage net, or network of stream channels in a 

drainage area, relates to the pattern of contributory and 

main-stem streams. This drainage net may be described 

by such descriptive terms as trellis or palmate, but more 

importantly it may also be quantitatively described by 

the method commonly referred to as the Horton analysis 

(Horton, 1945). A quantitative description of streamchannel networks is desirable as a rationale in the 

explanation of similarities and differences in hydrologic 

behavior between two or more drainage areas. 

The salient aspect of a Horton analysis is the relation 

of certain physical characteristics, primarily stream 

length, stream number, and other features of the 

drainage basin, to stream order. Stream order is defined 

as the position of a stream in the hierarchy of channel 

network. First-order streams are unbranched fingertip 

tributaries; second-order streams receive tributaries of 

the first order, but these only; third-order streams must 

receive one or more tributaries of the second order but 

may also receive first-order streams, and so on. By using 

this system, the order of the main stream is highest. In 

computing stream length, each higher order stream. is 

considered to extend head ward to the tip of the longe~t 

tributary it drains. 

In determining stream order, consideration must be 

given to the scale of map used. Certain small-scale m&.ps 

do not show all tributaries that are shown on large-sc:-1le 

maps, and this affects designation of order. It is 

estimated that the difference in using a 1:24,000-scale 

map instead of a 1:62,500-scale map changes the order 

of the Mississippi River at its mouth from a tenth-order 

to a twelfth-order stream. Likewise, detailed planetable 

mapping of a field area (Leopold and Miller, 1956) 

indicates that four orders of streams would have to be 

added to the smallest streams appearing on maps of 

scale 1:24,000 if the smallest rills occurring in the area 
CHANNELS AND WATERS A15 

were included in the stream ordering. But, for most 

purposes, one may restrict consideration only to the 

drainage net appearing on 1:24,000-scale maps. 

On U.S. Geological Survey topographic maps, perennial streams are usually shown by solid blue lines and 

intermittent streams with dotted blue lines. Both types 

of streams should be included in the ordering system. If 

only perennial streams were included, a drainage basin 

containing only intermittent streams would, in essence, 

show 0 drainage density, although it may have a 

considerable degree of basin development. For further 

simplicity, stream length is defined as the length of the 

blue line on the map rather than attempting to extend 

the channel length to the watershed divide. 

To define the drainage net in the area of present 

study, a Horton analysis was conducted on the 542 

square miles of the East Fork Salmon River drainage 

area. Base maps used in the analysis were 1:24,000-

scale U.S. Geological Survey topographic maps with the 

exception that a small part of the southernmost extreme 

of the area was unavailable at this map scale. Rather 

than use smaller scale U.S. Geological Survey topographic maps, same-scale planimetric maps available 

from the U.S. Forest Service were utilized. As will be 

shown later, use of the Forest Service maps perhaps 

was responsible for some inconsistencies in analysis of 

this area compared with the larger area. Further, the 

absence of topographic data precluded the computation 

of some channel slopes and watershed relief data in that 

area. However, the overall area involved is sufficiently 

small that generalizations of the analysis are not 

greatly affected. 

DRAINAGE AREAS TRIBUTARY TO 

EAST FORK SALMON RIVER 

A total of 24 tributaries to the East Fork Salmon 

River have well-developed stream-channel networks 

and are of sufficient size to warrant individual analyses 

of stream order. Among these principal tributaries, 25 

interfluvial areas accounting for about 11.5 percent of 

the total drainage area were analyzed individually to 

complete the Horton-type analysis for the entire East 

Fork Salmon River drainage. Table 4 gives the 49 

drainage units analyzed; parts of drainage areas 1-5 

and 11 are those areas not included on map coverage by 

the U.S. Geological Survey. 

Table 5 summarized some of the data for the 

individual basins. A complete Horton analysis is too 

detailed to present in this report, but table 5 includes 

values of the drainage area determined by planimetering subareas for each stream. High and low values of 

altitude are the high point on the watershed divide of 

the given drainage area and the altitude of the stream 

channel at the exit from the given area. Basin order is 

TABLE 4.-Drainage basin number and name of areas included in 

Horton analysis, East Fork Salmon River 

Drainage basin name 

l_ _______________ South Fork East Fork Salmon River. 2 _______________ West Fork East Fork Salmon River. 3______ ___ East Fork Salmon River (South Fork and West Fork to Ibex Creek). 

4 Ibex Creek. 5________ East Fork Salmon River (Ibex Creek to West Pass Creek). 6 ___________ ___ West Pass Creek. 7 ________________ East Fork Salmon River (West Pass Creek to Upper Gagel. 8 _______________ East Fork Salmon River (Upper Gage to Bowery Creek). 

9__________ Bowery Creek. 10 ______________ East Fork Salmon River (Bowery Creek to Germania Creek). 

1L_______ Germania Creek. 12__________ East Fork Salmon River (Germania Creek to Deer Creekl. 13________ Deer Creek. 

14 ---------·----- East Fork Salmon River (Deer Creek to Little Wickiup Creek). 

15________ Little Wickiup Creek. 16 _______________ East Fork Salmon River (Little Wickiup Creek to Wickiup Creek) 17 _______________ Wickiup Creek. 

18 _______________ East Fork Salmon River (Wickiup Creek to Sheep Creek). 19 _______________ Sheep Creek. 

20 _______________ East Fork Salmon River (Sheep Creek to Little Boulder Creek!. 21 _______________ Little Boulder Creek. 

22_ _ _ _ _ East Fork Salmon River (Little Boulder Creek to Big Boulder Creek). 

23________ Big Boulder Creek. 24 _______________ East Fork Salmon River (Big Boulder Creek to Baker Creek). 

25________________ Baker Creek. 

26 ________________ East Fork Salmon River (Baker Creek to Bluett Creek). 27 _ Bluett Creek. 28____ ___________ East Fork Salmon River (Bluett Creek to Dry Gulch). 

29 ____ -----··----- Dry Gulch. 30 _______________ East Fork Salmon River (Dry Gulch to Big Lake Creek). 

3L_______________ Big Lake Creek. 

· 32____ ____ East Fork Salmon River (Big Lake Creek to Pine Creek). 

33____ ___________ Pine Creek. 

34________________ East Fork Salmon River (Pine Creek to Marco Creekl. 35 ________________ Marco Creek. 

36__________ East Fork Salmon River (Marco Creek to Fox Creek). 37 ________________ Fox Creek. 

38________________ East Fork Salmon River <Fox Creek to McDonald Creek). 

39____ ___________ McDonald Creek. 

40__________ East Fork Salmon River (McDonald Creek to Herd Creek). 

4L_______ Herd Creek. 42________________ East Fork Salmon River (Herd Creek to Dry Hollow). 43 _______________ Dry Hollow. 

44------------~--- East Fork Salmon River (Dry Hollow to Road Creek). 45 ________________ Road Creek. 

46 _______________ East Fork Salmon River (Road Creek to Spar Canyon). 47 ________________ Spar Canyon. 

48 ________________ East Fork Salmon River (Spar Canyon to Lower Gagel. 49 _________ c______ East Fork Salmon River (Lower Gage to Mouth!. 

the maximum stream order in the individual drainage 

area. The total number of streams and the number of 

first-order streams are determined by count, and the 

total length, Lr, of streams is the sum length of streams 

of all orders, L1 , L2 , and so forth, as measured on the map 

with a pair of dividers. 

The last column in table 5 is the drainage density and 

is defined as the quotient of the cumulative or total 

stream length and the total drainage area. It is 

expressed in miles of stream per square mile of drainage 

area. Values of drainage density can range from less 

than 1 to about 1,000, for the land surface varies from a 

nearly undissected slope to the highly rilled surfaces of 

fresh fill slopes (Smith, 1950). Values of drainage 

density for the various drainage areas contributing to 

the East Fork Salmon River range from about 1.5 to 4.5. 

The values are a little higher than most of those 

reported by Horton (1945) but are about the expected 

value for highly dissected mountainous country as 

determined from 1:24,000-scale maps. 

The last line, or total, in table 5 is the average or 

representative value of the parameters for the East 

Fork Salm.on River drainage area in its entirety. The 

overall drainage density is 2.61 miles of stream per 
A16 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 5.-Characteristics of Horton analysis compiled by individual drainage basins, East Fork Salmon River 

Drainage Altitude (ft) Number of streams Total Drainage 

~:~~!1o~ area. Basin length of density DA High Low order First streams (mi/mi2 ) (mi 2 ) Total order (mi)1 

1 -------------- 18.05 11,250 7,110 25 93 68 68.45 3.79 

2 -------------- 8.62 11,118 7,110 4 47 34 33.80 3.92 

3 -------------- 5.11 10,662 6,950 23 27 21 21.53 4.21 

4 -------------- 6.24 11,602 6,950 3 23 17 21.73 3.48 

5 --------------- 7.57 10,267 6,675 23 26 19 23.82 3.15 

6 -------------- 26.06 11,714 6,675 97 76 73.61 2.82 

7 -------------- 3.91 9,430 6,570 23 14 10 10.53 2.69 

8 -------------- 2.95 8,891 6,410 22 5 4 5.50 1.87 

9 -------------- 16.98 10,883 6,410 4 39 29 41.37 2.44 

10 -------------- .30 7,400 6,370 20 0 0 .52 1.71 

11 -------------- 48.89 11,815 6,370 5 69 123 139.34 2.85 

12 -------------- 1.32 9,276 6,330 22 2 1 2.81 2.12 

13 -------------- 1.32 9,276 6,330 2 5 4 3.53 2.67 

14 -------------- 1.82 9,423 6,275 21 3 3 4.26 2.35 

15 -------------- 1.37 9,895 6,275 2 5 4 4.02 2.93 

16 -------------- .63 7,876 6,240 21 2 2 1.81 2.87 

17 -------------- 6.50 10,248 6,240 22 8 7 11.58 1.78 

18 -------------- .17 7,526 6,220 20 0 0 .38 2.29 

19 -------------- 5.78 10,301 6,220 4 20 16 15.46 2.67 

20 -------------- 2.14 8,440 6,120 22 6 6 6.46 3.02 

21 -------------- 18.13 11,815 6,120 3 22 16 28.43 1.57 

22 -------------- 2.82 8,773 6,050 22 5 3 5.68 2.01 

23 -------------- 27.39 11,487 6,050 4 61 46 61.61 2.25 

24 -------------- .18 6,820 6,040 20 0 0 .55 3.07 

25 -------------- 2.55 8,820 6,040 3 9 7 7.75 3.05 

26 -------------- .55 6,863 6,015 20 0 0 .90 1.63 

27 -------------- 2.56 8,532 6,015 3 9 7 7.12 2.78 

28 -------------- 1.27 7,826 5,950 22 4 2 5.54 4.37 

29 -------------- 1.87 8,283 5,950 3 12 9 8.24 4.42 

30 -------------- 2.87 8,102 5,900 22 9 7 9.02 3.15 

31 -------------- 22.54 9,750 5,900 4 74 56 65.14 2.45 

32 -------------- .28 10,910 5,870 21 1 1 1.33 2.27 

33 -------------- 8.49 6,240 5,870 3 21 15 22.67 2.67 

34 -------------- .05 6,240 5,860 20 0 0 .24 4.53 

35 -------------- 4.70 8,700 5,860 3 11 7 14.27 3.03 

36 -------------- 4.77 8,220 5,770 21 10 10 15.18 3.19 

37 -------------- 4.00 9,833 5,770 2 9 8 10.69 2.67 

38 -------------- .10 7,200 5,755 20 0 0 .45 4.37 

39 -------------- 6.72 10,910 5,755 3 19 16 19.53 2.90 

40 -------------- 1.02 7,800 5,730 21 3 3 3.71 3.63 

41 -------------- 112.54 11,057 5,730 6 275 213 287.61 2.56 

42 -------------- .91 7,400 5,700 21 1 1 1.79 1.97 

43 -------------- 4.14 8,347 5,700 2 9 8 10.20 2.46 

44 -------------- 4.49 8,296 5,630 22 7 5 11.79 2.63 

45 -------------- 84.98 9,542 5,630 5 176 136 195.19 2.30 

46 -------------- 7.01 8,402 5,530 23 10 8 15.60 2.23 

47 -------------- 34.26 9,391 5,530 4 73 55 86.62 2.53 

48 -------------- .85 7,559 5,520 21 2 2 2.95 3.47 

49 -------------- 10.09 7,827 5,350 22 18 14 26.10 2.59 

Total or average -- 541.86 11,815 5,350 7 1,441 1,098 1,416.41 2.61 

1

Reftects topographic map standards and not true stream lengths to the accuracy implied by significant figures. 2

Contains part of seventh-order main stem, East Fork Salmon River. 

square mile of drainage area, or 1,416 miles of streams 

in 542 square miles of area. Drainage density is the 

most useful of the parameters for comparison of 

stream-channel networks among various drainage 

basins and their deviations from the average value for 

the entire drainage area. The first several drainage 

basins in table 5 are extreme values of drainage density. 

However, for these basins a different map base was used 

for determining stream length, and thus values of 

drainage density are higher for this area than is 

average for the region. Because these drainage basins 

account for less than 10 percent of the entire area, 

values of drainage density for these areas, even if 

somewhat inconsistently high, do not greatly affect 

average values. Other higher-than-average values of 

drainage density occur for very small drainage areas. 

As extreme examples, drainage densities for interfluvial areas 34 and 38 in table 5 have values in excess of 4 

even though a part of the main-stem East Fork Salmon 

River is the only stream length involved. Thus, for very 

small drainage areas, an insufficient sampling size may 

yield valid, but inconsistent, values. 

The lowest drainage density value is for drainage 

basin 21, Little Boulder Creek. It appears that this 

drainage basin is a victim of topography and map scale. 

Confining mountains and ridgelines combine to create a 

long, narrow drainage area with primary drainage by 

the centrally located main-stem channel. Map scale is 
CHANNELS AND WATERS A17 

such that few first-order streams are shown contributing to the main stem, especially in the lower part of the 

drainage basin. The total number of streams counted is 

the least per unit of drainage area for any of the 

drainage basins excluding interfluvial areas and results 

in a small value of total length of streams and thus in 

drainage density. 

Further attempts to explain differences in drainage 

density were generally unsuccessful. Drainage density 

was considered a function of localized geology, but 

because so much of the total area is underlain by the 

Challis Volcanics, no correlation could be found. 

Topography was analyzed by plotting drainage density 

against maximum, minimum, and midpoint altitudes 

occurring within each basin. Likewise total basin relief 

was considered, but none of these measures of topography correlated with values of drainage density. The 

size of drainage basin using drainage area in square 

miles, degree of channel-network development using 

basin order, and aspect of drainage using principal flow 

direction in degrees from north also failed to indicate 

correlation with drainage density. Finally, no significant trend in drainage density is detectable as one 

traverses generally from southwest to northeast in the 

area. Precipitation and thus runoff decrease to the 

northeast, but the more arid basins tend to have the 

same degree of channel development as the wetter 

areas. This lack of correlation has been noted before. 

Although early textbooks on physiography commonly 

attributed differences in drainage density to differences 

in rainfall or relief, Horton (1945) pointed out that other 

factors are far more important than rainfall or relief in 

determining drainage density. Such factors include 

infiltration capacity of the soil and initial resistivity of 

the terrain to erosion factors not readily available for 

study. 

A summary of stream ordering data for the entire 

area is given in table 6. The graphs of figures 7-9, using 

the data of table 6, illustrate the essential features of 

the Horton analysis. These graphs show that stream 

order is related to the number of streams, channel 

length, and drainage area by simple geometric relations; that is, the value of each of the variables at any 

given stream order is a constant multiple of the value at 

the next-lower order. For the number of streams, the 

reciprocal of this multiple is termed the bifurcation 

ratio, and its value from figure 7 is about 4.0; or for 

example, if there were 1 third-order stream in a given 

basin, there would be about 4 second-order streams and 

16 first-order streams. Values of the ratio for the other 

variables may also be determined. The stream-length 

ratio is about 2.0, and the drainage-area ratio is about 

3.6. 

The altitude and slope data of table 6 may also be 

graphed as in figures 10-12. The watershed-relief and 

channel-drop data are respectively defined as the 

difference in altitude from the channel at its exit from 

the individual basin to (1) the high point in the 

watershed and (2) the channel altitude at its headwater 

(top of blue line on topographic map). The relations of 

stream order to watershed relief and channel drop are 

not single-line relations as before, but rather at a given 

value of stream order (and therefore at some given value 

of drainage area and stream length), the change in 

altitude difference decreases to a much lesser rate. The 

reason for the break in rate of change is apparent 

because only so much total relief exists in an area, and 

after the high peak of an area is included in the analysis, 

further increases in relief occur only by down valley 

decrease in stream altitude. For watershed relief, this 

decrease occurs at the inclusion of a fifth-order stream 

or a drainage area of about 50 square miles (see fig. 10) 

and for channel drop at a stream order of three or a 

drainage area of about 3 square miles. Figure 12, the 

relation of stream order to channel slope, is determined 

by combining figures 8 and 11. The slope data of figure 

12 define the characteristic concave profile of a typical 

stream, and the break in slope accents the concavity 

between very steep headwater reaches of channel and 

relatively flat lower reaches. 

An alternative to the compilation in table 6 is a 

Horton-type analysis in categories by size of drainage 

area. Table 7 is such a compilation for sizes of drainage 

areas each greater than the previous size by a factor of 

two. For each drainage-area size category, the average 

value of several basin or channel parameters is 

provided. These data may be plotted against size of 

drainage area to furnish graphs which may be more 

TABLE 6.-Summary of Horton analysis data, East Fork Salmon River 

Stream order 

Parameter 2 3 4 5 6 

Number 1,098 267 57 13 4 1 1 

Area (mi2) ____ .213 .801 3.228 19.225 49.818 112.543 541.836 

Length (mi) .62 1.34 3.18 6.71 12.84 20.85 42.43 

Slope (ft/ft) ____ 1 .2561 1 .1793 .1621 .1052 .0530 .0342 .0230 

Relief (ft) ______ 1 1,068 1 1,951 2,986 3,929 4,808 5,327 6,465 Drop (ft) ______ 1649 1 1,370 2,269 3,058 3,284 3,620 5,150 

1Does not include data from basins 1-5, 11. 
A18 

8 

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HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

I I I I I I I I I I I I I I 1 TTl I I I I I I 

-

~ East Fork Salmon River -

~ ~urcation ratio Nn1Nn+ 1 = 4.0 

'-' ........ 

~ ~ -

~ ~ 

~ 

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I I I I I I I I I I I I I I I I I I I I I I I I 

10 100 1000 10,000 

NUMBER OF STREAMS, N 

FIGURE 7.-Relation of number of streams to stream order. 

I I I T ! I I I I I I I T T T T-IT I I I I I I 

v· -

~ 

East Fork Salmon River l7 

/ -

/ ~ -

v '-' 

-

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v V'""" 

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1/ I I I I I I I I l I I I I I I I I I I I I I 

10 100 1000 

STREAM LENGTH, IN MILES 

FIGURE B.-Relation of length of streams to stream order. 
a: 

w 

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CHANNELS AND WATERS A19 

I I I I I I I I I I I 

v ~ 

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East Fork Salmon River 

~ v 

v -

/ 

v '-

v -

~ v 

v ~ 

-

I I I I I I I I I I I I I I I I I I I I I I I I 

10 100 1000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 9.-Relation of drainage area to stream order. 

I I I I I I I I I I I I 10 I I I I I I I I I I I 

-

I 

-

I -

I 8 

j- -

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East Fork Salmon River 

J 

v 

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1000 

WATERSHED RELIEF, IN FEET 

~ -

-

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10,000 

a: 

w 

0 

a: 

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-

2 

-

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100 

East Fork Salmon River I -

j~ 

-

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1000 10,000 

CHANNEL DROP, IN FEET 

FIGURE 10.-Relation of watershed relief to stream order. FIGURE H.-Relation of channel drop to stream order. 
A20 

10 

a: 

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0 

a: 

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Drainage area 

size category 

(mi2) 

-

8 

6 

-

4 

-

2 

f0 

0.001 

0.01- .02 

.02- .04 

.04- .08 

.08- .16 

.1&- .31 

.31- .62 

.62-1.25 

1.25-2.5 

2.5- 5 

5- 10 

10- 20 

20- 40 

40- 80 

80-160 

160-320 

320-640 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

I I I I I I I 

"" 1\. 

~ 

~ ~ 

East Fork Salmon River 

~~ 

" ~ 

I I I I I I I I I I I I I I I I I I 

0.01 0.1 

CHANNEL SLOPE, IN FEET PER FOOT 

FIGURE 12.-Relation of channel slope to stream order. 

TABLE 7.~haracteristics of Horton analysis compiled by size of drainage area, East Fork Salmon River 

Average Average Average 

drainage stream stream Average Average Total 

area, len_rh, slope, channel watershed number 

DA Sm drop relief streams (mi2) (mi) (ft/ftl (ft) (ft) 

0.016 0.16 10.4307 1387 1 799 13 

.031 .19 1 .3895 1 477 1 846 43 

.063 .35 1 .3435 1664 1 1,121 174 

.119 .47 1.2992 1735 1 1,296 345 

.227 .67 1.2435 1858 11,465 361 

.427 .99 1 .2006 11,012 1 1,710 254 

.922 1.50 .1697 11,276 12,019 142 

1.680 2.31 .1553 1,809 2,576 49 

3.238 3.17 .1258 2,083 2,816 27 

6.822 4.99 .1038 2,729 3,662 17 

15.747 7.45 .0841 3,193 4,083 6 

31.030 10.58 .0585 3,279 4,381 6 

48.886 14.06 .0381 2,830 5,445 1 

98.760 17.85 .0341 3,190 4,620 2 

0 

541.836 42.43 .0230 5,150 6,465 1 1Does not include data for basins 1-5, 11. 

-

-

Percentage 

of streams 

0.90 

2.98 

12.07 

23.94 

25.05 

17.63 

9.85 

3.40 

1.87 

1.18 

.42 

.42 

.07 

.14 

.00 

.07 
CHANNELS AND WATERS A21 

easily visualized than those of figures 7-12. As an 

example, stream length is plotted as a function of size of 

drainage area in figure 13, whereas stream length is the 

average length of the highest order stream in each size 

category of drainage area tabulated in table 7. As a 

numerical example, the average 30-square-mile drainage area will have a principal stream about 10 miles in 

length. Data of table 6 can also be plotted in the manner 

of figure 13, and for stream-length and drainage-area 

data, the plotted points are also shown in figure 13. With 

little scatter of the data, the plotted points of figure 13 

define a relation whose equation is 

L=l.5 DA 0·

55. 

On the average, a drainage basin of 1 square mile will 

produce enough overland flow and erosion to maintain a 

principal channel length of 1.5 miles. The exponent in 

the preceding equation has a value of 0.55. If basin 

width and length increased in the same proportion as 

basin size, the exponent would be 0.50. The value of0.55 

indicates that length increases more rapidly than 

width, resulting in typically elongated basin shapes. 

Interestingly enough, however, the average value of the 

exponent for several regions of the United States 

generally lies within 0.6--0.7 and indicates that basin 

elongation in the East Fork Salmon River drainage area 

is not as pronounced as for many other regions. The less 

elongated shapes in the present study are attributed to 

the confining nature of surrounding mountains and 

intervening ridges. 

The data of table 7 lend themselves to one particularly interesting analysis. The last two columns of the 

table give the total number of streams and percentage of 

grand total of streams included in each size category of 

drainage area. These data are plotted with the 

bar-graph distribution shown in figure 14 where each 

segment of the graph indicates the percentage of 

streams in a given drainage area size category. The 

100 ~----~--.-.-.-~~~----~--~~~~~~.-----~--.-~~~~,-----,---,-,-.-,,nn 

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L=1.5 DA 0

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EXPLANATION 

+ Compilation by stream order (table 6) 

0 Compilation by drainage area (table 7) 

100 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 13.-Relation of drainage area to stream length for tributaries to East Fork Salmon River. 

1000 
A22 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

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::::::::·::::::::r:·r:r:r:r:r:r:r:r:llililillll.~!ilo:-:'irr:·lll,...,iii! .... :! ... ······ .................... . ...................................... 

... ...... .......................... .. ...................................... 

...................................... ... ...... ··························· .. .. ....... ........................... .. ......... .......... ···························· ........................... . . ...................................... 

. ........ ........................... . ....................................... ......... ........................... .. ....................................... 

........................................ .......... ··························· .. ....................................... ·········· ............................. . .......... .......... ............................. ··························· .. 

. .... . ::::::::::::::::::::::::::::::::::::: ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::!-:-:::':""'::::·:::,...,I .... \:::::::::::::.:·:·:·:· ... ·.·:. 

0 ~~~~~~~~~~~~~~~~~~~~~~~~~-.------~----~~_j 

0.01 0.1 1 10 100 1000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 14.-Percentage of streams as a function of size of drainage area. 

bell-shaped curve represents a smoothing of this 

distribution. A distinct distribution of stream .frequency 

may be observed as well as the greatly extended tail of 

the curve which covers the larger drainage areas. Of the 

total number of streams, 25 percent have drainage 

areas in the single-size category of 0.16-0.31 square 

mile, while 65 percent of the streams have drainage 

areas less than0.31 square mile. Further, 97 percent of 

the total number of streams have drainage areas less 

than 5 square miles. The percentage distribution of 

streams would be different when measured on maps of 

larger or smaller scale, but the 1:24,000-scale maps 

used in this analysis are believed to realistically portray 

the drainage net. The large percentage of very . small 

streams is surprising when one considers that probably 

97 percent of the effort to obtain stream data is spent on 

streams with drainage areas greater than 5 square 

miles. Apparently, economic benefits dictate that most 

investigative effort be applied to larger rivers, but the 

student of river morphology and behavior would do well 

to concern himself with the smaller streams. 

MAIN-STEM EAST FORK SALMON RIVER 

The discussion of the Horton analysis has thus far 

concerned itself with the characteristics of the individual basins analyzed. The data can be accumulated in 

downstream order to discuss behavior with increasing 

size of drainage area. Table 8 gives some of the basin 

and stream characteristics as they accumulate along 

the East Fork Salmon River. For greater detail at the 

small drainage areas, the first several lines in table 8 

are values for subareas of drainage basin 1, the 

headward extension of the East Fork Salmon River. 

Altitude data may be plotted as in figure 15 to 

illustrate the long profile of the river channel. An 

accelerated decrease in channel slope occurs at a 

downstream distance of about 5 miles on the East Fork 

Salmon River. This distance corresponds to about where 

the East Fork Salmon River is a third-order stream and 

thus also corresponds to the point in figure 12 which 

coincides with the break on the channel slope versus 

stream order relation. The same trend is apparent from 

the slope data of table 8. Slope values of incremental 

reaches of the East Fork Salmon River downstream 

from drainage basin 1 are all less than 0.02 foot per foot 

while upstream reaches are greater than 0.05 foot per 

foot. Because the upstream reaches are steep, the 

overall gradient decreases continually, even though 

lower incremental reaches of the river have about the 

same slope and thus a straight line profile. Close 
CHANNELS AND WATERS A23 

TABLE B.-Characteristics of Horton analysis accumulated downstream along East Fork Salmon River 

Channel Drainage Channel Drainage length, L area, DA altitude basin No. (mil (mi 2 l (til 

3.00 3.085 8,250 

4.32 8.356 7,900 

5.62 13.616 7,350 1 ________________ 6.91 18.046 7,110 2 ________________ 6.91 26.665 7,110 3 ________________ 9.21 31.778 6,950 4 ________________ 9.21 38.018 6,950 

5---------------- 12.41 45.588 6,675 6 ________________ 12.41 71.650 6,675 

7---------------- 13.99 75.559 6,570 g ________________ 16.09 78.508 6,410 9 ________________ 16.09 95.489 6,410 10 ________________ 16.61 95.793 6,370 11 ________________ 16.61 144.679 6,370 12 ________________ 17.41 146.002 6,330 

13---------------- 17.41 147.325 6,330 14 ________________ 18.34 149.140 6,275 15 ________________ 18.34 150.510 6,275 16 ________________ 19.02 151.140 6,240 

17---------------- 19.02 157.640 6,240 18 ________________ 19.40 157.806 6,220 19 ________________ 19.40 163.590 6,220 20 ________________ 21.24 165.730 6,120 21 ________________ 21.24 183.860 6,120 

22---------------- 22.51 186.683 6,050 23 ________________ 22.51 214.073 6,050 24 ________________ 23.06 214.252 6,040 

25---------------- 23.06 216.797 6,040 26 ________________ 23.96 217.348 6,015 

27---------------- 23.96 219.908 6,015 28 ________________ 26.04 221.174 5,950 29 ________________ 26.04 223.040 5,950 30 ________________ 27.50 225.908 5,900 31 ________________ 27.50 252.444 5,900 32 ________________ 28.20 252.721 5,870 

33---------------- 28.20 261.214 5,870 34 ________________ 28.44 261.267 5,860 

35---------------- 28.44 265.971 5,860 36 ________________ 31.08 270.737 5,770 37 ________________ 31.08 274.736 5,770 38 ________________ 31.53 274.840 5,755 39 ________________ 31.53 281.564 5,755 40 ________________ 32.32 282.585 5,730 41 ________________ 32.32 395.128 5,730 42 ________________ 33.28 396.037 5,700 43 ________________ 33.28 400.177 5,700 

44 ---------------- 35.13 404.662 5,630 45 ________________ 35.13 489.639 5,630 46 ________________ 37.80 496.645 5,530 47 ________________ 37.80 530.902 5,530 48 ________________ 38.15 531.751 5,520 49 ________________ 42.43 541.836 5,350 

inspection of the profile in figure 15 reveals that the 

extreme lower end of the profile may be oversteepened 

relative to the remainder ofthe lower halfofthe profile. 

That is, the lower several miles of the East Fork Salmon 

River appear to have a slightly convex profile, while the 

remainder of the general profile is concave. If indeed 

this is true, it relates to downcutting by the lower East 

Fork Salmon River to reach the base level imposed by 

the main stem of the Salmon River, a condition 

reflective of general downcutting by the Salmon River 

at a rate that could not be maintained by upper reaches 

of the East Fork Salmon River. 

Channel 

Channel slope, Sm Total Drainage 

relief (ft/ftl length of density streams,Lr (ftl (mi/mi2 l 

Reach Total (mil 

2,250 0.1420 0.1420 10.55 3.42 

2,600 .0502 .1140 32.20 3.85 

3,150 .0801 .1062 49.20 3.61 

3,390 .0352 .0929 68.45 3.79 

3,390 .0929 102.25 3.83 

3,550 .0132 .0730 123.78 3.90 

3,550 .0730 145.51 3.83 

3,825 .0163 .0584 169.33 3.71 

3,825 .0584 242.94 3.39 

3,930 .0125 .0532 253.47 3.35 

4,090 .0144 .0481 258.97 3.30 

4,090 .0481 300.34 3.15 

4,130 .0146 .0471 300.86 3.14 

4,130 .0471 440.20 3.04 

4,170 .0095 .0454 443.01 3.03 

4,170 .0454 446.54 3.03 

4,225 .0112 .0436 450.80 3.02 

4,225 .0436 454.82 3.02 

4,260 .0097 .0424 456.63 3.02 

4,260 .0424 468.32 2.97 

4,280 .0100 .0418 468.59 2.97 

4,280 .0418 484.05 2.96 

4,380 .0103 .0391 490.51 2.96 

4,380 .0391 518.94 2.82 

4,450 .0104 .0374 524.62 2.81 

4,450 .0374 586.23 2.74 

4,460 .0034 .0366 586.78 2.74 

4,460 .0366 594.53 2.74 

4,485 .0053 .0355 595.43 2.74 

4,485 .0355 602.55 2.74 

4,550 .0059 .0331 608.09 2.75 

4,550 .0331 616.33 2.76 

4,600 .0065 .0317 625.35 2.77 

4,600 .0317 690.49 2.74 

4,630 .0081 .0311 691.82 2.74 

4,630 .0311 714.49 2.74 

4,640 .0079 .0309 714.73 2.74 

4,640 .0309 729.00 2.74 

4,730 .0065 .0288 744.18 2.75 

4,730 .0288 754.87 2.75 

4,745 .0063 .0285 755.32 2.75 

4,745 .0285 774.85 2.75 

4,770 .0060 .0280 778.56 2.76 

4,770 .0280 1,066.17 2.70 

4,800 .0059 .0273 1,067.96 2.70 

4,800 .0273 1,078.16 2.69 

4,870 .0072 .0263 1,089.95 2.69 

4,870 .0263 1,285.14 2.62 

4,970 .0071 .0249 1,300.74 2.62 

4,970 .0249 1,387.36 2.61 

4,980 .0054 .0247 1,390.31 2.61 

5,150 .0075 .0230 1,416.41 2.61 

The increase in drainage area with channel length 

along the East Fork Salmon River is also shown in 

figure 15. As is readily apparent, large increments of 

drainage area are added at each point where a tributary 

joins the main stem. Important increments of drainage 

area contribute directly to the main channel, but the 

largest increments of drainage area are contributed at 

several principal tributary junctions. At least to the 

scale of graphs presented in figure 15, the abrupt 

inclusion of large drainage areas and thus the addition 

of large volumes of water does not abruptly influence 

the general profile of the main-stem river. 
A24 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

11,000 600 

10,000 EXPLANATION 500 

_J • w Altitude 

> w 0 Drainage area en _J w <( ...J 

w 

en 9000 400 ~ 

z w <( a: w <( 

~ ::::) 

0 w en 

> 0 ~ 8000 300 CD 

<( <( 

1- w w a: w <( 

u. w 

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<( 

u.i 7000 200 z 

0 ~ ::::) c: 

1- 0 

~ <( 

6000 100 

0 

0 5 1 0 15 20 25 30 35 40 45 

EAST FORK SALMON RIVER, STREAM LENGTH, IN MILES 

FIGURE 15.-Altitude and drainage area as a function of downstream distance along East Fork Salmon River. 

Cumulative values of stream length and drainage 

area along the main-stem East Fork Salmon River may 

also be plotted on log-log coordinate paper as was done 

in figure 13 for individual values of stream length and 

drainage area. This relation is shown in figure 16. The 

series of discontinuous upward steps is still apparent as 

various tributaries add their drainage area, but the 

effect is damped by the logarithmic scale of the graph. 

The straight line relation shown in figure 16 has the 

same values of coefficient and exponent as the relation 

of figure 13. In figure 16, the relation becomes an 

envelope curve because the original relation was 

determined inclusive of all area contributing to drainage areas of given sizes. 

Values of drainage density in table 8 show a general 

decrease in magnitude as data accumulate downstream 

along the East Fork Salmon River. This trend, however, 

is perhaps more apparent than real. It is more likely 

that the first several values of drainage density in the 

table are inconsistenly high compared with the others, 

for the first values were obtained from maps of different 

standards. As previously discussed, most drainage 

basins have values of drainage density randomly higher 

or lower than the mean value for the area, and further, 

the mean value is not greatly affected by the inclusion of 

several inconsistent values. It is only a chance 

happening that the data obtained from maps of different 

standards appear first in table 8 and create the 

impression of downstream decrease in values of 

drainage density. By way of comparison, if drainage 

density were to be computed in the upstream direction, 

the initial drainage density would be 2.59, the 

cumulative or mean value would remain at 2.61, and in 

no instance would the progressive accumulative mean 

value deviate by more than 10 percent from the mean 

value. 

SUMMARY DISCUSSION OF DRAINAGE NET 

The East Fork Salmon River is a seventh-order 

stream, has a length of about 42 miles, and has a 

drainage area of about 542 square miles. The bifurcation ratio, or multiple number of each lower order 

stream, is 4.0, or more exactly, the drainage net of the 

East Fork Salmon River consists of 1,441 different 

stream channels. The average length of a first-order 

stream is about 0.6 mile. The length ratio, or multiple of 

length of each higher order stream, is 2.0; thus a total of 

about 1,416 miles of stream channel are within the 

drainage area of the East Fork Salmon River. The 

drainage area ratio is about 3.6, yielding an average 

size drainage area for first-order streams of about 0.2 

square mile. These data combine to indicate that about 
CHANNELS AND WATERS A25 

100 I I I I I I I I I 

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2 

1 I I I I I I I I I I I I I I I I 

1 2 5 10 20 50 100 200 500 1000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 16.-Stream length as a function of drainage area for the main-stem East Fork Salmon River. 

90 percent of the streams have drainage areas less than 

1 square mile and about 97 percent of the streams have 

drainage areas less than 5 square miles. In these computations, the size of drainage area is inclusive of all 

upstream area contributing to the stream. Channel 

slopes are generally very steep for third-order streams 

and smaller. Larger streams, those with drainage areas 

greater than about 5 square miles, have less steep 

slopes. 

This quantitative description of the East Fork 

Salmon River drainage area should be transferable to 

other regions within the upper Salmon River area, for 

cursory examination of topographic maps does not 

indicate any areal differences in drainage patterns or 

densities. The drainage-net data thus provide considerable insight into the following discussions of hydrologic characteristics of various rivers of various 

sizes. 

COLLECTION AND ANALYSIS OF STREAMFLOW 

DATA 

All sites where data observations and measurements 

were made are referred to as water-data stations. The 

principal water-data stations are presented in table 3, 

and brief descriptions in table 9. These stations include 

active recording-hydrograph gaging stations, usually 

with monthly streamflow observations to maintain 

updated records; crest-stage gages with devices to 

record peak stages of flow and generally with sufficient 

streamflow observations to provide a relation of gage 

height to water discharge; and miscellaneous stations 

where only discharge measurements are made. 

For many purposes of streamflow analysis, 

continuous-record hydrographs or values of daily mean 

discharge are necessary. Extensive data of this type are 

available from the records of discontinued but previously continuous-recording gaging stations. Later sections of this report utilize these records, and in 

subsequent tables of data, these stations are identified 

by their r~spective U.S. Geological Survey gagingstation number. Table 10 identifies the active and 

discontinued gaging stations whose streamflow records 

were used .in this study but whose locations may not 

have been data-collection sites. It also gives several 

crest-stage gage stations because those stations provide 

data useful in determining flow frequency. Overall 

utility of station streamflow data my be limited by the 
A26 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 9.--Summary of water-data station information 

U.S. Geological 

Survey Latitude Longitude 

station No. I

0

NI I

0

WI 

13-2922.00 ---------- 43°53'03" 114°45'47" 

2924.00 ---------- 43°55'10" 114°48'48" 

2932.00 ---------- 44°01'39" 114°49'54" 

2934.00 ---------- 44°01'48" 114°49'54" 

2950.00 ---------- 44°13'21" 114°55'49" 

2956.50 ---------- 44°15' 4 7" 114°49'03" 

2960.00 ---------- 44°17'15" 114°43'11" 

2965.00 ---------- 44°16'06" 114°43'55" 

2970.00 ---------- 44°14'50" 114°40'11" 

2971.00 ---------- 44°15'50" 114°38'50" 

2972.50 ---------- 44°15' 19" 114°33'48" 

2973.00 ---------- 44°14'52" 114°31'43" 

2973.10 ---------- 44°17'26" 114°33'25" 

2973.20 ----------- 44°17'18" 114°32'49" 

2973.30 ---------- 44°15'36" 114°30'50" 

2973.40 ---------- 44°18'05" 114°28'36" 

2973.50 ---------- 44°17'56" 114°28'50" 

2973.60 ---------- 44°15'35" 114°27'27" 

2973.80 ----------- 44°15'59" 114°19'34" 

2973.84 ---------- 43°55'44" 114°33'15" 

2973.88 ---------- 43°55'46" 114°33'18" 

2973.96 ---------- 43°59'07" 114°29'15" 

2974.00 ---------- 44°00'23" 114°28'48" 

2974.04 ---------- 44°02'21" 114°27'40" 

2974.18 ---------- 44°03'42" 114°27'43" 

2974.25 ---------- 44°04'58" 114°26'56" 

2974.40 ---------- 44°03'30" 114°34'27" 

2974.45 ---------- 44°03'56" 114°32'31" 

2974.50 ---------- 44°05'57" 114°26'56" 

2974.80 ---------- 44°07'47" 114°31'33" 

2974.85 ---------- 44°07'54" 114°31'43" 

2975.00 ---------- 44°05'58" 114°26'24" 

2975.30 ---------- 44°09'30" 114°22'43" 

2976.00 ---------- 44°09'11" 114°17'54" 

2976.70 ---------- 44°10'36" 114°12'03" 

2976.80 ---------- 44°10'40" 114°12'07" 

2977.00 ---------- 44°11'15" 114°17'09" 

2980.00 ---------- 44°13'29" 114°17'06'' 

2985.00 ---------- 44°22'43" 114°15'18" 

TABLE 10-Water-data stations with records available for streamflow 

frequency and duration analyses 

U.S. Geological 

st~ti~~e~o. 

Period of record Station name 

Continuous-record stations 

13--2925.00 - ________ 1940--53 2930.00 __________ 1940--53 

2950.00 __________ 1921-72 2955.00 __________ 1925--60 2960.00 __________ 1921-48 2965.00 __________ 1921-72 2973.50 __________ 1971-72 

297 4.50 --------- _1970--72 2975.00 ___________ 1926-30 2980.00 __________ 192~39 

2985.00 - _________ 192~ 72 

Salmon River near Obsidian, Idaho. Alturas Lake Creek near Obsidian, Idaho. Valley Creek at Stanley, Idaho. Salmon River below Valley Creek at Stanley, Idaho. Yankee Fork Salmon River near Clayton, Idaho. Salmon River below Yankee Fork near Clayton, Idaho. Bruno Creek near Clayton, Idaho. Little Boulder Creek near Clayton, Idaho. Big Boulder Creek near Clayton, Idaho. East Fork Salmon River near Clayton, Idaho. Salmon River near Challis, Idaho. 

Crest-stage gage stations 

13--2924.00 __________ 1963--72 2971.00 __________ 1962-72 

2973.00 __________ 1962-72 2983.00 __________ 1962-72 

Beaver Creek near Stanley, Idaho. Peach Creek near Clayton, Idaho. Holman Creek near Clayton, Idaho. Maim Gulch near Clayton, Idaho. 

length of record. The period of operation of each station 

is given in table 10. 

Discharge-measurement notes, hydrograph-recorder 

charts, and other field data obtained from routine 

operation of water-data stations are on file in the Idaho 

District Office, U.S. Geological Survey. Summaries of 

Drainage Channel slope 

area, Altitude DA lftl Surveyed, Map, 

lmi 2 1 Ss Sm 

lft/ftl lft/ftl 

17.5 7,340 0.0118 0.0133 

15.5 7,125 .0152 .0161 

17.5 6,820 .0162 .0230 

18.5 6,795 .0263 .0303 

147 6,220 .0040 .0030 

51 6,060 .0099 .0101 

195 6,060 .0036 .0122 

802 5,900 .0041 .0091 

79 5,900 .0089 .0205 

8.0 6,000 .0510 .0649 

31.0 5,660 .0260 .0253 

6.0 5,600 .0520 .0631 

22.5 6,040 .0128 .0244 

2.5 6,000 .0810 .0909 

30.0 5,650 .0148 .0199 

60 5,780 .0107 .0124 

6.0 5,840 .0369 .0529 

80 5,550 .0124 .0137 

1,170 5,350 .0046 .0036 

18.05 7,300 .0157 .0458 

8.62 7,300 .0307 .0523 

26.06 6,705 .0208 .0275 

75.56 6,570 .0106 .0126 

48.89 6,375 .0130 .0252 

6.50 6,260 .0755 .2040 

163.59 6,190 .0143 .0122 

2.83 8,840 .0009 .0399 

9.94 8,090 .0025 .0149 

18.13 6,160 .0460 .0758 

12.70 7,230 .0495 .0522 

3.43 7,320 .0625 .1033 

27.39 6,150 .0350 .0541 

26.54 6,035 .0604 .0329 

112.54 5,750 .0169 .0194 

37.86 6,120 .0165 .0505 

32.59 6,160 .0130 .0280 

84.98 5,650 .0356 .0344 

531.75 5,500 .0080 .0066 

1,800 5,165 .0018 .0031 

streamflow data my be found in publications of the U.S. 

Geological Survey (1956, 1963, 1971), and annual data 

since 1966 may be found in other Survey publications 

(U.S. Geological Survey, 1966-72). 

STREAM-GAGING MEASUREMENTS 

Measurements to determine quantity of streamflow, 

though one of the more routine observations made by 

the Geological Survey, provide a basis for all subsequent interpretation and presentation of data in this 

report. Streamflow measurements define the relation of 

water discharge to gage height or water-surface 

altitude. This relation allows computations of daily 

mean discharge from records of water-surface altitudes 

at continuous-record stations. The tabulation of mean 

daily discharges allows statistical manipulation of data 

to describe streamflow characteristics. 

Values of streamflow are equally important for an 

adequate description of water quality. For perhaps a few 

officials, such as public health officers, it may be that 

constituent concentration is adequate for such purposes 

as defining toxicity levels. However, as will be shown 
CHANNELS AND WATERS A27 

later, values of concentration generally are dependent 

on values of discharge. Thus streamflow characteristics 

become necessary to define how often and by how much 

various concentration levels are exceeded. Streamflow 

also becomes important with consideration of magnitude. A small but highly contaminated tributary 

stream may have less overall impact on water quality 

than a larger but only moderately contaminated 

stream. Otherwise stated, values of streamflow are 

necessary for determination of dissolved and suspended 

loads transported by the streams. 

Measurements of streamflow were made at every 

water-data station at each time of data collection. A 

nearly complete list of discharge measurements made 

in the 2-year period 1971-72 is included as part of the 

HSummary of data," tables 40, 41, and 42, at the end of 

this report. 

STREAMFLOW RUNOFF 

During the 3-year period 1970-72, five water-data 

stations were operating as partial- or continuous-record 

stations. Hydrographs of water discharge throughout 

these years are illustrated in figures 17-21. Peak 

discharges were generally highest in 1972 and lowest in 

1970. Annual volume of runoff, represented by the area 

under the curves in figures 17-21, was generally 

greatest in 1971 and lowest in 1970. Comparison of the 

yearly volume of runoff to values of mean annual runoff 

for those stations with adequate record to define a mean 

value indicates that the year 1970 had about 10 percent 

greater runoff than the average year. Since this was the 

lowest annual volume of runoff for any of the 3 years, all 

years during the principal period of study had higherthan-average runoff. 

Mean annual runoff in the study area is controlled 

mostly by the amount of winter precipitation falling as 

snow. In 1972, a warmer-than-average spring, perhaps 

aided by a few warm rains, created a sufficient rate of 

snowmelt to produce the highest peak rate of runoff of 

the 3 years, although 1971 had the greatest volume of 

runoff. 

1400 I I I 1111 II II IIIII IIIII IIIII 

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Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 

c. 1972 

FIGURE 17.-Streamfl.ow hydrograph, 1970-72, Valley Creek at 

Stanley, Idaho. A, 1970. B, 1971. C, 1972. 

Peak discharges in the years 1970-72 had recurrence 

intervals on the order of 3 years, 8 years, and 25 years, 

respectively. The last value represents a discharge that 

can be expected to occur four times in a century, a 

relatively rare eccurrence. Such a rare discharge does 

not affect any of the hydraulic measurements made 

during its occurrence but rather can be considered a 

fortunate happening which allowed data to be collected 

over an extended range in discharge. For some 

water-quality aspects, slight effects may occur if one 

considers that the consistently high runoff may be , 

likened to a flushing action in the river system. 

However, as will be shown later, the chemical composition of stream water is so dependent on magnitude and 

: frequency of streamflow that the extended range of 
A28 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

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"'--- ~~~~ ""' .J'o. 

I Ill II I Ill Ll_ __lUll _LU II UJJ I 

A. 1970 

Ill 1111 I'"" IIIII IIIII IIIII IIIII IIIII I II II 

Af I y 

~ t Station 13-2965.00 

1/ v 1\ 1/ 

~ ~ / IIIII IIIII IIIII I IIIII 1111 I 1111 Ill II I 

B. 1971 

II II IIIII IIIII II II IIIII IIIII IIIII 

IV 

\ Station 13-2965.00 

' p \I\ ~ \ (Record interrupted) J '-... 

lllll I, I Lll,ll II I 'Ill I I IIIII IIIII Ill I IIIII IIIII IIIII 

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. 

c. 1972 

IIIII IIIII 

I ill 

~ ~ 

IIIII IIIII 

~ ~ I 

IIIII I Ill 

IIIII Ill I 

Nov. Dec. 

FIGURE lB.-Streamflow hydrograph, 1970-72, Salmon River below 

Yankee Fork, Idaho. A, 1970. B, 1971. C, 1972. 

water-quality data provided by the rare discharges 

reduces to an insignificant level the effects introduced 

by the consecutive years of high runoff. 

HYDRAULIC GEOMETRY 

The term hydraulic geometry was used by Leopold 

and Maddock (1953) with reference to the many 

variations in hydraulic characteristics of river channels 

as the channels carry a wide range of streamflow. Such 

descriptions are equally valid whether applied to a 

given cross section of channel and referred to as 

at-a-station characteristics, or when applied to channels in the downstream direction. With few exceptions, 

30 Ill Ill I I I I Ill 1-

w 

w 

LL 

(.) 

iil~ 20 ::::>0 

(.)(.) 

~w 

.en 

Wa: 

CJw 10 ~a.. 

:r: 

(.) 

en 

15 0 

,,. 

IP ij \ Station 13-2973.50 

1/ \ 

Ill I 

(Record 

ill I IIIII 

initiated) 

Ill II II 1 

~ 

I IIIII IIIII ~ Ill- _]II 

A. 1971 

30 1- IIIII IIIII IIIII IIIII I I II I 

w 

w 

LL 

(.) 

iil~ 20 ::::>0 

(.)(.) 

zw 

-.en 

Wa: 

eJw 10 ~a.. 

:r: 

(.) 

en 

15 0 

uol 

v 

rN ~ Station 13-2973.50 

~ \ II Ill 

(Record 

II II I Iiiii 

interrupted) 

II II LUI 

J 

IIIli _j_J]_J ~ h-t-1 I I 

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 

B. 1972 

FIGURE 19.-Streamflow hydrograph, 1971-72, Bruno Creek near 

Clayton, Idaho. A, 1971. B, 1972. 

the subsequent discussion follows the procedures 

suggested by Leopold and Maddock. 

AT-A-STATION HYDRAULIC CHARACTERISTICS 

As a given cross section of channel transmits varying 

amounts of water, changes in values of the mean 

velocity, V, mean depth,D, and surface width, W, ofthe 

flowing water reflect the hydraulic characteristics of 

that cross section. To define these characteristics, field 

notes of individual discharge measurements at a given 

station are scanned to select about &--10 sets of notes 

which are representative of the full range of discharges 

measured. Values of mean velocity, mean depth, and 

surface width are obtained from the measurement notes 

and are plotted as a function of discharge, Q, on 

logarithmic graph paper. Figure 22 illustrates such 

plots with data for the gaging station Salmon River near 

Challis, Idaho (13--2985.00). It is the at-a-station curves 

of figure 22 which allow determination of the hydraulic 

variables for any desired discharge. 

The graphs of figure 22, as for most river channels, 

indicate straight-line relations. For the given cross 

section, values of the hydraulic characteristics vary 

with discharge as simple power functions: 

W=aQb 

D=cQr 

V=kQm. 

Further, from the continuity equation, 

WxDxV=Q, 

it can easily be shown that 
CHANNELS AND WATERS A29 

250 IIIII I I II II I IIIII 111111111 II I II II II II I IIIII 

0 

z 

0 

(.) 

w 200 (/) 

a: 

w 

Q.. 

1-

w 150 w 

u. 

(.) 

ii5 

::> 

(.) 100 

~ 

uj 

C} 

a: 

<t I 50 (.) 

(/) 

Station 13-2974.50 

lfl~ 

(Record initiated) \ 

u\ 

v ~ 0 

0 

~ ~ ~ L,.... IIIII IIIII IIIII IIIII IIIII II I I I I IIIII 

A. 1970 

250 Ill I II I Ill IIIII IIIII IIIII IIIII IIIII IIIII IIIII IIIII I II IT 

0 

z 

0 

(.) 

w 200 (/) 

a: 

w 

Q.. 

1-

w 150 w 

u. 

(.) 

ii5 

::> 

(.) 100 

~ 

uj 

C} 

a: 

<t 50 I 

(.) 

(/) 

0 

0 

~ Station 13-2974.50 

l 

v 

t\J N~ 

../"',. IJJ \ ""'-.. 

'""' I I I 

B. 1971 

300 IIIII IIIII I''' II I I IIIII I'"" I II IIIII II 'I II II Ill 

0 250 z 

0 

(.) 

w 

(/) 

a: 

w 200 Q.. 

1-

w 

w 

u. 

(.) 150 ii5 

Station 13-2974.50 

::> 

(.) -·· 

~ 

uj 

C} 100 

a: 

<t I 

(.) 

(/) 

0 50 

0 

~~~ 

~ij \ J! \..,. 

~ TiT(j' IIIII IIIII I Ill I IIIII IIIII IIIII 

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 

c. 1972 

FIGURE 20.-Streamflow hydrograph, 197{}-72, Little Boulder Creek 

near Clayton, Idaho. A, 1970. B, 1971. C, 1972. 

axcxk=l 

and 

b+f+m=l. 

Values of the coefficients, a, c, and k, and the exponents, 

10 I IIIII IIIII I I'"' I'"" I ., I I I 'I II 1111 I 

u. 

0 ~ (J)O 8 oz zO 

<t:U (J)W 

::>(/) 

Oa: 6 

Iw 

1-Q.. 

Zl-

-w 4 ~~ a:u 

~m u=> 2 (/)(.) 

0 

0 

~ I 

~ v I 

\Station 13-2985.00 

"' 

'\ 

fl \ 

1~ ~ /"'---- ~ J'o. 

II Ill I 1111 II IIIII IIIII IIIII IIIII IIIII IIIII 

A. 1970 

12 Ill I II I Ill I'"" I' I I I I 

u. 10 

0 

(J)O 

oz zO 

<t:U 8 (J)W 

::>(/) 

Oa: IW 

1-Q.. 6 Zl-

-w 

~~ a:u 4 

~m u=> 

(/)(.) 

/u 

N 

1'1 1 

Station 13-2985.00 

I v l \ 

I v \ 0 2 

0 ~ / "'- ---......_ ./ 

IIIII II II IIIII IIIII IIIII IIIII IIIII IIIII IIIII IIIII IIIII 

B. 1971 

0 14 z 

0 

(.) 

w 

(/) 

12 a: 

w 

·rrrrr IIIII IIIII jill II IIIII 

~Ill Ill Ill II I 

IV 

Q.. 

1-

w 

w 10 u. 

(.) 

ii5 

::> 

(.) 8 

~ 

u. 

0 

(/) 

0 

z 6 <t 

(/) 

::> 

0 I 4 1-

~ 

uj 

C} 2 

\ Station 13-2985.00 

~ I, 

I \ a: 

<t I 

(.) 

(/) 0 0 

(Record interrupted) ' '-

_LUI ~.I, I I I ,I,, ,.u..L_,, 1 I I I Ill II II II II IIIII 

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 

c. 1972 

FIGURE 21.-Streamflow hydrograph, 197{}-72, Salmon River near 

Challis, Idaho. A, 1970. B, 1971. C, 1972. 

b, f, and m, may be determined by applying logtransformed linear regression techniques to the field 

data. For the example of figure 22, values of b, f, and m 

were determined as 0.12, 0.40, and 0.48, respectively. 

These values of b, f, and m corresponding to the slope of 

the respective curves are shown in figure 22. 

Adequate data to prepare curves of hydraulic geometry for all the principal water-data stations given in 

table 3 were provided by discharge measurements. 

Analyses of these data provided values of the exponents 
A30 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

20 .------,----,---.--,--.-.-,-.-----------~------~---,---,--.--,-,-,-,----------~ 200 rCl 

z 

0 

w 

w 

u. 

~ 

:i 

b 

(.) 

~ 10 r--------------~----------~-----------4---------------+-----------+~~-------4 100 ~ a: 

w 

a.. 

rw 

w 

u. 

~ 

>-~ 

5 ru 

0 

....J 

w 

> 

0 

z 

<{ 

rw 

w 

u. 

~ 

:i 2 

ra.. 

w 

0 

1 

200 500 1000 2000 5000 10,000 20,000 

DISCHARGE, IN CUBIC FEET PER SECOND 

FIGURE 22.-At~a~station curves of hydraulic geometry, Salmon River near Challis, Idaho. 

of the hydraulic-geometry equations, and for all 

stations these exponents are given in table 11. For all39 

stations, the mean and median values of b, f, and m 

are 0.14, 0.40, 0.46 and 0.12, 0.40, 0.48, respectively. 

Although there is considerable variability in values of 

b, f, and m among individual streams, the average 

values for a group of streams are generally consistent. 

For comparison, the average values for 158 gaging stations in the United States are b=0.12,{=0.45, and 

m =0.43 (Leopold and others, 1964). 

The at-a-station curves of hydraulic geometry for 

some rivers may show a break in slope at bankfull 

discharge. That is, at stages just over bankfull, width 

increases rapidly as the flood plain becomes inundated, 

and there is corresponding decrease in the rate of 

increase in depth and sometimes in velocity. In the 

present study, however, at some locations the flood plain 

was too narrow to allow this, and at other locations no 

overbank discharge measurements were available to 

document a break in slope. Thus for the entire range of 

streamflow, single curves with slope values of b, f, and m 

were used to define the relations ofW, D, and V to Q for 

each stream. 

Variability among stations in the values ofb,f, andm 

in table 11 can be partly explained by the techniques of 

data collection. At some locations, for example the East 

Fork Salmon River near Clayton, Idaho (13-2980.00), 

discharge measurements were obtained at a bridge 

crossing. For all stages of flow, the width of the stream 

was confined by the bridge revetments. This constraint, 

or fixed width of channel, yields a value of b =0.00. To 

compensate, depth increases more rapidly than average 

and has an exponent value of {=0.55. At other locations where wading measurements were made, the 

original cross section was not always used during 

subsequent measurements. Because of inherent v:.riabilities from section to section even within a s!·· :)rt 

reach of channel, a scatter is introduced to data of the 

type plotted in figure 22 and makes the definition of the 

hydraulic geometry equations more tenuous. And, ~n 

some instances, the definition may become biased. (or 

example, at Beaver Creek near Stanley, Idaho (13-

2924.00), wider than average sections were used at high 

discharges to obtain shallow enough depths for wading. 

This creates the impression that width increases more 

rapidly than average, b=0.24, and is compensated by 

depths increasing less rapidly than average, f =0.31. 

Induced variability among station data, such as in these 

two examples, displays sufficient randomness in its 

effect that it is reasonable to expect that the mean or 
CHANNELS AND WATERS A31 

TABLE H.-Exponents of hydraulic-geometry equations for width, 

depth, and velocity 

U.S. Geological b f m Survey (WocQbl (DrxQf) (VxQml station No. 

13-2922.00 ---------------- 0.03 0.57 0.40 

2924.00 ---------------- .24 .31 .45 

2932.00 ---------------- .16 .39 .45 

2934.00 ---------------- .07 .41 .52 

2950.00 ---------------- .07 .35 .58 

2956.50 ---------------- .04 .48 .48 

2960.00 ---------------- .16 .43 .41 

2965.00 ---------------- .19 .31 .50 

2970.00 ---------------- .00 .36 .64 

2971.00 ---------------- .35 .30 .35 

2972.50 ---------------- .00 .48 .52 

2973.00 ---------------- .06 .52 .42 

2973.10 ---------------- .25 .35 .40 

2973.20 ---------------- . 27 .39 .34 

2973.30 ---------------- .29 .23 .48 

2973.40 ---------------- .18 .40 .42 

2973.50 ---------------- .15 .30 .55 

2973.60 ---------------- .15 .32 .53 

2973.80 ---------------- .13 .49 .38 

2973.84 ---------------- .05 .35 .60 

2973.88 ---------------- .03 .39 .58 

2973.96 ---------------- .05 .35 .60 

2974.00 ---------------- .25 .38 .37 

2974.04 ---------------- .02 .40 .58 

2974.18 ---------------- .03 .36 .61 

2974.25 ---------------- .00 .40 .60 

2974.40 ---------------- .00 .43 .57 

2974.45 ---------------- .24 .45 .31 2974.50 ________________ .33 .16 .51 

2974.80 ---------------- .21 .39 .40 

2974.85 ---------------- .12 .44 .44 

2975.00 ---------------- .00 .45 .55 

2975.30 ---------------- .18 .37 .45 

2976.00 ---------------- .00 .52 .48 

2976.70 ---------------- .16 . 53 .31 

2976.80 ---------------- .36 .54 .10 

2977.00 ---------------- .34 .41 .25 

2980.00 ---------------- .00 .55 .45 

2985.00 ---------------- .12 .40 .48 

Mean -------------- .14 .40 .46 ~edian ______________ .12 .40 .48 

median values are not greatly affected. And, at some 

locations, it is likely that the mean values more closely 

approximate natural values than the individual station 

data. 

In summary, the data of table 11 indicate that the 

average river channel accommodates about 40 percent 

of an increase in discharge by an increase in depth, 

about 10-15 percent by an increase in width, and about 

45-50 percent by an increase in velocity. 

Values of the coefficients a, c, and k have less 

significance than the exponents. Values of the 

coefficients are determined as the intercept values for a 

value of discharge equal to unity, or 1 cubic foot per 

second. Since river channels with sizable drainage 

areas do not have discharges this low, extrapolation of 

data corresponding to a discharge of unity has no physical significance and is not valid. 

ous sections along the length of a stream may be made in 

much the same manner as for the at-a-station analyses. 

Whereas in the previous analysis increases in diseharge 

were due to increases in water stage, in the downstream 

direction increases in discharge are due to tributary 

contributions. Because it would be improper to compare 

the hydraulic characteristics of some reaches at low flow 

with other reaches at high flow, the comparison must be 

made for a flow of given frequency. As Leopold, Wolman, 

and Miller (1964) emphasized, the most meaningful 

discharge for any discussion of channel morphology is 

that which forms or maintains the channel. They 

further state that the effective discharge can be approximated by bankful discharge . 

The next section of this report contains a discussion of 

bankfull discharge, its determination, and its importance. For the present discussion, it is important to 

know only that bankfull discharge was determined for 

each of the principal water-data stations given in table 

3. With the values of bankfull discharge, QB, known, 

individual station graphs of at-a-station hydraulic 

geometry such as figure 22 provide corresponding 

bankfull values of surface width, W B, mean depth, DB, 

and mean velocity, VB. These bankfull data are given in 

table 12. It may be noted that the combined data of 

tables 11 and 12 are sufficient to prepare the at-astation curves of hydraulic geometry for each of the 39 

water-data stations . 

Data of table 12 are unique for the purpose of 

illustrating downstream hydraulic geometry. To date, 

they represent the largest assembly of bankfull data for 

a given river system. Although all the water-data 

stations are not successively at downstream locations, 

all are within the tributary system of the upper Salmon 

River. Tributary stations can be considered as alternate 

headward extensions of the main-stem river. Data of 

table 12 are plotted in figures 23-26 to define the 

downstream curves of hydraulic geometry. Figure 26, 

the plot of bankfull flow area, AB, is essentially a plot of 

the multiplication of the width and depth plots of figures 

23 and 24 (A =WxD). Log-transformed linear regression equations (least-squares technique) were fitted to 

the data. With the correlation coefficient shown in 

parentheses, the following relations were determined: 

W B = 1.37 QB0.54 

DB =0.25 QB0.34 

VB =2.88 QB0.12 

AB=0.35 QB0.88 

(r=0.917), 

(r=0.887), 

(r=0.486), 

(r=0.972). 

These relations show values of b=0.54, {=0.34, and 

DOWNSTREAM HYDRAULIC CHARACTERISTICS 

1 

m =0.12. By comparison, Leopold and Maddock (1953) 

found the average value for a number of streams in the 

Comparison of the hydraulic characteristics at vari- midwestern United States to be b=0.50, {=0.40, and 
A32 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 12.-Summary of bankfull-stage data from channel-geometry surveys 

U.S. Geological Surface Mean width, depth, Survey WB DB station No. (ft) (ft) 

13-2922.00 ------------ 40 1.8 

2924.00 ------------ 33 1.2 

2932.00 ------------ 25 1.2 

2934.00 ------------ 25 1.5 

2950.00 ------------ 80 2.5 

2956.50 ------------ 32 2.7 

2960.00 ------------ 53 3.2 

2965.00 ------------ 116 6.2 

2970.00 ------------ 45 1.7 

2971.00 ------------ 28 1.2 

2972.50 ------------ 21 1.0 

2973.00 ------------ 9 1.5 

2973.10 ------------ 33 1.2 

2973.20 ------------ 16 .8 

2973.30 ------------ 40 1.1 

2973.40 ------------ 30 2.1 

2973.50 ------------ 8 .9 

2973.60 ------------ 28 2.4 

2973.80 ------------ 165 4.2 

2973.84 ------------ 29 1.8 

2973.88 ------------ 14 1.7 

2973.96 ------------ 23 1.7 

2974.00 ------------ 49 2.4 

2974.04 ------------ 32 2.0 

2974.18 ------------ 7 1.2 

2974.25 ------------ 44 2.5 

2974.40 ------------ 17 .9 

2974.45 ------------ 32 2.4 

2974.50 ------------ 44 1.3 

2974.80 ------------ 42 1.0 

2974.85 ------------ 9 1.3 

2975.00 ------------ 20 1.6 

2975.30 ------------ 23 1.5 

2976.00 ------------ 28 2.5 

2976.70 ------------ 9 1.3 

2976.80 ------------ 9 1.0 

2977.00 ------------ 23 1.2 

2980.00 ------------ 52 4.2 

2985.00 ------------ 165 4.9 

m=0.10. In a study of Alaskan channels, Emmett 

(1972a)reported valuesofb=0.50,{=0.35, andm=0.15. 

The data just given indicate that in the upper Salmon 

River area, downstream increases in discharge are 

accommodated by increases in width, depth, and 

velocity. Increases in width absorb 54 percent of the 

increase in discharge, depth absorbs 34· percent, and 

velocity absorbs 12 percent. Downstream increases in 

velocity are the most surprising because, without 

measurements, tumbling waters in headwater reaches 

of channels appear to have faster velocities than the 

apparent sluggish waters in downstream reaches. This 

phenomenon is only a deception by the eye, and the 

velocity data are generally consistent with downstream 

increases in velocity in other river systems (Leopold, 

1953). 

At stages of flow greater than bankfull, channel width 

increases rapidly as water flows over the full width of 

the flood plain, and velocities increase less rapidly or not 

at all as increased resistance to flow is encountered. 

Since extent of flood plains generally increases downstream, this effect is more pronounced in the downstream direction. The net effect is that for floodfl.ows of 

rarity greater than about once in 5 years, velocities tend 

Mean Flow Discharge, Runoff, velocity, area, 

VB AB QB RB 

(ft3/sec) (ft3/sec/mi2 ) (ft/sec) (ft2 ) 

5.0 72.0 360 20.6 

4.9 39.6 194 12.5 

6.5 30.0 195 11.1 

5.3 39.0 207 11.2 

5.0 200.0 1,000 6.8 

5.5 86.4 475 9.3 

4.2 169.6 712 3.7 

5.2 719.2 3,740 4.7 

7.9 76.5 604 7.7 

6.6 33.6 222 27.7 

5.7 21.0 120 3.9 

7.2 13.5 97.2 16.2 

5.2 39.6 206 9.2 

4.2 12.8 53.8 21.5 

6.2 44.0 273 9.1 

5.2 63.0 328 5.5 

7.4 7.2 53.3 8.9 

6.8 67.2 457 5.7 

7.4 693.0 5,128 4.4 

6.0 52.2 313 17.4 

5.2 23.8 124 14.4 

5.6 39.1 219 8.4 

7.6 117.6 894 11.8 

6.4 64.0 410 8.4 

8.0 8.4 67.2 10.3 

10.0 110.0 1,100 6.7 

3.9 15.3 59.7 21.1 

3.5 76.8 269 27.0 

5.5 57.2 315 17.4 

4.4 42.0 185 14.6 

6.8 11.7 79.6 23.2 

6.9 32.0 221 8.1 

7.0 34.5 242 9.1 

8.4 70.0 588 5.2 

3.2 11.7 37.4 1.0 

2.1 9.0 18.9 .6 

3.1 27.6 85.6 1.0 

8.5 218.4 1,856 3.5 

6.8 808.5 5,498 3.1 

to remain about constant in the downstream direction. 

Sufficient data are not available to illustrate this 

constancy of downstream floodflow velocities in the 

upper Salmon River, but that trend has been shown for 

limited data in other river basins (Leopold and others, 

1964). 

Values of the coefficients a, c, and k, in the 

hydraulic-geometry equations assume more physical 

significance in downstream hydraulic geometry than in 

analyses of at-a-station hydraulic geometry. In the 

downstream case, the coefficients represent values of 

width, depth, and velocity at that upstream reach where 

bankfull discharge is unity. Although in reality this 

represents an upstream reach with a drainage area so 

small that definite channels are nonexistent, it provides 

for a downstream comparison of channel shape. At the 

upstream reach of channel where the bankfull discharge is unity, the channel width-depth ratio is 

1.37:0.25, or about 5.5. This width-depth ratio increases 

significantly downstream, and at the exit from the study 

area (drainage area=l.800 square miles, bankfull 

discharge =5,500 cubic feet per second), the width-depth 

ratio of the Salmon River is 30. Although many factors 

actually control the shape of channels (see, for example, 
200 

100 

tij 

~ 50 

~ 

:i 

1-

0 

§ 

w 

() 20 

~ a: 

::> 

CJ) 

..J 

..J 

-

-

-

-

rrI I I I I I 

0 

/ ~ 

CHANNELS AND WATERS 

I I I I I I 

/ c / OL 0 

0 

~ y~ 0 

c 

o/ 

0 0 

0 

r"\ 

/ ......, 

0 Wa = 1.37 Oa o.s4 

~ 10 ~ 

z 

<( 

al 

rr-

:/ ~ 0 c 

0 

0 

1-

w 

w 

u. 

~ 

:i 

1-

0.. 

w 

0 

z 

<( 

w 

::E 

..J 

..J 

::> 

u. 

~ 

z 

<( 

al 

5 

rr2 

10 

5 

2 

0.5 

I 

20 

I I I I I I I I I I I 

50 1 00 200 500 1 000 2000 

BANKFULL DISCHARGE, IN CUBIC FEET PER SECOND 

FIGURE 23.-Bankfull surface width as a function of bankfull discharge. 

0 

0 

Da = 0.25 Oa 0.34 

A33 

I I y / -

-

-

-

-

-

-

-

-

-

-

-

I I I I I 

5000 10,000 

0.2 ~------~--~--~~~-L~~-------J----~~~~~~~~-------L---J--~~--~~~ 

10 20 50 100 200 500 1000 2000 

BANKFULL DISCHARGE, IN CUBIC FEET PER SECOND 

FIGURE 24.-Bankfull mean depth as a function of bankfull discharge. 

5000 10,000 
A34 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

20 I I I I I I I I I I I I I I I I I I 

10 v 1-

f- 0 0 0 

z 1- 0 0 c f?~ ~ 

C6 0 ~ ~-~ 0 - f- 2 - c. ,(1 0 

n 

0 

(.) 

w 

en 

a: 5 -- 0 ~ 

--- ___. ~ - 00 0 -

0 0 1- 0 -

w 

(L 

1-

w 

w 

u. 

~ 

>--

1- 2 0 

0 

0 

...J 

w 

> Va = 2.89 Oa 0.12 z 

<( 

w 

~ f- - ...J f- -

.... - ...J 

::J 

- - u. 

~ 

~ 0.5 Ill 

- -

- -

I I I I I l I I I I I I I I I I I I 0.2 

10 20 50 1 00 200 500 1 000 2000 5000 10,000 

BANKFULL DISCHARGE, IN CUBIC FEET PER SECOND 

FIGURE 25.-Bankfull mean velocity as a function of bankfull discharge. 

Schumm, 1960), the downstream curves of hydraulic 

geometry illustrate that even the largest rivers are not 

overly deep. 

Evaluation of the correlation coefficients of each of 

the equations fitted to the downstream hydraulic 

geometry data indicates a relatively high correlation (a 

good fit) of the width and depth data. The highest 

correlation is determined for the fit of the relation of 

flow area to discharge. Rationalization implies that as 

width increases or decreases from the predicted value, 

depth responds in the opposite direction. Flow area, the 

product of width and depth, remains near the predicted 

value. Thus, of measurements of width, depth, and flow 

area, values of flow area would be the most reliable in 

predictions of bankfull discharge. Although the product 

of flow area and velocity is discharge, known values of 

mean velocity are generally insufficient for the prediction of discharge. The small value of the exponent for 

velocity, m, reflects only slight dependency of velocity 

on discharge, and thus the velocity equation has a low 

correlation coefficient. 

CHANNEL GEOMETRY 

Much of the analysis of data in this report is based on 

the assumption that river channels are shaped by, and 

to accommodate, a dominant discharge. This is analogous to the statement that rivers which nominally 

transmit little water have small channels and rivers 

which nominally convey lots of water have large 

channels. Further, this statement appears more logical 

than other statements such as rivers which convey lots 

of water have large drainage areas because the amount 

of water depends more on the amount of precipitationand other factors-than on the size of drainage area. 

The discharge which appears most pertinent as a 

dominant discharge is bankfull discharge (Leopold and 

others, 1964; Wolman and Miller, 1960). Bankfull 

discharge is defined as that water discharged when 

stream water just begins to overflow onto the active 

flood plain; the active flood plain is defined as a flat area 

adjacent to the channel, constructed by the river, and 

overflowed by the river at a recurrence interval of about 

2 years or a little less (Wolman and Leopold, 1957). 

Bankfull discharge tends to have a constant frequency 

of occurrence among rivers, and furthermore discharges 

equal to a given percentage of bankfull discharge also 

appear to have a given frequency of occurrence. These 

characteristics of bankfull discharge have tended to be 
CHANNELS AND WATERS A35 

1000 r 

I I I I I I I I I I I I I I 

- v·-- - 0 -

-

/ -

-

/ -

- -

/o \. / 0 

/o 0 

- 0 v -

~ 

0~ 8 - I- -

I- -

500 

1-

w 

w 200 LL 

w 

a: 

<( 

::> 

0 

CJ) 

~ 100 

<i. 

w 

a: 

<( 

3: 

-

~ vo -

0 50 ....J 

LL 

...J 

...J 

:::> 

LL 

:X:: 

z 

<( 

CD 

I20 

10 1-

IIr5 

10 

0 

0 

/ ~ 0/ 0 

0 

I I I I 

20 50 100 

\P -

A a = 0.35 Q B 0.88 

-

-

-

-

j_ I I I I I I I I I I I 

200 500 1000 2000 5000 10,000 

BANKFULL DISCHARGE, IN CUBIC FEET PER SECOND 

FIGURE 26.-Bankfull flow area as a function of bankfull discharge. 

substantiated in the recent literature; see, for examples, 

Emmett (1972a), Brown (1971), Leopold and Skibitzke 

(1967), Woodyer (1968), Kilpatrick and Barnes (1964), 

Dury (1961), and Nixon (1959). 

The determination of bankfull discharge for each 

stream of interest involves field surveys of channel 

geometry and utilization of stream-gaging data. The 

technique is transferable to provide approximations of 

bankfull discharge in ungaged areas. Perhaps the most 

complete discussion of channel geometry surveys 

appears in Emmett (1972a), a summary of which 

follows. 

FIELD SURVEYS AND OBSERVATIONS 

The principal channel feature involved in the survey 

of channel geometry is the bankfull stage, or the stage 

at which the channel just begins to overflow onto the 

flood plain. Thus, a flood plain on one or both banks is a 

basic criterion for site selection. The river must be unconfined by rock walls; if terraces exist they must be 

distinguishable from the active flood plain. 

In the upper Salmon River area, the flood plain was 

often difficult to recognize in the field. Generally because of steep channel gradients and at other locations 

because of canyonlike confinement, the flood plain along 

many reaches of stream channel was extremely narrow 

or absent. At a few locations in the smaller drainage 

areas surveyed, the channels appeared to carry insufficient volumes of water to construct and maintain a 

flood plain. When the flood plain is difficult to recognize 

in the field, other evidence is useful to help distinguish 

it (Emmett, 1972a). Vegetation on surfaces lower than 

the flood plain is either absent or annual. On the flood 

plain, vegetation may be perennial but is generally 

limited to typical streamside types such as young willow 

and alder. The higher altitude surfaces, including terraces, support more mature woody vegetation; where 

trees grow along nearly vertical banks leading to these 

higher surfaces, the bottom of the tree line is often 

indicative of the flood plain. 

Principal measurements of channel geometry consist 
A36 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

of surveying the long profiles of riverbed, water surface, 

and flood plain. In addition, if terraces and high-water 

marks exist, the long profiles of these features are also 

surveyed. The riverbed survey is conducted along the 

approximate center of the channel for a distance equivalent to about 20 river widths. Sightings are spaced at no 

greater than one river width apart. This distance and 

spacing is generally sufficient to average out variability 

due to pools and riffles and to determine the mean slope 

for the surveyed reach of river. The water-surface 

profile is determined at the same time by the rodman's 

observing the depth of water at each shot location and 

adding this value to the bed elevation. A similar 

traverse is conducted downvalley on the flood plain 

through the same distance. Profiles of terrace and 

high-water marks are surveyed the same as for the flood 

plain. 

In places where wading was not possible, the riverbed 

profile was omitted, and water-surface elevations were 

determined from along one or both banks. All surveying 

is tied into the gage datum or reference point of the 

stream-gaging measurements. 

In addition to the channel surveys, the particle-size 

distribution of the bed and bank material is determined. 

These data are necessary not only for a complete description of the stream channel but are often required in 

various formulas describing river-channel behavior. 

Particle-size distribution of bed material from streams 

with coarse particles is best sampled by pebble counting 

(Wolman, 1954; Leopold, 1970). Acountof100particles 

is taken by pacing a reach of river and randomly picking 

up a pebble at each step. The intermediate axis of the 

pebble is measured, and the size distribution is expressed in percentage by number of particles. To obtain 

greater definition of the finer grained bed material, a 

bulk sample, excluding coarse particles, from the bed 

surface is obtained for sieve analysis, and the size distribution is expressed in percentage by weight. The 

compatibility and collating of data from these two 

techniques has been discussed by Kellerhals and Bray 

(1971), but for most purposes the particle-size distribution determined by pebble count is adequate. 

Representative samples of bank material are also obtained for sieve analysis. The bank considered for sampling was flood-plain material and was always composed of relatively fine-grained particles. A summary of 

the bed and bank material particle-size analyses is included in table 13. 

DETERMINATION OF BANKFULL DISCHARGE 

The longitudinal profile data from the channelgeometry surveys are plotted on arithmetic coordinate 

graph paper, and straight-line profiles are drawn 

TABLE 13.-Summary of channel-material particle-size analyses 

Sieve analysis 

U.S. Geological Pebble count of bed material Bed Survey Bank fines station No. dso d16 (~~) d84 ds0 1dts d84/dso d50 (mm) (mm) (mm) (mml 

13-2922.00 5.5 20.0 48 3.64 2.40 11.0 0.06 

2924.00 6.0 27.5 71 4.58 2.58 8.0 .10 

2932.00 4.0 11.0 64 2.75 5.82 2.8 .08 

2934.00 4.0 19.0 100 4.75 5.26 .5 .08 2950.00 8.0 30.0 48 3.75 1.60 1.8 .10 

2956.50 7.0 30.0 61 4.29 2.03 2.3 .15 

2960.00 5.5 28.5 70 5.18 2.46 1.4 .15 

2965.00 15.5 58.0 114 3.74 1.97 1.1 .31 

2970.00 17.0 40.0 64 2.35 1.60 1.4 .06 

2971.00 7.0 27.0 64 3.96 2.37 1.4 .17 

2972.50 16.0 43.0 74 2.69 1.72 7.5 3.00 

2973.00 6.0 15.5 54 2.58 3.48 2.2 .12 

2973.10 11.5 42.0 70 3.65 1.67 1.7 .12 

2973.20 11.5 29.0 61 2.52 2.10 2.7 .20 

2973.30 13.0 30.5 61 2.35 2.00 2.5 .11 

2973.40 ------ 11.0 31.0 64 2.82 2.06 1.2 .10 

2973.50 ------ 9.5 24.0 44 2.53 1.83 .2 .20 

2973.60 ------ 12.0 37.5 65 3.13 1.73 2.1 .12 

2973.80 19.0 56.0 125 2.95 2.23 1.8 .15 

2973.84 ------ 15.0 52.0 86 3.47 1.65 1.5 3.50 2973.88 ------ 8.5 46.0 135 5.41 2.93 3.2 .10 

2973.96 ------ 17.0 53.0 88 3.12 1.66 .2 .85 2974.00 ------ 23.0 51.0 100 2.22 1.96 1.5 .07 

2974.04 ------ 9.0 27.5 73 3.06 2.65 1.8 3.10 

2974.18 ------ 13.5 34.0 98 2.52 2.88 1.7 .18 2974.25 ------ 15.0 55.0 112 3.67 2.04 1.8 .12 

2974.40 2.0 42.0 96 21.00 2.29 1.5 .13 

2974.45 5.0 12.0 20 2.40 1.67 4.3 .11 

2974.50 9.5 31.0 98 3.26 3.16 4.0 1.90 

2974.80 2.5 30.5 64 12.20 2.10 1.7 .43 

2974.85 2.5 24.5 46 9.80 1.88 .4 .62 

2975.00 14.0 37.5 80 2.68 2.13 .3 .85 2975.30 7.5 19.5 44 2.60 2.26 3.2 .08 

2976.00 14.0 37.0 92 2.64 2.49 .5 .13 

2976.70 18.5 40.0 63 2.16 1.58 .5 .10 2976.80 5.0 19.0 36 3.80 1.89 3.3 .13 

2977.00 5.0 17.5 50 3.50 2.86 .9 .18 

2980.00 15.0 41.0 108 2.73 2.63 .2 .09 

2985.00 ------ 2.0 45.0 114 22.50 2.53 .2 .18 

Mean ______ 10.1 33.7 75 3.34 2.23 2.24 .47 

Median --- 9.5 30.5 65 3.21 2.13 1.7 .13 

through each set of points. These straight lines generally must be parallel for riverbed, water surface, and 

flood plain, and this criterion is considered when determining the best fit. In determining the best fit, bias or 

prominence is given to a surface containing the most 

surveyed points or extending for the greatest length of 

survey. Where the plotted profiles pass the channel stationing or location of the gage, the gage height corresponding to the elevation of each channel feature can be 

determined. Of primary interest is the gage height at 

bankfull stage or the average altitude of the flood plain 

at the location of the gage. Although only the flood-plain 

profile is used to determine bankfull stage, usually all 

profiles, especially the water surface, are instrumental 

in determining the best-fit line to the flood-plain data. 

Bankfull discharge is determined from the stagedischarge relation developed for the station, and as 

mentioned previously, sufficient data existed to establish stage-discharge relations for each of the 39 primary 

water-data stations utilized in the present study. With 

bankfull discharge known, this value is entered in the 

at-a-station curves of hydraulic geometry, such as 

figure 22, and bankfull values of surface width, mean 

depth, and mean velocity may be obtained. These are 

the bankfull values of the hydraulic parameters given 

in table 12. As previously noted, the values of the hy-
CHANNELS AND WATERS A37 

draulic parameters given in table 12 and the values of 

the exponents of hydraulic geometry compiled in table 

11 are sufficient to prepare at-a-station curves of hydraulic geometry for each station. 

DIMENSIONLESS RATING CURVE 

If the at-a-station hydraulic geometry data are expressed as nondimensional ratios to bankfull data, dimensionless curves of at-a-station hydraulic geometry 

may be expressed as 

and 

W/W B =(QIQB)b, 

D!Dn =(QIQB)f; 

V/V B =(Q!QnJm, 

A!An=(Q!Qn)b+f. 

These equations are valid for streams having the same 

values of b, {, and m or may serve as average equations 

for the region with values for the exponents of b=0.14, 

{=0.40, and m=0.46 (table 11). 

The foregoing equations may be considered forms of a 

dimensionless rating curve and, excluding the velocity 

equation, lend themselves to determination of bankfull 

discharge for ungaged areas. A single discharge m~asurement yields values of discharge, surface width, 

mean depth, and flow area. A channel-geometry survey 

including cross-section data will supply values of surface width, mean depth, and flow area at bankfull stage. 

These data are then sufficient to compute values of 

bankfull discharge from the appropriate equations, 

using the average values of the hydraulic exponents. 

The analysis of downstream hydraulic geometry has 

indicated that flow area is the channel-geometry 

parameter most correlative with values of bankfull discharge. Although depth is somewhat less correlative, 

statistically, than flow area, it perhaps offers a better 

visual indication of the amount of water in a channel. 

Figure 27 illustrates the dimensionless rating curves of 

depth and cross-sectional area of flow to discharge. 

These curves provide insight to the relations between 

hydraulic geometry and channel geometry. For exam-

< 5 ~----~--~~--~~~~~--------~----~--~--~--~-,~~--------,-----,----,--, 

w 

a: 

< 

~ ..J 

LL 

....J 

..J 

::::> 

LL 

~ 

1.05 

I 

1.25 

I 

2.0 

I 

10 50 

II I I I 

1.01 1.11 1.5 5 25 100 

RECURRENCE INTERVAL, IN YEARS 

~ 2 ~----------~----------~--------~------------~--------+---------~------~~~ m 

0 

1-

< w 

a: 

< 

~ 

0 

..J 

LL 

Q 

z 

< 

J: 

1-

(L. 

~ 0.5~----------~--------~~----~~~--~~------~--------~--------+-----------~ 

..J 

..J 

::::> 

LL 

~ 

z 

< m 

0 

1-

J: 

t 0.2 ~----------~~----------~--------~------------~--------+---------~----------~ w 

Q 

LL 

0 

en 

0 99.1 

99 

I 

90 

DURATION, IN PERCENTAGE OF TIME 

70 40 

I I 

50 30 20 10 5 0.1 

a: ~ 0.1 L_ ____ L_ __ L_~--L-~~L_L_ ________ L_ ____ L_ __ ~ __ L_J__L_L~L---------~----~--~~ 

0.02 0.05 0.1 0.2 0.5 1 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 27.-Dimensionless rating curves of depth and flow area as functions of discharge. 
A38 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

ple, at a discharge of 30 percent of bankfull discharge 

(QIQB =0.3) the channel is 52 percent full (AIAB =0.52) 

anrl is at 62 percent of bankfull depth (D!DB =0.62). 

The dimensionless rating curves are as reliable as the 

maximum scatter in the values of b and f (table 11). 

Generally if the value of b is somewhat less than average, the value off is somewhat greater. Thus, the values 

of b +f among rivers are somewhat more consistent than 

f alone, and the flow-area curve of figure 27 may be 

considered a little more reliable average rating than the 

depth curve. This is consistent with the downstream 

hydraulic geometry finding that flow area is the more 

correlative of the two parameters. 

Values ofbankfull discharge will be used extensively 

later in this report. Inaccuracies in determining values 

of bankfull discharge can occur, and these inaccuracies 

could affect later analyses involving use of bankfull 

discharge or the ratio of discharge to bankfull discharge. For example, and especially true for small 

streams with poor definition of the flood-plain surface, 

small errors in determination of bankfull stage may 

give rise to more significant percentage errors in determination of bankfull discharge. Such errors are probably random in occurrence. The use of data from 39 

water-data stations provides a large enough sample 

that mean or median values of any parameter are not 

greatly affected by random errors in measurement. 

Thus, relations established between various hydrologic 

parameters and the dimensionless ratio of discharge to 

bankfull discharge may be considered valid for the region of study. 

FREQUENCY OF FLOWS 

Depending on the manner of data collection and the 

length of record, flow frequency or the recurrence interval between events may be assigned to certain of the 

water-data stations. In simplicity, flow frequency is determined by arraying the flow events in order of magnitude and assigning the highest probability of recurrence to the median flow and the least probability of 

recurrence to the highest and lowest flows. A minimum 

of 10 years of record is desirable for predictions of flow 

frequency. Generally, flow frequency may be reasonably extrapolated to a recurrence interval of about twice 

the length of record. Flood frequency is determined by 

arraying annual peak discharges, and this requires 

data from continuous-record gaging stations or creststage gages. 

Within the study area, nine locations meet the 

criteria of annual peak-discharge tabulation and 

adequate length of record. The period of record for 

station 13-2975.00 was extended to 35 years (1926-60) 

by correlating it with the record for station 13-2965.00, 

and the period of record for station 13-2980.00 was 

extended to 32 years (1929-60) by correlating it with the 

records for stations 13-2965.00 and 13-2985.00. By 

using data of these stations, values of flow frequency 

were computed by the log-Pearson method, a technique 

analogous to the simple definition of flow frequency 

already given (U.S. Water Resources Council, 1967; 

Benson, 1968). It is a practice of some hydrologists to 

modify results of log-Pearson computations (Thomas 

and others, 1973), but to assure consistency in application, all data in the present report are unmodified. 

Values of streamflow for various recurrence intervals 

are given in table 14 for the nine stations. Values of 

discharge for recurrence intervals greater than the true 

or synthesized period of record were extended by the 

log-Pearson method. However, values in this range are 

not necessarily reliable estimates of rare-event floods 

and should be considered with caution. 

Data of table 14 are plotted in figure 28 to provide 

flow-frequency curves for the several stations with 

adequate records. The similar shape of the curves 

suggests similarity of flow-frequency behavior among 

stations. Presentation of values of streamflow as values 

of the ratio of discharge to bankfull discharge reduces 

TABLE 14.-Flow-frequency data: value of discharge at various recurrence intervals for water-data stations with adequate 

records 

Water-data station No. 

Recurrence 0 0 0 0 0 0 0 0 0 

interval 0 0 0 0 0 0 0 0 0 .q< oci 0 oci 0 oci oci 0 oci (yr) C"' C"' ar.> ar.> <C <C t- 00 00 0) 0) 0) 0) 0) 0) 0) 0) 0) 

C"' C"' C"' C"' C"' C"' C"' C"' C"' 

~ ~ ~ ~ ~ ~ ~ ~ ~ 

1.01 -------------------- 66 270 380 1,200 430 1,820 51 710 2,830 1.05-------------------- 83 330 510 1,610 620 2,490 70 900 3,830 1.11 -------------------- 93 360 590 1,870 750 2,930 83 1,020. 4,470 

1.25 -------------------- 105 410 700 2,220 940 3,530 100 1,140 5,350 2.0 -------------------- 140 510 960 3,020 1,440 4,930 135 1,400 7,390 5 ---------------------- 175 640 1,290 3,990 2,180 6,690 180 1,850 9,920 10 ---------------------- 200 720 1,490 4,550 2,690 7,760 210 2,200 11,450 25 ---------------------- 230 820 1,730 5,200 3,350 9,010 230 2,750 13,250 50 ---------------------- 250 880 1,890 5,640 3,850 9,880 250 3,250 14,500 100 ---------------------- 270 950 2,050 6,060 4,370 10,700 270 3,800 15,700 200 ---------------------- 290 1,010 2,200 6,440 4,890 11,500 280 4,500 16,800 

Mean annual 81 199 664 197 990 1,470 Bankfull _____ ~--~~~~~--194 1,000 712 3,740 221 1,856 5,498 
CHANNELS AND WATERS A39 

0 5000 

z 

0 

() 

w 

C/) 

a: 

w 

a.. 

1-

w 2000 w 

LL 

() 

m 

::J 

() 1000 ~ 

u.i 

(!:) 

a: 

<( 

I 500 () 

C/) 

a 

13-2975.00 

200 

100 ~--~--~--~~~~~~~--~--~--~--~~~~~~----~--~----~--~~~~~~~ 

1.01 1.05 1.2 1.5 2 3 5 10 20 50 100 

RECURRENCE INTERVAL, IN YEARS 

FIGURE 28.-Flow-frequency curves for selected stream-gaging stations in the upper Salmon River area. 

the data to a single curve defined by a surprisingly 

narrow range in values. This procedure is applicable 

only for those stations with channel-geometry surveys. 

For additional accuracy, only those stations with more 

than 10 years of record were considered. For all stations 

thus analyzed, values of the discharge ratio at selected 

recurrence intervals and the mean values for all 

stations are given in table 15. Mean values from the 

table are plotted in figure 29 and provide an average 

flow-frequency relation for the area. Data of table 15 are 

also superposed in figure 27 to provide frequency of 

occurrence for the regionalized dimensionless rating 

curves. 

The flow-frequency data related to the dimensionless 

discharge ratio greatly increase streamflow information. It has already been shown that bankfull discharge 

can be determined for any stream. With bankfull 

discharge known, flow frequency for any discharge and 

for any stream may now be approximated. The 

recurrence interval for bankfull discharge is determined from figure 29 as about 1.5 years. This is in close 

agreement with the frequency of bankfull discharge 

reported from other studies (Leopold and others, 1964; 

Emmett, 1972a). 

FLOW DURATION 

Flow duration is determined in much the same 

manner as flow frequency. The values of daily mean 

discharge are arrayed in order of magnitude, and the 

number of days of occurrence for each magnitude of flow 

determines the percentage of time or duration of each 

flow and the cumulative percentage of time a discharge 

equals or exceeds a certain value. Data are available 

only from continuous-record gaging stations and should 

have a minimum length of record of at least several 

years to minimize variability due to years of abnormally 

high or low runoff. 

Daily mean discharges adequate to define flow 

duration are available for seven water-data stations in 

the area. Values of flow duration and discharge for these 

stations are given in table 16 and are plotted in figure 

30. The curves in figure 30 are not as consistent among 

stations as are the curves in figure 28, but the 

probability units on the abscissa of figure 30 greatly 
A40 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

5 I 

w I I I I I I I I I I I I I I I I I 

(!) 

a: 1-

< :I: 

0 

CJ) 

i5 

...J 2 ...J 

1-

--------

---- ~ 

u. 

:::> ----

z 

-------~-

IXl 

<( .------

0 

...... 

w 

(!) 

a: 

<( 

J: 

0 0.5 CJ) 

i5 

- ~ 

~ - -

/ -

/ 

/ 

1- LL. 

0 

0 

~ 

< a: I I I I I I I _l_ I I I I I 0.2 

1.01 1.05 1.2 1.5 2 3 5 10 20 50 100 

RECURRENCE INTERVAL, IN YEARS 

FIGURE 29.-Dimensionless flow-frequency curve for streamflow in the upper Salmon River area. 

TABLE 15.-Flow-frequency data: value of discharge ratio, Q/QB, at 

various recurrence intervals for water-data stations with more 

than 10 years of record and channel survey available 

Water-data station No. 

Recurrence 0 0 0 0 0 0 0 0 0 0 0 0 

interval 0 0 .0 .0 0 .0 Mean (yr) 10 10 10 .,... <X> <X> a> a> a> a> a> a> c:-:1 c:-:1 c:-:1 c:-:1 c:-:1 c:-:1 

~ ~ ~ ~ ~ ~ 

l.OL ___________ 0.38 0.60 0.49 0.23 0.38 0.51 0.43 1.05 ____________ .51 .87 .67 .32 .48 .70 .59 1.11 ____________ .59 1.05 .78 .38 .55 .81 .69 1.25 ------------ 70 1.32 .94 .45 .61 .97 .83 2.0 .96 2.02 1.32 .61 .75 1.34 1.17 

5 --============ 1.29 3.06 1.79 .81 1.00 1.80 1.63 10 -------------- 1.49 3.78 2.07 .95 1.19 2.08 1.93 25 -------------- 1.73 4.71 2.41 1.04 1.48 2.41 2.30 50 -------------- 1.89 5.41 2.64 1.13 1.75 2.64 2.58 100 -------------- 2.05 6.14 2.86 1.22 2.05 2.86 2.86 200 -------------- 2.20 6.87 3.07 1.27 2.42 3.06 3.15 

Mean annual -- .20 .28 .26 .27 .25 

exaggerate the duration or abscissa scale. Between flow 

durations of about 2--98 percent of the time, reasonable 

consistency exists among the various flow-duration 

curves. 

For stations with channel-geometry surveys available and with at least 10 years ofrecord, table 17 gives 

values of flow durations and the ratio of discharge to 

bankfull discharge. The mean values of these data are 

plotted in figure 31 to provide an average flow-duration 

curve for the area. The data are also superimposed in 

figure 27 to designate flow duration on the dimension-

, less rating curves. Bankfull discharge appears to have a 

duration of about 4 percent of the time. 

Mean annual discharge can be determined from 

TABLE 16.-Flow-duration data: discharge that is equaled or exceeded 

during percentage of time indicated, for water-data stations with 

adequate records 

Water-data station No. 

0 0 0 0 0 0 0 

Percentage 0 0 0 0 0 0 0 

of time .0 0 .0 0 .0 0 .0 c:-:1 10 10 10 10 <X> <X> a> a> a> a> a> a> a> c:-:1 c:-:1 c:-:1 c:-:1 c:-:1 c:-:1 c:-:1 

~ ~ ~ ~ ~ ~ ~ 

0.1 -------------- 650 1,300 4,440 2,300 7,500 2,750 11,500 

.5 -------------- 580 1,140 3,700 1,950 6,200 2,000 9,200 

1.0 -------------- 530 1,040 3,250 1,650 5,500 1,600 8,000 

2 ---------------- 460 920 2,800 1,350 4,700 1,200 6,800 

4---------------- 370 770 2,350 960 3,800 850 5,500 

6---------------- 310 660 2,050 780 3,250 660 4,750 

8---------------- 270 580 1,800 640 2,900 530 4,150 

10 ---------------- 240 510 1,600 540 2,500 440 3,600 

14---------------- 190 400 1,300 380 2,000 330 2,850 

18---------------- 130 ~10 1,030 280 1,500 280 2,200 

22 ---------------- 90 240 800 200 1,150 220 1,700 

26---------------- 60 185 630 150 880 160 1,350 

30---------------- 50 150 530 115 710 135 1,120 

35 ---------------- 45 130 460 92 620 120 980 

40---------------- 40 115 420 82 560 110 870 

45 ---------------- 37 105 400 74 530 100 810 

50---------------- 34 98 380 68 500 93 750 

55---------------- 32 93 360 63 470 87 720 

60---------------- 30 90 340 59 450 82 690 

65 ---------------- 28 86 320 55 430 77 660 

70---------------- 27 82 310 52 410 73 640 

75 ---------------- 25 78 300 49 390 69 610 

80 ---------------- 24 75 285 46 370 66 580 

85 ---------------- 21 71 270 43 360 62 550 

90 ---------------- 16 68 255 40 340 59 530 

95---------------- 8 62 235 36 320 54 490 

98---------------- 6 56 215 33 290 51 450 

99---------------- 5 52 195 31 280 49 430 

99.5 -------------- 4 48 155 29 260 47 400 

99.9 -------------- 3 44 125 20 220 33 330 

water-data stations with continuous records, and for the 

available stations the ratio of mean annual discharge to 

bankfull discharge is 0.25. Actually, values of the ratio 

range from about 0.20 for smaller drainage areas to 0.27 

for larger drainage areas, but within accuracies 

involved in determination of bankfull discharge and 
CHANNELS AND WATERS A41 

500 

Cl 

z 

0 

() 

w 

en 

a: 

w 

[l. 

1- 200 w 

w 

u. 

() 

iD 

:::> 

() 100 ~ 

u.i 

(!) 

a: 

<( 

:::c 

() 50 en 

0 

2 ~~~--~~---L---L~~L--L--~~~--~~~--~--~--~~--~~~ 

0.1 10 20 40 60 80 90 99 99.9 

DURATION, IN PERCENTAGE OF TIME 

FIGURE 30.-Flow-duration curves for selected stream-gaging stations in the upper Salmon River area. 
A42 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 17 .-Flow-duration data: discharge ratio, Q/Qs, that is equaled 

or exceeded during percentage of time indicated, for water-data 

stations with more than 10 years of record and channel survey 

available 

Percentage 8 oftime g 

a. 

~ 

0.1 ---------------- 1.300 .5 ---------------- 1.140 1.0 ---------------- 1.040 2 ------------------ .920 4 ------------------ .770 6 ------------------ .660 8 ------------------ .580 

10 ------------------ .510 14 ------------------ .400 18 ------------------ .310 22 ------------------ .240 26 ------------------ .185 30 -------- --------- .150 35 ------------------ .130 40 ------------------ .115 45 ------------------ .105 50 ------------------ .098 55 ------------------ .093 60 ------------------ .090 65 ------------------ .086 70 ------------------ .082 75 ------------------ .078 80 ------------------ .075 85 ------------------ .071 90 ------------------ .068 95 ------------------ .062 

98 ------------------ .056 99 ------------------ .052 99.5 ---------------- .048 99.9 ---------------- .044 

0 

0 

0 

tO 

a. 

~ 

3.230 

2.739 

2.317 

1.896 

1.348 

1.096 

.899 

.758 

.534 

.393 

.281 

.211 

.162 

.129 

.115 

.104 

.096 

.088 

.083 

.077 

.073 

.069 

.065 

.060 

.056 

.051 

.046 

.044 

.041 

.028 

2.005 

1.668 

1.471 

1.257 

1.016 

.869 

.775 

.668 

.535 

.401 

.307 

.235 

.190 

.166 

.150 

.142 

.134 

.126 

.120 

.115 

.110 

.104 

.099 

.096 

.091 

.086 

.078 

.075 

.070 

.059 

0 

0 

.0 

IXl 

a. 

~ 

2.092 

1.673 

1.455 

1.237 

1.000 

.864 

.755 

.655 

.518 

.400 

.309 

.246 

.204 

.178 

.158 

.147 

.136 

.131 

.126 

.120 

.116 

.111 

.105 

.100 

.096 

.089 

.082 

.078 

.073 

.060 

Mean 

2.157 

1.803 

1.571 

1.328 

1.034 

.872 

.752 

.648 

.497 

.376 

.284 

.219 

.177 

.151 

.135 

.125 

.116 

.110 

.102 

.100 

.095 

.091 

.086 

.082 

.078 

.072 

.066 

.062 

.058 

.048 

within limits of available data, it appears appropriate to 

consider mean annual discharge as about one-fourth of 

bankfull discharge. Figure 28 indicates that a discharge 

of this magnitude has a flow duration of about 25 

percent, or for approximately one-fourth of the year, 

streamflow is equal to or greater than the average 

annua! discharge. 

The extremes of the flow-duration data presented in 

table 16 and illustrated in figure 30 are less consistent 

among stations than is the middle range of data. The 

cause of the inconsistency is probably related to a 

number of factors but predominantly is a function of size 

of drainage area. Small drainage areas are more likely 

to have flash-flood runoff than large drainage areas and 

thus have larger values of Q!Q8 at flow durations less 

than 2 percent. Likewise, the small drainage areas are 

more likely to nearly dry up at low flow and thus have 

smaller values ofQ!QB at flow durations greater than 98 

percent. This reasoning is explained by the fact that for 

a large drainage area to behave as erratically as a small 

drainage area, all small areas contributing to the large 

area must be identically and simultaneously acting erratically. The likelihood of this happening is remote. 

Further, other circumstances may contribute to inconsistent streamflow behavior. For example, a large lake 

near the downstream end of a small drainage area may 

sufficiently damp high-flow runoff and contribute to 

low-flow runoff that overall runoff may be more similar 

to runoff from a large area than a small area. Adequate 

leeway in the interpretation of data should be allowed 

for the variability in behavior from channel to channel. 

Still, the thesis of this report is based on the concept of a 

dominant discharge, and this discharge is adjusted to all 

upstream contributing factors. Thus, the technique not 

only provides average regionalized relations but also 

approximates streamflow characteristics for most individual streams. 

OTHER STREAMFLOW CHARACTERISTICS 

Computer storage and manipulation of streamflow 

data have greatly shortened analytical time and opened 

new doors in presentation of streamflow characteristics. 

One technique now commonly available is determination of the frequency of occurrence of cumulative 

streamflow events such as consecutive numbers of days 

of high and low flows. The need for data descriptive of 

such streamflow characteristics assumes great importance in many management decisions regarding regulatory controls on water use. For examples, the fishery 

biologist would be concerned with low-flow characteristics as related to in-stream needs of the aquatic biota. 

The irrigator or reservoir manager might be concerned 

with high-flow characteristics as related to the availability of water. 

Data sufficient to describe such streamflow characteristics are available only from gaging stations with 

continuous records. Generally, prediction of the frequency of occurrence is limited to a time interval twice 

the length of record. Thus, a long period of record is a 

valued asset. Within the study area, four streams have 

adequate data to define high- and low-flow characteristics. The data are summarized in table 18. Data are 

grouped by the number of days in the flows. Values of 

discharge are mean values for the number of consecutive days of that grouping. The recurrence interval is 

the expected frequency of occurrence for various mean 

values of discharge. 

For selected groupings of data, figure 32 illustrates 

high- and low-flow characteristics at the gaging station 

Salmon River near Challis, Idaho (13--2985.00). Explanation of the curves is best accomplished by an example. 

For a recurrence interval of 2 years, there will be 30 

consecutive days of high flow with a mean discharge of 

about 5,000 cubic feet per second or greater. At the same 

frequency of occurrence, there will be a 90 consecutiveday period with a mean discharge of about 3,500 cubic 

feet per second or greater. By contrast, there will be a 90 

conilecutive-day period of low flow with a mean 

discharge of 600 cubic feet per second or less and a 

30-day low flow with a mean discharge of 550 cubic feet 

per second or less. 

Because a recurrence interval of2 years represents an 

every-other-year, or average, characteristic (half the 

years will be higher, half will be lower), the curves of 

365-day high and low flow must cross at this recurrence 
CHANNELS AND WATERS A43 

5 I I I I I I I 

f-

~ 

' ~ 

2 

w 

(!) 

C( 

<( 

:I: 

() 

(f) 

0.5 0 

...J 

...J 

:::::> 

u.. 

~ 

rrr-

~ \ -

r- \ 

z 

<( 

Ill 

0 

1-

w 0.2 

(!) 

a: 

<( 

:I: 

() 

(f) 

0 

u.. 

0 0.1 

0 

~ a: 

0.05 

\ -

\ ~ ~'"" 

~ ~ 

~ ~-l::IJ 

f- -

-

0.02 

I I 0.01 

0.1 10 20 40 60 80 90 99 99.9 

DURATION, IN PERCENTAGE OF TIME 

FIGURE 31.-Dimensionless flow-duration curve for streamflow in the upper Salmon River area. 

interval, and the value of discharge represents the 

mean annual value. 

Preparation of curves similar to figure 32 for the other 

stations of record indicated that presentation of data on 

a dimensionless discharge basis would yield a single set 

of curves valid for all locations in the study area. The 

curves would be analogous to the dimensionless 

flow-frequency curve in figure 29 which utilizes annual 

peak discharges. 

Values of discharge in table 18 may be transformed to 

the dimensionless ratio discharge to bankfull discharge, 

and these values are given in table 19. 

DIMENSIONLESS HIGH-FLOW CHARACTERISTICS 

Mean values of the high-flow characteristics from 

table 19 are given in table 20 and plotted in figure 33 to 

provide dimensionless curves of high-flow characteristics for stream channels in the upper Salmon River 
A44 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 18.-High- and low-flow characteristics: value of discharge for 

given number of consecutive days at various recurrence intervals 

[Significant figures for values of discharge taken from computer analysis] 

A. High flow 

TABLE 18.-High- and low-flow characteristics: value of discharge for 

given number of consecutive days at various recurrence intervals 

-Con. 

B. Low flow-Continued 

Recurrence Recurrence interval 

(yrl 

1 day 3 days 7 days 15 days 30 days 90 days 365 days interval 1 day 3 days 7 days 15 days 30 days 90 days 365 days 

1.01 

1.05 

1.11 

1.25 

2 ------------

5------------

10 ------------ 25 ------------

50------------

100------------

200 

Salmon River near Challis (13-2985.00) 

2,770 

3,703 

4,299 

5,124 

7,060 

9,538 

11,077 

12,919 

14,224 

15,479 

16,696 

2,708 

3,588 

4,150 

4,929 

6,764 

9,134 

10,619 

12,411 

13,691 

14,929 

16,138 

2,538 

3,357 

3,882 

4,611 

6,337 

8,586 

10,006 

11,730 

12,969 

14,174 

15,355 

2,356 

3,075 

3,536 

4,179 

5,719 

7,764 

9,082 

10,708 

11,895 

13,063 

14,223 

2,231 

2,861 

3,260 

3,811 

5,109 

6,800 

7,873 

9,185 

10,134 

11,063 

11,979 

1,583 

1,992 

2,250 

2,605 

3,438 

4,523 

5,213 

6,060 

6,675 

7,278 

7,876 

Salmon River below Yankee Fork (13-2965.00) 

1.01 

1.05 

1.11 

1.25 

2 ------------

5 ------------ 10------------

25------------

50--------- -- 100------------

200 ------------

1.01 

1.05 

1.11 

1.25 

2 ------------

5 ------------

10------------

25----- ------ 50------------

100 ------------ 200 ------------

1.01 

1.05 

1.11 

1.25 

2 ------------

5 ------------ 10------------

25 ------------ 50------------

100 ------------ 200 ------------

, Q07 

2, .. ..;o 

2,877 

3,456 

4,806 

6,512 

7,555 

8,786 

9,647 

10,645 

11,250 

425 

603 

724 

901 

1,355 

2,010 

2,457 

3,032 

3,465 

3,902 

4,344 

381 

497 

570 

671 

903 

1,194 

1,372 

1,583 

1,731 

1,873 

2,010 

1,774 

2,399 

2,799 

3,352 

4,645 

6,285 

7,292 

8,485 

9,323 

10,122 

10,892 

1,647 

2,238 

2,617 

3,143 

4,374 

5,936 

6,896 

8,035 

8,833 

9,595 

10,328 

1,505 

2,039 

2,382 

2,857 

3,975 

5,402 

6,284 

7,334 

8,075 

8,783 

9,468 

Yankee Fork (13-2960.00) 

393 

565 

682 

852 

1,284 

1,897 

2,308 

2,828 

3,214 

3,599 

3,985 

363 

520 

626 

780 

1,172 

1,728 

2,100 

2,573 

2,924 

3,274 

3,626 

329 

471 

567 

705 

1,056 

1,550 

1,878 

2,292 

2,198 

2,901 

3,205 

Valley Creek (13-2950.00) 

367 

476 

544 

637 

853 

1,126 

1,295 

1,495 

1,638 

1,775 

1,907 

339 

441 

506 

594 

800 

1,062 

1,225 

1,420 

1,559 

1,692 

1,823 

302 

398 

459 

542 

736 

980 

1,129 

1,306 

1,431 

1,551 

1,666 

B. Low flow 

1,444 

1,913 

2,210 

2,617 

3,558 

4,739 

5,462 

6,316 

6,915 

7,486 

8,036 

308 

435 

518 

637 

930 

1,324 

1,578 

1,890 

2,116 

2,336 

2,552 

286 

372 

426 

499 

668 

878 

1,006 

1,157 

1,263 

1,364 

1,461 

1,031 

1,345 

1,541 

1,806 

2,404 

3,131 

3,564 

4,066 

4,412 

4,738 

5,048 

200 

279 

330 

400 

567 

777 

905 

1,056 

1,160 

1,259 

1,354 

216 

278 

316 

368 

484 

625 

709 

807 

874 

938 

999 

821 

950 

1,030 

1,140 

1,400 

1,740 

1,970 

2,240 

2,450 

2,660 

2,860 

522 

625 

687 

770 

955 

1,180 

1,317 

1,478 

1,592 

1,701 

1,806 

83 

108 

123 

143 

190 

247 

282 

322 

350 

378 

404 

106 

126 

139 

155 

192 

236 

264 

296 

319 

341 

362 

Recurrence 

interval (yrl 1 day 3 days 7 days 14 days 30 days 90 days 365 days 

1.01 

1.02 

1.04 

1.11 

1.25 

2 ------------

5 ------------ 10 ------------ 20 ------------ 100 ------------

Salmon River near Challis (13-2985.00) 

585 

566 

544 

509 

476 

413 

351 

320 

296 

252 

591 

578 

563 

537 

510 

453 

391 

358 

331 

281 

648 

635 

619 

592 

564 

505 

440 

406 

377 

323 

680 

667 

651 

623 

595 

536 

471 

436 

407 

353 

704 

691 

675 

648 

620 

561 

497 

462 

433 

378 

763 

748 

730 

700 

669 

604 

534 

495 

463 

404 

Salmon River below Yankee Fork (13-2965.00) 

1.01 

1.02 

1.04 

1.11 

1.25 

2 ------------

5 ------------

10 ------------ 20 ------------ 100 ------------

423 

414 

403 

383 

362 

314 

260 

232 

208 

166 

418 

413 

406 

391 

374 

329 

273 

242 

215 

167 

436 

431 

425 

411 

393 

347 

289 

254 

226 

174 

461 

453 

443 

425 

405 

357 

301 

270 

244 

196 

488 

477 

463 

440 

417 

368 

314 

286 

263 

220 

523 

510 

495 

471 

446 

394 

339 

310 

286 

242 

2,649 

2,462 

2,269 

2,000 

1,777 

1,415 

1,127 

1,001 

907 

754 

1,707 

1,606 

1,498 

1,339 

1,201 

963 

760 

668 

598 

482 

Cyrl 

1.01 

1.02 

1.04 

1.11 

1.25 

2 ------------

5 ------------ 10 ------------ 20 ------------ 100 ------------

1.01 

1.02 

1.04 

1.11 

1.25 

2 --------------

5 -------------- 10 --------------

20---------------

100 --------------

48 

48 

47 

46 

43 

36 

25 

20 

16 

9 

87 

84 

80 

74 

69 

59 

50 

46 

42 

36 

Yankee Fork (13-2960.00) 

46 

46 

45 

45 

43 

37 

28 

23 

18 

11 

52 

50 

49 

46 

43 

38 

32 

29 

27 

22 

53 

52 

50 

47 

44 

39 

33 

30 

28 

24 

Valley Creek (13-2950.00) 

90 

87 

83 

77 

72 

61 

52 

47 

43 

36 

95 

91 

87 

81 

75 

63 

53 

48 

44 

36 

101 

96 

92 

84 

78 

66 

54 

49 

45 

37 

56 

54 

52 

49 

46 

41 

35 

32 

30 

25 

104 

99 

94 

87 

81 

69 

58 

53 

49 

42 

60 

58 

57 

53 

50 

44 

38 

35 

32 

28 

116 

110 

104 

95 

88 

76 

66 

61 

57 

51 

387 

358 

327 

283 

247 

187 

140 

119 

104 

80 

334 

315 

294 

264 

238 

193 

154 

137 

124 

101 

area. Interpretation of the curves in figure 33 is the 

same as for the station curves in figure 32; however, it 

should be remembered that the curves in figure 33 are 

average curves for the area, and thus individual 

streams may deviate somewhat from the average. It 

may be noted that the 365-day high-flow curve for the 

average year has a discharge ratio value of about 0.25. 

This value of discharge ratio corresponds to the value at 

mean annual discharge and is in agreement with an 

earlier determination of the mean annual discharge 

being approximated by a discharge ratio of 0.25. 

The number of available water-data stations contributing to the information presented in figure 33 is 

less than the number of available stations contributing 

to the dimensionless peak-flow frequency relation in 

figure 29. This difference in number of stations does not 

affect the concepts of analysis but does provide slight 

inconsistencies in results. For example, the curve in 

figure 29 indicates that instantaneous bankfull discharge has a frequency of occurrence of about 1.5 years. 

However, figure 33 indicates that 1-day bankfull 

discharge (a slightly rarer event than instantaneous 

bankfull discharge) has a frequency of occurrence of 

about 1.3 years. Such inconsistencies are sufficiently 

minor that it is justified to use all available data for any 

given analysis rather than a select set of data common 

to all analyses. 

DIMENSIONLESS LOW-FLOW CHARACTERISTICS 

In the same manner as for high-flow characteristics, 

dimensionless values of discharge for low-flow characteristics are given in table 21, and mean values are 
CHANNELS AND WATERS A45 

High flow 

-- Lowflow 10,000 f-----...:r-.:.:_:_:::::.:..:._ __ -+----+--------+--=-~::::::::::;~-~::::::::...__----t--------==-+-__,=:::::::::==-1 

Cl 

z 

0 

() 

w 5000 

en 

a: 

w 

a.. 

..... 

w 

w 

LL 

() 2000 

iD 

::::> 

() 

~ 

u.i 1000 (!) 

a: 

<( 

:c 

() 

en 

Ci 500 

200 ~--~--~--~~~~~~~--~---k--~---L~~~~_L----~---L----~--~~--L_~~ 

1.01 1.1 1.5 2 5 10 20 50 100 

RECURRENCE INTERVAL, IN YEARS 

FIGURE 32.-High- and low-flow characteristics, Salmon River near Challis, Idaho. 

plotted in figure 34. The 365-day low-flow curve, which 

represents the annual mean values of discharge, again 

shows a value of mean annual discharge ratio of about 

0.25 at a recurrence interval of 2 years. The 365-day 

low-flow curve is the inverse of the 365-day high-flow 

curve, and either of these curves can be utilized to 

illustrate some average characteristics of runoff. For 

example, at a 100-year recurrence interval, maximum 

daily mean discharge will be at least 3.2 times as large 

as bankfull discharge. There will be a 30 consecutiveday period with a mean discharge at least 2.2 times as 

large as bankfull discharge, a 90 consecutive-day period 

with a discharge ratio of about 1.3 or larger, and a 

maximum mean annual discharge about 40 percent of 

bankfull discharge. Likewise at the same 100-year 

recurrence interval, the lowest daily mean discharge is 

about 3.5 percent ofbankfull discharge. The mean value 

of discharge for 30 consecutive days is less than 5.1 

percent of bankfull, for 90 consecutive days is less than 

5.7 percent of bankfull, and the lowest mean annual 

discharge is about 12 percent of bankfull discharge. 

SUMMARY DISCUSSION OF STREAMFLOW DATA 

Discharge measurements made at 39 locations were 

sufficient to define streamflow-rating curves for each 

station and allowed preparation of at-a-station 

hydraulic-geometry curves of surface width, mean 

depth, and mean velocity as functions of discharge. 

Channel-geometry surveys allowed determination of 

bankfull discharge; bankfull values of the other 

hydraulic- and channel-geometry parameters were 

determined from the at-a-station curves. These 

bankfull values when plotted as functions of bankfull 

discharge constitute downstream curves of hydraulic 

geometry and, in essence, allow the prediction of 

bankfull discharge for any measured values of bankfull 

width, depth, or flow area. 

Alternative to this presentation (figs. 23-26), 

bankfull values of the hydraulic- and channel-geometry 

parameters may be plotted against size of drainage 

area, which itself may be considered a measure of 

downstream location. Figure 35 illustrates bankfull 

discharge as a function of drainage area, and figure 36 

shows the same data expressed as a unit discharge or 

runoff, R, in cubic feet per second per square mile. 

Values of the other hydraulic parameters are shown as 

functions of drainage area in figures 37-40. Comparison 

of these figures with the similar downstream curves of 

hydraulic geometry indicates one significant fact. This 

is that the scatter of data is less in the downstream 
A46 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 19.-High- and low-flow characteristics: value of discharge TABLE 19.-High- and low-flow characteristics: value of discharge 

ratio, Q/QB, for given number of consecutive days at various ratio, Q/QB, for given number of consecutive days at various 

recurrence intervals recurrence intervals-Continued 

A. High flow B. Low flow-Continued 

Recurrence Recurrence 

interval 1 day 3 days 7 days 15 days 30 days 90 days 365 days interval 1 day 3 days 7 days 15 days 30 days 90 days 365 days 

(yrl (yrl 

Salmon River near Challis (13-2985.00) Yankee Fork (13-2960.00) 

1.01 ---------- 0.504 0.493 0.462 0.429 0.406 0.288 0.149 1.01 ---------- 0.067 0.065 0.073 0.074 0.079 0.084 0.544 

1.05 ---------- .674 .653 .611 .559 .520 .362 .173 1.02 ---------- .067 .065 .070 .073 .076 .081 .502 

1.11 ---------- .782 .755 .706 .643 .593 .409 .187 1.04 ---------- .066 .063 .069 .070 .073 .080 .459 

1.25 ---------- .932 .897 .839 .760 .693 .474 .207 1.11 ---------- .065 .063 .065 .066 .069 .074 .397 

2 ------------ 1.284 1.267 1.153 1.040 .929 .625 .255 1.25 ---------- .060 .060 .060 .062 .065 .070 .347 

5 ------------ 1.735 1.661 1.562 1.412 1.237 .823 .316 2 ------------ .051 .052 .053 .055 .058 .062 .263 

10 ------------ 2.015 1.931 1.820 1.652 1.432 .948 .358 5 ------------ .035 .039 .045 .046 .049 .053 .197 

25 ------------ 2.350 2.257 2.136 1.918 1.671 1.102 .407 10 ------------ .028 .032 .041 .042 .045 .049 .167 

50 ------------ 2.587 2.490 2.359 2.164 1.843 1.214 .446 20 ------------ .022 .025 .038 .039 .042 .045 .146 

100 ------------ 2.815 2.715 2.578 2.376 2.012 1.324 .484 100 ------------ .013 .015 .031 .034 .035 .039 .112 

200 ------------ 3.037 2.935 2.793 2.587 2.179 1.433 .520 

Salmon River below Yankee Fork (13-2965.00) Valley Creek (13-2950.00) 

1.01 ---------- 0.483 0.474 0.440 1.01 ---------- 0.087 0.090 0.095 0.101 0.104 0.116 0.334 0.402 0.386 0.276 0.140 1.02 ---------- .084 .087 .091 .096 .099 .110 .315 1.05 ---------- .658 .641 .598 .545 .511 .360 .167 1.04 ---------- .080 .083 .087 .092 .094 .104 .294 1.11 ---------- .769 .748 .700 .637 .591 .412 .184 1.11 ---------- .074 .077 .081 .084 .087 .095 .264 1.25 ---------- .924 .896 .840 .764 .670 .483 .206 1.25 ---------- .069 .072 .075 .078 .081 .088 .238 2 ------------ 1.285 1.242 1.170 1.063 .951 .643 .255 2 .059 .061 .063 .066 .069 .076 .193 5 1.741 1.680 1.587 1.444 1.267 .837 .316 ------------ ------------ 5 .050 .052 .053 .054 .058 .066 .154 10 ------------ 2.020 1.950 1.844 1.686 1.460 .953 .352 ------------

10 .046 .047 .048 .049 .053 .061 .137 ------------ 25 ------------ 2.349 2.269 2.148 1.961 1.689 1.087 .395 20 ------------ .042 .043 .044 .045 .049 .057 .124 50 ------------ 2.579 2.493 2.362 2.159 1.849 1.180 .426 100 .036 .036 .036 .037 .049 .051 .101 100 ------------ 2.798 2.706 2.566 2.348 2.002 1.267 .455 ------------

200 ------------ 3.008 2.912 2.761 2.532 2.149 1.350 .483 

Yankee Fork (13-2960.00) TABLE 20.-High-flow characteristics: mean value of discharge ratio, 

1.01 ---------- 0.597 0.552 0.510 0.462 0.432 0.281 0.117 Q/QB, for given number of consecutive days at various recurrence 

1.05 ---------- .847 .794 .730 .662 .611 .392 .152 intervals for water-data stations with more than 10 years of record 1.11 ---------- 1.017 .958 .879 .796 .728 .463 .173 

1.25 ---------- 1.265 1.197 1.096 .990 .895 .562 .201 and channel survey available 2 ------------ 1.903 1.803 1.646 1.483 1.306 .796 .267 5 ------------ 2.823 2.664 2.427 2.177 1.860 1.091 .347 Recurrence 10 ------------ 3.451 3.242 2.949 2.638 2.216 1.271 .396 25 ------------ 4.258 3.972 3.614 3.219 2.654 1.483 .452 interval 1 day 3 days 7 days 15 days 30 days 90 days 365 days 

50 ------------ 4.867 4.514 4.107 3.649 2.972 1.629 .492 (yrl 

100 ------------ 5.480 5.055 4.598 4.074 3.281 1.768 .531 200 ------------ 6.101 5.597 5.093 4.501 3.584 1.901 .567 1.01 ---------- 0.491 0.472 0.438 0.399 0.378 0.265 0.128 

1.05 ---------- .669 .641 .595 .541 .504 .348 .155 

Valley Creek (13-2950.00) 1.11 ---------- .785 .751 .698 .634 .585 .400 .171 

1.25 ---------- .948 .907 .842 .764 .689 .472 .192 

2 ------------ 1.344 1.291 1.192 1.081 .964 .637 .242 

1.01 ---------- 0.381 0.367 0.339 0.302 0.286 0.216 0.106 5 ------------ 1.873 1.783 1.660 1.503 1.211 .844 .304 

1.05 ---------- .497 .476 .441 .398 .372 .278 .126 10 ------------ 2.215 2.105 1.960 1.775 1.529 .970 .343 

l.lL ___________ .570 .544 .506 .459 .426 .316 .139 25 ------------ 2.635 2.498 2.330 2.101 1.793 1.120 .388 

1.25 ---------- .671 .637 .594 .542 .499 .368 .155 50 ------------ 2.941 2.784 2.597 2.351 1.982 1.224 .421 

2 .903 .853 .800 .736 .668 .484 .192 100 ------------ 3.242 3.063 2.859 2.587 2.165 1.324 .453 ------------ 200 3.539 3.338 3.118 2.822 2.343 1.421 .483 5 ------------ 1.194 1.126 1.062 .980 .878 .675 .236 ------------

10 ------------ 1.372 1.295 1.225 1.129 1.006 .709 .264 25 ------------ 1.583 1.495 1.420 1.306 1.157 .807 .296 50 ------------ 1.731 1.638 1.559 1.431 1.263 .874 .319 100 ------------ 1.873 1.775 1.692 1.551 1.364 .938 .341 200 ------------ 2.010 1.907 1.823 1.666 1.461 .999 .362 TABLE 21.-Low-flow characteristics: mean value of discharge ratio, 

B. Low flow Q/QB> for given number of consecutive days of various recurrence 

intervals for water-data stations with more than 10 years of record 

Recurrence and channel survey available interval 1 day 3 days 7 days 14 days 30 days 90 days 365 days 

(yr) Recurrence 

interval 1 day 3 days 7 days 14 days 30 days 90 days 36' .iays 

Salmon River near Challis (13-2985.00) (yr) 

1.01 ---------- 0.106 0.107 0.118 0.124 0.128 0.139 0.482 1.01 ---------- 0.093 0.094 0.101 0.106 0.110 0.120 C.454 

1.02 ---------- .091 .092 .098 .103 .108 .116 424 1.02 ---------- .103 .105 .115 .121 .126 .136 .448 1.04 ---------- .088 .090 .096 .100 .104 .112 ~~$12 

1.04 ---------- .099 .102 .113 .118 .123 .133 .413 1.11 ---------- .084 .086 .091 .094 .098 .106 .. NS 1.11 ---------- .093 .098 .108 .113 .118 .127 .364 1.25 ---------- .078 .081 .086 .089 .093 .100 '?.G7 1.25 ---------- .087 .093 .103 .108 .113 .122 .323 

2 .025 .082 .092 .097 .102 .110 .257 2 ------------ .070 .071 .075 .078 .082 .088 ~4.1 

------------ 5 .055 .059 .064 .067 .070 .077 .J.90 5 .064 .071 .080 .086 .090 .097 .205 ------------ ------------ 10 .049 .053 .058 .061 .065 .071 .166 10 ------------ .058 .065 .074 .079 .084 .090 .182 20 ------------

.044 .051 .053 .056 .060 .066 .149 20 .054 .060 .069 .074 .079 .084 .165 ------------ ------------ 100 .035 .037 .043 .047 .051 .057 .120 100 ------------ .046 .051 .059 .064 .069 .073 .137 ------------

Salmon River below Yankee Fork (13-2965.00) 

1.01 ---------- 0.113 0.112 0.117 0.123 0.130 0.140 0.456 

1.02 of hydraulic geometry than in the ---------- .111 .110 .115 .121 .128 .136 .429 curves curves 1.04 ---------- .108 .109 .114 .118 .124 .132 .401 relating to size of drainage area. Several data points in 1.11 ---------- .102 .105 .110 .113 .118 .126 .358 

1.25 ---------- .097 .100 .105 .108 .111 .119 .321 2 figures 37-40 consistently account for the largest ------------ .084 .088 .093 .095 .098 .105 .257 5 ------------ .070 .073 .077 .080 .084 .091 .203 10 scatter in data, and these are data from the Road Creek ------------ .062 .068 .068 .072 .076 .083 .179 20 ------------ .056 .074 .060 .065 .070 .076 .160 100 basin (stations 13-2976.70 to 13-2977 .00). The expla- ------------ .044 .047 .046 .052 .059 .065 .129 
w 

(,!) 

a: 

~ 

:I: 

CHANNELS AND WATERS A47 

g 2 r-------~----------+-----~----~---------+=-~~--~~~~~--~~------~~~~~--~ 

iS 

.....1 

.....1 

::> 

LL. 

::.::: 

z 

~ 

m 

0 

1-

w 

~ 0.5 ~~~~-+----~~~+-----~---------------+----------~--------+-----------~--------~ ~ 

:I: 

() 

CJ) 

0 

LL. 

0 

~ 0.2 r-------~----~~~+------r---------------+----------~--------+-------------~------~ 

~ 

a: 

w 

(,!) 

0.1 1.01 1.1 1.5 2 5 10 20 50 100 

RECURRENCE INTERVAL, IN YEARS 

FIGURE 33.-High-flow characteristics for upper Salmon River area. 

~ 0.5 r--------+----------+-----+---------------4---------~--------~------------~------~ :I: 

() 

CJ) 

0 

.....1 

.....1 

::> 

u. 

~ 0.2 r--------+----------~----+-------~---=--+----------r---------r------------~------~ 

~ 

m 

0 

1-

w 

~ 0

·

1 

0 

~ 0.05 ~~~~~!:~~~:::t~~~~~~~~~3~0~-d~a~y~~~~i!~ii~~~~;;;;;;;;;;~~~~;;;J 0 

~ a: 

0.02 ~--~--~--~--~~~~~~--~--L---~--~_L~~~-L----~---L----~--~--L-~~~~ 1.01 1.1 1.5 2 5 10 20 50 100 

RECURRENCE INTERVAL, IN YEARS 

FIGURE 34.-Low-flow characteristics for upper Salmon River area. 

nation is that this basin is wholly in the extreme reflected in the graphs of figures 37-40. Stream 

northeast part of the study area and receives much channels in this area oflower runoff are still dependent 

lower amounts of precipitation than other areas. The on a dominant discharge for their size and shape. 

result is significantly lower values of runoff, and this is Because of the lower runoff, the channel size is smaller, 
A48 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

10,000 I T - I I I I I I I I I I I I I I / I I I I 

Ii-

- -

" 0 

0 

z 

0 

() 

w 

(/') 

a: 

w 

a.. 1000 

1-

w 

-

v v -

- -

[7 0 

r-.0/ 

i- 0 - i- -

1- - w 

LL 

() 

Vc 1- / 0 -

co v ~ 0 :::> 

() 

~ 

i0 0 ..... 0 - CD 

u..i 

(!) 

a: 

<( 

I 

() 

(/') 

0 100 

....J 

....J 

::::> 

LL 

::::.:::: 

z 

<( 

CD 

0 ~ 

/ ~ =28.3DA0·

69 

1-

? ~ - 1- -

I- 0 -

I- -

0 

v~ -

10 I I I I I I I I I I I I I 

1 10 100 1000 10,000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 35.-Bankfull discharge as a function of drainage area. 

and this is illustrated by the several data points which 

plot low in the figures. 

Because the hydraulic- and channel-geometry 

parameters are plotted against dominant discharge 

(bankfull discharge) in the downstream curves of 

hydraulic geometry, a scatter to the data because of the 

reasons just discussed does not occur in the graphs of 

figures 23-26. It appears then that the size of the stream 

channel is a more accurate measure of bankfull 

discharge than is the size of drainage area, and this fact 

further reinforces the concepts of channel geometry and 

bankfull discharge as used in this paper. 

Excluding the Road Creek basin data, logtransformed regression equations were fitted to the data 

of figures 3&-40. The equations and their respective 

correlation coefficients are 

WB=8.1DA0.3B 

DB =0.69 DA 0.27 

AB =5.6 DA 0.65 

VB=5.1 DA0·

05 

(r=0.844), 

(r=0.879), 

(r=0.924), 

(r=0.324), 

or 

QB=28.3 DA0.69 (r=0.959), 

RB=28.3 DA -0.3! (r=0.831). 

Data other than the Road Creek basin data fit these 

equations fairly well and indicate that other than in the 

northeast corner of the study area, physiographic 

factors are sufficiently homogeneous to allow drainage 

area to be correlative with other hydraulic- and 

channel-geometry parameters. But this statement does 

not override the fact that for any drainage area and 

physiographic setting, channel size is a better determinant of discharge than drainage area size. 

Exponents in the foregoing equations indicate the 

rate of increase in the various parameters as size of 

drainage area increases. Because the product of width, 

depth, and velocity is discharge, the rate of increase of 

the three individual parameters as functions of discharge (downstream hydraulic geometry) is in about the 

same ratio as their rate of increase as functions of 

drainage area size. 
CHANNELS AND WATERS A49 

100 I I I I I I I I I I I I I I I I I I I I 

r- -

1- -

r- -

w 

....J -

~ 

w 

a: 

<( 

::::> ~ o cp -

~0 (\ 

0 

C/) 

a: 

w 

a.. 

0 10 

z 

0 

(.) 

w 

C/) 

............... 

~ 0 

n ~ ~ 0 

rr- 0 0~0~ 

~ -

r-

~ -

1- 0 0 -

n r---...... a: 

w 

a.. 

1-

w 

w 

u. 

(.) 

m 

-......_ 0 0 0 c ~ -

j---.Q -

R8 = 28.3 DA-0·

31 I'----

--...... ::::> 

(.) 

~ n n 

u." r- ~ .._, -

u. 

0 

z 

::::> 

,_ -

r- - ,_ 0 -

a: 

...J 

...J -

::::> 

u. 

~ -

z 

<( 

Ill 

0.1 I 

1 10 100 1000 10,000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 36.-Bankfull runoff as a function of drainage area. 

Within the study area, seven current and discontinued gaging stations provide records to determine 

average annual discharge. These records indicate that 

average annual discharge relates to size of drainage 

area according to 

QA =2.49 DA 0·

87 (r=0.974). 

Comparison of this equation with the equation for 

bankfull discharge allows the expression 

QA/QB=0.088 DA 0.173, 

which for a drainage area of 10 square miles yields a 

QA/QB value of0.13, for 100 square miles a value of0.20, 

and for 1,000 square miles a value of 0.29. The same 

type analysis using only those gaging stations with 

paired data for which values of both average annual 

discharge and bankfull discharge are available provides 

the expression 

This equation gives a QAIQB value of0.22 for a drainage area of 100 square miles and 0.26 for a drainage 

area of 1,000 square miles. 

It is normally expected that the ratio QAIQB increases 

with increases in size of drainage area, and the 

foregoing equations indicate the range in values of 

QA/QB expected in the area of study. The only data 

available to confirm these values are given in table 15 

and range from a QA/QB value of 0.20 for 147 square 

miles to 0.27 for 1,800 square miles. The mean 

QAIQBvalue of all data is 0.25. For convenience and 

simplicity of analysis, the ratio QAIQB is considered to 

be 0.25 for all sizes of drainage areas, or in the upper 

Salmon River area, average annual discharge is about 

25 percent ofbankfull discharge. This value will be used 

in the water-quality data section of this report. It should 

be noted, however, that the QAIQB value of0.25 cannot 

be used indiscriminately. For example, values of 

bankfull runoff given in table 12 cannot be multiplied 

by 0.25 to obtain exact values of mean annual flow. 
A 50 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

1000 r- I I I I I I I I I I I I I I I I I I I I 

'-

-

-

,.... 

~ 

o ....... ~ 

0 0 ~ 

0 

~ ~ 

~ D h 

~ 

w 

w 100 LL 

~ 

::C 

~ 

0 () 7 ......... 0 - 0 

D o ~ Po 0 

0 

~ 

w 

0 c W8 = 8.1 OA0·

38 -

~ 0 9n 0 

() 

<( 

LL 

a: 

:::> 

~ ~ 

oo 

~ 

~ 0 8 00 -

C/) 

...J 

...J 

:::> 

LL 

~ 10 z 

<( 

co 0 -

-

- -

1 1 _l I I I I I 

1 10 100 1000 10,000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 37 .-Bankfull surface width as a function of drainage area. 

The at-a-station curves of hydraulic geometry may be 

converted to dimensionless curves by dividing the 

values of all parameters by the value of bankfull 

discharge for each station. The result is a set of 

single-curve relations descriptive of all stream channels 

at all locations. Two of the curves, those for depth and 

flow area and described by 

and 

D/DB =(Q/QB)0.40 

A/AB =(Q!QB )0.54, 

may be considered forms of a dimensionless rating curve 

and are useful in predicting values of bankfull 

discharge in ungaged areas. 

Flow duration is defined as the percentage of time a 

given flow is equaled or exceeded. On a dimensionless 

basis, flows of magnitude QIQB=2.0 are exceeded about 

0.2 percent of the time, bankfull stage (Q/QB = 1.0) is 

exceeded about four percent of the time, and average 

annual discharge (Q!Q8 =0.25) is exceeded about 25 

percent of the time. The flow exceeded 50 percent of the 

time is about 12 percent of bankfull discharge. 

Flow frequency is defined in terms of a recurrence 

interval, or the average time between recurrence of a 

given event. Bankfull discharge has a recurrence 

interval of about 1.5 years, which is about 2 out of every 

3 years. Every year should have a flow of at least 

one-half of bankfull· discharge, while a flow of magnitude QIQB =3.0 occurs only once in every 100 years. A 

recurrence interval of 2 years implies a normal year; 

that is, half the years should experience higher flows 

and the other half should experience lower flows. The 

noriJJ.al or median year can expect a peak streamflow of 

about 120 percent of bankfull discharge. 

Likewise, the median year can expect 30 consecutive 

days with a mean discharge of about 90 percent or more 

of bankfull and 90 consecutive days with a mean 

discharge of about 60 percent or more of bankfull. 

Conversely, in the low-flow season, the median year can 
1-

w 

w 

LL 

~ 

:i 

b: 

w 

c 

z 

<( 

w 

::; 

0 

z 

0 

u 

w 

rn 

ct 

w 

a.. 

1-

w 

w 

LL 

~ 

>-=' 1-

5 

0 

..J 

w 

> 

z 

<( 

w 

:::!: 

..J 

..J 

::::> 

LL 

:::.::: 

z 

<( 

m 

10 

0.1 

100 

10 

1 

t-

~ 

rrr1-

0 

t;_..---

1-

~ 

rtr-

_l J 

1 

1-

1-

rr1-

1-

r1- 0 1-

1- Oo 

1-

I 1 

1 

CHANNELS AND WATERS A51 

-

~ 0 

-~ -

~ ~v -

( v---- -

<D p_.P-~ 

0 <D 

~ 0 

;~ 

0 

~ 0~ 0 0 8 = 0.69 DA 0·

27 

D 

0 ~ ~ 

-

-

-

::) -

-

-

_1_ I I I I I _l _l_ _l _l I I I I I I I I I I _L 

10 100 1000 10,000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 38.-Bankfull mean depth as a function of drainage area. 

I I I I I I I I I I I I ·-

-

-

-

-

V 8 = 5.1 DA 0·

05 

= '-' - 0 

oCOo cg 0 __0_ ...;;;; 

<0(1 0 -

~ ( - x_ ~u Pn -= OVJ "' '-' c -

(D 0 0 -

_0_ 

I _l _l_ _.[ 

10 100 1000 10,000 

DRAINAGE AREA, IN SQUARE MILES 

FIGURE 39.-Bankfull mean velocity as a function of drainage area. 

expect 30 consecutive days with a mean discharge of 

about 8.2 percent or less of bankfull and 90 consecutive 

days with a mean discharge of about 9.0 percent or less 

of bankfull. 

COLLECTION AND ANALYSIS OF 

WATER-QUALITY DATA 

Water samples for the laboratory determination of 
A 52 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

1000 1- I I I I I I I I I I v I I I I 1. 

1- 0 0 I- 0 / IIr- v / -

,.-... b 

./" 

1-

w 

0/ Va w 

LL. 100 ~ 

( 

~ - - CD -

- 0 / 0 - -

_R 

0 0 -

w 

a: 

<t 

::::) 

0 

(f) 

-

Va ~ -

0 - <6 -

Y. 

0 

n 

~ 

<i. 

w 

a: 

<t 

~ 

0 

~ v A8 = 5.6 DA 0·

65 ...J 

LL. 

0 

0 I 

v / 0 0 -

-

0 -

-

....J 

...J 

::::) 

LL. 10 ~ 

z 

<( 

cc 

I- -

'-- -

1 I I I I I I I I I I I I I I I I I I I I I I I 

1 10 100 1000 10,000 

DRAINAGE AREA, IN SQUARE MILES 

FIGuRE 40.-Bankfull flow area as a function of drainage area. 

the chemical composition of stream water were collected 

from the 39 principal water-data stations given in table 

3 and at 16 additional sites. These additional sites are 

among the water-data stations given in table 22 as 

locations of biological studies. 

The chemical-quality analyses were of two types. One 

type primarily includes determination of major-ion 

concentrations and is referred to and published by the 

U.S. Geological Survey as a standard analysis. Such 

analyses were performed on 250 water samples collected at 55 different locations. These analyses are 

included in table 40. The second type of analysis 

includes determination of concentrations of 21 selected 

trace elements chosen because of their suspected relevance to the stream-water composition. One hundred 

thirteen such analyses were performed on samples 

collected at 17 locations. These data are included in 

table 41. 

Sediment characteristics were documented with 271 

determinations of mean suspended-sediment concentrations for the 39 principal water-data stations. These 

mean values of suspended-sediment concentration 

represent only a fraction of the total number of samples 

obtained and analyzed. These data are included in 

table 42. 

Other water-quality data collected include temperature, turbidity and bedload transport, and bacterial and 

biotic observations. These are presented in later 

sections of this report. 

It should be noted that subsequent introductory 

paragraphs and brief definitions are not intended to be 

reviews of principles and methods of analysis, but to 

span the gaps between concepts, data collected, and 

interpretations. For more detailed discussions of principles and methods, the reader is referred to the 

bibliography, particularly standard references such as 

Hem (1970), Rainwater and Thatcher (1960), Fairbridge (1972), and McKee and Wolf (1963). 
CHANNELS AND WATERS A 53 

TABLE 22.-Water-data stations for biological studies and for which water-quality data exist in addition to data for stations given in table 3 

U.S. Geological Altitude Drainage 

Survey Stream Longitude Latitude area station No. (ft) (mi2 ) order 

13--2933.50-------- 114°38'29" 44°02'53" 9,040 0.87 1 2973.84_ _______ 114°33'15" 43°55'44" 7,110 18.05 5 2973.88 ________ 114°33'18" 43°55'46" 7,110 8.62 4 2973.94 ________ 114°30'32" 43°58'02" 6,850 41.22 5 2974.00 ________ 114°28'42" 44°00'23" 6,570 75.56 6 2974.02 ________ 114°38'33" 43°58'42" 7,900 4.10 3 2974.04 ________ 114°28'48" 44°02'21" 6,370 48.89 5 297 4.34-------- 114°36'08" 43°03'13" 9,840 .36 1 297 4.36-------- 114°36'04" 44°03'15" 9,800 .38 1 2974.38 ________ 114°35'39" 44°03'06" 9,280 1.01 1 2974.40 ------- 114°34'29" 44°03'30" 8,:<~.o 2.83 2 

2974.45-------- 114°32'18" 44°03'59" 8,( 0 9.94 3 2974.50 ________ 114°36'44" 44°05'57'' 6,' jO 18.13 3 2974.60 ________ 114°37'04" 44°06'43" 10,190 .16 1 2974.62-------- 114°37'00" 44°06'47" 10,010 .18 1 2974.66 ________ 114°35'04" 44°07'03" 9,1 20 1.65 2 2974.70 ________ 114°34'13" 44°06'39" 8,440 7.20 3 2974.7 4-------- 114°31'56" 44°06'39" 8,200 .72 1 

2974.80 ________ 114°31'16" 44°07'47" 7,230 12.77 3 2974.85 ________ 114°32'07" 44°07'55" 7,300 3.32 3 2975.00 ________ 114°26'47" 44°07'03" 6,300 16.61 4 2975.80-------- 114°14'47" 44°06'01" 6,070 85.44 5 2975.90 ________ 114°10'52" 44°05'45" 6,870 10.40 3 2976.00-------- 114°17'54" 44°09'11" 5,730 112.54 6 2976.70 ________ 114°02'03" 44°10'36" 6,140 37.86 4 2976.80 ------- 114°12'07" 44°10'40" 6,140 32.59 4 2977.00-------- 114°17'09" 44°11'15" 5,630 84.98 5 2978.80-------- 114°16'09" 44°13'19" 5,710 34.00 4 2979.00 ________ 114°16'52" 44°13'31" 5,530 34.26 4 2980.00-------- 114°17'07'' 44°13'29" 5,520 531.75 7 2973.12 1 ------

2973.14 1 ------

2973.16 1 ------

'Miscellaneous water-quality data stations. 

It should also be emphasized that any part of a 

water-quality study is only as valid as the water sample 

is characteristic of the stream from which it was 

collected and at best represents a single site on the 

stream at a moment in time-an at-the-site condition. 

Techniques of sample collection are detailed by Brown, 

Skougstad, and Fishman (1970). Elaboration of these 

techniques is not necessary, but it should be stated that 

all samples were carefully collected in clean bottles at a 

point in the stream representative of the entire flow in 

the stream at that instant. Samples collected for 

trace-element analysis were generally filtered immediately, and always within a few hours, through a 

0.45-micrometer membrane filter, acidified with 

triple-distilled reagent-grade nitric acid to a pH value of 

less than 3.0, and shipped to the laboratory in 

acid-rinsed bottles. Samples for major-ion and nutrient 

analyses were collected in bottles prerinsed with stream 

water from the sampling locale. All samples were kept 

cool from time of collection to time of analysis. For 

preservation, especially of the nutrients, in 1972 the 

samples were shipped to the laboratory in insulated 

containers packed with ice. In 1970 and 1971, separate 

samples for nutrient analysis were collected, and these 

were preserved with mercuric chloride. 

All chemical analyses except streamside determinations were made by the Central Laboratory, U.S. 

Geological Survey, Salt Lake City, Utah. Suspendedsediment concentrations in 1971 were determined by 

the Sediment Laboratory, California District, U.S. 

Geological Survey, Sacramento, Calif. SuspendedName 

Fourth of July Creek below Fourth of July Lake near Obsidian. Idaho. South Fork of East Fork Salmon River near Clayton, Idaho. West Fork of East Fork Salmon River near Clayton, Idaho. East Fork Salmon River below Ibex Creek near Clayton, Idaho. East Fork Salmon River below Bowery Guard Station near Clayton, Idaho. Germania Creek above Galena Gulch near Clayton, Idaho. Germania Creek near Clayton, Idaho. Little Boulder Creek above Avalanche Dam at Four Lakes Basin near Clayton, Idaho Little Boulder Creek below Avalanche Dam at Four Lakes Basin near Clayton, Idaho. Little Boulder Creek above Quiet Lake near Clayton, Idaho. Little Boulder Creek above Baker Lake near Clayton, Idaho. Little Boulder Creek below Boulder Chain Lake outlet near Clayton, Idaho Little Boulder Creek near Clayton, Idaho. Mountain Goat Basin Lake outlet above Walter Lake near Clayton, Idaho. Snowbank tributary to Big Boulder Creek above Walter Lake near Clayton, Idaho. Tin Cup Lake tributary to Big Boulder Creek near Clayton, Idaho. Big Boulder Creek below Tin Cup Lake Creek near Clayton, Idaho. Slack Creek tributary to Big Boulder Creek above Little Redfish Lake Creek near Clayton, Idaho. Big Boulder Creek at Livingston Mill near Clayton, Idaho. Jim Creek at Livingston Mill near Clayton, Idaho. Big Boulder Creek near Clayton, Idaho. Herd Creek above Lake Creek near Clayton, Idaho. Lake Creek below Herd Lake near Clayton, Idaho. Herd Creek near Clayton, Idaho. Road Creek above Horse Basin Creek near Clayton, Idaho. Horse Basin Creek near Clayton, Idaho. Road Creek near Clayton, Idaho. Spar Canyon at Lower Sprina near Clayton, Idaho. Spar Canyon near Clayton, I aho. East Fork Salmon River near Clayton, Idaho. Pat Hu!hes Creek above mine adit discharge. Mine a it discharge. Mine adit discharge below stilling pool. 

sediment concentrations in 1972 were determined by 

the Idaho District, U.S. Geological Survey, Boise, Idaho. 

A BASIS FOR COMPARISON AND INTERPRETATION 

OF WATER QUALITY 

A source of the chemical constituents of stream water 

is the chemical makeup of precipitation falling on the 

area, but the primary source is the composition of the 

earth's crust over and through which the waters of 

precipitation travel to reach the river channel. 

No measurements of dissolved solids in precipitation 

were made in the study area, but analysis of data 

reported by Junge and Werby (1958) indicates the 

average mineral content of precipitation in the study 

area would be less than 10 milligrams per liter. This 

value is in good agreement with data collected or used in 

the Sierra Nevada mountains to the west (Feth and 

others, 1964), the Sangre de Cristo Mountains to the 

south (Miller, 1961), and the Wind River Mountains to 

the east (Hembree and Rainwater, 1961). Though no 

data are available, it is reasonable to assume that 

precipitation is responsible for only minor contributions 

to the dissolved-solids content of stream water. 

Major rock types in the earth's crust are sufficiently 

consistent in their composition that one can use some 

average values of their composition. Table 23 gives the 

average composition of rock types in terms of oxides of 

the major elements. Data of table 23 do not imply the 

concentration of chemical constituents in stream 

waters, but only the relative composition of the 

constituents. Other factors controlling rates of solution 
A 54 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 23.-Average composition in percentage by weight of various 

oxides in the earth's crust 

[From Ronov and Y aroshevsky (19721] 

Granitic Basaltic Sedimentary 

Silicon-------------------- 63.9 58.2 49.9 Aluminum ---------------- 15.2 15.5 13.0 Iron 4.9 7.6 5.8 

Magnesium Mang~~;;;================ .1 .2 .1 ________________ 2.2 3.9 3.1 Calcium 4.0 6.1 11.7 

Sodium--================== 3.1 3.1 1.7 Potassium 3.3 2.6 2.0 Phosphorus================ .2 .3 .2 Carbon ____________________ .8 .5 8.2 Hydrogen ---------------- 1.5 1.0 2.9 Titanium ------------------ .6 .9 .7 

Total _______________ 99.8 99.9 99.3 

are responsible for concentration of dissolved minerals 

in water. For example, the crystalline granites and 

basalts are more resistant to weathering than many 

sedimentary rocks, and other factors being equal, 

streams draining these areas of crystalline rock should 

be more dilute than streams draining the sedimentary 

areas. 

Detailed studies of the area's mineral resources are 

currently under way in a major part of the area but have 

been completed for only a small part. These studies are 

being made by the U.S. Geological Survey in accordance 

with the provisions of the Wilderness Act (Public Law 

88-577, September 3, 1964) and the Conference Report 

on Senate Bill 4, 88th Congress. These mineral surveys 

include reconnaissance geologic mapping and extensive 

sampling and mineral analysis of stream sediments, 

altered and unaltered rocks, and soil. One study 

(Killsgaard and others, 1970) includes only the extreme 

western fringe of the study area, and its data are 

pertinent to only two streams of the present study. 

Another study (Tschanz and others, 197 4) encompasses 

most of the present study area south and east of the 

main-stem Salmon River. Data of this study will be 

extremely useful in interpretation of trace elements in 

stream waters; however, they were not available at the 

time of the present analyses. In lieu of these data, table 

24 gives all elements for which analyses were made. 

This table includes the average weight percentage each 

element contributes to the composition of the earth's 

crust. Although table 24 includes only those elements 

analyzed in the present study, it includes all significant 

elements except titanium, which accounts for about 0.5 

percent of the earth's crust. The chemical composition of 

stream-water data can be compared with the ranking of 

data in table 24. 

STREAM-WATER TEMPERATURE 

Stream-water temperature was measured at the time 

of each observation or collection of data; usually, this 

TABLE 24.-Weight percentages of the earth's crust for those elements 

analyzed in stream waters of this study 

[Data from Mason (1958), Parker (1967), Taylor (19641, and Fleisher (19531] 

Oxygen1 ----------------------------- 46.7 

Silicon ------------------------------ 27.7 

Aluminum -------------------------- 8.15 

Iron -------------------------- _____ 5.00 

Calcium______________________________ 3.65 

Sodium------------------------------ 2.85 Potassium____________________________ 2.60 

Magnesium-------------------------- 2.10 

Hydrogen---------------------------- .15 Phosphorus ___ ___ __ __________ _____ ___ .15 

Total ____________ ______________ 99.05 

Manganese -------------------------- 0.10 

Fluorine ------------------------------ .05 

Sulfur -------------------------------- .05 

Barium-------------------------------- .03 

Carbon -------------------------------- .03 Chlorine ___________ ________ __________ _ .03 

Strontium _____ __ _ _______ __________ ____ .03 

Chromium ---------------------------- .025 

Vanadium______________________________ .015 

Copper -------------------------------- .010 

Zinc ---------------------------------- .010 

Nickel -------------------------------- .008 Lithium________________________________ .006 

Nitrogen ------------------------------ .005 

Cobalt -------------------------------- .002 

Lead ---------------------------------- .002 

Molybdenum -------------------------- .0015 

Beryllium-------------------------_____ .0010 

Boron---------------------------------- .0010 

Arsenic-------------------------------- .0005 

Mercury ------------------------------ .00005 

Cadmium------------------------------ .00002 

Selenium ------------------------------ .00001 

Silver--------- _____ -------------------- .00001 

Grand total _______________________ 99.46 

1 Elemental oxygen not analyzed 

collection of data involved retention of a water sample 

for chemical analysis. The values of water temperature 

are presented in table 40 with data of the respective 

chemical analyses. Only one continuous-recording 

thermograph was operated in the area, and this was at 

the water-data station Little Boulder Creek near 

Clayton (13-2974.50). Data of this thermograph record 

are illustrated in figure 41 with traces of the daily 

minimum and maximum temperatures. 

Figure 41 indicates water temperatures in winter 

(November to March) are generally less than goc and 

have diurnal fluctuations of 1 oc or less. Stream 

temperature begins warming in April and generally 

peaks in early August. Summer diurnal fluctuations are 

as large as 5°C and reflect a combination of snowmelt 

source of stream water and warming of the stream 

water by solar radiation. The seasonal trends of 

temperatures are indicated by the mean monthly data 

in table 25. 

Comparison of stream-temperature trends in figure 

41 to stream-runofftrends in figure 20 indicates a partly 

inverse relation between the two parameters, especially 

in the spri11:g months, and this probably indicates an 
CHANNELS AND WATERS 

20 

(f) 

:::> 

Cii 

..J 15 w 

() 

(f) 

w 

w 

a: 

(!) 

w 

0 

~ 

uj 10 a: 

:::> 

~ a: 

w Station 13-2974.50 c.. 

:rE 

w 

1-

a: 

w 5 1-

<( 

3: (Record initiated) 

0 

A. 1970 

15 

(f) 

:::> 

Cii 

..J 

w 

() 

(f) 

w 

w 

a: 10 (!) 

w 

0 

~ 

uj Station 13-2974.50 a: 

:::> 

1-

<( 

a: 

w 5 c.. 

:rE 

w 

1-

a: 

w 

~ 

3: 

0 

B. 1971 

15 

(f) 

:::> 

Cii 

..J 

w 

() 

(f) 

w 

w 

a: 10 (!) 

w 

0 

~ 

uj Station 13-2974.50 

a: 

:::> 

1-

<( 

a: 

w 5 c.. 

:rE 

w 

1-

a: 

w 

1-

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0 Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 

c. 1sn 

FIGURE 41.-Stream-water temperature, 197~ 72, Little Boulder Creek near Clayton, Idaho. A. 1970. B. 1971. 

c. 1972. 

A 55 
A 56 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 25.-Mean monthly temperatures, in degrees Celsius, for Little Boulder Creek near Clayton (station 

13-2974.50) 

1970 

Month Mean Mean Mean high low Mean high 

January ------------ 1.1 February ____________ 1.4 

March -------------- 2.0 April ________________ 3.9 May ________________ 5.7 June ________________ 8.4 July ________________ 12.8 9.2 11.0 12.6 August ______________ 13.2 10.0 11.6 13.7 

September ---------- 7.5 5.6 6.5 7.9 

October ------------ 3.0 2.1 2.5 4.4 

November ---------- 1.3 .7 1.0 1.9 

December ---------- 1.3 1.1 1.2 1.0 

inverse relation between water and air temperatures. 

That is, warm spring days cause snowmelt runoff to 

augment streamflow, but this snowmelt runoff is colder 

than water previously in the channel. Thus, spring rises 

in the runoff hydrograph are accompanied by colder 

water in the channel. 

Although the temperature graphs in figure 41 are for 

a single tributary stream with a drainage area 

primarily in a mountainous area, both the general trend 

of temperature and values of temperature are considered to closely approximate the conditions at other 

locations. For example, comparison between Little 

Boulder Creek (13-2974.50) and Salmon River near 

Challis (13-2985.00) of individual temperatures in 

table 40 indicates that the Salmon River tended to be 

about 2°C warmer than Little Boulder Creek. Perhaps 

the biggest difference between stations is that streams 

in mountainous areas begin a fall cooling earlier than 

some of the downstream stations. The temperature data 

in table 40 also indicate the general cool temperatures 

of the area's stream water. Of the 250 observations in 

that tabl~, which were generally collected over the 

spring and summer months, only 10 (4 percent) show 

temperatures greater than 15°C, and only one temperature is greater than 20°C. 

STANDARD CHEMICAL ANALYSES 

Data of standard chemical analyses include the date 

of measurement, stream discharge, water temperature, 

several physical characteristics of the water, concentration of major ions, and several computations based on 

these measurements, such as dissolved solids expressed 

in tons per day. All data of the standard analysis are 

tabulated in table 40. 

Analytical techniques utilized in the chemical determinations were those standard to the Geological Survey 

at the time of analysis (see Brown and others, 1970) and 

are of sufficient accuracy to report at the significance 

level used in table 40. 

1971 1972 Period of 

Mean Mean Mean Mean Mean record, 

low high low mean 

0.9 1.0 1.0 1.0 1.0 1.0 

.8 1.1 1.2 1.1 1.2 1.2 

1.4 1.7 2.3 1.2 1.7 1.7 

2.1 3.0 3.7 1.7 2.7 2.9 

2.9 4.3 6.3 2.8 4.5 4.4 

4.6 6.5 8.3 4.3 6.3 6.4 

8.9 10.7 11.6 7.6 9.6 10.4 

10.7 12.2 12.3 8.0 10.1 11.3 

5.8 6.8 7.7 5.7 6.7 6.7 

3.2 3.8 3.2 

1.4 1.6 1.3 

.8 .9 1.0 

At some stations, values of three water-quality 

parameters were determined in the field as well as later 

in the laboratory. For these three parameters, pH, 

specific conductance, and bicarbonate concentration, a 

delay in analysis influences the measurement such that 

a laboratory determination can be considered applicable only to the solution in the sample bottle. Values of 

field measurements are also included in table 40. 

Comparison of field and laboratory values indicates that 

usually the field values are higher for all three 

parameters, but the difference is not always consistent 

nor greatly significant. Accordingly, since laboratory 

values are available for all parameters at all locations, 

analysis of data in this section is based on the laboratory 

data. 

The major cations constituting the dissolved-solids 

content include calcium, magnesium, potassium, and 

sodium; the major anions are bicarbonate, chloride, 

fluoride, and sulfate. Nitrite and nitrate concentrations 

are summed and reported as nitrogen, and orthophosphorus and total phosphorus are reported as phosphorus. Silicon present is reported in terms of an 

equivalent concentration of the oxide silica. Other 

elements are reported as trace elements even though 

some, such as iron and aluminum, occur with regularity 

in the analyses. 

As emphasized by Hem (1970), the implication given 

in this report that discharge or flow measurements 

should be obtained at the sampling sites is intentional. 

Chemical analyses of river water generally require 

some sort of extrapolation, because the water sampled 

has long since passed on downstream by the time a 

laboratory analysis is completed. The discharge record 

provides a means of extrapolating the chemical record if 

the two are closely enough related. The discharge data 

also serve as a means of averaging the water analyses 

and give an idea of total solute discharges. 

pH AND SPECIFIC CONDUCTANCE 

The concentration (activity) ofhydrogen ions in water 
CHANNELS AND WATERS A57 

solutions is very low when expressed in terms of 

milligrams per litre or moles per litre. The abbreviation 

pH was adopted to represent the negative base-10 

logarithm of the hydrogen-ion activity in moles per 

litre. At 25°C, pure water has a neutral pH value of7 .00. 

As temperature increases, the neutral value of pH 

becomes slightly smaller. 

River waters in areas not affected by pollution 

generally have a pH between about 6.5 and 8.5, and this 

is the range of values for streams in the study area. 

Values of pH seemingly do not correlate significantly to 

values of other water-quality parameters. In fact, the 

range in values of pH is no greater than might be 

expected in the normal diurnal cyclic fluctuation of pH 

that has been observed in near-surface water of rivers 

(Livingston, 1963). For the individual water-data 

stations, the mean or median value of pH at each station 

ranges from about 7.0 to 7.9 and indicates that 

generally within the study area, stream waters are 

about neutral. 

The specific electrical conductance, or conductivity, is 

the ability of a substance to conduct an electrical 

current and is expressed as the reciprocal of the 

resistance in ohms (mhos) per centimetre at a temperature of25°C. Common usage omits the inclusion of 

the length unit, multiplies the value by 106 , and 

expresses values as micromhos. Pure water has a very 

low specific conductance, but as ionic concentrations 

increase, conductance of the solution increases. Therefore, the conductance measurement provides an indication of ionic concentration. 

The relation between specific conductance and simple 

solutions is nearly linear over a moderately dilute range 

in concentration, but as concentrations increase, the 

relation becomes more curvilinear. The relation is not 

quite as simple for natural waters containing a variety 

of ionic species, but a plot of specific conductance versus 

dissolved solids on log-log graph paper generally gives a 

straight-line relation over the usually encountered 

range of concentration. The specific-conductance and 

dissolved-solids data in table 40 were analyzed using 

log-transformed regression techniques. The relation 

DS = 1.039 SC 0.914 

was determined for the 250 pairs of data and has a 

correlation coefficient of 0.985. Dissolved solids, DS, is 

in milligrams per litre, and specific conductance, SC, is 

in micromhos. Often the ratio of dissolved solids to 

specific conductance is considered a constant value of 

about two-thirds, but the preceding equation shows the 

dependence on concentration. For various values of 

dissolved solids and specific conductance, stream water 

in the study area has the following values of the ratio 

DS/SC: 

sc 

10 

25 

50 

100 

200 

500 

DS 

8.5 

19.7 

37.1 

69.9 

131.8 

304.4 

DSISC 

0.85 

.79 

.74 

.70 

.66 

.61 

Because regression relations exist for the dominant 

ions and specific conductance, a recent trend in 

water-quality analysis has been the application of such 

statistical analyses to the synthesis and regionalization 

of data (Steele, 1971; Blakey and others, 1972). That is, 

on the basis of measurements of conductivity, reliable 

predictions of the component amounts of dissolved 

solids may be made, and these predictions are general 

for an entire area of moderate homogeneity. The high 

degree of correlation for the area-wide relation of 

dissolved solids and conductivity in the present study 

indicates that such techniques would be applicable 

here. But in keeping with the earlier thesis in this 

report of relating streamflow characteristics to hydraulic and channel geometry at bankfull stage, the 

water-quality data will be analyzed in the same 

manner. A combination of both concepts allows such 

predictions as the mean annual discharge of dissolved 

solids from ungaged streams. 

DEPENDENCY OF IONIC CONCENTRATION ON SOLUBILITY 

OF ROCK AND MAGNITUDE OF DISCHARGE 

Under natural conditions, dissolved-solids concentrations are usually highest during periods of low flow. At 

times of low flow, water reaches a stream only after a 

slow subsurface journey which often spans a considerable distance. During its underground passage, the 

water dissolves a large variety of chemical constituents 

from the soil and rocks. During high-flow periods, water 

movement, either overland or through the upper soil 

layers, is much more rapid than at low flow, and 

high-flow runoff is much more dilute than low flow 

because its contact with the soil and rocks is for a 

shorter period of time. 

To illustrate the dilution effect of high flow on the 

concentration of dissolved solids, the specific-conductance data in table 40 were log-transformed and 

regressed against values of discharge. To provide a 

dimensionless abscissa scale, the discharge ratio, Q/QB, 

was used rather than the absolute values of discharge, 

and the re_gression-equation technique was applied 

individually to each water-data station set of measurements. The results of these regressions yield a set of 

equations, one for each water-data station, of the form 

SC =b (QIQB 'f, 

where SC is the specific conductance in micromhos, b is 

a coefficient (to be discussed later), QIQBis the discharge 
A 58 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

ratio, and s is an exponent indicating the rate of change 

in values of specific conductance as values of the 

discharge ratio change. Table 26 gives the station 

numbers, correlation coefficients, values of the exponent s (slope of the specific conductance versus 

discharge ratio relation), and computed values of 

specific conductance at a bankfull discharge (Q!Qn = 1.0) 

and at mean annual discharge (Q!Qn =0.25). It should 

be noted that values of specific conductance at 

Q!Qn =1.0 are equal to values of the coefficient b. Figure 

42 is a graph of the relations in table 26; the end points 

of each line in figure 42 indicate the range in values of 

the discharge ratio observed at each location. 

Negative values of the exponents in table 26 and the 

downward-to-the-right slope of the lines in figure 42 

illustrate the dilution effects of increased streamflow on 

values of dissolved solids (specific conductance). The 

lines in figure 42 indicate that the relation is not 1 to 1. 

That is, even though discharges were measured over a 

20-fold range in magnitude, values of specific conductance varied only over about a 2-fold range in magnitude. 

The rather high values of correlation coefficient in 

table 26 indicate well-defined relations between specific 

conductance and discharge at the individual water-data 

station locations, and this can be verified graphically by 

plotting the actual data of specific conductance as a 

function of discharge. Further, considerable parallelism 

exists in the lines of the graph in figure 42-there is no 

trend of convergence or divergence of the lines. These 

factors indicate that an average value ofthe exponents 

would provide a reasonable approximation for all 

streams in the study area. Analysis of standard 

deviations indicates that two-thirds of the values of s 

range between values of -0.13 to -0.33. Mean and 

median values of s are shown in table 26 and indicate 

that an average value of s = -0.23 is suggested for the 

area. This leads to an equation of the form 

TABLE 26.-Summary of log-transformed regression data of specific 

conductance as a function of discharge 

Graph 

plotting 

number 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38 

39 

U.S. Geological 

st~tfo~e~o. 

Correlation 

coefficient, r 

13-2922.00 ~~~~~~~~~~~~ -0.933 

2924.00~~~~~------~~- -.915 2932.00~~-~~~~-~~~~~~ -.955 

2934.00_~-~---~~----- -.927 2950.00- ~- ~-- ~- ~- ~- ~ ~ -.842 

2956.50----------~--- -.814 2960.00 _____ ~-~~-~--~ -.909 

2965.00------~-~----~ -.950 2970.00_~-~----~----- -.988 2971.00______________ -.883 2972.50______________ -.535 2973.00______________ -.732 2973.10______________ -.874 2973.20______________ -.996 2973.30______________ -.669 

2973.40 __ ~----------- -.970 2973.50______________ -.988 2973.60______________ -.988 2973.80______________ -.973 2973.84______________ -.988 2973.88______________ -.954 

2973.96---~----~--~-- -.944 2974.00______________ -.949 

2974.04--------~--- -.984 2974.18______________ -.873 

2974.25------~------- -.942 2974.40______________ -.754 2974.45______________ -.977 2974.50______________ -.822 2974.80______________ -.972 

2974.85~------------- -.986 2975.00 ___________ -- -.967 2975.30______________ -.478 2976.00______________ -.942 2976.70______________ -.957 2976.80 _____________ ~ -.592 

2977.00 __________ ~--- -.833 

2980.00------~------- -.962 2985.00______________ -.930 

Mean ------------------------------ Median______________________ -.944 

Slope, s, of Value of specific · fi conductance 

co~a~~~a~ce -------

and 

QIQB 

relation 

-0.223 

-.214 

-.159 

-.261 

-.077 

-.126 

-.204 

-.424 

-.456 

-.340 

-.117 

-.101 

-.177 

-.620 

-.252 

-.219 

-.313 

-.235 

-.371 

-.266 

-.227 

-.244 

-.281 

-.224 

-.136 

-.253 

-.069 

-.261 

-.243 

-.309 

-.187 

-.297 

-.052 

-.140 

-.214 

-.081 

-.158 

-.229 

-.281 

Bankfull Mean annual 

(Q/QB=l.Ol (Q/QB=0.25l 

79 

33 

112 

74 

51 

58 

58 

56 

64 

72 

239 

154 

56 

24 

63 

76 

90 

82 

74 

43 

76 

100 

82 

96 

66 

97 

17 

32 

43 

36 

87 

60 

122 

126 

139 

367 

213 

118 

96 

107 

45 

140 

106 

57 

69 

77 

100 

120 

115 

281 

177 

72 

57 

89 

103 

139 

113 

123 

62 

104 

137 

121 

131 

80 

137 

18 

46 

60 

55 

112 

90 

131 

153 

187 

410 

265 

162 

142 

-.232----------------------------

-.229------------ ~- --------------

together constituted less than 1 percent of the rock. 

Thus, it may be expected that the concentration of 

dissolved solids, as expressed by the value of specific 

conductance, is dependent on the rock type through 

which its contributory waters drain. 

Within the study area, the diversity of rock types is 

such that water-data stations do not represent singlerock-type drainages. Compositing rock types tend to 

average results, but the effect is still visible. For 

Absolute values of specific conductance at each water- example, Little Boulder Creek (13-2974.50) drains 

data station location, or in reality the individual values primarily crystalline rocks of the Idaho batholith and 

of the coefficient b, are determined largely by the Challis Volcanics and has a specific conductance at 

chemical composition of the different rock types and bankfull discharge of 29 micromhos (table 26); Slate 

their solubility and to a lesser degree by the length of Creek (13-2972.50) drains an area primarily in the 

time water is in contact with them. Milligan Shale and has a specific conductance at 

Chemical composition, solution, and solute concen- bankfull discharge of 150 micromhos; and the Salmon 

tration in waters draining a single rock type have been River at Challis (13-2985.00) composites the lithology 

documented elsewhere. For example, Miller (1961) has oft~ entire study area and has a specific conductance at 

shown that solute concentrations of waters draining bankfull discharge of 78 micromhos. 

quartzite, granite, and sandstone are in the proportion Values of specific conductance at bankfull and mean 

1:2.5:10. The importance of solubility was shown by annual discharge are given in table 26. It can be 

Miller in that most of the solute content of water I inferred that the highest values of specific conductance 

draining the sandstone is derived from the easily are associated with rock types of the highest solubility 

soluble carbonate cement and the limestone which and that the reverse is true for the lowest values. 
CHANNELS AND WATERS A59 

EXPLANATION 

38 Station number from table 3 and 26 

10 ~------~----~--~~--~~~~--------L---~--~--~~~~~--------~----~--~~ 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 42.-Specific conductance as a function of discharge ratio. 

Intermediate values of specific conductance may have 

that value because the rock type is of intermediate 

solubility, but most likely such values indicate that the 

upstream drainage is a composite of highly and poorly 

soluble rock types. The important item to note is that in 

areas other than those composed of single rock types, 

the solute content of stream waters is variable and 

dependent on rock type. Thus, determination of an 

average coefficient for the area is not possible. 

In an effort to document rock type or composite of rock 

types for each water-data station, lithologic counts were 

conducted at those sites with channel-geometry surveys 

(table 3). The technique consisted of randomly selecting 

20 rocks from the streambed and identifying their 

lithologies. The results are summarized in table 

27.These data are not particularly definitive because 

some results are partly concealed. For example, the 

great extent of sedimentary rock in Slate Creek 

drainage (13-2972.50) is masked because of the 

abundance of quartzite found in the streambeds. 

However, rocks in the streambed of Slate Creek are 

orthoquartzite and imply a sedimentary origin. 

One useful aspect of table 27 is the relative 

abundance of the rock types found on the streambeds, 

which in order of the most abundant are andesite, 

quartzite, basalt, quartz· monzonite, and shale. These 

five rock types account for more than 70 percent of all 

types, and all five are considered to be relatively 

resistant to weathering. Their relative resistance to 

weathering is a dominant reason for their abundance in 

the streambeds, but the presence of these resistant 

rocks in a given streambed is not necessarily indicative 

of low solute content. 

Next to rock type, the largest factor in determining 

solute concentration of stream water appears to be the 

trend of decreasing precipitation toward the northeast 

corner of the study area. In this region as detected by the 

Road Creek stations (13-2976. 70 to 1~2977 .00), 
TABLE 27.-Summary of streambed lithology (percentage of each rock type on streambed) 

U.S. Geological Igneous 

st~t~e~o. m~~::;,~te Grandiorite Rhyodacite Trachyte Quartz Primarily Granite Rhyolite Latite Andesite Basalt Tuff hornfels 

13-2922.00 ------ ---- ---- ---- ---- ---- ---- ---- 15 10 20 ---- 2924.00 ------ ---- 30 5 60 ---- 5 ---- ---- ----

2932.00 ------ ---- 5 ---- ---- ---- 5 30 20 

2934.00 ------ ---- 5 15 ---- 5 5 

2950.00 ------ 5 10 ---- 40 ---- ---- 5 20 15 

2956.50 ------ ---- 10 5 35 5 ---- ---- 5 30 ---- ---- ---- 2960.00 ---- 10 25 5 5 ---- 15 5 10 ---- 5 

2965.00 ------ ---- 25 10 ---- 5 20 10 ---- ----

2970.00 ------ ---- 5 ---- 10 ---- ---- ---- ---- ---- 15 ----

2971.00 ------ ---- 10 5 5 ---- 5 25 10 5 

2972.50 ---- ---- ---- ---- ---- ---- ---- 15 25 

2973.00 5 ---- 5 ---- 5 5 5 20 40 10 ---- 2973.10 ------ ---- 5 ---- ---- 5 ---- 10 40 15 

2973.20 ------ ---- ---- 15 25 ---- 10 35 

2973.30 ------ ---- ---- ---- 5 ---- ---- 5 25 ---- ---- 10 

2973.40 ---- ---- ---- ---- ---- 5 5 ---- 20 

2973.50 ------ ---- ---- ---- ---- ---- 15 25 ----

2973.60 ------ 5 ---- ---- 10 5 25 40 5 ----

2973.80 ------ ---- ---- ---- 5 5 5 ---- 5 30 25 ----

2973.84 ------ 5 5 5 ---- 5 5 5 65 5 ----

2973.88 ------ 5 ---- 65 15 ---- ----

2973.96 ------ 5 5 5 5 ---- 15 30 ---- ---- ---- 2974.00 ------ ---- ---- ---- 10 5 5 40 5 

2974.04 ------ ---- ---- ---- ---- ---- 10 ---- 10 65 10 ---- ----

2974.18 ------ ---- 5 ---- 5 10 ---- 10 45 25 ---- ---- 2974.25 ------ ---- ---- ---- 5 10 10 50 ---- ----

2974.40 ------ . 35 ---- 50 5 5 ---- 2974.45 ------ 5 5 5 ---- ---- ---- ---- 30 ---- ---- ----

2974.50 ------ ---- ---- 5 5 ---- 10 ---- 60 15 ---- 2974.80 ------ ---- 5 25 5 ---- ---- ---- 35 5 5 10 

2974.85 ------ ---- ---- ---- 10 ---- 60 ---- 5 10 

2975.00 ------ 10 5 ---- 45 20 10 

2975.30 ------ 10 ---- ---- 10 5 50 15 10 ----

2976.00 ------ ---- ---- 5 5 75 15 ----

2976.70 ---- ---- ---- ---- ---- 25 75 

2976.80 ------ ---- ---- 5 ---- 15 25 15 5 ----

2977.00 ------ ---- ---- ---- ---- 5 45 5 5 ---- 2980.00 ------ ---- ---- 10 ---- 20 5 10 5 40 ---- 5 5 

2985.00 ------ 5 ---- 5 ---- 5 5 15 ---- ----

Average ____ .8 4.0 1.8 8.7 1.9 4.2 .9 4.2 29.7 12.8 1.8 2.9 

Metamorphic 

Primarily Primarily slate quartzite 

40 

---- ----

35 

25 25 

5 

10 

20 

5 20 

25 30 

10 25 

15 45 

---- ----

20 5 

10 5 

40 15 

20 35 

35 

---- 10 

---- 10 

----

5 

---- 30 

25 

---- 5 

5 20 

5 

50 

---- ----

----

---- 5 

---- 10 

---- ----

---- ---- ----

---- 30 

---- 15 

5 ----

35 15 

6.4 14.1 

Sedimentary 

Primarily Primarily siltstone sandstone 

15 ----

----

5 ----

15 5 

5 ----

----

5 

15 

5 ----

----

---- ----

15 ----

25 

----

15 ----

---- ----

10 

5 

---- 10 

----

----

---- ----

5 ---- 5 ----

5 ---- 10 ----

----

----

----

---- ----

5 

20 

---

10 5 

4.2 1.2 

> 

~ 

0 

::r: 

~ 

0 

~ 

0 

~ 

0 

e 

0 

t:zj 

~ ~ 

c::: 

2:3 

~ 

0 

z 

0 

~ 

1-3 

::c: 

t:zj 

e 

'ij 

~ ~ 

00 

~ ~ 

0 

z 

~ 

< t:zj 

~ 

> 

~ 

? 

~ 

0 

> ::r: 

0 
CHANNELS AND WATERS A61 

stream waters are high in solute concentration. It is 

reasoned that precipitation in this region is sufficiently 

low that dilution comparable with that in other regions 

of the study area never occurs. But also because of the 

low precipitation, water runoff in the northeast region 

is some 10-fold less than the average for the study area. 

(See fig. 36.) Thus, even though solute concentrations 

are highest in this region, the dissolved-solids yield in 

tons per year is among the lowest of any in the study 

area. 

It should be noted that some within-channel factors 

may also influence stream-water composition. These 

factors include reaction of water with minerals in the 

streambed and in solution, evaporation and transpiration losses, and effects of the stream biota. Within the 

study area, these effects are considered minimal. 

Although the influences of man are superimposed on all 

natural conditions, the effects of minor flow diversions 

and augmentation and any subsequent stream pollution are considered minimal in the upper Salmon River 

area. 

CONTENT OF MAJOR IONS 

Concentration values of major cations and anions for 

each water sample collected are among the data 

included in table 40. The major cations include calcium 

(Ca), sodium (N a), magnesium (Mg), and potassium (K). 

If the data of the Salmon River near Challis (13-

2985.00) are used as a composite of the upstream 

waters, the relative abundance of these cations expressed in milligrams per litre and in the ratio Ca:Na:Mg:K 

is about 1.0:0.22:0.12:0.04. The major anions include 

bicarbonate (HC03), sulfate (S04), chloride (Cl), and 

fluoride (Fl). Nitrogen and phosphorus components 

will be discussed later under ((Nutrients." The relative 

abundance of the anions expressed in milligrams per 

litre and in the ratio HC03:S04:Cl:Fl is about 

1.0:0.06:0.01:0.005. Stream waters are clearly typed as 

calcium bicarbonate. 

The more significant of the major cations and anions 

have characteristics very similar to those shown by 

specific conductance and noted by the data of table 26 

and the graphs of figure 42. For ions which occur in less 

significant amounts, for example, potassium, chloride, 

and fluoride, the characteristics become more erratic, 

and the resemblance of data to figure 42 becomes more 

remote. In the manner of preparing table 26, table 43 

gives details of log-transformed regression equations 

fitted to the more significant ion concentrations and 

dissolved solids for each station. Table 44 gives similar 

details for the less significant ion concentrations and 

some of the computed data, but for only the 15 stations 

with the largest amount of data. Figures 43-48 are 

graphs of the regression equations available from the 

data in table 43. 

For the major cations, figures 43-45 indicate similarity to the relation of specific conductance to discharge 

(fig. 42), but the similarity decreases as ionic concentration decreases. Values of concentration for each of the 

cations are dependent on individual locations, but an 

average value for the slope of the relation of calcium, 

sodium, and magnesium as a function of discharge is 

-0.22 for each of the three parameters. A median value 

of the correlation coefficient, however, decreases from 

0.95 for calcium to 0.81 for magnesium. Potassium, a 

cation occurring in much more dilute quantities, has a 

relation slope of -0.08 and a median correlation 

coefficient of only 0.35. 

The relations of concentration of the major anions to 

discharge are shown in figures 46-48. The trend is much 

the same as for the major cations; the average slope of 

the relation to discharge is -0.21 for bicarbonate, -0.27 

for sulfate, and -0.15 for chloride. Median values of the 

correlation coefficient for the relations range from 0.91 

for bicarbonate to 0.55 for chloride. Fluoride, the least 

significant of the anions in terms of concentration, has a 

slope to discharge relation of -0.35. 

Generally, the relations of the major ions as functions 

of discharge indicate that ionic concentrations decrease 

as discharge increases. Figures 43-48 indicate, however, that some individual locations show reversals to 

this trend. For example, the station Little Boulder 

Creek above Baker Lake (13-297 4.40, graph plotting 

number 27) shows slight, but positive, increases in concentration of magnesium and sulfate with increases in 

discharge. The data indicate that generally these exceptions occur for concentrations so dilute that the analyses 

are borderline with analytical accuracy or for 

streamflows so low (Q!Q8 <0.05) that the results are not 

correlative with the majority of streamflows presented 

in this report. An exception to this explanation appears 

to be values of chloride concentration for the majority of 

the water-data stations in Stanley Basin. Stanley Basin 

is the only area within the study area with extensive 

surfaces of near-level topography, and these surfaces 

are often boggy after spring runoff and later irrigation. 

It appears likely that evaporation from these surfaces 

increases the ionic concentrations of standing water and 

at times leaves behind residual deposits. The following 

spring's runoff collects these mineral concentrates and 

delivers them to the river channels at time of high flow. 

For most major ions, an influx of ionic concentrate is 

insufficient to reverse or even alter the normal relations 

of concentration to discharge, but for the normal ionic 

concentrations of chloride ( <0.5 mg/1), the percentage 

increases could easily alter the relations. 

The dissolved-solids graph of figure 49 illustrates a 

compositing of individual constituents, primaily the six 

major constituents illustrated in figures 43-48. As 

expected, the appearance of figure 49 is similar to the 
A62 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

w 

a: 

1-

::i 

a: 

w 

a.. 

(j) 

~ 20 <( 

a: 

C) 

::i 

_J 

~ 

~ 

z 10 

0 

~ a: 

1-

z 

w 

() 

z 5 

0 

() 

~ 

:::> 

u 

_J 

<( 

() 

EXPLANATION 

36 Station number from tables 3 and 43 

1 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 43.-Calcium concentration as a function of discharge ratio. 

graphs of the major constituents and is nearly identical 

to the graph for specific conductance (fig. 42). The slope 

of the relation to discharge is -0.20 for dissolved solids 

compared with --:-0.23 for specific conductance. The 

difference in value of the two exponents relates to the 

previously established relation indicating that dissolved solids do not decrease in concentration as rapidly 

as values of specific conductance. Furthermore, increasing an1ounts of suspended solids at high flow give some 

decreased measure of electrical conductivity but do not 

alter amounts of dissolved solids. In this respect, values 

of dissolved solids used in this report are computed 

values obtained by summing the concentrations reported for the various dissolved constituents. This 

summation actually includes the sum of constituents in 

their solid phase rather than the ions in solution. For 

example, the bicarbonate ions in solution are converted 

to carbonate in the solid phase by the factor HC03 

(mg/l)x0.49=C03 (mg/1). Thus, values of dissolved 

solids in milligrams per litre given in table 40 are 

always less than the straight arithmetic sum of the 

various constituents. 

SILICA 

Silicon, as noted in table 24, is second only to oxygen 

in abundance in the earth's crust. Oxides of silicon ar-e 

an important constituent of all igneous and metarnnrphic rock, and thus one would expect signific iint 

quantities of silicon in stream water if that were ':he 

only factor involved. The term silica for Si02 is 

commonly used in referring to silicon in water, ;; nd 

dissolved silica is the term used in this report. 

In reality, the range of concentrations of silica most 

commonly observed in stream waters is from about 2 to 

40 milligrams per litre. The higher concentrations are 

related to the temperature of the water, the mineralogy 

and relative solubility of the rock type, and the mode of 

flow conveyance to the channel whether it be overland 

flow or ground-water inflow. 

Because of the abundance of silicon in the rock 
CHANNELS AND WATERS A63 

50 

14 

w 20 a: 

1-

:J 

a: 

w 

a.. 

en 

:iE 10 <( 

a: 

(!) 

:::i 

_.J 

~ 

~ 

7 

Station number from tables 3 and 43 

0.5 ~------~-----L---L--~~-L~~L-------~----_L __ _L __ L_~~~~--------~----_L __ _L~ 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 44.-Sodiurn concentration as a function of discharge ratio. 

minerals and its ready release from mineral surfaces in 

the presence of water, dissolved silica concentrations in 

stream waters do not decrease with increases in 

streamflow as rapidly as the major ion concentrations. 

Thus, stream waters are likely to have near constant 

values of silica concentration regardless of discharge. 

Table 28 is a summary of regression equation data for 

silica as a function of discharge. A number of the 

individual water-data stations show a very slight 

increase in silica concentration with increases in 

streamflow, but the majority show slight decreases. An 

average value for the slope of the silica-discharge 

relation is -0.05, and the median value of correlation 

coefficient is 0.78. The data of table 28 are graphically 

represented in figure 50 and show the nearly constant 

value of silica content as a function of discharge. 

The variation of silica content in stream water just 

mentioned has been observed before. Kennedy (1971) 

showed in an analysis of water from several stream 

channels that as streamflow increased, some of the 

streams increased in silica concentration, others decreased, and in still others the trend was uncertain. His 

explanation is that silica concentrations are higher in 

water that seeps through the soils (subsurface flow) 

than in either overland flow or in ground water. During 

a stream rise, silica decreases initially, while overland 

flow comprises much of the streamflow and then 

increases as subsurface flow becomes the major component of streamflow. With decreasing discharge, ground 

water becomes an increasing proportion of streamflow, 

and silica concentration slowly decreases. Thus, correlation between silica and stream discharge is poor 

during storm runoff. 

In the present study area, however, storm runoff is 

secondary to spring snowmelt as the source of increases 

in discharge. Snowmelt is relatively gradual, and it can 

be assumed that during the spring rise in the runoff 

hydrograph, water is reaching the stream channels in a 
A64 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

10 

35 35 Station number from tables 3 and 43 

5 

w 

a: 

I-

:::J 

a: 

w 

a.. 

CJ) 33 

~ 

<t: 2 a: 

C) 

:::J 

....J 

~ 

~ 

z 

0 

i= 

<t: 

a: 

Iz 

w 

(.) 

~ 0.5 

(.) 

~ 

::::> 

U5 

w 

z 

C) 

<t: 

~ 

0.2 

__ L-----~----+----+------~--~-27 0.1 

0.01 0.02 0.05 0.1 0.2 0.5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 45.-Magnesium concentration as a function of discharge ratio. 

2 5 

TABLE 28.-S ummary of log-transformed regression data of silica as a' TABLE 28.-Summary of log-transformed regression data of silica as a 

function of discharge function of discharge -Continued 

Slope of Value of silica Slope of Value of silica 

Graph U.S. Geological Correlation silica and Graph U.S. Geological Correlation silica and plotting No. Survey coefficient, QIQB plotting No. Survey coefficient, QIQB station No. r Bankfull Mean annual station No. Bankfull Mean annual relation <QIQ'B=l.O) <QIQB=0.25) relation (Q/Q'B = 1.0) <Q!Q8 =0.25l 

1 13-2922.00 ------------ -0.827 -0.058 9.2 10 2 2924.00 ------------ -.966 -.127 5.4 6.5 28 2974.45 ------------ -.839 -.130 6.8 8.1 

3 2932.00 ------------ -.991 -.090 19 21 29 2974.50 ------------ -.632 -.121 9.1 11 

4 2934.00 ------------ -.784 -.111 12 14 30 2974.80 ------------ -.795 -.136 6.7 8.1 

5 2950.00 ~----------- ·-.368 -.078 10 11 31 2974.85 ------------ -.804 -.112 11 13 

6 2960.00 ------------ -.917 -.063 18 19 32 2975.00 ------------ -.486 -.084 11 13 

7 2960.00 ------------ -.917 -.063 18 19 33 2975.50------------- .930 .078 30 27 

8 2965.00 ------------ -.777 -.210 12 15 34 2976.00 ___ ---------- .325 .017 14 14 

9 2970.00 ------------ -.950 -.189 11 14 35 2976.70 ------------ -.925 -.123 31 37 

10 2971.00------------- .732 .028 22 22 36 2976.80 ------------ -.420 -.047 39 41 

11 2972.50_ ------------ .102 .009 14 14 37 2977.00 ___ ---------- .096 .005 38 38 

12 2973.00------------- .454 .021 29 28 38 2980.00 ------------ -.840 -.101 11 12 

13 2973.10 ------------ -.240 -.016 18 19 39 2985.00 ------------ -.712 -.073 13 14 

14 2973.20------------- .736 .138 33 27 15 2973.30------------- .322 .008 19 19 Mean -.056 16 2973.40 ------------ -.566 -.032 26 27 Media;~~~~~~~~~~~~~~~~~~~~ -.778 -.076 17 2973.50 __ ----------- .906 .069 24 22 18 2973.60 ------------ -.649 -.017 24 25 19 2973.80 ------------ -.764 -.106 12 14 20 2973.84 ------------ -.809 -.096 3.8 4.3 consistent This provides for al- 21 2973.88 ------------ -.778 -.081 5.2 5.8 manner. manner an 22 2973.96 ------------ -.923 -.153 6.2 7.7 most constant value of silica which be in 23 2974.00 ------------ -.872 -.173 5.6 7.1 may near 24 2974.04 -.878 -.076 11 12 25 equilibrium with the rock type and water temperature. 2974.18 ============ -.716 -.026 18 19 26 2974.25 ------------ -.453 -.043 9.7 10 Low values of silica content, such data line 17 in 27 297 ~.40- ------------ .396 .080 3.3 3.0 as 
CHANNELS AND WATERS A65 

w 

a: 

1- 200 

:J 

a: 

w 

a.. 

en 

~ 

<( 

a: 100 C!J 

:J 

..J 

~ 

~ 

z 

0 50 i= 

<( 

a: 

1-

z 

w 

() 

z 7 0 

() 

w 

1- 20 <( 

z 

0 

Ill 

a: 

<( 

() 

iii 

EXPLANATION 

36 Station number from tables 3 and 43 

5 L_ ______ ~ ____ _L __ _L __ L_J_~~~--------~----_L __ _L __ L_~~~LJ ________ _L ____ ~--~~ 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 46.-Bicarbonate concentration as a function of discharge ratio. 

figure 50, indicate a less soluble silica source in the 

quartz-rich environment in upper Little Boulder Creek. 

High values of silica content, such as data lines 35-37, 

indicate a more soluble silica source in the amorphous 

silica environment of Road Creek drainage. In both of 

these examples and for intermediate values of silica 

content, concentrations of silica are nearly constant 

with changes in discharge. 

NUTRIENTS 

Although nitrogen and phosphorus may be found in 

rocks, a significant source of their presence in stream 

waters is due to byproducts of biological processes. 

Further, both nitrogen and phosphorus are essential 

nutrients for plant growth. For these reasons, nitrogen 

and phosphorus are frequently labeled as nutrient 

constituents rather than major or trace ions, though 

certainly they would fall in one of the latter categories 

also. 

Nitrogen is usually present in soil or biological 

matter, and oxidation of nitrogenous materials generally produces nitrite and nitrate. Nitrite is seldom 

present in amounts large enough to influence the ionic 

balance, and in the present study nitrite and nitrate 

ions are combined in terms of an equivalent concentration of elemental nitrogen. Nitrogen concentrations are 

included in table 40, and for 15 selected water-data 

stations, details of regression-equation analyses of 

nitrogen concentration as a function of discharge are 

presented in table 44. 

Phosphorus is more common in rock than nitrogen, 

but like niirogen the most important sources for the 

element in stream water are animal metabolic waste, 

decaying vegetation, and cultural application by man, 

especially fertilizer application where irrigation is 

practiced. The more common phosphorus ion is the 

orthophosphate anion. Orthophosphate ions in terms of 

equivalent concentrations of elemental phosphorus and 
A66 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

Note: Station 14 plots off graph 

11 

w 20 

a: 

1-

:J 

a: 

w 

a. 

CJ) 

~ 10 

<( 

a: 

(!) 

:J 

....J 

~ 

~ 5 z 

0 

~ 39 

a: 

1- 7 z 

w 8 () 

z 

0 

() 2 w 25 

1-

<( 

u. 

....J 

::::> 

CJ) 

EXPLANATION 

11 

0.5 ~------~----~--~--~_L_L_L~L_------~----~--~--~_L_L_L~L-------~----~--~~ 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 47 .-Sulfate concentration as a function of discharge ratio. 

concentrations of total phosphorus are presented in the 

same uSummary of Data" as for nitrogen. 

Because nitrogen and phosphorus in stream waters 

are more dependent on what may be considered mobile 

sources (biological and man-related activity) rather 

than stationary sources (rock types), concentrations of 

these nutrients in stream waters are somewhat erratic. 

Water samples from a given water-data station may 

show a range from zero to significant levels of nutrients. 

Regression relations to discharge are less meaningful 

for nutrients than other ionic concentrations. For 

examples, a spring application of fertilizer may give 

highest phosphate concentrations in stream water 

during spring floods; likewise, low flows of late fall may 

show higher concentrations of nitrate than low flows of 

early fall because of the nitrogen input from decay of 

seasonal organic matter. For these reasons, regression 

analysis data in table 44 indicate some streams have 

positive relations of nutrient contents to discharge and 

others have negative relations. For nitrite and nitrate 

expressed as nitrogen, the average concentration varies 

with discharge to the 0.14 power. For orthophosphates 

as phosphorus, the value of this exponent is 0.19, and for 

total phosphorus, the exponent is 0.13. All these 

average values indicate a positive relation of nutrients 

to discharge, but the relation is reversed at a number of 

streams. 

As noted by Hem (1970), aquatic vegetation of the 

free-floating types, such as algae, depends on dissolved 

nitrogen and phosphorus compounds for its nutrient 

supply. Growth of these species may also be influenced 

by the availability of other required elements. Dense, 

rapidly multiplying algal growths or blooms sometimes 

occur in water bodies that periodically receive increased 

concentrations of nitrogen or phosphorus. These dense 

growths are generally undesirable to water users and 

may interfere with other forms of aquatic life, especially 

if the water body becomes overloaded with oxidizable 

debris as a result of the sudden dieback of an algal 

bloom. 
CHANNELS AND WATERS A67 

5 

w 

CI: 

1-

::J 

a: 

w 

a.. 

CJ) 

~ 

<( 2 

CI: 

0 

:J 

..J 

~ 

~ 

z 

0 

~ <( 

a: 

1-

z 

w 

(.) 

~ 0.5 

(.) 

w 

0 

a: 

0 

_J 

:I: 

(.) 

0.2 7 

36 

0.1 ~------~----~--~~~~~~~--------~--~--~--~~~~~~------~----~--~~ 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 48.-Chloride concentration as a function of discharge ratio. 

The enrichment of a water body with nutrients is pool to which the adit water is directed. The algal 

tern1ed ((eutrophication" by limnologists and is accom- growth was observed only downstream of these stations. 

panied by a high rate of production of plant material in Station 13-2973.20 is on Pat Hughes Creek about 1 mile 

the water. Troublesome algal production within the downstream from the influx of the stilling-pool water. 

study area occurred only along Pat Hughes Creek, Data of June 11, 1971, for station 13-2973.20 indicate 

tributary to Thompson Creek, in the period of February water-quality characteristics of Pat Hughes Creek 

to April1972. High flows occurring in late May flushed before mine blasting operations; nutrient and other 

the stream not only of any causative constituents, but chemical-characteristic values may be considered noralso of most evidence of the algal growth itself. This mal. The later data of 1971 show increasing concentraflushing action occurred before water samples were tion of chemical constituents, but allowing for normal 

collected for analysis, but not before local residents low-flow concentrating, only the increased values for 

documented the algal growth with a photographic nitrogen and sulfate are significant. The June 29, 1972, 

record. However, the data in table 40 for the four data show normal quality characteristics on Pat 

water-data stations 13-2973.12 to 13-2973.20 provide Hughes Creek upstream of the mine blasting but for the 

some information for determining the cause. Station adit and stilling-pool waters, show high concentrations 

13-2973.12 is located on Pat Hughes Creek at a of nitrogen and sulfate. Although the downstream Pat 

headwater location. Station 13-2973.14 records dis- Hughes Creek station indicates dilution of the sulfate 

charge water from a mine adit being blasted into a and nitrogen, it can be inferred that the mine adit 

hard-rock slope adjacent to Pat Hughes Creek, and waters were responsible for the algal growth. The 

station 13-2973.16 records runoff water from a stilling sudden influx of nitrite- and nitrate- concentrated 
A68 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

EXPLANATION w 36 Station number from tables 3 and 43 a: 

1-

:J 

a: 

w 

a.. 

(J) 

~ 200 

<X: 

a: 

~ 

:J 

...J 

~ 

~ 100 

z 

0 

i= 

<X: 

a: 

1-

z 

w 

{) 50 

z 

0 7 

{) 

(J) 

Cl 

:J 

0 

(J) 

6 30 

w 

> 20 ...J 

0 

(J) 

(J) 

C5 

27 

10 ~------~----~--~--~~~~~---------L----~--~--~~~~~--------~----~--~~ 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 49.-Dissolved solids as a function of discharge ratio. 

water, the higher pH and temperature of the adit water, 

and the primary algal growth season of early spring are 

all factors contributing to the healthy growth of algae. 

The nitrogen source for the adit waters was not 

identified, but suspected sources would include nitrate 

content of explosives used in blasting. 

ALKALINITY AND HARDNESS 

Chemical analyses commonly include the concentration of those anions contributing to alkalinity, and these 

are most generally assumed to be bicarbonate and carbonate. In the stream waters of the study area, 

bicarbonate is the primary ion contributing to alkalinity, which is most often expressed as milligrams per litre 

of calcium carbonate. Bicarbonate can be converted to 

equivalent concentration of calcium carbonate by multiplyingthe former by 0.82. Thus, within the study area, 

values of alkalinity are 0.82 values of bicarbonate. Accordingly, alkalinity varies as the -0.21 power of discharge, the same as for bicarbonate. 

Hardness is a chemical property of water to which 

many people refer. Most often it is related to the effects 

of sudsing (or lack of sudsing) observed in the use of 

water with soap. Most of these effects are associated 

with the presence of calcium and magnesium. It is conventional to consider hardness as calcium plus magnesium hardness and to express the results as total 

hardness in terms of an equivalent concentration of 

calcium carbonate. Values of total hardness are included in table 40, and details of the regressionequation analyses are included in table 44. Total hardness varies with discharge to the -0.28 power for the 15 

stations included in table 44, and this value, along with 

the high values of correlation coefficient, reflect the 

predictable amounts of calcium ions found in the water. 

A scale for evaluating hardness is a relative matter. 

Persons living in areas of water with low dissolvedsolids content might consider waters found elsewhere 

hard, while residents of the other location might consider the same waters soft based on their experience. 

Har~ness in water used for ordinary domestic purposes 

does not become particularly objectionable until it 

reaches a level of about 100 milligrams per litre. Waters 

within the study area generally are softer than this 

level. 
CHANNELS AND WATERS A69 

100 I 

50 

- 36 w 

a: 

I-

:J 

37 

----35 

a: 

w 

a_ 

(/) 

~ 20 

<( 

a: 

(9 

:J 

...J 

~ 

~ 10 z 

0 

f= 

<( 

a: 

Iz 

12 

16 

4 17 18 

33 - - 3 

10 13 25 

3r-- 4 

~ 

15 

~ :=:::::------ 34 6 7 

--== ~ ::::---=:: ~ 11 

---= 26 ~ 5, :---: ~9 39 --=-- 2 ---------= ~ 1 

29 

38 8 

~ ~ 28 30 

21 -

~ 23 22 w - (.) 5 

z 

0 

(.) 20 

<( 

(.) 

:J 

27 

Ui 

2 

EXPLANATION 

35 Station 

1

number from tables

1

3 and 28 

1 

0.01 0.02 0.05 0.1 0.2 0.5 2 5 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 50.-Silica concentration as a function of discharge ratio. 

AREAL COMPOSITION OF STREAM WATER 

The analysis of the principal constituents of stream 

water, especially the regression analyses of each chemical parameter as a function of discharge, lends itself to a 

regional portrayal of the composition of the stream water. For example, from the graphs in figure 42, for values 

of specific conductance as a function of discharge, values 

of specific conductance at any given value of the discharge ratio may be determined for each of the waterdata stations. These values can then be plotted on an 

area map at the respective station locations, and 

equal-value lines of water quality can be assigned to the 

map on the basis of the value of the plotted data points. 

The author (Emmett, 1972b) has prepared an atlas 

with a series of 19 such maps, each portraying one of the 

parameters of a standard chemical analysis and also 

including suspended-sediment and turbidity data. This 

atlas includes only data collected in 1971, but the data of 

1972 reinforce the validity of the 1971 data rather than 

conflict with it. 

The preparation of such maps involves (1) the selection of a discharge ratio for which water-quality 

parameter values are to be selected and (2) following the 

laws of contouring in assigning equal-value lines to the 

data. It was decided that mean annual discharge (approximated by a value of discharge ratio equal to 0.25) 

would be as meaningful a value of discharge as could be 

selected. Higher values of the discharge ratio would 

typically provide overly dilute concentrations for the 

parameters, and lower values of the discharge ratio 

would typically be the reverse. It should be noted that 

this technique for selecting representative values of the 

water-quality parameters has inherent advantages 

over the widely used system of presenting data for low 

flow or high flow. Inspection in figures 42-50 of the end 

points of the range in discharge indicates that if the 
A70 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

EXPLANATION 

CONCENTRATION . 

IN MILL IG RAMS 

PER LITRE 

D 

Less than 10 

10 to 15 

15 to 20 

More than 20 

Drainage boundary 

T 14 N 

0 5 10 15 MILES 

0 5 10 15 20 KILOMETRES 

FIGURE 51.-Areal concentration of calcium in streams at mean annual discharge. 

latter method had been chosen, low-flow data would 

actually cover a range of the discharge ratio from 0. 01 to 

0.34 and the high-flow data would cover a range of 

discharge ratio from 0.06 to 3.8. Such ranges in the 

discharge ratio provide for a greater range in waterquality values at a given station than among stations at 

a given discharge. Thus, equal-value lines of water 

quality were assigned to the maps on the basis of the 

values of the water-quality parameters representative 

of mean annual discharge. As the equal-value lines 

trend away from the data positions, the accuracy in 

locating the lines decreases; however, the relations established between the equal-value lines and geology, 

especially in the better defined areas, allowed reasonable extrapolation of data. 

Figures 51-56 are water-quality maps of the type 

presented in the atlas (Emmett, 1972b). Maps selected 

for inclusion here include the major cations of calcium 
CHANNELS AND WATERS A71 

EXPLANATION 

CONCENTRATION. 

IN MILLIGRAMS 

PER LITR E 

D 

Less than 2 

2 to 4 

4 to 6 

More than 6 

Drainage boundary 

T 14 N 

0 5 10 15 MILES 

0 10 15 20 KILOMETRES 

FIGURE 52.-Areal concentration of sodium in streams at mean annual discharge. 

and sodium, the major anions of bicarbonate and sulfate, dissolved silica, and dissolved solids. Figures such 

as figures 43--47 show a strong tendency toward parallelism of the individual major ionic parameters versus 

discharge relations. If the parallelism were exact, the 

equal-value lines of water quality on maps such as 

figures 51-56 would, for any value of the discharge 

ratio, be identically located on the map but have different absolute values for the water-quality parameters, 

such as sodium or calcium. For the present data, as 

exemplified by the slight nonparallelism shown in 

figures 43--47, the configuration of maps ofwater quality for any discharge would be similar, but not identical, 

to the configuration as presented for mean annual discharge. 

Maps showing equal-value lines for the chemical 

parameters occurring in less significant amounts than 

the major ions would not necessarily bear any re-
A72 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

EXPLANATION 

CONCENTRATION, 

IN MILLIGRAMS 

PER LITRE 

D 

Less than 40 

mss:1 

E2i2l 

40 to 60 

60 to 80 

More 

-

than 80 

Drainage boundary 

0 

0 

A 19 E 

T 14 N 

5 10 1 5 MILES 

5 10 15 20 KILOMETRES 

FIGURE 53.-Areal concentration of bicarbonate in streams at mean annual discharge. 

semblance to the trend established in figures 51-56. For 

example, a map of phosphate values might bear more 

resemblance to a map illustrative of fertilizer use than 

to a geologic map. Further, a map of phosphate at small 

values ofthe discharge ratio might bear no resemblance 

to a map prepared for large values of the discharge ratio 

because parallelism of the phosphate versus discharge 

relation for individual stations is nonexistent. Still, in 

the manner described, it is physically possible to prepare maps for any of the parameters, but because of the 

vagaries involved, maps for the lesser constituents are 

less physically significant. For details of these lesser 

constituents, the reader is referred to the original publication (Emmett, 1972b). 

The maps of figures 51- 56 indicate at a glance some of 

the characteristics of the major components of water 

quality in the upper Salmon River. Deviations in the 

quality can be related to the geology, topography, and, 
CHANNELS AND WATERS A73 

EXPLANATION 

CONCENTRATION. 

IN M I LL IG RAMS 

PER LIT RE 

D 

Less than 2 

r:s::TI 

Lllliliill 

2 to 4 

4 to 6 

More than 6 

Drainage boundary 

0 

0 

R 19 E r·---~-l 

. I 

T 14 N 

5 10 15 MILES 

10 15 20 KILOMETRES 

FIGURE 54.-Areal concentration of sulfate in streams at mean annual discharge. 

to a certain extent, man-induced environmental impacts. The effect of geology is noted by the generally 

more dilute waters in areas of more resistant rock. 

Thus, areas of the Idaho batholith show lower mineral 

concentrations than areas of sedimentary rock. Topography has its greatest importance on the orographic 

effect of precipitation and, thus, on runoff and the dilution factor. Most striking is the eastward increase in 

mineral concentration as mean annual precipitation 

decreases. Man's impacts are most often very localized 

and are difqcult to include on generalized maps such as 

figures 51- 56. 

TRACE-ELEMENT ANALYSES 

No exact definition exists for trace element as it relates to constituents of stream water. Some investigators prefer to include only the eight most abundant 

elements (see table 24) as major elements, but these 
A74 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

EXPLANATION 

CON CENTR ATI ON. 

IN MI L LI G RA MS 

PER LIT RE 

D 

Less tha n 10 

10 to 15 

15 to 20 

More than 20 

Drainage boundary 

T 14 N 

0 10 15 MILES 

0 10 15 20 KILOMETRES 

FIGURE 55.-Areal concentration of silica in streams at mean annual discharge. 

include aluminum and iron, which are seldom found in 

greater than trace amounts in stream waters. Others 

prefer to include as trace elements those substances 

typically occurring in stream waters in concentrations 

of 1.0 milligram per litre or less, but these include 

chloride, fluoride, potassium, and other constituents 

which are commonly determined and considered major 

ions. In this study, those elements not routinely 

analyzed in the standard analyses (table 40) are considered trace elements. Concentrations of these trace 

elements, except in isolated and singular instances, 

wel"e less than 1.0 milligram per litre; in fact, as will be 

shown later, the sum of the trace metals totals less than 

1.0 milligram per litre in most samples. 

No part of a water-quality study is more singularly 

time consuming and expensive, both in the field and the 

laboratory, than the analyses for trace elements. Yet, 

these are the data which indicate relations between 
CHANNELS AND WATERS A75 

EXPLANATION 

CON CENTRAT ION . 

IN M ILLIG RAMS 

PER LITRE 

D 

Less than 60 

60 to 80 

60 to 100 

More than 100 

Drainage boundary 

0 

0 

5 10 

5 10 15 

15 MILES 

2 0 KILOMETRES 

T 14 N 

A 19 E ,--~ 

FIGURE 56.- Areal concentration of dissolved solids in streams at mean annual discharge. 

water composition and environmental degradation, 

either through water pollution or natural conditions. A 

summary of the trace-element determinations from the 

present study is included as table 41. It should be noted 

that the concentrations of trace elements are reported in 

micrograms per litre, or 1,000-fold smaller units than 

used for the major-ion data. 

The occurrence of trace elements in surface water is 

considerably more random in time, space, and concentration than that of the major ions. The frequency of 

reported occurrence of the trace elements is given in 

table 29. Of the 21 elements for which analyses were 

made, all were detected in one sample or another. The 

elements found in the fewest number of samples were 

chromium, beryllium, and silver in 9, 10, and 12 percent 

of the samples, respectively. Though one could not predict that these elements would be found least frequently, the results are not surprising considering the posi-
A76 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 29 .-Frequency of reported occurrence of trace elements 

Element 

Aluminum ---------------- Arsenic ---- - -- Barium -- --- --- --------- Beryllium .. ----------------- Boron - - ---------- Cadmium Chromium __ -_---_- ---- ----_-_~ --____ 

Cobalt 

Copper --- ----------------- Iron ________________ ____ ---

Lead ------------- Lithium - ---- -- ------------- Manganese ------ ------- Mercury ------------------- Molybdenum -- ---- ---- -- Nickel --- ----- Se niu~ -- --

Silver _____ :========= === ==-- Strontium __ __ --------- ---- Vanadium ___________ ___ ---_ Zinc __ __ ______ __ 

Total or average 

Number 

of analyses 

11 3 103 

111 

I l l 

106 

112 

103 112 

112 

113 112 

103 113 

99 

109 

112 11 2 11 2 

113 110 

113 

2,304 

Analyses showing 

detectable occurrenc(' Locations showing 

------detectable occurrence 

Number Percentage lPercentagel 

70 6 1.9 100 

53 51.5 100 

28 25.2 83 

11 9.9 75 

64 60.4 100 

49 43.8 100 

9 8.7 67 45 40. 2 100 

84 75.0 100 

111 98.2 100 

77 68.8 100 46 44.7 100 

57 50.4 100 

72 72.7 100 

85 78.0 100 

89 79.5 100 

60 53.6 100 

14 12.5 83 

112 99.1 100 

84 76.4 100 

79 69.9 100 

1,300 56.4 96 

tion of these elements in the earth's crustal abundance 

ranking in table 24. The trace elements most frequently 

found in the stream waters were strontium, iron, nickel, 

and molybdenum in 99, 98, 80, and 78 percent of the 

samples, respectively. The inclusion of molybdenum in 

this ranking might normally be surprising except for 

the known low-grade but widespread molybdenum deposits in the area. The exclusion of aluminum from the 

most-found element list is misleading, but the laboratory detection limits for aluminum is 10 micrograms per 

litre and for many of the other elements is 1 microgram 

per litre or less. Had values for aluminum concentrations of 1-10 micrograms per litre been reported, 

aluminum would have been one of the most frequently 

reported trace elements. 

Of the 2,304 individual analyses summarized in table 

29, 1,300, or 56 percent, indicated the presence of the 

element being sought. Alternative to such a statistical 

breakdown, the last column of table 29 shows the percentage of locations where at least two samples were 

collected and at least one of the samples included the 

sought element. There are 12 such locations. These data 

are somewhat surprising in that they indicate the elements are significantly more widespread in occurrence 

than they are consistent in occurrence. For example, 

chromium was the least found element and occurred in 

only 9 out of 103 samples. But the 9 samples in which it 

was found were collected at 8 of the 12locations. Of the 

21 trace elements analyzed, 17 were found at least once 

at all locations sampled. As a sort of average, data of 

table 29 indicate that about 96 percent of all locations 

would, at one time or another and to the level of the 

detection limits, indicate the presence of the 21 trace 

elements in stream water. 

The range of concentration for each occurring trace 

element is summarized in table 30. The smallest values 

of concentrations of trace elements in table 30 generally 

imply the laboratory detection limit for each ofthe trace 

elements. For each 10 percentile of the samples analyzed for each element, the concentration for that element is given. At 0 percentile, the concentration for 

each element is 0 because analyses for each element 

included at least one sample for which the element was 

not detected (table 29). At 50 percentile, the concentration is the median concentration for the number of samples analyzed. Since 14 of the 21 elements have a nonzero concentration as the median concentration, twothirds of the elements occur in over 50 percent of the 

samples. Values of concentration at 100 percentile are 

maximum values recorded for each element. It may be 

noticed that there is considerable difference in concentrations at the 90 percentile level and the maximum 

observed concentration. Since the 100 percentile column makes no allowance for a contaminated sample or 

an analytical error, values of concentration at the 90 

percentile level may be considered more reasonable 

values of normally occurring maximum concentrations. 

Data at the 90 percentile level indicate that even if 

maximum concentrations for each element occurred in 

the same sample, and this is highly unlikely, the sum of 

the trace elements totals only about 1.0 milligram per 

litre. In most instances, therefore, this sum is well below 

1.0 milligram per litre. 

The preceding data indicate that the trace elements 

are not necessarily consistent in their occurrence. A 

further analysis can show the existence of any variation 

in concentration with discharge. In the manner of 

analysis for the major ions, table 31 is a summary of 

r egression-equation data for iron concentration as a 

function of discharge. Iron was selected for the analysis 

because of its relative abundance in the earth's crust 

and the reported frequency of occurrence in stream 

waters. Data of table 31 do not show such a correlation; 

values of the slope exponent relating iron to discharge 

varied from + 1.04 to -0.20, and the correlation 

coefficients are only moderate in value. Further, the 

value of iron concentrations at mean annual discharge 

is relatively consistent among stations and indicates 

the normal range of iron concentration in the study 

area. 

On the advice of V. C. Kennedy (1973, written commun.), a similar analysis was conducted for dissolved 

strontium. Kennedy reasoned that although iron appeared useful for such analysis, it was a poor choice 

because its solubility in natural stream waters is very 

low. A significant amount of the iron variation would 

probably be due to clays passing the filters during field 

preservation of the water samples. Similar problems 

would arise with aluminum. The regression data for the 
CHANNELS AND WATERS A77 

TABLE 30.-Trace-element concentration, in micrograms per litre, at selected percentiles of samples analyzed 

[0 = a concentration less than that detectable] 

Inclusive percentage of samples analyzed 

Element 

0 10 20 30 

Aluminum ______________ 0 0 0 0 

Arsenic ---------------- 0 0 0 0 

Barium ---------------- 0 0 0 0 

Beryllium -------------- 0 0 0 0 

Boron ------------------ 0 0 0 0 

Cadmium -------------- 0 0 0 0 Chromium ______________ 0 0 0 0 Cobalt __________________ 0 0 0 0 Copper __________________ 0 0 0 1 Iron ____________________ 0 10 10 20 Lead ____________________ 0 0 0 0 Lithium ________________ 0 0 0 0 ~anganese ______________ 0 0 0 0 ~ercury ________________ 0 0 0 .1 ~olybdenum ____________ 0 0 0 1 Nickel __________________ 0 0 0 2 

Selenium -------------- 0 0 0 0 

Silver ------------------ 0 0 0 0 

Strontium -------------- 0 40 50 50 Vanadium ______________ 0 0 0 .2 Zinc ____________________ 0 0 0 0 

TABLE 31.--,S ummary of log-transformed regression data for iron concentration as a function of discharge 

U.S. Geological 

Survey 

station No. 

Correlation 

coefficient. 

13-2950.00 ------ 0.576 2965.00__________________ .538 2975.50__________________ .684 2973.80__________________ .916 2974.25__________________ .123 2974.40 __________________ - .398 2974.45 __________________ - .559 2974.50 __________________ - .097 2974.80 __________________ - .213 

2974.85__________________ .478 2980.00__________________ .682 2985.00__________________ .351 

Mean _______________ _ Median ______________ .538 

Slope of _ iron and 

Q!QB 

relation 

0.557 

.402 

.516 

.897 

.065 - .171 - .199 - .037 - .131 

.229 

1.04 

.378 

.296 

.229 

Iron concentration in micrograms per litre 

Bankfull Mean annual 

<QIQB =1.0) <QIQB =0.25l 

85.9 

48.2 

98.1 

50.6 

14.5 

11.1 

16.2 

23.0 

13.7 

30.4 

96.9 

58.2 

40.0 

27.6 

48.0 

14.6 

13.3 

14.1 

21.3 

24.2 

16.4 

22.1 

22.9 

34.5 

strontium analysis are presented in table 32. The results are considerably more consistent than the iron 

analysis, although the relations still show only moderate correlation. Values of the slope exponent relating 

strontium concentration to the discharge ratio are all 

negative and range in value from -0.04 to -0.70. The 

correlation coefficients range from nearly 0 to about 0. 7. 

Values of the strontium concentration at mean annual 

discharge are consistent with the exception of the two 

East Fork Salmon River Stations (13-2974.25 and 13-

2980.00). Data for these stations show a concentration 

of strontium about twice that of average and indicate 

that somewhere upstream of station 13- 297 4.25, one or 

more tributary streams contained amounts of strontium 

that were unusual for the area. 

In a similar analysis, the station Jim Creek above 

Livingston Mill (13-297 4.85) indicated significantly 

higher levels of zinc than other locations (see table 41). 

Further study indicated that past mining in the area 

40 50 60 70 80 90 100 

10 10 100 100 200 400 1,500 

0 1 2 2 4 6 106 

0 0 0 0 100 200 4,500 

0 0 0 0 0 0 30 

10 10 10 20 20 30 80 

0 0 1 1 1 1 4 

0 0 0 0 0 0 6 

0 0 1 1 2 3 4 

1 1 2 3 3 5 24 

20 20 30 30 40 60 1,100 

1 1 3 3 4 7 11 

0 0 7 10 12 17 70 

0 1 10 10 20 75 570 

.1 .1 .1 .2 .2 .3 1.0 

2 2 3 4 5 8 34 

2 3 3 4 4 6 16 

0 1 2 4 6 10 66 

0 0 0 0 0 1 1 

78 90 120 150 180 270 380 

.4 .8 .9 1.1 1.3 2.2 7.2 

10 10 10 20 20 40 170 

TABLE 32.--,Summary of log-transformed regression data for strontium concentration as a function of discharge 

U.S. Geological 

Survey 

station No. 

Correlation 

coefficient, 

13-2950.00 ---------------- -0.427 2965.00 __________________ - .554 2973.50 __________________ - .494 2973.80 __________________ - .258 2974.25 __________________ - .407 2974.40 __________________ - .260 2974.45 __________________ - .732 2974.50 __________________ - .367 2974.80 __________________ - .067 2974.85 __________________ - .443 2980.00 __________________ - .111 2985.00 __________________ - .625 

Mean _______________ _ 

Median ______________ - .427 

Slope of strontium and 

QIQB 

relation 

-0.580 

- .698 - .263 - .139 - .226 - .222 - .375 - .134 - .036 - .272 - .063 - .541 

- .296 - .263 

Strontium concentration in micrograms per litre 

Bankfull Mean annual 

(QIQB = 1.0) lQIQB =0.25 l 

43 

29 

69 

74 

128 

38 

45 

88 

54 

31 

161 

52 

96 

76 

99 

90 

175 

52 

76 

106 

57 

46 

175 

110 

involved a zinc-enriched ore. The zinc was not removed 

as part of the milling operation, and zinc-enriched tailings, as well as the original zinc ore body, became 

sources of extraordinary amounts of zinc in the surface 

waters. To a considerable extent, this zinc content in the 

waters can be traced through the remaining three 

downstream water-data stations. 

STREAM BlOT A 

Biological observations and sample collections of 

freshwater life were made at 30 locations. These locations and a brief description of each site are given in 

table 20. The biological surveys were started in 1972, 

and during the period of July to October, as many as 

three visits were made to each site. These studies are 

continuing; because the field studies are incomplete and 

laboratory identification and analyses of samples 

already collected are even more incomplete, the 
A78 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

following is only a brief discussion of the nature and 

techniques of the study and a tentative indication of 

stream quality based on the aquatic biota observed. 

The purpose of the biological survey was to determine 

the types of aquatic life at selected stream locations and 

to note any condition in the aquatic life that reflected a 

change in water quality. A measure of the water quality 

or healthiness of the stream is indicated by the relative 

population sizes of the three major groups of organisms; 

namely, algae, invertebrates, and insects. In natural, 

healthy streams a large number of species is present, 

and generally total populations are large. Conclusions 

relative to stream healthiness are drawn from the kinds 

and numbers of species which form the majority of the 

biota. 

As described by Patrick and Grant (1971), in healthy 

conditions where nutrient levels are low, the algae 

population is primarily diatoms; there is an assortment 

of insects with the larger population being mayflies, 

caddisflies, and stoneflies, and there are several invertebrate species including some worms, although their 

number is small. As streams become overenriched with 

nutrients, patches of blue-green algae appear along 

with some filamentous green algae. Snails may also 

become more plentiful. With organic pollution of the 

stream water, the diatoms become less common, and 

flatworms may become very common. If toxic conditions 

exist in the stream, flatworms disappear, mayflies become rare, and the species of caddisflies shift. As toxicity increases, the total number and diversity of species 

decrease. 

The moving waters of streams offer a variety of aquatic environments as discharge increases in the 

downstream direction. This variation includes temperature, types of substratum and soils over and through 

which the water flows, areas of sunshine and shade, and 

successions of riffles, falls, and pools. To provide a representative sampling of the environments, the sampling locations in table 20 include all slope aspects or 

directions of stream drainage. Within this division of 

locations, further division by stream order assures all 

sizes of streams being sampled. Further, first-order 

stream locations include sites above and below lakes as 

well as several sites just below snowpack origins of 

first-order streams. 

To assure representative sampling at each stream 

location, several techniques were employed. The most 

comprehensive was dip-net sampling of the biota from 

rocks, logs, plants, and debris as well as sifting mud, 

sand, and gravel from the stream-bottom material. A 

drift net placed in a representative reach of streams 

collected floating o'rganisms. Seston sampling collected 

even microscopic living and nonliving bodies of plants 

or animals floating in the water. Rocks selected frorn the 

stream bottoms were cleaned of organisms, and 

plankton and algae samples were collected. Several 

types of artificial substrates were left in the streams to 

be collected on each succeeding visit. These visits were 

timed to coincide with seasonal variations in stream 

biota. Complete details of the sampling procedures are 

discussed by Slack, Averett, Greeson, Lipscomb (1973). 

Data thus far indicate that stream waters in the area 

are generally healthy. As indicated by the data in table 

40, nutrient levels in stream waters are low to only 

slightly enriched. Algal growths and blooms present 

few problems. The total number and diversity of aquatic 

biota species indicates general stability in the chemical 

constituency of the stream water and near-ideal concentrations of the chemical contents. Preliminary identification of organisms indicate that stonefly, mayfly, 

and caddisfly dominate, and these groups are indicative 

of healthy conditions. Likewise, preliminary identification indicates that predominant organisms at some locations deviate somewhat from the dominant types just 

mentioned. For example, at Big Boulder Creek near 

Clayton (station 13--2975.00), a generally smaller diversity and population of species indicated some imbalance in stream habitat. Initially, it was supposed that 

upstream ore-processing activities-the zinc enrichment previously noted-were responsible. Subsequent 

investigations showed healthy stream conditions only a 

short distance upstream in the same channel, and a 

more reasonable explanation appears to be that unnatural bank sloughing associated with road construction was responsible. As another example, the westflowing streams of Road Creek and Herd Creek drainages indicate a higher, though still low, level of organic 

content than the east-flowing streams of Big and Little 

Boulder Creek drainages. Though not definitive, the. 

higher levels of organic content are probably related to 

more intense grazing activity in Road Creek and Herd 

Creek drainages than elsewhere. Both of these examples of stream waters deviating from generally healthy 

characteristics should be considered tentative urf:il 

further laboratory analyses and field data verify the 

results. They are included here as examples of the L sefulness of biological observations in water-quaL.ty 

studies. It is apparent that when the full results of :he 

biological studies become available they will amp:tfy 

the validity of water-quality determinations based en 

the chemical quality alone. 

OTHER BIOLOGICAL OBSERVATIONS 

Several other types of biological measurement add to 

the-overall evaluation of water quality. Table 33 gives 

data for dissolved oxygen, total organic carbon, and 

fecal and total coliform bacteria. Data are available for 

five water-data stations, and these stations coincide 
CHANNELS AND WATERS A79 

TABLE 33.-Summary of microbiological, dissolved oxygen, and organic carbon parameters for five water-data stations 

U.S. Geological Discharge, Temperature, Coliform Fecal Field Total coliform dissolved Percent organic Survey Date Q T (colonies (colonies oxygen saturation carbon station No. (ft3/sec) (oC) per 100m!) per 100 mi) (mg/1) '(mg/1) 

13-2974.40 6--23-70---------- 73 1.5 11 0 10.6 105 

8--27-70---------- 3.2 11.0 40 1 7.8 98 

10--13-70---------- 2.2 .0 0 0 10.6 101 6--29--71 __________ 18 1.0 0 0 10.5 103 

8--31-71 __________ 4.3 11.0 220 0 10-- 5--71 __________ .89 5.5 14 0 9.8 109 

6--20--72---------- 27 1.5 0 0 9.5 95 0.0 

7-18--72---------- 18 9.5 1 0 8.0 97 1.0 

8--29--72---------- 3.8 10.0 0 0 7.7 96 .0 

10-- 3-72---------- 1.5 2.0 0 0 9.7 98 

13-2974.45 6--23-70---------- 172 3.5 152 0 10.4 107 

8--27-70---------- 13 9.5 22 3 8.6 101 

10--13-70---------- 7.0 .0 4 0 10.6 98 

6--29--71 __________ 82 2.5 3 0 10.6 106 

8--31-71 __________ 17 9.5 55 6 

10-- 5--71 __________ 8.1 5.5 18 0 10.0 107 

6--20--72---------- 104 2.5 1 0 9.7 96 .0 

7-18--72---------- 61 9.5 11 0 9.0 106 .0 

8--29--72---------- 13 10.0 12 5 8.0 95 .0 

10-- 3-72---------- 6.5 2.5 0 0 9.9 98 .0 

13-2974.50 6--24-70---------- 198 7.0 36 10.2 104 

8--28--70---------- 14 10.5 37 37 9.3 104 

10--12-70---------- 9.4 5.0 4 1 10.3 101 

6--28--71 __________ 120 7.0 30 0 9.9 103 

8--30--71 __________ 19 11.0 72 3 8.7 99 

10-- 6--71 __________ 12 5.5 9 2 9.8 98 

6--20--72---------- 107 6.5 8 1 9.1 92 .5 

7-17-72---------- 66 10.5 3 0 8.0 91 .0 

8--30--72 ---------- 16 10.0 8 1 8.8 96 1.0 

10-- 2-72 ---------- 9.0 5.0 1 0 10.0 98 1.5 

13-2974.80 6--22-70---------- 164 7.0 1 9.5 103 

8--26--70---------- 13 11.5 154 8.5 102 

10--12-70---------- 9.3 3.5 0 0 10.4 102 

6--28--71 __________ 82 3.5 5 0 10.3 101 

8--31-71 __________ 21 11.0 25 3 

10-- 6--71 __________ 6.9 2.0 8 1 10.7 103 

6--19--72---------- 71 5.5 0 0 9.4 97 .0 

7-18--72---------- 46 11.5 1 0 7.8 120 1.0 

8--29--72---------- 16 11.0 0 0 8.2 96 .0 

10-- 3-72---------- 11 5.0 0 0 10.0 102 .0 

13-2974.85 6--22-70---------- 26 8.5 2 9.2 104 

8--26--70---------- 3.1 10.0 545 111 8.6 100 

10--12-70 -------- 2.4 3.0 0 0 10.5 102 

6--28--71 __________ 17 3.0 5 1 10.3 101 

8--31-71 __________ 3.7 8.5 160 2 

10-- 6--71 __________ 3.6 2.0 16 4 10.5 100 

6--19--72---------- 17 5.0 1 0 9.4 96 .0 

7-18--72---------- 9.9 9.5 22 0 8.7 135 .0 

8--29--72 ---------- 4.4 10.0 6 1 8.5 96 1.0 

10-- 3-72 __________ 3.5 3.5 0 1 9.9 98 1.5 

with stations for which major-ion and trace-element levels at all times. Owing to the rapidly changing input 

analyses are available and at which stream-biota ob- and consumption rates, the oxygen content of a stream 

servations were made. is highly variable and meaningful only for the location 

The source of most oxygen in stream water is the and time of sampling. Values of dissolved oxygen in 

atmosphere, but some is contributed as a byproduct of table 33 expressed as concentration in milligrams per 

photosynthesis. Streams in which there is considerable litre are variable; however, the solubility of oxygen in 

organic productivity often have wide fluctuations of dis- water is primarily a function of temperature and pres- . 

solved oxygen in response to biological activity. The sure. In terms of percentage of saturation, values of 

dissolved-oxygen content of stream water is an indica- dissolved oxygen in table 33 indicate all data are cention of the biochemical condition of the water, and de- tered around 100 percent saturation. Because the data 

sirable stream biota require high dissolved-oxygen are consistent at near-saturation values, they are con .. 
ABO HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

sidered to be transferable to most other locations in the 

study area. Thus, dissolved oxygen does not appear to be 

deficient in the studied streams. 

Recent developments indicate that measurements of 

total organic carbon provide a more comprehensive indication of organic pollution in streams than measurements of dissolved oxygen. The few measurements of 

total organic carbon in table 33 show concentrations 

ranging from 0.0 to 1.5 milligrams per litre. These concentrations are not excessive and like the dissolvedoxygen data indicate that organic pollution is not a 

problem in the streams sampled. 

One of the dangers in considering stream water as 

safe for drinking is that it may have been recently 

contaminated by waste of human or animal fecal origin. 

The danger is that water so contaminated contains 

pathogenic organisms which are carriers of such infectious diseases as dysentery. The organisms most commonly used as indicators of pathogenic pollution are 

fecal coliform bacteria and the coliform bacteria group 

as a whole. Fecal coliform bacteria are superior to total 

coliform as indicators of pathogenic contamination of 

water because the latter group includes organisms not 

necessarily of fecal origin. They have no sanitary significance as they can come from soils and vegetation. 

Fecal- and total-coliform data, expressed as colonies 

per 100 millilitres of water sampled, are included in 

table 33. With few exceptions, fecal-coliform colonies 

per 100 millilitres were either 0 or very small. It is not 

possible to tell if the fecal coliform colonies present are 

of human or animal origin. Although the number of 

fecal-coliform colonies counted is very small, waters 

with fecal bacteria cannot be recommended for drinking 

without some purification. In reality, the water is much 

purer than most natural water swimming areas frequented by millions of recreationists every year. As 

mentioned, the total-coliform count is not as significant 

as the fecal-coliform· count. Although total-coliform colonies are considerably higher than fecal-coliform colonies, the number of colonies is few enough to indicate 

no serious problems. Most likely, the coliform data could 

be extrapolated to indicate that pathogenic quality may 

improve in the upstream direction and degrade in the 

downstream direction. The first three stations in table 

33 are in downstream order and tend to verify this 

trend, but the data are so few that this trend should be 

considered as speculative. 

SUSPENDED SEDIMENT 

Unlike dissolved solids, which tend to have only a 

severalfold range in values of concentration over a wide 

range in discharge, suspended sediment commonly has 

more than a 1,000-fold range in conc·entration. Also, 

unlike dissolved-solids concentrations, sediment concentrations are generally higher during high flow than 

during low flow. For a given value of the discharge ratio, 

differences in values of suspended-sediment concentration between locations are largely dependent on the 

rock and soil types and such factors as erodibility. At 

high values of discharge, the increased competence of a 

stream to transport sediment is important only to the 

extent that sediment is available for transport. Owing 

to extremes of erodibility rates among soil types and 

man-induced impacts on natural erosion rates, concentrations of suspended sediment for a given value of the 

discharge ratio are highly variable among locations. 

Table 42 presents all suspended-sediment data 

collected during the study. Because suspendedsediment concentrations within the stream commonly 

are variable both laterally and vertically, the values of 

suspended-sediment concentration in table 42 are 

actually composite values obtained from at least three 

verticals in each section. Thus, the composite values 

may be considered representative for the discharge. 

Because suspended-sediment concentrations are also 

extremely variable with discharge, the composite 

values should be further considered instantaneous 

values and representative only of the respective 

discharge. For a given discharge, many streams show a 

difference in suspended-sediment concentration depending on whether the water stage is rising or falling. 

Data of this report are too few to define a hysteresis for 

suspended-sediment concentrations, and values of the 

concentration may be considered intermediate of any 

hysteresis effect. 

Suspended-sediment samplers utilized were the 

DH-48 for wading measurements and the D-49 for 

cable measurements. Details of these samplers and 

sampling techniques have been described by Guy and 

Norman (1970). 

Commonly, values of instantaneous suspendedsediment concentrations are plotted as a function of 

discharge to obtain a type of sediment rating curve. 

Although only two data points are required to develop 

such a curve, the data are usually so variable that 

reliance can be placed only where several data points 

describe the same curve. Of the 39 water-data stations 

in table 42, 20 stations have at least six values of 

suspended sediment. For these 20 stations, table 34 

includes details of log-transformed regression-equation 

analyses for the suspended-sediment concentration as a 

function of the discharge ratio. The curves described by 

these regression-equation data are shown in figure 57. 

This illustration shows at a glance which of the data 

stations have the highest suspended-sediment concentrations for a given value of the discharge ratio. For the 

20 stations in figure 57, water-data stations 11, 31, and 
CHANNELS AND WATERS A81 

TABLE 34.-Summary of log-transformed regression equation data for 

suspended-sediment concentration as a function of discharge 

Graph u.s. Correlation Slope of Value of suspended Geological suspended-sediment 

plotting coefficient, concentration sediment (mg/1) 

No. st~ti~~e~o. r andQIQB 

relation QIQB=l.O QIQB=0.25 

5 13-2950.00 ------- -0.069 -0.045 4.3 4.6 

8 2965.00 __ .938 1.352 18.1 2.8 

9 2970.00 .933 1.872 74.4 5.6 

11 2972.50 .934 4.926 2,770 3.0 

17 2973.50 ________ .724 1.127 107 22.5 

19 2973.80 .858 1.507 34.9 4.3 

22 2973.96 __ .878 1.220 93.8 17.3 

23 2974.00 ________ .895 .985 75.5 19.3 

24 2974.04 _____ .960 2.038 262 15.5 

25 2974.18 _____ .953 2.239 320 14.4 

26 2974.25 _______ .912 1.501 50.7 6.3 

27 2974.40 ------- -.246 -.173 1.3 1.6 

28 2974.45_ .407 .229 4.2 3.1 

29 2974.50 ____ .923 1.089 89.6 19.8 

30 2974.80 .761 .700 17.9 6.8 

31 2974.85 __ .819 1.631 742 77.3 

32 2975.00 .780 2.449 1,511 50.7 

34 2976.00 .661 1.127 175 36.7 

38 2980.00 .948 1.863 223 16.8 

39 2985.00 .946 2.020 80.9 4.9 

32 have the ((dirtiest" water. Stations 31 and 32 are in 

Big Boulder Creek drainage area, and high values of 

suspended sediment are associated with road construction and maintenance practices, minor mining activity, 

and natural instability of soils on steep slopes of glacial 

origin. Station 11 is in Slate Creek drainage area, and 

high values are associated with channel instability 

resulting from an extremely rare flood in 1963, natural 

instability of the Milligan Formation within the area, 

and to a minor extent some mining-related activities. 

Stations 5 and 27 in figure 57 indicate slightly 

negative slopes for the relation of suspended-sediment 

concentration to discharge. Both of these streams have a 

naturally low content of suspended sediment with 

concentrations borderline with analytical accuracy and 

large percentage errors. The statistical regression of 

data for stations 5 and 27 is misleading in indicating 

((cleaner" water at high discharges, and the data should 

be interpreted that for any discharge these stations 

have insignificant concentrations of suspended sediment. 

Maps showing the areal concentration of suspended 

sediment were prepared by the author in the same 

manner described for the parameters of chemical 

composition (Emmett, 1972b). Figure 57 indicates that 

considerable differences would appear between maps 

prepared for concentration at mean annual discharge 

(Q!Qn=0.25) and bankfull discharge. Because most 

suspended sediment is transported at high stages, the 

map prepared for bankfull stage would be the more 

appropriate to illustrate the presence of suspended 

sediment. Such a map is not presented here because 

extremely variable concentrations of suspended sediment create many difficulties in extrapolating between 

water-data station locations. However, the original map 

(Emmett, 1972b) isolated with a series of equal-v.alue 

lines the areas of high suspended-sediment concentrations discussed. 

Perhaps of more interest than the relation of suspended-sediment concentration to discharge is the 

relation of suspended-sediment load,, G, to discharge. Table 35 provides the details of regressionequation techniques applied to the same data of table 

34, with the results expressed as suspended-sediment 

load in tons per day. These relations are plotted in figure 

58. In terms of Leopold and Maddock (1953), hydraulicgeometry values of the slopes of the lines in figure 58 are 

designated as the exponent j. Values of j range from 

0.6 to 5.9, but an average value is 2.5. This value is the 

same as the average value determined for a number of 

streams in the midwest United States (Leopold and 

others, 1964). For further comparison, values of 

suspended-sediment load for each water-data station 

may be regressed against values of bankfull discharge 

to determine the downstream hydraulic geometry 

characteristics of suspended sediment. Such an analysis 

yields 

G =0.89Qn0.75 (r=0.500). 

Although the moderate value of the correlation 

coefficient indicates considerable scatter to the data, the 

downstream exponent of }=0.75 compares with an 

average value of j = 0.8 for streams in the midwest 

United States (Leopold and others, 1964). 

In figure 58, each successive downstream station 

must indicate a greater sediment load for a given ratio 

of Q!Qn; otherwise, the inference is of sediment deposition in the channel. As an example, the curve (39) for 

the Salmon River at Challis (13-2985.00) envelopes the 

curve (19) for the Salmon River upstream of the East 

Fork (13-2973.80) which in turn envelopes the curve (8) 

for the Salmon River below the Yankee Fork (13-

2965.00). Some minor irregularities to this pattern do 

exist and probably indicate that, locally, during the 

short period of sediment record (1971-72) some reaches 

of channel were aggrading and others were degrading. 

Such irregularities do not indicate that the Salmon 

River drainage is not in equilibrium (neither aggrading 

nor degrading), for equilibrium is thought of in terms of 

at least several years and of the channel's response to 

flows of a variety of magnitude and frequency. 

One obs~rvation of suspended-sediment concentration is of unusual interest but alone provides information of uncertain usefulness. The data are for Maim 

Gulch (13-2983.00), an ephemeral tributary with a 

drainage area of 9.4 square miles and located in the 

semiarid extreme northeast of the study area. A flash 
A82 

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10,000 

1000 

100 

10 

1 

0.01 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

11 

EXPLANATION 

0.1 1 10 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 57.-Suspended-sediment concentration as a function of discharge ratio. 
CHANNELS AND WATERS A83 

TABLE 35.-Summary of log-transformed regression equation data for 

suspended-sediment load as a function of discharge 

Graph U.S. Geological Slope,), of Correlation suspended-sediment Value of suspended plotting Survey coefficient, load and sediment (tons/day) No. Station No. r QIQB 

relation QIQB=l.O QIQB=0.25 

5 1~2950.00 ________ 0.829 0.955 11.6 3.1 8 2965.00 ____ ---- .979 2.353 1.83 7.0 9 2970.00 ________ .970 2.864 121 3.5 11 2972.50 __ .953 5.924 892 .24 17 2973.50 ____ .781 2.249 18.7 .83 19 2973.80 __ .941 2.506 482 14.9 22 2973.96 ________ .962 2.230 55.7 2.5 23 2974.00 ____ .969 1.956 180 11.9 24 2974.04 __ .982 2.669 182 4.5 25 2974.18 ________ .978 3.267 58.4 .63 26 2974.25 __ .966 2.502 150 4.7 27 2974.40 ________ .685 .620 .2 .06 28 297 4.45_----- -- .901 1.208 2.9 .83 29 2974.50 __ .976 2.053 72.8 4.2 ~~0 2974.80 ____ .942 1.699 8.98 .85 31 2974.85 ________ .911 2.651 167 4.2 32 2975.00 ________ .869 3.433 891 7.6 34 2976.00 ____ .802 1.967 222 14.5 38 2980.00 _________ .977 2.868 1,116 20.9 39 2985.00 ________ .977 3.079 1.169 16.4 

Mean -------------- 2.452 Median ---- .962 2.506 

flow resulting from a thunderstorm was measured 

indirectly to have a peak flow of 450 cubic feet per 

second. This corresponds to about the 10-year flood. Two 

measurements at about 4 cubic feet per second on the 

receding hydrograph indicated a suspended-sediment 

concentration ranging from about 112,000 to 245,000 

milligrams per litre, or an average of about 180,000 

milligrams per litre (table 42). The two samples were 

collected ~~simultaneously," and each represents a 

composite average across the channel. Prior to concentration analysis, the two samples appeared similar in 

the amount of settled solids. On the basis of estimated 

porosity and the volume percentage of sample settled, 

the smaller of the two concentrations is probably in 

error, but even ifthis smaller concentration of sediment 

persisted during the estimated four hours duration of 

flow, several tens of thousands oftons of sediment were 

supplied to the main-stem Salmon River. This amount 

of sediment is more than half the estimated average 

annual sediment yield from the entire East. Fork 

Salmon River tributary. 

Ten of the analyses for suspended-sediment concentration included determination of particle-size distribution. Data of these particle-size distributions are 

included in table 36. Nominally, the median particle 

size is at about 0.06 millimetre, or at the break between 

silt- and sand-size particles. The median particle size, 

however, appears to be somewhat variable with 

discharge, and as discharge increases, the percentage of 

fine particles increases and the median particle size 

decreases. 

In contrast to the silt-sand size distribution of 

suspended sediment included in table 36, the particlesize distribution for the samples from Maim Gulch 

indicate 90 percent of the sediment is silt size or finer 

and more than 50 percent is in the clay-size range. 

TURBIDITY 

Turbidity is an expression of the optical property of 

water that causes light rays to be scattered and 

absorbed rather than transmitted in straight lines and 

is caused by a variety of suspended particulate matter. 

Such matter may be living or dead plant and animal 

cells, silt, clay, or many other inorganic and organic 

waste materials. The resulting effect is to give a cloudy 

or opaque appearance to water. 

Fine particulate materials in suspension limit the 

penetration of sunlight and thus restrict the growth of 

bottom and suspended plant life. The solids may also 

flocculate plant and animal life resulting in streambottom deposits of settleable solids and in a smothering 

and crushing action deleterious to benthic organisms. 

Food chains are interrupted, and all animal life becomes 

TABLE 36.--Particle-size distribution of suspended sediment 

Sieve 

size Percentage finer than sieve size (mml 

Station No. 1~29 1~29 1~29 1~29 1~29 1~29 1~29 1~29 1~29 1~29 

72.50 75.00 80.00 80.00 80.00 80.00 85.00 85.00 85.00 85.00 Date 6--1&--72 &--31-71 &--29--72 &--31-72 6--1-72 6--2-72 &--29--72 &--31-72 6--1-72 6--2-72 Disch~g~- (fii;~~~)- == == 109 63 1,380 2,250 2,700 3,170 7,200 10,500 12,300 13,600 Concentration (mg/1) __ 1,390 2,120 237 330 403 415 213 506 641 583 

2.0 ------------------ 100 1.0 ----------------- 99 100 100 100 100 

.50 .. ----------------- 77 100 100 100 100 90 81 77 93 

.25------------------ 60 100 90 92 92 94 58 61 65 73 .125 ---------------- 40 99 67 74 73 80 41 52 57 62 .0625 -------------- 34 96 56 65 63 76 33 46 53 55 .0442 -------------- 22 56 41 41 .0312 --------------- 20 88 55 39 39 .0221 -------------- 18 54 38 38 .0156 ------------- 14 68 50 34 35 .0110 -------------- 11 45 31 33 .0078 -------------- 11 51 40 27 28 .0055 -------------- 10 35 24 24 .0039 -------------- 8 34 32 21 22 .0028 -------------- 6 25 17 18 .0019 -------------- 5 34 20 14 15 
A84 

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0.01 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

EXPLANATION 

0.1 1 10 

RATIO OF DISCHARGE TO BANKFULL DISCHARGE 

FIGURE 58.-Suspended-sediment load as a function of discharge ratio. 
CHANNELS AND WATERS A85 

sparse or stunted. Thus excessively high values of 

turbidity may be extremely detrimental to stream biota 

as well as esthetically displeasing. 

Turbidity in the present study was measured in most 

water samples retained for suspended-sediment 

analysis. Values of turbidity are included in table 42 

and are expressed in Jackson Turbidity Units. The 

sediment suspended in the streams contains large 

quantities of silt- and clay-size particles, and it is this 

size fraction of the suspended sediment that is primarily 

responsible for high values of turbidity. Values of 

turbidity should correlate with values of suspendedsediment concentration, and further, because suspended sediment correlates with discharge, turbidity 

should also correlate with discharge. By using data from 

table 42 for the two stations with the most turbidity 

data, the following typical relations and correlation 

coefficients were determined: 

Station 13-2980.00, 

t=l.33Gc 0.61 

and 

t=36.2 (QIQnJ 1.13 

station 13-2985.00, 

t=0.73 Gc 0·

70 

and 

t=17.2 (Q/QB)l.26 

(r=0.933) 

(r=0.933); 

(r=0.938) 

(r=0.816), 

where t is turbidity in Jackson Turbidity Units and G c 

is suspended-sediment concentration. 

The foregoing equations indicate that when turbidity 

is primarily caused by suspended sediment, values of 

turbidity are roughly proportional to the two-thirds 

power of suspended-sediment concentration. Suspended 

sediment is not the only contributor to turbidity, 

however, and at discharges below about mean annual 

(Q/QB =0.25) and as suspended sediment continues to 

decrease, turbidity begins to increase as very fine 

particulate matter remains in suspension (but contributes little to values of suspended sediment) and 

concentrates as the flow decreases. 

Generally, values of turbidity are reasonable for the 

aquatic population. However, even within the range of 

the yearly variation, out-of-season changes could be 

detrimental. For example, values of turbidity normally 

occurring during spring high water could be extremely 

harmful if they occurred during the fall fish-spawning 

season. Few unusually high values of turbidity other 

than those occurring in association with high values of 

suspended-sediment concentration were observed during the study, and these are probably insignificant in 

the overall evaluation of the area's water quality. 

BEDLOAD TRANSPORT 

Several sets ofbedload-transport measurements were 

made in 1972. These measurements were preliminary 

to continuing studies ofbedload transport in the area. A 

brief discussion of the preliminary data follows to 

indicate the magnitude of bedload-transport rates. 

The bedload sampler used was the Helley-Smith 

modification of the original Arnhem sampler design 

(Helley and Smith, 1971). The sampler was adapted to 

be weighted by lead and lowered by cable or hand held 

and carried to position in streams that were wadeable. 

Two types of bedload observations were made. One 

series consisted of repetitive cross-sectional measurements to define spatial variations in transport rate and 

also to determine average bedload-transport rate for the 

stream. A second series consisted of repetitive measurements at a single vertical in the stream cross section 

to determine temporal variations in bedload rate and 

also to interrelate some aspects of the hydraulics of flow 

to the transport rate. 

Table 37 summarizes most of the preliminary 

TABLE 37.-Summary of bedload-transport measurements obtained with Helley-Smith bedload sampler. 

u.s. Bed material Average Average Total Geological size, d 50 , Date of Discharge, maximum-section channel-wide bedload s:fi':!~f- Survey by pebble observation Q bedload bedload transport transport 

Station No. count (1972) (ft3/sec) transport transport (tons/day) (tons/day) (mm) (tons/day/ft) (tons/day/ft) 

13-2972.50 -- 43.0 5-29 42.8 0 0 5.22 

~ 1 81.2 .19 4.18 53.9 

~2 80.0 .61 13.49 97.2 

~15 108.3 18.42 1.40 30.79 290 

~16 97.6 16.68 8.27 181.91 242 

~17 108.4 19.29 238 

2974.18 -- 34.0 5-31 50.8 .49 5.42 52.0 

~ 1 60.0 .78 8.60 66.0 

2980.00 -- 41.0 5-29 1,374 .22 11.15 1,020 

NOTE.-All transport rates expressed in terms of dry weight of sediment. 
A86 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

measurements of bedload transport. Bed-material sizes 

included in table 37 are by pebble count (see table 13), 

and suspended-sediment data are from table 42. The 

average channel-wide transport rates were determined 

from the cross-sectional series of measurements and 

multiplied by the channel width to obtain total bedload 

transport. The few data available from table 37 suggest 

bedload transport rates are correlative with discharge 

and, at least up to some high value of discharge, 

increase with increases in discharge at a somewhat 

greater rate than suspended-sediment transport. Below 

some nominal but high stage of flow (unpublished data 

collected elsewhere by the author suggest this stage to 

be about minimum annual peak discharge), bedload 

transport is about o.· For most moderately high flows, 

bedload transport is about 1-50 percent of suspendedload transport. Over the course of a year, bedload 

transported by a stream, at least by the gravel-bed 

streams of the present study, is probably on the order of 

1-10 percent of the suspended-load transported. 

The data are insufficient to provide an understanding 

of the mechanics of bedload transport, and a comparison 

with theoretical or empirical formulas is not necessarily 

valid because adequate field data do not exist to test the 

reliability of empirical equations of bedload transport. 

However, L. B. Leopold (1972, written commun.), in 

compiling all known bedload data and plotting them in 

the manner of the Bagnold (1966) approach, used the 

data of the present study, and they were corroborative 

with extrapolation of other data. 

The average maximum-section transport rates in 

table 37 were obtained from the series of repetitive 

measurements at a single vertical in the section. The 

location of this vertical was selected on the basis of 

maximum observed rates of bedload transport from the 

cross-sectional set of measurements. The data are 

consistent in that they show about the same rate of 

average transport for each of3 days with about the same 

discharge; however, individual measurements composing the average rate of transport show large variation. 

Figure 59 illustrates temporal variations in bedloadtransport rates along with hydraulic measurements 

made at the same location. 

Temporal variations in bedload-transport rate are 

about tenfold; however, the variations tend to correlate 

with some of the hydraulics measurements. A change 

from moderate to high bedload-transport rates was 

accompanied by a surge in velocity, the scouring and 

then filling of the channel bed, and an initial increase 

and then decrease in depth of flow. Data of figure 59 are 

from the June 17 data at station 1~2972.50 (table 37). 

They are unique in that they are some of the few, 

perhaps only, such data in existence. However, in 

themselves, they are insufficient to separate cause from 

effect. 

A particle-size analysis of the composite of all 

transported bedload sediment indicated in the graph of 

figure 59 is presented in figure 60. The median particle 

size of bedload material is 22 millimetres (by sieve 

analysis), and this compares with a median bedmaterial size of 43 millimetres (by pebble count). 

ANNUAL RUNOFF OF SOLIDS 

Data collected and presented in this report are 

sufficient to allow approximate computations of annual 

runoff of suspended sediment and dissolved solids. By 

using a technique described by Johnson (1971), duration curves and instantaneous ratings of suspended 

sediment and dissolved solids are combined to provide 

the discharge of solids at each representative flow. 

These values are multiplied by the duration of each 

representative flow and totaled to obtain annual 

discharge of solids. 

Table 38 includes the computation for the annual 

suspended-sediment yield for the water-data station 

Salmon River near Challis (1~2985.00). In this table, 

columns 1 and 2 are the duration-curve data based on 

the entire length of station record. Column 3 shows 

values of the instantaneous suspended-sediment concentration in milligrams per litre associated with water 

discharges of column 2. Column 4 is the multiplication 

of column 2, column 3, and a constant to express 

suspended-sediment discharge in tons per day. Column 

5 is the average suspended-sediment discharge during 

the time increment of column 1. Column 6 is the annual 

runoff of suspended sediment contributed by each 

representative value of discharge from column 2. It is 

obtained by multiplying column 5 by the increment of 

time from column 1 and the number of days in the year. 

Column 7 is a cumulative summation of the percentage 

of annual runoff of suspended sediment contributed by 

each entry in column 6. The summation of column 6 is 

the average annual discharge of suspended sediment. 

From the 1,800-square-mile study area, the average 

annual discharge of suspended sediment is about 70,000 

tons, or 38.6 tons per square mile. 

Cumulative values of suspended sediment in tons per 

year may be plotted as a function of percentage of time 

to indicate the importance of a few days of high flows on 

the magnitude of annual sediment load. Such a plot is 

illustrated by the average-year plot in figure 61. 

Alternative illustration is provided in figure 62 by 

plotting the cumulative percentage of annual sediment 

yield as a function of cumulative percentage of flow 

duration. These data and graphs indicate that more 

than 90 percent of the average annual sediment yield is 
CHANNELS AND WATERS A87 

,-------~--------~------~------~,-------~------~--------,--------,-----, 1.5 

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0 20 40 60 80 100 120 140 160 

TIME, IN MINUTES 

FIGURE 59.- Measurements of bedload transport and concurrent hydraulic and channel data, Slate Creek near Clayton, Idaho. 

contributed in less than 10 percent of the time 

(high-flow runoff). Bankfull stage has an associated 

water discharge of about 5,500 cubic feet per second and 

occurs about 4 percent of the time. About three-quarters 

of the average annual discharge of suspended sediment 

occurs during this 4 percent of the time. 

In much the same manner, annual suspendedsediment yield for the particular study years of 1971 

and 1972 were also computed. For these years, values of 

mean daily discharge were tabulated by rank, and each 

discharge was given a duration of 1 day in 365 days per 

year. Other computations are the same as for the 

average-year data. Results of these computations are 

shown as the 1971 and 1972 curves in figures 61 and 62. 

From figure 61, suspended-sediment yield in 1971 was 

about 195,000 tons and in 1972 was about 322,000 tons, 

or about 275 and 450 percent, respectively, of 

suspended-sediment yield for the average year. The 

influence of peak flows on the amount of suspendedsediment yield is apparent. The year 1972 had a 29 

percent greater peak flow than the year 1971, but the 

suspended-sediment yield was 65 percent greater. Both 

years 1971 and 1972 had greater annual runoff of water 

than average, and even though 1972 experienced the 

greater peak discharge, 1971 had the greater annual 

runoff of water. Bankfull stage was exceeded 11.5 

percent of the time in 1971 and 8.5 percent of the time in 

1972. From figure 62, discharges greater than bankfull 

were responsible for 93 percent of the suspendedsediment yield in 1971 and 89 percent in 1972. 

Similar analyses may be conducted for dissolved 

solids, and table 39 shows the computations for 

dissolved-solids discharge based on average-year data. 

The average annual dissolved-solids load is about 

122,000 tons, or abou~ 75 percent greater than the 

discharge of suspended sediment. The dissolved-solids 
ASS HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

100 Q 

I I I I I I I I I I I I I I I I I I V- -

80 

1-

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0.05 0.1 0.2 0.5 1 2 5 10 20 50 100 

BEDLOAD PARTICLE SIZE, IN MILLIMETRES 

FIGURE 60.- Particle-size distribution of bedload material. 

data are illustrated in figures 63 and 64, and the 

average-year curves for suspended-sediment data are 

included for comparison. The most striking difference in 

the two curves is the more uniform contribution of 

dissolved solids throughout the year. Unlike suspended 

sediment, dissolved solids increase in concentration as 

discharge decreases, and these compensating factors 

provide for more temporal uniformity in dissolvedsolids yield. Whereas 20 percent of the time (high flows) 

accounts for virtually all the suspended-sediment yield, 

the same time accounts for less than half the dissolvedsolids yield. 

The total average annual solids yield of suspended 

sediment and dissolved solids is about 191,370 tons. 

Bedload transport might increase this value to about 

200,000 tons. On the basis of a weight of about 150 

pounds per cubic foot, approximately 2.5 million cubic 

feet of material leaves the area during an average year. 

Distributed over the entire drainage area, this represents a lowering of the ground surface of about 0.06 inch 

per century. Obviously, average erosion rates in the· 

area are very low. 

SYNOPTIC APPROACH TO WATER QUALITY 

An alternative approach to the areal determination of 

water quality for a given stage of flow regardless of the 

simultaneity of data collection between locations is a 

synoptic or simultaneous analysis. Both approaches 

have their merits, but in reality the synoptic approach is 

impossible for small study teams, for at a given instant 

an individual can be at only one location. Also, because 

a large range of discharges was desired for the present 

study, the primary approach chosen was the sampling of 

high-, medium-, and low-water characteristics and the 

interpolation of data to flows of a common frequency 

among stations. 

To supplement these nonsimultaneous data, several 

synoptic runs were made to document water temperature and specific conductance and to estimate discharge 

at as many locations as could be sampled in a single day. 

An example of such data is illustrated in figure 65 for a 

run conducted on June 2S, 1972. Data of figure 65 are 

generally consistent in that main-stem values respond 

to tributary inputs, but without precise discharge 
CHANNELS AND WATERS A89 

TABLE 38.-Computations of annual suspended-sediment yield, Salmon River near Challis (13-2985.00) 

Discharge 

equaled or Suspended- Suspended-sediment Annual Percentage Percentage exceeded, sediment discharge (tons/day) sediment of annual of time Q concentration yield sediment 

(f't3/sec) (mg/l) Instantaneous Average (tons) yield 

o.o __________ 15,400 770 32,017 .1 __________ 11,000 360 10,692 21,355 7,802 11.23 .3 __________ 10,000 295 7,965 9,329 6,816 21.04 .5 __________ 9,000 230 5,589 6,777 4,949 28.17 l.L _________ 7,900 170 3,626 4,608 10,099 42.71 

1.8 __________ 7,000 130 2,457 3,042 7,776 53.90 2.8 __________ 6,200 96 1,607 2,032 7,422 64.59 4.0 __________ 5,500 74 1,099 1,353 5,932 73.13 5.6 __________ 4,900 57 754 927 5,417 80.93 7.5 __________ 4,300 42 488 621 4,310 87.13 

9.3 __________ 3,800 32 328 408 2,681 90.99 11.0 __________ 3,400 25 230 279 1,731 93.48 

13.0 __________ 3,000 18.5 150 190 1,388 95.48 15.4 __________ 2,600 13.5 94.8 122 1,070 97.02 

17.5 __________ 2,300 10.3 64.0 79.4 610 97.90 18.9 __________ 2,100 8.3 47.1 55.6 285 98.31 21.5 __________ 1,800 5.8 28.2 37.7 358 98.83 

23.5 __________ 1,600 4.5 19.4 23.8 146 99.04 25.2 __________ 1,400 3.3 12.5 16.0 117 99.20 

26.5 __________ 1,300 2.8 9.8 11.4 55 99.28 30.4 __________ 1,100 1.9 5.6 7.7 110 99.44 33.5 __________ 1,000 1.5 4.1 4.9 55 99.52 

39.7---------- 880 1.2 2.9 3.5 80 99.64 

48.6 __________ 780 .9 1.9 2.4 77 99.75 

60. l_ ___ ------ 690 .7 1.3 1.6 66 99.84 74.8 __________ 610 .5 .8 1.1 58 99.93 

87.9 __________ 540 .4 .6 .7 33 99.97 

95.3 __________ 480 .3 .4 .5 15 99.99 

100.0 ________ 290 .2 .2 .3 4 100.00 

TotaL ___ ------------ ------------ ------------ ------------ 69,462 ------------

measurements and greater frequency of sampling, little 

additional quantitative interpretation can be provided. 

The synoptic data do provide an especially useful 

technique for isolating contributions of unusual quality. The stream water with the highest conductivity 

presented in figure 65 is from Slate Creek (specific 

conductance equals 242 micromhos). Stream water in 

the main-stem Salmon River responds by an increase in 

conductance from 69 micromhos upstream of Slate 

Creek to 82 micromhos downstream. Thus, even though 

the synoptic data were not of particular usefulness in 

themselves, they were a valuable aid in the interpretation of other data. 

SUMMARY DISCUSSION OF WATER-QUALITY DATA 

A large number of water samples analyzed for their 

chemical and other properties indicate that stream 

waters in the upper Salmon River area may generally 

be classified as of very good quality. The primary 

composition of the stream water is calcium bicarbonate. 

Secondary common cations include sodium, magnesium, and potassium; secondary common anions 

include sulfate, chloride, and fluoride. Little or no 

carbonate is present. Silica contents are moderate, and 

nutrients expressed as nitrogen or phosphorus are not 

excessive. The average pH value is mildly basic, ideal 

for most uses of water. 

Analyses for 21 selected trace elements, including 

many of those considered as toxic to man, indicate that~ 

none are present in troublesome amounts. Generally 

the chemical composition of the surface water is within 

the recommended limits for public water supplies (U.S. 

Public Health Service, 1962; World Health Organization, 1971). Except for the Road Creek drainage area 

(the northeast quadrant of the East Fork Salmon River 

region), dissolved solids were less than 200 milligrams 

per litre, and even the Road Creek area had dissolved 

solids less than the recommended limit of 500 milligrams per litre. A few widely scattered trace-element 

analyses showed concentrations exceeding recommended limits, but these were so few that the 

detrimental aspects appear minimal. Generally, the 

sum of the trace-element concentrations totaled less 

than 1.0 milligram per litre and thus is within 

conservative limits established by some resource 

agencies (McKee and Wolf, 1963). 

Other observations of stream biota and bacterial 

. content also indicate a general healthiness of stream 
A90 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

en 

z 

0 

1-

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en 

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({) 

1,000,000 

100,000 

Station 13-2985.00 

10,000 

1000 t__....J....__....J....__...L__L.__ _ ___l __ _[__l.___[_ _ _L _ _J 

0.1 10 

PERCENTAGE OF TIME 

20 40 

FIGURE 61.-Discharge of suspended sediment as a function of 

percentage of time. 

1-

z 20 w 

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0 

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Station 13-2985.00 

10 

PERCENTAGE OF TIME 

20 40 

FIGURE 62.-Percentage of annual discharge of suspended sediment 

as a function of percentage of time. 

waters, although these studies show that no single set of 

criteria is sufficient to define water-quality standards. 

For example, maximum concentration of dissolved zinc 

in public water supplies is set at 5 milligrams per litre 

(U.S. Public Health Service, 1962); however, except for 

taste, concentrations as much as 700 milligrams per 

litr~ are probably not harmful to humans. At the same 

time, concentrations of zinc in excess of 0.1-1.0 

milligram per litre are fatal to many fish. 

In terms of the popularly used concepts of alkalinity 

and hardness, the water quality is rated very good. 
CHANNELS AND WATERS A91 

TABLE 39.-Computation of annual dissolved load, Salmon River near Challis (13-2985.00) 

Discharge Dissolved Dissolved-solids Annual Percentage 

Percentage equaled or solids discharge (tons/day) dissolved of annual 

of time exceeded concentration solids dissolved 

solids (ft3/sec) (mg/1) yield Instantaneous Average (tons) yield 

o.o __________ 15,400 57 2,376 .1 __________ 11,000 57 1,693 2,032 742 0.61 

.2 __________ 10,000 58 1,566 1,630 1,191 1.59 

.5 __________ 9,000 58 1,409 1,488 1,087 2.48 

l.L _________ 7,900 59 1,258 1,334 2,923 4.87 

1.8 __________ 7,000 60 1,134 1,198 3,063 7,39 2.8 __________ 6,200 61 1,021 1,078 3,940 10.62 

4.0 __________ 5,500 62 921 971 4,256 14.11 

5.6 __________ 4,900 63 833 877 5,125 18,31 7.5 __________ 4,300 64 743 788 5,469 22.80 

9.3 __________ 3,800 66 677 710 4,668 26.63 

11.0 __________ 3,400 68 624 650 4,036 29.94 

13.0 __________ 3,000 70 567 596 4,354 33.51 

15.4 __________ 2,600 73 512 540 4,734 37.40 

17.5 __________ 2,300 76 472 492 3,774 40.40 

18.9 __________ 2,100 78 442 457 2,337 42.41 

21.5 __________ 1,800 82 399 420 3,989 45,68 23.2 __________ 1,600 85 367 383 2,378 47.63 

25.2 __________ 1,400 89 336 352 3,302 50.34 

26.5 __________ 1,300 92 323 330 1,567 51.62 

30.4 __________ 1,100 97 288 306 4,359 55.20 

33.5 __________ 1,000 101 273 280 3,170 57.80 

39.7---------- 880 106 252 262 5,933 62.67 

48.6 __________ 780 111 234 243 7,899 69.15 

60.L _________ 690 117 218 226 9,493 76.93 74.8 __________ 610 122 201 210 11,275 86.18 

87.9 __________ 540 129 188 194 9,282 93.80 

95.3 __________ 480 136 176 182 4,912 97.83 

100.0 __________ 290 168 132 154 2,644 100.00 

Total ________________________________________________________ 121,908 ----------

The sediment quality of water is also good, with only 

moderate amounts of suspended sediment except in 

ti1nes of high flow and at a few locations where man's 

impact accelerates sediment contributions to stream 

channels. Proper land use can minimize man's impact, 

but in any event the high-flow concentrations of 

suspended sediment are not excessive for natural rivers. 

Relations were established between stream discharge 

and the concentration of dissolved and suspended solids.· 

Generally, dissolved solids become more dilute with 

increases in streamflow, and the relation with discharge 

is a power equation with an exponent of -0.20. Major 

ion concentrations vary with discharge about as 

dissolved solids vary with discharge, but the relations of 

trace elements to discharge become erratic as their 

concentrations decrease. The suspended-sediment concentration increases with increases in streamflow, and 

the relation with discharge is somewhat variable but 

generally follows a power law with an exponent of2.5. 

By using the concept of average duration of flow for 

flows of various frequencies, the total annual runoff of 

solids from the study area is about 200,000 tons, and the 

ratio of dissolved-solids runoff to suspended-sediment 

runoff is about 1.75 to 1.0. 

The behavioral characteristics of the chemical and 

sediment properties of stream water are generally 

similar between water-data stations of different locations. That is, the dilution or concentration rate of 

change with discharge and the general composition of 

the chemical constituents were about the same at most 

locations. This indicates some uniformity in both the 

chemical composition of crustal rocks and the runoff 

rate of water available for dilution of chemical 

constituents and transport of suspended solids. The 

expression of these relations in terms of the ratio of 

discharge to bankfull discharge provides a basis for 

comparison of the quality parameters between stations. 

For a given value of the discharge ratio, individual 

stations have concentrations of dissolved and suspended 

solids that primarily reflect solubility and erodibility of 

upstream rock types. Annual yields of total solids 

further depend on annual runoff of water, but because of 

general consistency in data, considerable extrapolation 

of data is possible. For example, a single measurement 

of specific conductance will allow determination of 

dissolved solids and the proportionate amount of each 

constituent, especially of the common ions. Further, the 

concentration change with discharge is predictable. 
A92 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

C/) 

z 

0 

1-

~ 

ui 

(.!) 

a: 

<( 

I 

() 

C/) 

15 

C/) 

0 

::::i 

0 

C/) 

6 

w 

> 5 

C/) 

C/) 

15 

1 ,000,000 r-rl-.l-.--.---,-,-o-r----.--,.-,,r--r--,---1.--.--rl----.--.l-,-l-,-

- - - -

- -

-

-

100,000 t------+----1---+---+--.J::.....-~-~~-1-------1 

~ v -

~ Suspended sedi/~V -

-

-

-

-

10,000 t-tt---t-;--t---t---+---t---t---t---+-----J= I I - -

=/ 

-

-

1-

_[_ _l_ _l_ I 

0.1 

Station 13--2985.00 

(average year) 

I I I 

10 20 40 60 80 90 

PERCENTAGE OF TIME 

-

-

-

I J 

99 

FIGURE 63.-Discharge of dissolved solids as a function of percentage 

of time. 

The section on streamflow characteristics has shown 

that a single discharge measurement combined with a 

channel geometry survey is sufficient to determine a 

value of bankfull discharge. By using the dimensionless 

ratio of discharge to bankfull discharge, a single set of 

curves define streamflow characteristics for the area. 

Combination of streamflow characteristics and waterquality characteristics as a function of the dimensionless\ discharge ratio allow further computations. For 

example, conversion of the specific conductance measurement to dissolved-solids concentrations, the distribution of dissolved-solids concentration over a range 

in values of the discharge ratio, and use of the duration 

curve of the discharge ratio allow the computation of 

annual yield of dissolved solids from an otherwise 

ungaged and unmeasured stream. It should be emphasized that such extrapolation of data is only 

incidental to the primary purpose of the present study 

which is to document the baseline hydrologic characteristics at measured locations. But the masses of data 

allowing extrapolation serve to confirm that the 

baseline characteristics have been adequately described. 

SUMMARY OF FINDINGS 

The upper 1,800 square miles of the Salmon River 

drainage area in south-central Idaho has a little 

disturbed, natural environment, where for the most 

part the surface waters are in a pristine state. Geology 

within the area is relatively simple and consists of 

extensive areas of Idaho batholith and Challis Volcanics and smaller areas of sedimentary rock. The area 

is rather highly mineralized, and this fact has promoted 

areawide mineral exploration and mining, which today 

is less intense than in the past. The topography is 

mountainous, and main-stem rivers flow in canyonlike 

gorges except in Stanley Basin, where there is a fairly 

wide alluvium-filled depression. The ruggedness of the 

terrain allows little land use except grazing of stock, 

and thus the area is little populated. However, this 

ruggedness and the remoteness of the terrain have 

fostered increasing recreational use, which promises to 

be the largest economic use of the land in the future. In 

1972, the Congress of the United States set aside a large 

part of the area as the Sawtooth National Recreation 

Area, and parts of the recreational and other areas are 

under study for inclusion in wilderness, primitive area, 

or national park classification. 

The area is drained by the main-stem Salmon River 

and a principal tributary, the East Fork Salmon River, 

which drains about 30 percent of the total area of study. 

On the basis of a Horton analysis conducted for the 

entire drainage of the East Fork Salmon River, the 

drainage density is about 2.61 miles of stream per 

square mile of area and indicates about 4, 700 miles of 

stream channel in the study area. There are about 2.66 

stream channels per square mile, or about 4,800 

streams in the area. About 76 percent of the streams are 

first-order streams, the East Fork Salmon River is a 

seventh-order stream, and the main-stem Salmon River 

within the study area is inferred to be an eighth-order 

stream. The stream bifurcation ratio is about 4.0. 

Climate in the area is typically characterized by long, 

cold winters and short summers. Because of the 

mountainous terrain, precipitation is variable, ranging 

from more than 60 inches per year in parts of the 

mountains to less than 10 inches per year in the 

northeast corner of the study area. The major part of the 

area receives about 30 inches of precipitation per year, 

and the average annual runoff is about 12 inches per 

year. 

Stream runoff at bankfull stage varies with size of 
CHANNELS AND WATERS A93 

100 I I I I VI I I I 

~ ....... I I 

-

/ ~ v -

f- -

/ 

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0 

::::i 

0 

(/) 

0 

w 

> ....J 

0 

(/) 

(/) 

C5 

>- ....J 

a: 

<( 

w 

>-

u. 

0 

w 

(!) 

<( 

Iz 

w 

0 

a: 

w 

(l. 

50 

f20 

v 

10 

1--

1--

ff5 

2 

1 

0.1 

I 

Vsuspended 

v 

v 

sediment 

-

I Dis7 solids Station 13-2985.00 

(average year) 

-

-

-

I 

-

-

_l l 

10 20 40 60 80 90 99 99.9 

PERCENTAGE OF TIME 

FIGURE 64.-Percentage of annual discharge of dissolved solids as a function of percentage of time. 

drainage area according to the approximate relation 

RB =28.3 DA -0.31, but this relation is locally variable, 

for precipitation is locally greater or less than the mean 

for the area. More exacting than size of drainage area, 

the size of stream channel is everywhere related to the 

magnitude of bankfull discharge by the approximate 

relations Wn=l.37 QB0.54 and DB=0.25 QB0.34. 

Bankfull discharge has a recurrence interval of about 

1.5 years, and flows proportional to bankfull discharge 

tend to have a common frequency of occurrence among 

streams. Mean annual discharge is about equal to 25 

percent of bankfull discharge, and flows equal to or 

greater than mean annual discharge occur about 25 

percent of the time. The magnitude of high- and 

low-flow stream characteristics is presented in terms of 

the ratio of discharge to bankful discharge, Q!Qn, and 

the frequency and duration characteristics of these 

flows are approximately the same for all streams in the 

area. 

A r"ecurrence interval of 2 years implies a normal or 

median year; that is, half the years should produce 

higher flow, and the remainder should produce lower 

flows. The median year will have a peak streamflow of 

about 120 percent of bankfull discharge. Likewise, this 

median year should have 30 consecutive days with a 

mean discharge of90 percent or more ofbankfull and 90 

consecutive days with a mean discharge of60 percent or 

more of bankfull. Conversely, in the low-flow season, 
A94 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

11.5 

94 

9.0 

43 

9.0 

61 

EXPLANATION 

Temperature, in degrees Celsius 

Specific conductance, 

in micromhos 

--• • -- Drainage boundary 

13.0 

197 

0 

0 5 

5 

I 

10 

10 

I I 

15 

I 

11.5 

94" 

15 MILES 

20 KILOMETRES 

FIGURE 65.-Values of synoptic observations of specific conductance and temperature. 

the median year should have 30 consecutive days with a 

mean discharge of8.2 percent or less ofbankfull and 90 

consecutive days with a mean discharge of9.0 percent or 

less of bankfull. 

Stream waters are mostly calcium bicarbonate, and 

the waters generally are of high quality. Typified by 

data from the main stream at the exit from the study 

area, major cations in the weight ratio Ca:N a:Mg:K are 

present in the amounts 1.0:0.22:0.12:0.04; major anions 

in the weight ratio HC03 :S04 :Cl:Fl are present in the 

amounts of 1.0:0.06:0.01:0.005. Dissolved solids vary 

with discharge approximately as DSIX(Q/QB)-0.20. 

Values of the concentration of dissolved solids at a given 

value of the discharge ratio are locally variable 
CHANNELS AND WATERS A95 

depending on solubility of upstream rock types and 

magnitude of runoff. At the exit from the study area, the 

main stream has a concentration of dissolved solids of78 

milligrams per litre at bankfull stage and 101 milligrams per litre at mean annual discharge. The 

concentrations of individual major ions follow the trend 

of dissolved solids. Ions with trace concentrations are 

erratic with respect to both time and spatial occurrence. 

The frequency of occurrence of the true trace elements 

generally is in proportion to their relative abundance in 

the average composition of the earth's crust. Taking an 

average of the whole of 2,304 analyses for 21 different 

trace elements, an element was detected in 56 percent of 

the samples analyzed and occurred at one time or 

another at 96 percent of the locations sampled. 

Raw stream water is seldom recommended for 

domestic supply, but on the basis of only chemical 

composition, stream waters in the area are within even 

recommended limits of concentration for public water 

supplies. Waters generally are suitable for any domestic 

or agricultural use, and with the exception that some 

forms of stream biota are sensitive to even minute 

quantities of some of the trace metals, the waters are 

adequate for biological instream needs. 

Suspended sediment transported varies with discharge approximately as Grx(Q/QB)2.5. Values of the 

concentration of suspended sediment at a given value of 

the discharge ratio are locally variable, depending on 

erodibility of upstream rock. types, man-induced impacts, and the competence of the stream to transport its 

imposed sediment load. At the exit from the study area, 

the concentration of suspended sediment in the main 

stream is 80 milligrams per litre at bankfull discharge 

and 5 milligrams per litre at mean annual discharge. 

On the basis of the average duration of flows of 

various frequency, the average annual discharge of 

suspended and dissolved solids is about 200,000 tons. 

The ratio of quantity of dissolved solids to quantity of 

suspended solids is about 1. 75 to 1.0. 

Aspects of the study are continuing and will result in 

definition of interrelations which include biological 

parameters and total sediment yields. These observations, and continued monitoring of all aspects of the 

study, will allow detection and documentation 

changes in initial or baseline relations. 

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from general physics: U.S. Geol. Survey Prof. Paper 422-I, 37 p. 

Benson, M.A., 1968, Uniform flood-frequency estimating methods for 

Federal agencies: Water Resources Research, v. 4, no. 5, p. 

891-907. 

Blakey,J. F., Hawkinson,R. 0., and Steele, T. D., 1972,Anevaluation 

of water-quality records for Texas streams: U.S. Geol. Survey 

open-file report, 54 p. 

Brown, D. A., 1971, Stream channels and flow relations: Water 

Resources Research, v. 7, no. 2, p. 304-311. 

Brown, Eugene, Skougstad, M. W., and Fishman, M. J., 1970, Methods 

for collection and analysis of water samples for dissolved minerals 

and gases: U.S. Geol. Survey Techniques Water-Resources Inv., 

book 5, chap. A1, 160 p. 

Dury, G. H., 1961, Bankfull discharge-an example of its statistical 

relationships: Internat. Assoc. Sci. Hydrology Bull., v. 6, no. 3, p. 

4&-55. 

Emmett, W. W., 1970, The hydraulics of overland flow on hillslopes: 

U.S. Geol. Survey Prof. Paper 662-A, 68 p. 

--1972a, The hydraulic geometry of some Alaskan streams south 

of the Yukon River: U.S. Geol. Survey open-file report, 102 p. 

--1972b, Quality of stream waters of the White Cloud Peaks area, 

Idaho: U.S. Geol. Survey Water Resources Inv. 6--72,5 sheet atlas. 

Fairbridge, R. W., ed., 1972, The encyclopedia of geochemistry and 

environmental sciences: New York, Van Nostrand Reinhold, 

1321 p. 

Fenneman, N. M., 1931, Physiography ofWestern United States: New 

York, McGraw-Hill, 534 p. 

Feth, J. H., Robertson, C. E., and Polzer, W. C., 1964, Sources of 

mineral constituents in water from granitic rocks, SierraN evada, 

California and Nevada: U.S. Geol. Survey Water-Supply Paper 

1535--I, 70 p. 

Fleischer, Michael, 1953, Recent estimates of the abundances of the 

elements in the earth's crust: U.S. Geol. Survey Circ. 285, 7 p. 

Guy, H. P., and Norman, V. W., 1970, Field methods for measurement 

of fluvial sediment: U.S. Geol. Survey Techniques WaterResources Inv., book 3, chap. C2, 59 p. 

Helley, E. J., and Smith, Winchell, 1971, Development and 

calibration of a pressure-difference bedload sampler: U.S. Geol. 

Survey open-file report, 18 p. 

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

characteristics of natural water [2d ed.]: U.S. Geol. Survey 

Water-Supply Paper 1473, 363 p. 

Hembree, C. H., and Rainwater, F. H., 1961, Chemical degradation on 

opposite flanks of the Wind River Range, Wyoming: U.S. Geol. 

Survey Water-Supply Paper 1535--E, 9 p. 

Horton, R. E., 1945, Erosional development of streams and their 

drainage basins; hydrophysical approach to quantitative morphology: Geol. Soc. America Bull., v. 56, p. 275--370. 

Johnson, L. E., 1971, Continuing sediment investigations in Indiana: 

U.S. Geol. Survey open-file report, 17 p. 

Junge, C. E., and Werby, R. T., 1958, The concentration of chloride, 

sodium, potassium, calcium, and sulfate in rainwater over the 

United States: Jour. Meteorology, v. 15, p. 417-425. 

Kellerhals, Rolf, and Bray, D. I., 1971, Sampling procedures for coarse 

fluvial sediments: Am. Soc. Civil Engineers Proc., Jour. Hydraulics Div. v. 97, no. HY-8, p. 1165--1180. 

Kennedy, V. C., 1971, Silica variation in stream water with time and 

discharge, N onequilibrium systems in natural water chemistry: 

Am. Chern. Soc., in Advances in Chemistry Ser., no. 106, p. 

94-130. 

Killsgaard, T. H., Freeman, V. L., and Coffman, J. S., 1970, Mineral 

resources of the Sawtooth Primitive Area, Idaho: U.S. Geol. 

Survey Bull. 1319--D, 174 p. 

Kilpatrick, F. A., and Barnes, H. H., Jr., 1964, Channel geometry of 

Piedmont streams as related to frequency of floods: U.S. Geol. 

Survey Prof. Paper 422-E, 10 p. 

Leopold, L. B., 1953, Downstream change of velocity in rivers: Am. 

Jour. Sci., v. 251, p. 606--624. 

--1970, An improved method for size distribution of stream bed 

gravel: Water Resources Research, v. 6, no. 5, p. 1357-1366. 

Leopold, L. B., and Maddock, Thomas, Jr., 1953, The hydratilic 

geometry of stream channels and some physiographic implica-
A96 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

tions: U.S. Geol. Survey Prof. Paper 252, 57 p. 

Leopold, L. B., and Miller, J.P., 1956, Ephemeral streams-hydraulic 

factors and their relation to the drainage net: U.S. Geol. Survey 

Prof. Paper 282-A, p. 1-37. 

Leopold, L. B., and Skibitzke, H. E., 1967, Observations on 

unmeasured rivers: Geografiska Annaler, v. 49, ser. A, p. 

247-255. 

Leopold, L. B., Wolman, M. G., and Miller, J. P., 1964, Fluvial 

processes in geomorphology: San Francisco, W. H. Freeman and 

Co., 522 p. 

Livingstone, D. A., 1963, Chemical composition of rivers and lakes: 

U.S. Geol. Survey Prof. Paper 440--G, 64 p. 

McKee, J. E., and Wolf, H. W., 1963, Water quality criteria [2d ed.]: 

California Water Quality Control Board Pub. 3--A, 548 p. 

Mason, Brian, 1952, Principles of geochemistry [2d ed.]: New York, 

John Wiley and Sons, 276 p. 

Miller, J. P., 1961, Solutes in small streams draining single rock 

types, Sangre de Cristo Range, New Mexico: U.S. Geol. Survey 

Water-Supply Paper 1535--F, 23 p. 

Miller, R. A., Troxell, J., and Leopold, L. B., 1971, Hydrology of two 

small river basins in Pennsylvania before urbanization: U.S. 

Geol. Survey Prof. Paper 701-A, 57 p. 

National Oceanic and Atmospheric Administration, 1971a, 

Climatological Data: Idaho Ann. Summ., v. 7 4, no. 13, p. 203-213. 

--1971b, Climate of Idaho: Climatography of the United States 

no. 60--10, 18 p. 

Nixon, M., 1959, A study of the bankfull discharges of rivers in 

England and Wales: Inst. Civil Engineers, Proc., Paper 6322, p. 

157-174. 

Parker, R. L., 1967, Composition of the earth's crust: U.S. Geol. 

Survey Prof. Paper 440--D, 19 p. 

Patrick, Ruth, and Grant, R. R., Jr., 1971, Observations of stream 

fauna, in Hydrology of two small river basins in Pennsylvania 

before urbanization: U.S. Geol. Survey Prof. Paper 701-A, p. 

24-39. 

Rainwater, F. H., and Thatcher, L. L., 1960, Methods for collection and 

analysis of water samples: U.S. Geol. Survey Water-Supply Paper 

1454, 301 p. 

Ronov, A. B., and Y aroshevsky, A. A., 1972, Earth's crust 

geochemistry, in Fairbridge, R. W., ed., The encyclopedia of 

geochemistry and environmental sciences: New York, Van 

Nostrand Reinhold, p. 243--254. 

Ross, C. P., 1937, Geology and ore deposits of the Bayhorse Region, 

Custer County, Idaho: U.S. Geol. Survey Bull. 877, 161 p. 

Ross, C. P., and Forrestor, J.D., 1947, Geologic map of the St~te of 

Idaho: U.S. Geol. Survey and Idaho Bur. Mines and Geology. 

Schumm, S. A., 1960, The shape of alluvial channels in relation to 

sediment type: U.S. Geol. Survey Prof. Paper 352-B, p. 17-30. 

Slack, K. V., Averett, R. C., Greeson, P. E., and Lipscomb, R. G., 1973, 

Methods for the collection and analysis of aquatic biological and 

microbiological samples: U.S. Geol. Survey Techniques WaterResources Inv., book 5, chap. A4, 165 p. 

Smith, K. G., 1950, Standards for grading texture of erosional 

topography: Am. Jour. Sci., v. 248, p. 655--668. 

Steele, T. D., 1971, A study of the chemical quality of streamflow in 

Arkansas: U.S. Geol. Survey open-file report, 40 p. and 

appendixes. 

Taylor, S. R., 1964, Abundance of chemical elements in the 

continental crust; a new table: Geochim. et Cosmochim. Acta, v. 

28, no. 8, p. 1273--1285. 

Thomas, C. A., Harenberg, W. A., and Anderson, J. M., 1973, 

Magnitude and frequency of floods in small drainage basins in 

Idaho: U.S. Geol. Survey Water Resources Inv. 7-73, 61 p. 

Tschanz, C. M., Killsgaard, T. H., Seeland, D. A., VanNoy, R. M., 

Evans, R. K., Federspiel, S. E., Ridenour, J., Zilka, N. T., Tvchek, 

E. T., McMahan, A. B., 1974, Mineral resources of the eastern 

part of the Sawtooth National Recreation Area, Custer and 

Blaine County, Idaho: U.S. Geol. Survey open-file report, part 1, 

314 p., part 2, 648 p. 

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Report PC(VI}-14, Idaho, October 1970, 8 p. 

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Compilation of records of surface waters of the United States 

through September 1970: U.S. Geol. Survey Water-Supply Paper 

1317, 560 p. 

---1963, Snake River basin, pt. 13 of Compilation of records of 

surface waters of the United States, October 1950 to September 

1960: U.S. Geol. Survey Water-Supply Paper 1737, 282 p. 

---1971, Snake River basin, pt. 13 of Surface water supply•ofthe 

United States, 1961-1965: U.S. Geol. Survey Water-Supply 

Paper 1934, 776 p. 

---1966--1972 yearly reports, Water resources data for Idaho, since 

1969 issued separately: Part 1, Surface water records and Part 2, 

Water quality records. 

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U.S. Public Health Service Pub. 956, 61 p. 

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determining flood-flow frequencies: U.S. Water Resources Council, Hydrology Comm., Bull. 15, 15 p. 

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---1971, TheN ation's Rivers: Science, v. 17 4, no. 4010, p. 905--918. 

Wolman, M.G., and Leopold, L. B., 1957, River flood plains-some 

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v. 6, p. 114-142. 

World Health Organization, 1971, International standards for 

drinking water [3d ed.]: Geneva, 70 p. 
SUMMARY OF DATA-TABLES 40-44 
A98 

Water-data 

station No. 

13-2922.00 

2924.00 

2932.00 

2934.00 

2950.00 

2956.50 

2960.00 

2965.00 

2970.00 

2971.00 

2972.50 

2973.00 

2973.10 

2973.12 

2973.14 

2973.16 

2973.20 

2973.30 

2973.40 

&-08-71 

7-21-71 

8-09-71 

&-20-72 

~24-71 

7-21-71 

9-03-71 

&-1&-72 

&-09-71 

7-21-71 

8-09-71 

&-20-72 

&-09-71 

7-21-71 

8-09-71 

&-27-72 

~24-71 

&-21-71 

7-19-71 

8-30-71 

10-04-71 

&-1&-72 

7-24-72 

&-10-71 

7-19-71 

8-10-71 

&-2&-72 

~2~71 

&-22-71 

8-30-71 

&-1&-72 

~2~71 

&-22-71 

7-23-71 

9-03-71 

10-08-71 

&-1&-72 

7-24-72 

10-0~72 

~2~71 

&-22-71 

9-03-71 

&-14-72 

7-24-72 

~2~71 

7-23-71 

9-03-71 

&-14-72 

&-10-71 

7-02-71 

8-10-71 

&-1~72 

~2~71 

7-22-71 

8-1&-71 

9-02-71 

&-14-72 

&-11-71 

7-24-71 

8-10-71 

&-18-72 

&-29-72 

&-29-72 

&-29-72 

&-11-71 

7-24-71 

8-10-71 

&-18-72 

&-29-72 

~2&-71 

&-22-71 

9-02-71 

&-14-72 

&-11-71 

7-24-71 

121 

52 

23 

85 

31 

53 

3.0 

90 

32 

9.3 

3.7 

57 

114 

34 

20 

87 

561 

1,110 

522 

138 

132 

1,090 

264 

636 

92 

48 

196 

889 

2,710 

119 

1,850 

2,920 

6,440 

2,410 

706 

716 

5,820 

1,340 

668 

175 

560 

103 

400 

153 

21 

10 

7.2 

28 

76 

81 

41 

102 

4.0 

1.2 

1.1 

7.3 

6.3 

141 

23 

9.8 

99 

1.0 

.50 

.50 

4.3 

1.5 

1.3 

2.3 

1.7 

99 

134 7.8 105 

368 

41 

10.0 

7.0 

11.0 

7.0 

4.0 

10.5 

10.0 

8.5 

6.5 

16.5 

21.0 

6.0 

6.0 

13.5 

14.0 

5.0 

9.0 

13.5 

13.5 

12.0 

11.0 

10.5 

12.0 

4.5 

14.5 

8.0 

7.5 

3.5 

4.5 

12.5 

6.5 

4.0 

6.5 

12.5 

10.0 

6.0 

6.5 

11.0 

8.0 

5.0 

6.0 

7.0 

7.5 

9.0 

6.5 

9.5 

8.0 

8.0 

9.5 

7.0 

8.0 

11.0 

8.0 

12.0 

9.5 

11.0 

8.0 

6.5 

8.0 

13.0 

8.5 

7.5 

13.0 

15.0 

6.5 

11.0 

16.0 

9.0 

13.0 

8.0 

4.5 

9.5 

10.5 

7.0 

16.5 

7.6 

7.1 

8.0 

7.4 

8.5 

7.2 

7.7 

7.6 

7.7 

7.8 

8.1 

7.7 

7.2 

7.1 

7.9 

7.8 

7.3 

7.0 

7.7 

7.2 

7.4 

7.6 

7.7 

7.6 

7.4 

7.7 

7.9 

7.2 

7.1 

7.6 

7.8 

7.8 

7.0 

7.7 

7.4 

7.5 

7.3 

7.9 

7.5 

8.0 

7.3 

7.8 

7.7 

7.8 

7.8 

7.7 

8.0 

7.5 

7.9 

7.7 

8.1 

7.6 

7.7 

7.9 

8.0 

7.7 

7.8 

7.5 

7.4 

7.6 

7.7 

8.0 

8.0 

7.9 

7.8 

7.6 

7.6 

7.6 

8.2 

7.4 

7.4 

7.6 

7.9 

7.3 

7.4 

TABLE 40.-Summary of selected water-quality characteristics 

[Data, except as indicated, are in milligrams per 

107 

115 

152 

103 

61 

40 

78 

37 

140 

178 

218 

146 

88 

106 

148 

95 

60 

37 

43 

65 

64 

49 

55 

60 

67 

85 

58 

67 

43 

79 

43 

72 

52 

61 

104 

121 

38 

79 

122 

106 

69 

145 

73 

125 

186 

193 

234 

130 

277 

230 

268 

243 

227 

224 

259 

214 

182 

69 

77 

104 

57 

101 

255 

274 

118 

224 

254 

170 

197 

108 

67 

189 

79 

78 

112 

6' 

~ u 

53 

62 

80 

53 

30 

22 

39 

20 

70 

97 

115 

74 

44 

52 

71 

48 

27 

21 

20 

30 

32 

25 

24 

29 

41 

44 

29 

33 

21 

37 

23 

37 

30 

31 

51 

54 

20 

35 

53 

54 

34 

72 

41 

59 

!)3 

103 

116 

66 

116 

107 

121 

106 

110 

119 

131 

107 

87 

34 

38 

48 

28 

51 

85 

83 

55 

84 

78 

77 

88 

53 

34 

78 

35 

46 

62 

49 

59 

71 

47 

25 

18 

32 

15 

67 

89 

100 

69 

39 

53 

66 

42 

20 

14 

20 

22 

27 

19 

21 

19 

27 

32 

22 

24 

13 

27 

16 

29 

20 

27 

41 

54 

15 

32 

48 

49 

29 

66 

35 

59 

92 

100 

110 

58 

130 

120 

130 

110 

94 

96 

110 

92 

77 

25 

32 

42 

21 

28 

26 

15 

38 

62 

56 

44 

47 

46 

27 

75 

31 

32 

51 

65 

74 

94 

65 

42 

29 

52 

27 

97 

126 

147 

100 

63 

75 

98 

66 

50 

35 

35 

46 

53 

43 

42 

45 

55 

59 

45 

55 

41 

62 

43 

58 

45 

48 

73 

89 

31 

57 

78 

75 

52 

92 

56 

80 

129 

132 

145 

90 

171 

151 

164 

148 

160 

157 

171 

140 

129 

58 

62 

79 

48 

79 

189 

190 

87 

159 

173 

115 

134 

86 

57 

125 

61 

72 

92 

0.09 

.10 

.13 

.09 

.06 

.04 

.07 

.04 

.13 

.17 

.20 

.14 

.09 

.10 

.13 

.09 

.07 

.05 

.05 

.06 

.07 

.06 

.06 

.06 

.07 

.08 

.06 

.07 

.06 

.08 

.06 

.08 

.06 

.07 

.10 

.12 

.04 

.08 

.11 

.10 

.07 

.13 

.08 

.11 

.18 

.18 

.20 

.12 

.23 

.21 

.22 

.20 

.22 

'".1 

.23 

.19 

.18 

.08 

.08 

.11 

.07 

.11 

.26 

.26 

.12 

.22 

.24 

.16 

.18 

.12 

.08 

.17 

.08 

.10 

.13 

21.2 

10.5 

5.84 

14.9 

3.55 

4.15 

.42 

6.56 

8.38 

3.16 

1.47 

15.4 

19.4 

6.97 

5.29 

15.5 

75.7 

105 

49.3 

17.1 

18.9 

127 

29.9 

77.3 

13.8 

7.65 

23.8 

132 

300 

19.9 

215 

457 

782 

312 

139 

172 

487 

206 

141 

35.4 

78.6 

25.6 

60.5 

33.0 

7.31 

3.74 

2.82 

6.80 

35.1 

33.0 

18.2 

40.8 

1.75 

.51 

.51 

2.78 

2.19 

22.1 

3.85 

2.09 

12.8 

.21 

.26 

.26 

1.01 

.64 

.61 

.71 

.62 

23.0 

5.33 

2.65 

17.3 

71.5 

10.2 
CHANNELS AND WATERS A99 

and concentrations of major ions at water-data stations litre. O=value below limit of detection] 

0.. 0.. 

rn rn Ol Ol 

rn rn ~ ~ ~ ~ Ql 

'5 Ol 

0 0 0 z ..c ..c 

~ ~ s .3 .3 ]~ 0 0 ::l s ~ Ol Ol Ql ..c ..c s ·;; -~ ~ ~ Ql ol$ 

0. 0. s 0 0 ~ "CI 

~ Q>Ol 

0 

-~ ::l ~ ::l £ £ 0 ·::::: .3 ..c '"@ ~~ ~ ~ ~ .@ Ol ~ 0 0 .! t: "5 ~ ;g Jl :a ::l ;3 ~= 

0 E-< u ::?J 0.. r:t:J p:) u u i:i: r:t:J z 

0.02 0.15 10 17 1.7 0.3 1.7 64 0 0.04 0.0 1.8 0.06 

.01 .05 9.9 20 2.3 .2 1.6 75 0 .6 .2 2.5 .00 

.01 .05 11 24 2.7 .4 1.7 98 0 .2 .4 5.0 .01 

.00 9.9 16 1.7 .4 1.3 64 0 .3 .1 3.7 .04 

.01 .04 8.0 9.0 .5 .2 2.2 36 0 .8 .1 3.0 .02 

.01 .04 5.8 6.8 .3 .2 1.1 27 0 .4 .2 1.0 .00 

.00 .04 8.9 12 .4 .6 2.0 47 0 .4 .4 4.3 .00 

.03 5.8 5.5 .2 .4 .7 24 0 .2 .0 2.5 .00 

.03 .10 22 25 1.1 .7 2.1 85 0 .8 .0 3.3 .03 

.02 .07 24 33 1.6 .6 2.0 118 0 .0 .2 6.5 .02 

.04 .08 27 39 1.8 1.0 2.3 140 0 .2 .5 6.0 .01 

.01 21 26 1.1 1.3 .8 90 0 .9 .1 5.4 .01 

.01 .08 14 14 1.1 .5 2.3 54 0 .9 .0 4.0 .02 

.02 .06 14 19 1.3 .2 2.1 63 0 .5 .1 6.3 .00 

.02 .06 17 24 1.4 .6 2.4 86 0 .3 .4 9.0 .01 

.00 13 15 1.1 .4 1.7 58 0 .6 .1 5.7 .01 

.02 .05 11 6.8 .7 .3 2.9 33 0 .6 .5 5.5 .43 

.01 .02 8.1 5.1 .3 1.1 1.7 25 0 .2 .2 5.3 .00 

.01 .05 8.2 7.1 .5 .3 2.1 24 0 3.5 .5 1.3 .02 

.03 .04 12 8.1 .4 .4 3.3 37 0 .3 .7 1.3 .02 

.01 .04 12 10 .6 .7 3.4 39 0 .6 .4 6.0 .06 

.00 .04 13 6.7 .6 .8 2.5 31 0 .6 .2 3.4 .01 

.00 .02 10 7.2 .7 .3 4.2 29 0 1.0 .9 3.7 .00 

.02 .06 15 6.4 .8 .4 3.1 35 0 .8 .0 1.3 .06 

.02 .06 14 9.1 1.1 .5 3.4 50 0 .5 .2 .5 .26 

.01 .05 14 11. 1.1 .6 3.7 54 0 .2 .4 1.3 .05 

.00 14 7.5 .8 .6 2.6 35 0 .7 .1 1.5 .00 

.04 .08 17 8.0 1.0 .5 3.8 40 0 .2 .1 4.3 .00 

.04 .10 17 4.7 .4 .4 3.0 25 0 .1 .0 2.5 .00 

.03 .05 20 9.5 .8 .8 4.5 45 0 .1 .4 3.3 .01 

.06 16 5.3 .6 .5 2.7 28 0 .3 .2 3.3 .02 

.04 .06 15 10 1.0 .3 3.6 45 0 .5 .2 5.0 .00 

.02 .05 12 6.8 .7 .4 2.4 36 0 .1 .2 3.5 .00 

.01 .05 13 9.5 .8 .4 2.7 38 0 .6 .3 2.0 .01 

.01 .04 16 15 .9 .6 4.4 62 0 .4 .7 3.8 .02 

.01 .04 16 19 1.5 1.1 4.5 66 0 1.0 .5 6.0 1.60 

.00 .03 7.6 5.5 .4 .6 1.8 24 0 .4 .4 2.5 .02 

.01 .02 14 11 1.1 .5 3.2 43 0 1.0 .4 4.7 .00 

.01 16 17 1.4 .6 4.6 65 0 .9 .5 5.0 .00 

.03 .06 14 18 1.1 .8 2.2 66 0 .8 .0 5.8 .00 

.01 .03 11 11 .4 .4 1.7 41 0 .0 .0 6.8 .03 

.00 .03 15 25 .8 1.0 1.9 88 0 .7 .4 4.0 .01 

.03 11 13 .7 .9 1.5 50 0 .6 .1 3.3 .02 

.01 13 22 1.1 .7 1.7 72 0 1.0 .1 5.4 .00 

.05 .07 21 32 3.0 .7 2.5 113 0 .4 .1 13 .03 

.02 .05 21 35 3.2 .7 2.3 126 Q 1.0 .1 6.5 .01 

.03 .05 20 40 3.6 .8 2.2 141 0 .2 .3 8.0 .02 

.06 21 20 2.0 .7 2.1 80 0 .3 .0 4.6 .00 

.05 .30 15 47 3.3 1.5 4.4 142 0 1.2 .3 28 .09 

.04 .38 14 43 2.9 1.4 3.2 130 0 .7 .4 21 .05 

.04 .07 14 45 3.2 1.5 3.9 147 0 .5 .7 23 .00 

.03 14 41 2.8 1.5 3.0 129 0 .6 .4 21 .03 

.MI .17 27 29 5.2 .7 11 134 0 1.9 .2 19 .06 

.r~ .10 27 30 5.2 .7 12 145 0 1.3 .2 9.0 .00 .(If; .17 25 34 1.8 .9 12 160 0 2.4 .5 11 .01 

.04 .07 26 22 9.1 2.1 6.8 130 0 .9 .4 8.3 .01 

.20 28 25 3.6 .9 9.5 106 0 1.8 .2 7.1 .09 

.04 .10 20 8.4 1.1 .5 3.8 42 0 .7 .0 2.3 .02 

.03 .07 18 10 1.6 .6 3.6 46 0 .2 .1 4.8 .00 

.02 .07 20 13 2.3 .7 4.4 59 0 .6 .3 8.3 .07 

.02 17 6.7 1.0 .5 2.6 34 0 .3 .1 3.1 .00 

.03 22 8.9 1.4 .5 11 62 0 .7 .1 3.8 .00 

.18 17 9.1 .7 1.8 54 104 0 2.1 .7 51 .29 

.04 18 5.7 .2 .7 53 101 0 1.3 .3 59 .50 

.04 .12 24 12 2.0 .6 10 67 0 1.1 .0 4.5 .03 

.02 .04 20 20 2.9 .9 25 102 0 .8 .4 38 .14 

.03 .17 21 19 2.0 1.0 30 95 0 1.5 .8 49 .47 

.oi 20 14 2.3 .8 18 94 0 .7 .2 13 .00 

.01 19 15 2.4 1.1 24 107 0 .8 .2 19 .01 

.04 .10 19 14 2.6 1.5 4.8 64 0 .3 .1 12 .01 

.05 .12 19 8.2 1.5 .5 3.6 41 0 .5 .0 3.8 .01 

.01 .05 18 22 4.9 1.0 7.8 95 0 .7 .4 23 .07 

.07 18 9.7 1.7 .7 3.6 43 0 .4 .1 5.5 .02 

.()7 .13 27 8.2 2.8 1.2 4.0 56 0 1.0 .0 .3 .02 

.fll .10 28 12 5.2 1.2 4.9 75 0 .8 .2 1.8 .10 
AlOO 

Water-data 

station No. 

13.2973.40 

2973.50 

2973.60 

2973.80 

2973.84 

2973.88 

2973.94 

2973.96 

2974.00 

2974.02 

2974.04 

2974.18 

2974.25 

2974.34 

2974.36 

2974.38 

2974.40 

2974.45 

8--11-71 

6-19-72 

6-26-71 

6-22-71 

7-23-71 

9-02-71 

10-07-71 

6-14-72 

7-24-72 

5-26-71 

6-23-71 

9-02-71 

6-15-72 

6-01-71 

6-23-71 

7-22-71 

9-01-71 

10-08-71 

6-19-72 

7-25-72 

10-04-72 

7-01-71 

7-23-71 

8--13-71 

9-29-72 

7-01-71 

7-23-71 

8--13-71 

9-29-72 

9-29-72 

5-27-71 

6-27-71 

9-02-71 

5-30-72 

6-29-72 

10-01-72 

5-27-71 

6-27-71 

9-02-71 

6-29-72 

7-25-72 

10-04-72 

10-04-72 

5-27-71 

6-27-71 

9-02-71 

6-29-72 

9-30-72 

10-04-72 

6-12-72 

7-26-72 

8--11-72 

5-31-72 

5-27-71 

6-27-71 

7-22-71 

9-02-71 

10-07-71 

6-21-72 

7-25-72 

10-04-72 

10-02-72 

10-02-72 

10-02-72 

6-23-70 

8-27-70 

10-13-70 

6-29-71 

8-31-71 

10-05-71 

6-20-72 

7-18-72 

8-29-72 

10-03-72 

6-23-70 

8--27-70 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

23 

177 

11 

19 

2.9 

.95 

.66 16 

2.0 

215 

343 7.4 273 

7,590 

7,600 

3,120 

1,180 

1,070 

6,560 

1,950 

983 

97 

103 

41 

5.5 

56 

38 

8.5 

5.9 

26 

90 

169 

16 

172 

155 8.1 

314 

569 

60 

500 

135 

39 

6.3 

128 

386 

46 

225 

43 

36 

65 

9.3 

6.6 

51 

504 

1,300 

496 

126 

107 

725 

230 

97 

.32 

.40 

.46 

73 

3.2 

2.2 

18 

4.3 

.89 27 

18 

3.8 

1.5 

172 

13 

8.5 

6.5 

3.5 

11.0 

8.0 

2.5 

7.0 

9.0 

10.0 

4.0 

5.0 

11.0 

8.0 

6.0 

9.0 

12.0 

12.0 

6.5 

8.5 

10.0 

7.0 

7.0 

7.0 

9.0 

4.5 

6.0 

6.5 

16.0 

3.0 

8.0 

3.5 

4.0 

9.5 

7.5 

10.5 

7.0 

5.5 

5.0 

12.0 

11.5 

8.5 

7.0 

4.5 

4.0 

5.0 

7.0 

10.5 

3.0 

4.5 

6.5 

8.0 

9.0 

6.0 

7.5 

5.5 

6.0 

9.0 

5.0 

5.0 

8.5 

6.5 

4.0 

5.0 

7.0 

1.5 

11.0 .0 

1.0 

11.0 

5.5 

1.5 

9.5 

10.0 

2.0 

3.5 

9.5 

7.7 

8.2 

8.1 

8.1 

8.1 

8.2 

7.3 

7.1 

7.7 

7.1 

6.4 

6.1 

7.4 

7.2 

8.2 

7.2 

6.7 

7.6 

7.1 

7.4 

7.6 

7.8 

7.0 

7.5 

7.6 

7.3 

7.9 

7.9 

7.6 

8.0 

7.5 

7.5 

7.7 

7.6 

7.2 

7.1 

8.0 

7.6 

7.6 

7.7 

7.4 

7.7 

7.3 

7.5 

7.5 

7.3 

8.1 

7.8 

8.1 

7.8 

7.7 

8.0 

7.4 

7.8 

7.1 

8.0 

7.5 

8.2 

7.5 

7.8 

8.0 

7.8 

7.8 

7.8 

7.7 

7.6 

8.0 

8.2 

7.7 

7.9 

7.6 

7.8 

7.6 

7.2 

8.2 

7.5 

7.9 

7.8 

7.7 

8.0 

7.9 

7.5 

7.4 

7.4 

7.3 

6.8 

7.7 

8.1 

7.4 

6.7 

7.0 

6.8 

7.7 

7.5 

6.4 

7.2 

7.6 

TABLE 40.--Summary of selected water-quality characteristics 

134 

175 

154 

202 

197 

168 

14 

18 

31 

20 

21 

24 

16 

20 

24 

20 

18 

22 

15 

32 

74 

145 

82 

148 

112 

221 

318 

339 

140 

276 

107 

82 

214 

91 

73 

68 

76 

130 

140 

64 

103 

138 

63 

54 

75 

125 

96 

94 

128 

163 

160 

142 

97 

184 

107 

109 

218 

125 

87 

173 

93 

1~5 

208 

184 

130 

100 

156 

102 

161 

163 

72 

80 

98 

64 

131 

99 

100 

166 

179 

107 

133 

189 

14 

19 

30 

19 

21 

23 

16 

19 

21 

16 

17 

20 

22 

32 

72 

79 

44 

68 

56 

112 

142 

150 

61 

115 

56 

43 

107 

47 

41 

37 

39 

62 

66 

28 

47 

66 

30 

26 

32 

47 

46 

48 

61 

68 

63 

67 

43 

71 

46 

43 

80 

56 

36 

71 

39 

49 

79 

87 

70 

50 

78 

53 

77 

79 

39 

42 

51 

31 

62 

48 

52 

76 

76 

48 

60 

81 

7 

9 

13 

9 

7 

9 

11 

7 

11 

10 

10 

14 

34 

61 

33 

65 

51 

110 

150 

190 

66 

140 

45 

30 

92 

37 

33 

26 

37 

54 

74 

28 

44 

61 

29 

25 

32 

9 

49 

48 

58 

74 

72 

64 

42 

73 

44 

48 

84 

56 

37 

73 

38 

56 

87 

90 

59 

47 

73 

50 

72 

79 

31 

33 

36 

24 

59 

47 

52 

72 

76 

49 

57 

80 

5 

5 

12 

6 

8 

10 

7 

7 

7 

6 

7 

12 

10 

12 

34 

112 

69 

105 

88 

151 

196 

219 

99 

171 

89 

69 

140 

74 

65 

51 

57 

85 

98 

49 

69 

91 

39 

34 

46 

71 

55 

58 

76 

94 

92 

87 

58 

112 

60 

64 

126 

77 

51 

102 

53 

75 

124 

111 

87 

63 

96 

70 

97 

102 

63 

63 

73 

51 

79 

64 

69 

103 

109 

67 

83 

112 

12 

14 

20 

12 

15 

17 

17 

13 

19 

12 

14 

18 

21 

21 

51 

0.15 

.09 

.14 

.12 

.21 

.27 

.30 

.13 

.23 

.12 

.09 

.19 

.10 

.09 

.07 

.0 

.12 

.13 

.07 

.09 

.12 

.05 

.05 

.06 

.10 

.07 

.08 

.10 

.13 

.13 

.12 

.08 

.15 

.08 

.09 

.17 

.10 

.07 

.14 

.07 

.10 

.17 

.15 

.12 

.09 

.13 

.10 

.13 

.14 

.09 

.09 

.10 

.07 

.11 

.09 

.09 

.14 

.15 

.09 

.11 

.15 

.02 

.02 

.03 

.02 

.02 

.02 

.02 

.02 

.03 

.02 

.02 

.02 

.03 

.03 

.07 

6.96 

'33.0 

3.12 

4.59 

1.22 

.51 

.39 

4.17 

.92 

51.7 

63.9 

2.78 

54.5 

1,330 

1,050 

480 

271 

283 

868 

363 

242 

10.2 

9.46 

5.09 

1.06 

8.32 

5.95 

1.74 

1.50 

6.48 

21.1 

26.5 

5.05 

27.9 

26.8 

2.75 

65.3 

78.4 

16.6 

71.6 

27.3 

13.0 

1.89 

30.1 

65.7 

12.0 

42.5 

11.3 

9.83 

11.1 

1.58 

1.30 

7.02 

108 

225 

92.4 

35.0 

31.5 

131 

51.5 

29.3 

.01 

.02 

.02 

2.96 

.09 

.10 

.83 

.15 

.05 

.87 

.69 

.18 

.08 

10.2 

1.86 
CHANNELS AND WATERS AlOl 

and concentrations of major ions at water-data stations -Continued 

Q.. Q.. 

"' UJ 

<!l a:l ~ "' UJ ..c e ::I 'i 0 s s ~ z ..c ..c Po. ~ 8 .2l .2l Q) -g~ ~ 0 ::I 8 o:J o:J ~ Q) 

..c ..c 8 "fii ::I s:: s:: Q) a:s.2J Po. Po. Q) "i 8 0 .f s:: "' ~ Q) Q)a:l 

0 3 ~ ·E s:: ::I "f 0 -~ .... ....... ..c ~ o:J o:J o:J "f 0 .;g ·;::::: t: 0 <a ~ ;g ~ -~ o:J ::2 ::I '"3 ;<;::S:: 

0 E-< 00 u ::g Q.. rfJ Ill u u i:i: rfJ z 

0.07 0.10 28 14 6.3 1.6 5.6 96 0 0.5 0.5 8.0 0.01 

.03 24 7.8 3.2 1.2 3.3 54 0 .6 .1 2.3 .00 

.06 .10 22 19 4.2 .6 5.1 83 0 .9 .1 37 .05 

.05 .07 23 15 3.4 .5 4.3 68 0 .8 .0 6.3 .00 

.04 .06 20 30 8.9 .8 4.8 137 0 .8 .2 18 .01 

.06 .07 18 40 13 .9 4.9 173 0 1.1 .4 32 .06 

.01 .08 17 50 16 1.1 4.8 183 0 1.3 .2 38 .02 

.01 .07 20 19 4.5 1.3 4.1 74 0 .9 .2 12 .02 

.04 .05 19 36 11 .8 4.7 140 0 1.0 .4 29 .00 

.07 .10 26 11 4.2 1.2 4.8 68 0 1.1 .1 6.8 .03 

.07 .17 24 7.5 2.8 .9 4.9 53 0 .6 .0 2.5 .00 

.04 .07 26 22 9.1 2.1 6.8 130 0 .9 .4 8.3 .01 

.10 24 9.0 3.6 1.3 3.6 57 0 .7 .1 3.6 .01 

.04 .15 14 11 1.3 2.5 2.9 50 0 .3 .2 8.0 .01 

.02 .14 12 9.0 .9 .6 2.5 45 0 .4 .1 2.5 .03 

.01 .04 12 13 1.1 .3 2.6 48 0 1.3 .3 2.0 .00 

.01 .04 15 19 1.5 .3 4.5 76 0 .5 .7 5.3 .01 

.01 .05 15 26 2.1 .9 4.5 80 0 .9 .5 7.8 .02 

.01 .05 11 9.9 .9 .4 2.6 34 0 1.0 .2 5.4 .13 

.00 .01 13 15 1.6 .6 3.3 57 0 1.0 .6 5.5 .00 

.00 15 21 2.1 .6 4.6 80 0 1.2 .5 7.0 .00 

.01 .05 4.8 10 .9 .1 1.1 36 0 .3 .1 3.8 .02 

.01 .04 3.8 9.2 .5 .3 .8 32 0 .4 .1 3.5 .01 

.01 .05 4.5 12 .6 .6 1.1 39 0 1.4 .3 6.3 .03 

.02 5.6 20 1.3 .3 2.0 59 57 0 .7 .1 13 .00 

.00 .07 6.0 17 1.5 .3 1.1 56 0 .3 .1 1.5 .02 

.01 .05 5.2 17 1.3 .1 .9 58 0 .3 .2 4.3 .00 

.01 .05 6.4 20 2.0 .2 1.3 74 0 .1 .4 9.0 .05 

.01 6.8 24 3.5 .7 1.9 81 83 0 1.1 .1 15 .00 

.00 7.5 25 2.3 .3 3.0 78 77 0 1.0 .1 15 .00 

.02 .04 8.1 22 2.1 .4 3.1 82 0 1.0 .2 9.5 .05 

.01 .05 6.1 15 1.1 .4 1.9 53 0 .2 .0 6.8 .03 

.00 .03 9.4 26 2.0 1.0 6.6 87 0 1.1 .6 22 .06 

.07 6.9 15 1.5 .4 1.8 56 0 .7 .1 5.8 .09 

.00 5.9 17 1.3 .5 2.4 53 0 1.1 .0 9.8 .01 

.00 10 29 2.8 1.3 11 98 0 1.6 .8 21 .02 

.00 .03 7.8 19 2.0 .3 2.9 68 0 1.0 .1 9.8 .04 

.01 .02 6.1 13 1.1 .3 1.9 44 0 .2 .0 6.5 .02 

.00 .03 9.2 25 2.5 .9 5.4 87 0 1.0 .6 15 .01 

.00 5.6 13 1.3 .4 2.1 47 0 .7 .1 7.1 .01 

.00 .01 6.9 19 2.1 .6 3.4 60 0 1.0 .3 12 .00 

.01 10 29 3.6 1.0 7.5 85 96 0 2.4 .7 22 .00 

.02 14 34 1.3 .4 1.1 104 106 0 .9 .1 7.3 .01 

.03 .05 13 20 2.2 1.6 2.6 85 0 .4 .0 5.3 .01 

.03 .14 11 17 1.1 .3 1.8 61 0 .2 .0 1.8 .00 

.01 .04 13 26 1.9 .4 2.6 95 0 .7 .3 4.3 .02 

.01 11 18 1.3 .3 1.9 65 0 2.4 .1 2.8 .03 

.02 13 25 2.4 .4 3.0 88 94 0 .9 .1 5.9 .00 

.01 13 28 2.1 .5 2.9 96 0 1.2 .1 6.4 .00 

.05 .20 19 9.2 2.0 .4 3.1 48 0 2.0 .0 3.3 .03 

.05 .07 19 9.8 2.0 .1 4.1 51 0 .5 .2 1.8 .00 

.05 .08 20 11 2.1 .3 5.3 62 0 .6 .5 2.3 .03 

.39 18 7.1 1.5 .2 2.8 38 0 .8 .1 1.4 .01 

.02 .04 10 20 2.2 .4 3.3 76 0 1.0 .3 5.3 .04 

.01 .04 9.2 16 1.7 .6 2.5 59 0 .5 .0 3.8 .06 

.00 .04 7.7 18 1.8 .2 2.3 64 0 1.0 .2 5.8 .00 

.03 .04 12 25 2.3 .6 4.6 93 0 .7 .4 11 .01 

.04 .06 12 26 2.7 .9 5.2 93 0 1.1 .3 14 .00 

.00 .03 8.4 17 1.7 .3 2.6 58 0 .8 .1 7.4 .05 

.01 .04 10 19 2.4 .6 3.4 73 0 1.0 .4 9.9 .00 

.01 12 27 3.1 .7 5.6 99 0 1.1 .3 13 .00 

.05 2.3 1.7 .2 .6 .4 10 8 0 1.0 .1 2.0 .00 

.04 2.6 1.7 .3 .1 .7 15 11 0 .7 .1 2.2 .01 

.00 3.4 4.2 .3 .1 1.0 19 16 0 .7 .2 2.6 .02 

3.6 2.2 .2 .2 .7 8 11 0 .0 .1 .0 

1.3 2.9 .2 .6 1.1 11 14 0 .0 .1 1.5 .13 3.0 3.6 .1 .2 1.0 11 18 0 .1 .2 .0 .00 .00 .01 3.4 2.6 .1 .1 .7 8 8 0 .1 .0 2.5 04 .01 .05 2.9 2.6 .1 .0 .7 11 11 0 .2 .3 .5 .00 .00 .04 2.9 3.0 .0 .2 .7 12 13 0 .3 .1 .8 .02 .00 .01 3.3 2.1 .1 .3 .4 9 9 0 .2 .1 1.0 .08 .00 .01 2.9 2.3 .2 .1 .7 15 13 0 .0 .0 1.6 .00 .00 .03 2.6 4.4 .2 .2 .6 15 12 0 .3 .1 3.7 .02 .00 2.9 3.7 .1 .2 .9 15 12 0 .9 .1 2.6 .71 

6.1 4.2 .5 .2 1.0 17 18 0 .0 .0 .0 

10 12 .8 .9 1.6 41 42 0 .0 .1 4.2 
A102 

Water-data 

station No. 

13-2974.45. 

2974.50 

2974.62 

2974.66 

2974.70 

2974.74 

2974.80 

2974.85 

2975.00 

2975.30 

2975.80 

2975.90 

2976.00 

2976.70 

2976.80 

2977.00 

2978.80 

2979.00 

10--13-70 

~12-71 

~29-71 

&-31-71 

10--05.-71 

~20--72 

7-1&-72 

&-29-72 

10--03-72 

~24-70 

&-10--70 

&-2&-70 

10--12-70 

5-27-71 

~2&-71 

7-22-71 

&-30--71 

10--0~71 

~20--72 

7-17-72 

&-30--72 

10--02-72 

10--03-72 

10--03-72 

10--03-72 

10--03-72 

~22-70 

&-2~70 

10-12-70 

~2&-71 

&-31-71 

10-0~71 

~12-72 

7-1&-72 

&-29-72 

10-03-72 

~22-70 

&-2~70 

10-12-70 

~2&-71 

&-31-71 

10-0~71 

~12-72 

7-1&-72 

&-29-72 

10--03-72 

5.-31-71 

~2~71 

9-02-71 

~20--72 

7-25-72 

10-02-72 

5.-31-71 

~23-71 

&-15.-71 

~21-72 

10--04-72 

9-2&-72 

~01-71 

~23-71 

9-01-71 

~15.-72 

10-04-72 

6-13-71 

7-20-71 

&-11-71 

5.-31-72 

9-2&-72 

~13-71 

7-20--71 

&-11-71 

5.-31-72 

9-2&-72 

~01-71 

~23-71 

&-15-71 

~21-72 

9-2&-72 

9-30-72 

9-2&-72 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

7.0 

82 

17 

8.1 104 

61 

13 

6.5. 

198 

21 

14 

9.4 

55. 

120 

92 

19 

12 

107 

66 

16 

9.0 

.07 

1.8 

7.8 

.31 

164 

13 

9.3 

82 

21 

6.9 

71 

46 

16 

11 

26 

3.1 

2.4 

17 

3.7 

3.6 

17 

9.9 

4.4 

3.5 

63 

198 

27 

106 

44 

16 

25. 

21 

3.9 

16 

23 

3.3 

186 

275. 

30 

200 

26 

13 

4.1 

3.3 

16 

3.8 

3.9 

1.7 

.86 

5.9 

1.3 

12 

3.8 

2.6 

11 

4.3 

.25 

.15 

0.0 

3.5. 

2.5 

9.5 

5.5. 

2.5. 

9.5. 

10.0 

2.5 

7.0 

12.0 

10.5. 

5..0 

7.0 

7.0 

11.0 

11.0 

5..5. 

6.5. 

10.5. 

10.0 

5.0 

1.5 

2.5 

7.0 

1.5. 

7.0 

11.5 

3.5 

3.5. 

11.0 

2.0 

5..5. 

11.5 

11.0 

5.0 

8.5 

10.0 

3.0 

3.0 

8.5. 

2.0 

5.0 

9.5 

10.0 

3.5. 

4.0 

5..0 

8.0 

3.5. 

8.5 

3.5 

5..0 

4.0 

19.0 

12.5 

5..5 

7.0 

6.0 

10.0 

7.0 

7.5 

6.5 

13.5 

16.0 

16.5 

11.0 

4.5 

16.5 

15.0 

17.0 

13.0 

3.0 

7.0 

14.0 

9.0 

10.5 

5..5 

20.0 

9.0 

6.6 

7.7 

7.8 

8.1 

7.3 

7.5. 

8.0 

7.6 

7.5. 

7.3 

8.1 

7.9 

7.8 

8.2 

7.9 

7.6 

8.2 

7.9 

7.9 

7.1 

7.5 

7.9 

7.4 

7.4 

7.3 

7.6 

8.0 

7.4 

7.6 

7.7 

8.1 

7.8 

7.9 

7.4 

7.4 

7.9 

8.4 

7.6 

8.0 

8.0 

8.3 

8.1 

7.8 

8.3 

8.0 

8.2 

8.3 

8.1 

8.3 

7.8 

8.5 

7.8 

7.4 

7.3 

7.2 

7.5. 

6.9 

6.0 

7.3 

6.6 

7.2 

7.4 

7.7 

8.0 

7.2 

7.5. 

7.8 

7.4 

7.6 

6.9 

7.0 

7.3 

6.5 

7.2 

6.6 

7.4 

7.6 

7.2 

7.7 

8.3 

7.3 

7.3 

7.5 

7.2 

6.3 

7.4 

6.8 

7.2 

7.6 

8.0 

7.5 

7.8 

7.7 

7.2 

7.7 

7.5 

7.3 

8.0 

7.4 

7.5 

7.8 

7.7 

7.5 

7.4 

7.6 

7.1 

8.0 

7.9 

8.1 

7.5 

7.5 

7.8 

7.9 

7.8 

7.7 

7.6 

7.8 

7.8 

8.0 

8.1 

7.5 

8.2 

7.8 

8.3 

7.6 

7.7 

8.0 

8.1 

8.1 

7.7 

8.2 

TABLE 40.~ummary of selected water-quality characteristics 

84 

51 

66 

83 

53 

44 

66 

84 

40 

88 

104 

56 

45 

86 

64 

66 

62 

115 

42 

50 

68 

134 

34 

84 

94 

50 

74 

94 

56 

51 

79 

94 

97 

159 

94 

117 

148 

156 

128 

141 

153 

157 

137 

195 

110 

196 

262 

410 

340 

1,020 

1,280 

84 

47 

50 

66 

83 

44 

45 

67 

82 

38 

76 

88 

106 

80 

49 

45 

85 

107 

56 

52 

90 

105 

41 

47 

65 

122 

35 

80 

92 

54 

71 

91 

47 

49 

78 

94 

105 

160 

157 

118 

155 

157 

113 

130 

154 

158 

99 

61 

110 

71 

90 

131 

152 

133 

155 

129 

195 

107 

162 

133 

188 

141 

195 

167 

213 

236 

172 

240 

461 

469 

486 

374 

387 

283 

340 

402 

316 

313 

1,.034 

957 

10 

22 

26 

32 

37 

25 

20 

30 

39 

16 

38 

53 

25 

24 

42 

48 

26 

25 

41 

48 

21 

17 

25 

62 

15 

32 

35 

20 

30 

35 

23 

20 

30 

34 

39 

61 

63 

54 

66 

67 

51 

53 

62 

65 

44 

28 

45 

30 

34 

46 

77 

62 

80 

60 

91 

51 

82 

66 

90 

66 

90 

84 

113 

125 

88 

117 

221 

248 

267 

186 

180 

134 

170 

205 

150 

148 

376 

326 

38 

20 

22 

29 

35 

19 

20 

27 

41 

15 

34 

39 

45 

32 

22 

25 

35 

47 

24 

21 

36 

47 

16 

15 

26 

49 

14 

26 

41 

20 

29 

40 

21 

22 

34 

42 

48 

76 

76 

56 

70 

76 

51 

59 

69 

78 

45 

27 

44 

32 

40 

60 

57 

47 

53 

47 

80 

44 

70 

58 

78 

61 

85 

69 

93 

100 

72 

100 

200 

220 

220 

170 

170 

120 

140 

170 

130 

130 

260 

200 

58 

33 

38 

47 

55 

34 

33 

44 

58 

28 

57 

52 

71 

59 

42 

36 

59 

73 

41 

38 

59 

73 

27 

31 

45 

90 

22 

50 

66 

40 

48 

61 

35 

35 

50 

62 

67 

105 

110 

83 

102 

105 

76 

87 

97 

103 

71 

45 

60 

52 

61 

90 

117 

98 

111 

95 

115 

76 

105 

86 

112 

87 

117 

131 

161 

176 

129 

171 

293 

314 

333 

240 

247 

190 

224 

262 

208 

204 

636 

601 

0.08 

.04 

.05 

.06 

.07 

.05 

.04 

.06 

.08 

.04 

.08 

.07 

.10 

.08 

.06 

.05 

.08 

.10 

.06 

.05 

.08 

.10 

.04 

.04 

.06 

.12 

.03 

.07 

.09 

.05 

.07 

.08 

.05 

.05 

.07 

.08 

.09 

.14 

.15 

.11 

.14 

.14 

.10 

.12 

.13 

.14 

.10 

.06 

.08 

.07 

.08 

.12 

.16 

.13 

.15 

.13 

.16 

.10 

.14 

.12 

.15 

.12 

.16 

.18 

.22 

.24 

.18 

.23 

.40 

.43 

.45 

.33 

.34 

.26 

.30 

.36 

.28 

.28 

.87 

.82 

1.10 

8.41 

2.16 

1.20 

9.55 

5.42 

1.52 

1.01 

15.0 

3.36 

2.02 

1.81 

8.76 

13.6 

8.94 

3.03 

2.31 

11.8 

6.81 

2.60 

1.78 

.01 

.15 

.95 

.08 

9.74 180 1.66 

8.86 

2.72 

1.13 

6.72 

4.38 

2.19 

1.84 

4.91 

.81 

.72 

3.81 

1.02 

1.03 

3.39 

2.32 

1.14 

.98 

12.1 

24.1 

4.37 

14.9 

7.20 

3.79 

7.90 

5.66 

1.17 

4.21 

7.27 

.67 

52.7 

64.3 

9.25 

47.0 

8.25 

4.60 

1.78 

1.57 

5.57 

1.73 

3.09 

1.44 

.77 

3.82 

.85 

6.16 

2.30 

1.84 

6.07 

2.37 

.43 

.24 
CHANNELS AND WATERS A103 

and concentrations of major ions at water-data stations -Continued 

c.. c.. 

"' o:s"' o:s~ 

e "' ..c 2 Qi 

0 0 'S ~ z ..c:: ..c:: s Q) 

~~ 0. ~ s ..., ~ rg 0 

-~ s o:s o:s Q) ..c:: ..c:: s ;:j !':: ,;:: Q) o:ss 0. 0. Q) ·~ s 0 0 ,;:: :g :g s Q) o:s 0 ] ~ ·5 ,;:: ;:I -€ -€ 0 ..... ..c:: bll o:s ;g o:s e -€ 0 0 .s ·c.~ 

t: 0 03 o:s & ~ o:s ::2 ;:j :; .-:= s:: 0 E-< U3 u ::E en Q5 u u ri: en z 

0.04 11 14 0.8 0.3 1.9 13 47 0 0.3 0.3 6.5 0.02 .01 .20 9.5 7.2 .4 .1 1.5 27 0 .8 .0 .5 .03 .01 .04 9.7 7.6 .7 .3 1.3 28 32 0 .3 .0 2.0 .02 .01 .06 9.6 11 .4 .1 1.3 36 39 0 .4 .4 3.3 .01 .01 .04 11 13 .5 .3 1.8 49 45 0 .7 .2 5.3 .01 .00 .03 8.5 6.8 .5 .2 .8 28 30 0 .2 .1 2.3 .03 .00 .03 7.4 7.1 .5 .1 .9 35 24 0 1.0 .1 3.4 .01 .01 .03 9.2 10 .4 .4 1.2 40 37 0 .3 .1 3.8 .01 11 14 1.5 .3 1.7 46 47 0 .6 .2 5.2 .00 

7.0 5.1 .6 .2 1.3 20 22 0 .0 .1 1.0 12 12 1.0 .2 2.4 46 42 0 .0 .2 4.4 13 14 1.0 .5 3.0 46 53 0 2.0 .1 5.2 15 16 .4 1.2 4.0 65 62 0 .6 .3 3.2 .02 .03 .08 14 11 .5 1.0 3.0 50 0 .4 .1 4.5 .00 .02 .04 9.8 7.3 .4 .8 2.0 31 36 0 .1 .0 3.0 .00 .00 .03 8.5 9.0 .2 .7 1.4 29 29 0 .4 .1 .5 .03 .01 .05 13 13 .3 .7 2.7 47 51 0 .7 .4 3.0 .00 .01 .06 15 17 1.1 .3 3.7 59 0 .8 .2 5.3 .01 .00 .07 11 8.3 .7 .3 1.5 33 32 0 .3 .1 2.6 .03 .00 .03 9.1 7.5 .5 .3 1.7 61 31 0 1.0 .1 2.7 .00 .01 .02 12 13 .8 .3 2.8 56 50 0 .8 .2 4.4 .00 .01 14 17 1.2 .3 3.8 59 59 0 1.9 .3 5.3 .01 

.01 6.9 6.2 .2 .4 .2 26 25 0 .2 .0 .9 .01 .01 7.6 5.6 .2 .2 1.4 23 21 0 .6 .1 5.2 .00 .02 7.8 10 .3 .1 1.3 27 31 0 .9 .3 8.6 .01 .05 22 17 1.6 .3 5.9 68 76 0 1.2 .1 4.4 .00 

5.9 4.8 .4 .2 1.0 18 18 0 .0 .1 2.4 9.3 13 .8 .6 1.7 39 41 0 1.0 .1 9.0 11 15 .9 .3 2.0 42 54 0 .4 .3 9.5 .02 .02 9.5 7.3 .5 .2 1.5 25 35 0 .1 .0 3.0 .00 .01 .05 9.0 11 .4 .3 1.3 37 38 0 .4 .4 6.5 .00 .01 .05 10 15 .7 .3 1.8 44 43 0 .7 .2 9.8 .01 .00 .04 8.2 7.4 .5 .3 .9 27 28 0 .3 .2 3.1 .08 .00 .02 7.1 8.1 .5 .2 1.0 32 24 0 1.0 .1 4.7 .00 .01 .03 9.0 12 .9 .2 1.3 44 37 0 .2 .1 7.9 .00 .01 10 15 1.0 .3 1.7 46 42 0 1.6 .2 11 .01 

11 16 1.8 .6 1.2 48 45 0 .0 .1 14 16 25 3.1 1.5 1.9 74 81 0 1.0 .1 16 16 26 2.8 .7 2.0 77 80 0 .6 .7 18 .02 .04 .08 14 19 2.0 .5 1.6 57 66 0 .1 .0 12 .07 .04 .11 16 24 2.5 .4 1.9 73 80 0 .7 .3 16 .00 .03 .09 17 26 2.6 .5 1.9 82 0 .8 .2 15 .03 .01 .09 15 17 2.0 .7 1.3 61 62 0 .4 .2 8.8 .05 .02 .08 14 20 2.2 .5 1.6 93 65 0 1.0 .1 15 .04 .03 .05 15 24 2.3 .5 1.7 80 76 0 .7 .1 15 .00 .03 15 27 2.6 .5 2.0 88 79 0 1.2 .1 15 02 

.20 1.00 16 14 2.4 1.0 3.1 54 0 2.0 .1 5.5 .03 .09 1.20 11 9.0 1.2 .7 1.7 34 0 .7 .0 3.5 .00 .01 .05 13 16 1.1 .5 2.5 49 0 .8 .4 2.0 .01 .05 11 11 1.1 .2 2.0 36 0 .7 .0 8.2 .03 .01 .02 11 14 1.3 .3 1.9 42 0 1.0 .3 10 .00 .01 14 21 1.9 .6 3.5 61 56 0 1.2 .2 18 .38 

.09 .11 25 18 2.9 1.8 10 94 0 1.9 .1 10 .11 .08 .10 26 15 2.3 .2 9.8 76 0 1.5 .0 5.0 .04 .06 .15 22 17 2.6 .6 11 98 0 2.7 .4 4.0 .63 .11 24 15 2.3 .4 9.3 73 0 1.7 .1 6.0 .00 

.02 13 23 5.5 .4 7.2 117 111 0 1.8 .2 9.7 .00 .07 19 13 2.9 .8 4.3 61 62 0 2.2 .2 3.1 .00 

.04 .15 15 20 5.0 .8 5.8 100 0 1.4 .1 7.8 .02 .04 .30 14 17 3.9 .5 4.9 81 0 1.2 .0 4.5 .09 .01 .04 14 23 5.1 .7 6.9 110 0 1.6 .4 5.8 .01 .16 13 18 4.0 .6 4.3 81 0 1.2 .1 5.3 .06 .01 13 25 5.6 .5 7.4 102 110 0 2.1 .2 7.9 .00 

.10 .12 36 16 7.1 2.8 7.5 102 0 3.3 .1 7.8 .03 .15 .18 41 22 9.3 3.6 8.3 138 0 3.9 .3 4.3 .05 .17 .29 44 22 11 3.7 10 152 0 5.0 .5 4.8 .04 .23 34 17 7.2 2.8 7.8 107 0 3.6 .2 4.1 .01 .17 39 23 11 4.3 10 166 143 0 66 .3 6.8 .01 

.09 .20 46 42 24 4.7 18 270 0 11 .3 14 .07 .12 .33 45 47 24 5.3 20 302 0 10 .4 13 .06 .11 .19 46 49 24 4.9 21 325 0 12 .7 15 .02 .42 38 37 19 3.5 14 227 0 7.6 .4 8.9 .00 .23 40 36 19 3.5 16 183 219 0 11 .4 13 .00 

.14 .20 38 27 12 3.3 12 163 0 5.7 .2 11 .03 

.12 .40 38 34 14 2.8 16 207 0 6.4 .3 9.8 .16 

.10 .14 36 40 16 2.7 22 250 0 7.8 .6 13 .19 

.15 37 32 13 2.8 14 183 0 7.2 .3 12 .02 

.14 40 30 14 3.4 13 185 181 0 7.6 .3 7.0 .00 

.03 21 59 27 19 120 454 459 0 20 4.1 140 .00 

.01 22 35 27 19 140 385 397 0 21 3.0 140 .00 
A104 

Water-data 

station No. 

13-2980.00 

13-2985.00 

Water-data 

station No. 

6-01-71 

6-13-71 

6-23-71 

7-22-71 

9-01-71 

10-07-71 

5-29-72 

6-15-72 

7-25-72 

10-04-72 

5-26-71 

6-26-71 

7-23-71 

9-01-71 

10-07-71 

5-17-72 

6-14-72 

7-24-72 

10-05-72 

13-2950.00 5-24-71 

6-21-71 

7-19-71 

8-30-71 

10-04-71 

6-16-72 

7-24-72 

2965.00 5-25-71 

2973.50 

6-22-71 

7-23-71 

9-03-71 

10-08-71 

6-16-72 

7-14-72 

10-05-72 

5-26-71 

6-22-71 

7-23-71 

9-02-71 

10-07-71 

6-14-72 

7-24-72 

2973.80 6-01-71 

6-23-71 

7-22-71 

9-01-71 

10-08-71 

6-19-72 

7-25-72 

10-04-72 

2973.96 10-04-72 

2974.00 7-25-72 

10-04-72 

2974.04 10-04-72 

2974.25 5-27-71 

6-27-71 

7-22-71 

9-02-71 

10-07-71 

6-21-72 

7-25-72 

10-01-72 

2974.40 6-23-70 

8-27-70 

10-13-70 

6-29-71 

8-31-71 

HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 40.-Summary of selected water-quality characteristics 

1,070 

2,500 

2,670 

943 

268 

201 

1,377 

1,740 

390 

183 

4,680 

10,100 

3,700 

1,160 

1,100 

13,000 

8,760 

2,020 

1,090 

5.0 

9.5 

7.0 

7.0 

11.0 

5.5 

6.5 

8.0 

9.0 

7.0 

8.5 

8.0 

12.5 

13.0 

11.5 

7.0 

8.0 

14.5 

7.0 

8.0 

7.4 

7.3 

7.3 

7.6 

7.7 

7.1 

7.7 

7.6 

8.0 

7.9 

7.4 

7.6 

7.7 

7.7 

7.2 

7.2 

7.7 

7.2 

144 

119 

103 

131 

197 

194 

135 

108 

157 

199 

96 

79 

94 

157 

159 

95 

76 

119 

162 

71 

61 

51 

55 

91 

89 

59 

51 

69 

89 

45 

43 

48 

75 

72 

41 

38 

54 

75 

65 

52 

48 

52 

83 

83 

59 

48 

71 

90 

39 

40 

44 

66 

69 

33 

35 

54 

73 

96 

77 

76 

82 

119 

121 

81 

70 

97 

122 

65 

64 

64 

99 

93 

59 

57 

78 

104 

TABLE 41.-Summary of concentrations of dissolved trace elements at water-data stations 

[Data, except as indicated, are in micrograms per litre. O=value below limit of detection] 

§ 

.s 

§ 

< 561 500 

500 

400 

500 

100 

0 0 0 1,110 

522 

138 

132 

0 

2 

4 

0 

1 

0 0 0 0 0 0 0 20 0 10 10 1,090 0 

10 0 0 20 264 0 0 0 

2,290 

6,440 

2,410 

300 0 400 10 0 300 0 50 706 

716 

5,820 

1,340 

668 

200 4 0 100 3 0 0 0 0 10 2 100 0 2 0 

11 600 19 500 3.0 200 .95 200 .66 100 16 0 2.0 0 

7,590 

7,600 

3,120 

1,180 

1,070 

6,560 

1,950 

983 

8.1 

135 

39 

36 

504 

1,300 

496 

126 

107 

725 

230 

97 

300 

500 

200 

200 

200 

50 

0 

0 

0 

0 

0 

0 

400 

400 

300 

200 

200 

50 

0 

0 

73 0 3.2 0 2.2 0 

18 200 4.3 200 

0 0 0 0 50 0 0 

2 0 

0 0 0 200 

0 1 0 0 0 0 100 5 100 1 0 4 0 

2 0 

2 

2 

6 

8 

0 

0 

0 

0 

0 0 0 1 

0 100 5 0 

0 0 

0 0 3 0 

0 0 0 500 20 0 0 0 3 100 

0 10 0 0 0 10 0 20 0 10 0 20 0 0 0 10 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

30 

10 

20 

20 

0 80 10 0 0 0 0 20 0 20 0 20 0 0 

0 0 

0 60 

0 20 0 30 

0 10 

0 0 

0 0 

0 10 30 0 30 0 20 0 10 0 10 

0 

10 0 

0 0 0 0 40 

0 

0 

0 

0 

0 

1 

0 

0 

0 

0 

0 

0 

0 

0 

1 

1 

1 

1 

0 

0 

2 

1 

0 

0 

0 

0 

0 

1 

0 

1 

0 

1 

0 

0 

0 

0 

0 

0 

0 

1 

1 

0 

0 

0 

0 

1 

1 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

1 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

6 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

1 

0 

0 

0 

0 

0 

0 

0 4 100 0 10 260 0 5 40 0 2 20 2 5 40 2 1 30 0 0 40 

1 

0 

1 

0 

0 

1 

0 

3 

0 

0 

0 

0 

0 

4 

0 

1 

0 

0 

4 

1 

1 

0 

2 

2 

0 

3 

2 

0 

0 

0 

0 

0 

1 

0 

3 

3 

0 

0 

0 

6 120 2 60 2 20 1 40 5 10 1 50 0 20 0 20 

3 80 9 30 3 10 1 0 6 20 1 110 0 10 

5 120 1 50 19 30 11 10 2 10 1 60 1 20 0 20 

0 20 

1 10 0 30 

0 10 

3 40 1 10 3 30 4 0 3 20 1 20 0 20 0 10 

3 

0 

1 

0 

10 

50 

30 

10 

10 

1 0 20 0.1 7 17 85 .2 0 7 10 .1 0 9 0 .0 0 0 0 .7 1 0 10 .1 2 10 10 .2 

0 0 20 4 15 440 0 9 0 0 12 60 1 50 0 2 0 0 1 10 0 3 0 10 

1 

6 

0 

0 

2 

1 

1 

1 

7 

3 

0 

0 

4 

1 

4 

4 

0 

6 

3 

0 

13 

12 

9 

30 

0 

10 

10 

75 

0 

0 

10 

10 

20 

0 10 15 180 0 10 0 30 10 0 0 0 10 0 

0 0 

0 30 

0 0 0 20 

0 0 

0 0 0 6 19 140 0 0 10 0 12 0 10 70 10 3 0 0 1 10 20 8 0 20 

7 

1 

4 

0 

0 

0 

10 0 18 110 0 0 

.2 

.1 

.1 

.1 

.4 

.0 

.1 

.1 

.1 

.2 

0 

.0 

.2 

.1 

.3 

.1 

.1 

.1 

.1 

.2 

.0 

.3 

.1 

.0 

.1 

.2 

.0 

.1 

.1 

.0 

.1 

.3 

.0 

.2 

.0 

.1 

.3 

1 

5 

3 

1 

3 

0 

3 

3 

0 

0 

2 

2 

0 

2 

2 

1 

10 

2 

3 

7 

0 

4 

3 

1 

0 

2 

2 

2 

4 

2 

2 

3 

4 

5 

0 

1 

6 

1 

1 

0 

0 

0 

0 

4 

5 0 0 0 3 0 4 4 

3 10 

0 0 

2 0 

0 10 2 0 

3 0 

2 5 

3 7 

0 1 

2 0 6 0 

4 

0 

4 

0 

5 

0 

3 

10 

3 

10 

5 

7 

0 

1 

0 20 0 2 7 0 

0 4 4 20 6 1 

2 1 

2 0 

2 

2 

2 

4 

0 

9 

0 

3 

2 

3 

2 

2 

16 

0 

4 

0 

0 

0 

0 

0 

0 

0 

4 

10 

1 

0 

0 

3 

2 

40 

0 

6 

0.13 

.10 

.10 

.11 

16 

.16 

.11 

.10 

.13 

.17 

.09 

.09 

.09 

.13 

.13 

.08 

.08 

.11 

.14 

§ 

l 

277 

523 

548 

209 

86.1 

65.7 

301 

329 

102 

60.3 

821 

1,750 

639 

310 

276 

2,070 

1,350 

425 

306 

<> .s 

N 

0 310 0.3 0 0 10 .0 10 0 170 .4 0 0 180 .2 30 0 90 .0 20 0 40 .6 20 0 30 .0 10 

0 250 .9 10 0 10 .0 0 0 10 .0 0 0 130 .6 10 0 100 .0 10 0 30 1.3 10 0 40 .0 0 1 80 .8 10 

0 280 0 80 0 110 0 320 0 290 0 70 0 60 

1.8 . 50 .8 30 .8 30 .9 20 .7 20 1.5 50 .2 30 

0 150 1.6 10 0 50 .0 0 0 50 .3 0 0 140 .2 20 0 130 .0 10 0 70 .7 10 0 50 .0 0 1 80 1.2 10 

0 310 

0 80 0 260 

.6 10 

.0 20 .6 20 

0 100 1.3 10 

0 310 1.2 0 0 130 .0 0 0 60 .3 0 0 290 .6 0 0 270 .3 10 0 160 1.1 10 0 150 .3 20 1 160 1.0 10 

1 120 0 160 

210 0 3 0 160 

.0 

.0 

.0 

.0 

.0 

0 

0 

0 

8 

0 
CHANNELS AND WATERS A105 

and concentrations of major ions at water-data stations -Continued 

----------·-------------- ------------- ----------~---

CL. CL. 

rJJ rJJ 

tiS tiS 

rJJ rJJ ~ Q) .0 e e '5 ~ z 0 0 

..<:: ..<:: a 2l ~ ~ IIJ ]~ E tiS ~ 0 0 -~ c: c: ~ IIJ IIJ <~~2l ,.c: ..<:: a -~ a 0 0 c: ~ ~ 2l Q)tl! p. p. ·6 IIJ -e -e 0 ...... 0 ] c: ::l -e ,.c: 3 bll tiS ;g e tiS :::2 

0 ~ :~-2 0 

t: ai tiS & ~ tiS ::l 0 '3 iii ~ ~ u u ~ z 0 ..... u Cfl Cfl 

0.02 0.10 12 21 3.0 0.4 4.6 87 0 1.4 0.1 11 0.03 

.02 .20 11 17 2.3 .6 4.5 74 0 .7 .0 4.3 .11 

.05 .35 10 15 2.6 .7 3.6 62 0 1.0 .0 7.8 .10 

.01 .07 9.9 17 2.4 .5 3.3 67 0 8.9 .3 6.5 .00 

.03 .04 14 27 3.8 .8 6.2 111 0 1.3 .4 9.8 .09 

.01 .09 13 27 3.9 .7 6.5 109 0 1.5 .2 14 .00 

.47 11 19 2.8 .4 4.3 72 0 .3 .2 6.8 .12 

.00 .07 10 16 2.0 .9 2.9 62 0 .8 .2 5.9 .06 

.00 .02 12 23 3.2 .5 4.6 84 0 2.0 .3 9.8 .01 

.01 13 29 4.2 .7 6.8 108 0 1.9 .3 13 .00 

.04 .06 14 13 1.7 .6 3.5 55 0 1.1 .2 3.5 .01 

.02 .20 12 14 1.2 .4 2.7 53 0 .1 .1 6.8 .00 

.01 .04 11 15 1.5 .5 3.0 58 0 .9 .3 3.3 .00 

.01 .04 15 22 2.6 .8 5.2 91 0 .7 .6 5.8 .03 

.00 .05 14 23 2.8 .9 5.3 88 0 1.5 .4 1.3 .11 

.33 12 9.6 2.3 1.5 2.8 50 0 1.2 .2 4.4 .13 

.01 .07 12 12 1.2 .9 2.8 46 0 .8 .3 3.9 .04 

.00 .02 13 18 2.2 .6 3.7 66 0 1.0 .5 6.1 .00 

.00 14 24 3.1 .7 5.4 92 0 1.4 .5 8.7 .00 

TABLE 41.-Summary of concentrations of dissolved trace elements at water-data stations-Continued 

'f) 

;;--

~ a Water-data IIJ a a a ~ ::l 

c: E c: a a station No. ):ll ::l ::l IIJ ,__;: IIJ a ::l '-' :5 :l a c: ~ .:::! tiS c: c E E ... tiS ] ::l 0+' ;; E ::l c: E IIJ ::l ::l Q) ·a ... c ~~ ~ ~ ~ l: l: ai p. -o ~ bll ~ b ~ IIJ tiS 

::l -~ -o ..c p. c: tiS c: IIJ .!: ~ c: c.> 

<~~- 0 tiS ..c 0 0 E IIJ tiS IIJ 0 z Q) tiS c: o8 0 ;;: ~ co co co u u u u ....l .3 ~ ~ ::;;:: Cfl iii > N 

13-2974.40 10-05-71 0.89 100 0 4.500 0 30 0 0 2 0 10 5 0 0 0.2 4 1 6 0 70 0.0 0 6-20-72 27 0 0 0 0 10 1 2 1 1 20 1 10 0 .0 1 3 3 0 50 .1 10 7-18-72 18 10 1 0 0 30 1 0 0 0 10 1 0 1 .0 1 3 0 0 50 .0 10 8-29-72 3.8 10 2 0 0 0 1 0 0 1 30 4 0 10 .6 2 3 0 0 70 .0 10 10-03-72 1.5 0 3 0 0 0 1 0 2 1 20 3 0 0 .1 3 2 0 0 40 .4 0 

2974.45 6-23-70 172 0 1 0 0 1 0 3 1 20 7 0 2 5 3 1 90 0 8-27-70 13 0 0 0 30 0 0 0 0 0 40 1 10 5 5 13 0 170 1.0 0 10-13-70 7.0 0 0 0 0 0 0 1 0 2 40 0 0 0 5 6 18 0 380 .5 0 6-29-71 -- 82 200 0 0 0 0 0 0 2 10 3 9 250 .1 9 0 0 0 40 .2 8 8-31-71 17 200 2 300 0 30 0 0 1 30 0 5 0 .2 7 8 5 0 160 .8 0 10-05-71 8.1 100 1 100 0 0 0 0 1 1 20 0 0 10 .2 9 0 5 0 150 3.8 10 6-20-72 104 10 0 0 0 10 1 0 0 1 30 1 0 0 .0 4 3 0 0 60 .4 10 7-18-72 61 10 0 0 0 70 0 0 0 1 20 3 0 17 .0 4 4 0 0 70 .6 10 8-29-72 13 10 3 0 0 0 1 0 0 0 40 3 0 58 .4 9 8 0 0 100 .0 10 10-03-72 6.5 0 4 0 0 10 1 0 3 0 30 4 0 10 .0 11 2 0 1 110 1.0 10 

2974.50 6-24--0 ·--·--- -- 198 0 0 0 0 1 0 2 1 20 6 0 3 4 1 1 110 0 8-28-70 14 0 0 200 0 0 1 0 0 1 30 1 0 6 0 6 0 200 1.0 0 10-12--70 9.4 0 0 0 0 0 0 0 0 40 0 0 0 .0 0 2 18 0 260 1.0 20 5-27-71 55 400 0 0 0 0 0 1 60 0 0 0 .1 4 2 0 0 190 1.3 10 6-28-71 120 600 2 300 0 10 0 0 3 30 2 7 140 .2 0 0 2 0 90 .2 0 7-22--71 92 200 0 50 0 20 0 0 0 8 10 0 11 30 .1 3 4 0 0 60 .5 0 8-30-71 19 200 10 0 0 10 0 0 0 3 20 0 7 0 .2 3 2 10 0 140 1.6 0 10-06-71 12 100 1 400 0 10 0 0 1 0 20 1 20 0 .1 6 0 2 0 130 .4 60 6-20-72 107 10 0 0 0 10 1 0 0 1 20 2 0 0 .0 4 3 2 0 70 .9 30 7-17-72 66 10 0 0 0 0 1 0 1 1 20 1 0 0 .1 0 2 0 0 80 .2 0 8-30-72 16 20 0 0 0 10 1 0 0 3 20 3 0 20 .4 8 3 0 0 130 1.1 20 10-02--72 9.0 0 5 0 0 0 1 0 4 3 40 6 0 20 .1 9 2 0 1 80 1.3 30 

2974.80 6-22--70 164 0 0 0 0 1 0 3 2 20 7 0 1 7 2 0 40 0 8-26-70 13 0 0 0 0 0 0 0 2 10 0 0 2 3 36 0 44 1.0 20 10-12--70 9.3 0 106 0 10 0 0 0 4 40 0 0 0 3 2 66 0 140 1.2 0 6-28-71 82 300 4 0 0 10 0 1 0 3 20 6 10 2.5 .2 0 0 3 0 120 .6 0 8-31-71 21 100 8 100 0 20 0 0 0 0 10 0 7 0 .3 8 4 2 0 80 1.2 0 10-06-71 6.9 200 0 900 10 10 0 0 1 0 20 0 0 0 .2 5 1 9 0 60 .8 20 6-19-72 71 10 0 0 0 20 1 0 0 1 40 2 0 0 .0 6 2 0 0 40 .8 10 7-18-72 46 10 1 0 0 30 0 0 0 0 10 3 0 8 .0 7 3 1 0 50 .9 10 8-29-72 16 10 0 0 0 0 1 0 0 0 10 3 0 30 .4 9 7 0 0 80 1.1 10 10-03-72 11 0 6 0 0 0 1 0 3 0 60 3 0 10 .2 10 3 0 1 20 1.2 10 

2974.85 6-22--70 26 0 0 0 0 4 0 3 4 20 9 10 2 9 4 1 50 .0 150 8-26-70 3.1 0 0 0 10 0 2 0 0 2 10 1 10 0 5 9 0 78 .3 10 10-12-70 2.4 0 0 100 10 0 1 3 3 20 0 0 0 5 13 0 180 2.7 10 6-28-71 17 300 20 0 0 10 1 0 10 20 7 3 180 .1 2 0 14 0 0 1.7 100 8-31-71 3.7 200 4 100 0 30 1 0 0 2 10 0 2 0 .1 4 4 0 100 2.4 80 10-06-71 3.6 200 0 600 0 0 2 0 1 0 20 0 40 10 .2 1 1 5 0 50 2.3 90 6-19-72 17 10 0 0 0 10 2 0 0 1 20 1 10 0 .0 2 3 3 0 50 2.2 130 7-18-72 9.9 10 2 0 0 30 3 0 0 1 30 0 0 0 .0 1 4 2 0 50 2.6 170 8-29-72 4.4 20 15 0 0 0 2 0 0 1 20 3 0 0 .4 1 4 2 0 70 2.2 90 10-03-72 3.5 0 6 0 0 10 2 0 2 0 10 3 0 10 .0 2 3 0 1 30 3.4 10 

2975.00 7-25-72 44 0 0 100 0 0 0 0 0 1 10 1 0 0 .1 6 3 0 0 40 .0 10 10-02--72 16 0 2 0 0 0 3 0 2 9 30 5 0 10 .1 9 3 0 0 40 1.7 30 

2976.00 10-04--72 26 0 2 400 0 10 0 2 0 30 6 0 0 .1 0 3 0 250 3.2 20 
A106 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 41.-Summary of concentrations of dissolved trace elements at water-data stations-Continued 

(fJ 

~ 

~ s Water-data <li E E E ::l 

E ~ E station No ~ ::l u E ::l ::l s ~ ~ <li s ~ E .~ E ... ] ::l ~ E 2 ::l ~ E ..., <li ::l ~ 

@ Qj ·a ... -;:: ~ <li "& 2 2 -a 0. "0 :s bll ~ ~ <li 

::l 

~ ~ "0 ..0 0. ~ ~ ~ <li ~ 2 u 

0 :;;: <li 0 ~ ..<: 0 0 

~ <li ~ <li 0 z Qj .s p:) p:) p:) u u u u ...J ;.:3 ::E ::E ::E U) i:/3 U5 N 

13-2980.00 6-01-71 -- 1,070 300 100 0 10 0 0 2 4 40 1 0 0 0.1 1 3 0 0 250 2.1 10 6-23-71 2,670 1,500 2 200 0 30 0 3 0 24 1,100 11 16 570 .1 34 I 2 0 210 4.5 30 7-22-71 943 0 50 0 0 0 1 1 10 0 18 0 .0 0 4 0 0 160 1.4 10 9-01-71 268 200 0 0 10 40 0 0 0 4 10 0 16 0 .0 0 4 4 0 270 2.0 20 10-07-71 --- 201 200 1 0 0 20 0 0 1 3 20 0 60 10 1.0 5 4 4 0 300 7.2 20 6-15---72 1.740 0 0 0 0 20 1 0 4 2 40 3 0 0 .0 0 0 1 0 120 1.3 0 7-25---72 390 0 1 0 0 10 1 0 0 2 10 2 10 30 .2 2 3 0 0 50 1.0 20 10-04--72 183 0 7 0 0 40 1 0 2 3 20 4 0 10 .1 2 6 0 1 190 1.8 10 

2985.00 5---26-71 4,680 500 0 0 30 0 0 0 2 60 1 0 20 .3 7 0 0 0 130 .2 30 6-26-71 10,100 500 10 0 0 0 0 0 0 1 90 9 12 220 .1 0 0 0 0 40 .0 7 7-23-71 3,700 100 0 0 0 10 0 0 0 2 20 0 1 30 .0 0 7 0 0 20 .1 0 9-01-71 1,160 200 0 400 0 30 0 0 0 7 210 9 14 10 .1 0 2 10 0 180 .8 40 10-07-71 1,100 100 0 0 10 30 0 0 2 1 20 0 40 0 .2 4 1 7 0 170 .0 10 6-14--72 8,760 0 0 0 0 20 1 0 1 3 so 3 0 10 .0 0 1 0 0 50 .9 30 7-24--72 2,020 10 0 0 0 0 0 0 0 1 50 1 10 0 .1 2 2 1 0 50 .0 70 10-05---72 1,090 0 5 700 0 10 1 0 2 0 10 4 0 0 .1 3 3 0 1 120 .9 10 

TABLE 42.-Summary of suspended sediment and turbidity data 

Water Suspended- Sediment Unit Discharge Water-data discharge, sediment discharge. sediment Turbidity ratio, station No. Date Q concentration G discharge (JTUI Q!QB (ft3/secl (mg/1) (tons/day! (tons/day/mi2 ) 

1~2922.00 6- 8--71 -------- 121 50 16.3 0.93 10 0.34 

7-21-71 -------- 52 3 .42 .02 2 .14 

8-- 9-71 -------- 23 3 .19 .01 7 .06 

6-20-72 -------- 85 27 6.19 .35 4 .24 

2924.00 5-24-71 -------- 31 1 .08 .01 4 .16 

7-21-71 -------- 53 2 .29 .02 2 .27 

9- ~71 -------- 3.0 1 .01 .00 6 .02 

6-16-72 -------- 85 8 1.83 .12 8 .44 

2932.00 6- 9-71 -------- 32 57 4.92 .28 15 .16 

7-21-71 -------- 9.3 6 .15 .01 2 .05 

8-- 9-71 3.7 9 .09 .01 8 .02 

6-20-72 -------- 57 1,260 194 11.09 12 .29 

2934.00 6- 9-71 -------- 114 34 10.4 .56 8 .55 

7-21-71 -------- 34 2 .18 .01 2 .16 

8-- 9-71 -------- 20 3 .16 .01 6 .10 

6-27-72 -------- 87 369 86.5 4.68 4 .42 

2950.00 4-28--71 -------- 215 7 4.06 .03 .22 

5-24-71 -------- 561 4 6.05 .04 3 .56 

6-21-71 -------- 1,110 3 8.98 .06 2 1.11 

7-19-71 -------- 522 2 2.81 .02 1 .52 

8--30-71 -------- 138 8 2.98 .02 6 .14 

10- 4-71 -------- 132 3 1.07 .01 .13 

6-16-72 --------· 1,090 10 29.4 .20 2 1.09 

7-24-72 -------- 264 4 2.85 .02 1 .26 

2956.50 6-10-71 -------- 636 53 90.9 1.78 25 1.34 

7-19-71 -------- 92 2 .50 .01 2 .19 

8--10-71 -------- 48 4 .52 .01 6 .10 

6-26-72 -------- 196 6 3.17 .06 2 .41 

2960.00 5-25-71 -------- 889 12 28.8 .15 8 1.25 

6-22-71 -------- 2,710 45 329 1.69 18 3.81 

8--30-71 -------- 119 2 .64 .00 8 .17 

6- 2-72 -------- 3,700 471 4,700 24.10 71 5.20. 

6-16-72 -------- 1,850 38. 190 .97 10 2.60 

2965.00 4-28--71 -------- 919 5 12.4 .02 .25 

5-25-71 -------- 2,920 17 134 .17 6 .78 

6-22-71 -------- 6,440 32 556 .69 14 1.72 

7-2~71 -------- 2,410 7 45.5 .06 1 .64 

9- ~71 -------- 706 3 5.71 .01 8 .19 

10- 8--71 -------- 716 1 1.93 .00 .19 

6-16-72 -------- 5,820 41 643 .80 10 1.56 

7-24-72 -------- 1,340 3 10.8 .01 1 .35 
CHANNELS AND WATERS A107 

TABLE 42.~ummary of suspended sediment and turbidity data-Continued 

Water s:si:~~t- Sediment Unit Discharge Water-data Date discharge, discharge, sediment Turbidity ratio, station No. Q concentration G discharge (JTU) Q/QB (ft3 /secJ (mg/1) (tons/day) (tons/day/mi2 J 

13-2970.00 5-25-71 -------- 175 16 7.55 0.10 8 0.29 

6-22-71 -------- 560 34 51.3 .65 6 .93 

9- 3-71 -------- 103 2 .56 .01 6 .17 

6- 2-72 -------- 560 98 148 1.87 13 .93 

6-14-72 -------- 400 37 39.9 .51 4 .66 

7-24-72 -------- 153 4 1.65 .02 1 .25 

2971.00 5-25-71 -------- 21 7 .40 .05 3 .09 

7-23-71 -------- 11 1 .03 .00 1 .05 

9- 3-71 -------- 7.2 1 .02 .00 6 .03 

6- 2-72 -------- 32 230 19.8 2.48 15 .14 

6-14-72 -------- 28 21 1.59 .20 2 .13 

2972.50 6-10-71 -------- 76 314 64.3 2.07 32 .63 

6-14-71 -------- 92 2,105 522 16.84 235 .77 

7- 2-71 -------- 81 582 127 4.10 65 .68 

8-10-71 -------- 41 5 .55 .02 7 .34 

5-29-72 -------- 43 45 5.22 .17 4 .36 

6- 1-72 -------- 81 247 53.94 1.74 22 .68 

6- 2-72 -------- 81 445 97.2 3.14 31 .68 

6-15-72 -------- 109 987 290 9.35 51 .91 

6-16-72 -------- 98 916 242 7.81 47 .82 

6-17-72 -------- 99 890 238 7.68 40 .83 

2973.00 5-25-71 -------- 4.0 73 .79 .13 15 .04 

7-22-71 -------- 1.2 7 .02 .00 4 .01 

8-16-71 -------- 1.1 12 .04 .01 8 .01 

6- 3-72 -------- 6.0 1,700 27.5 4.58 42 .06 

6-14-72 -------- 6.3 365 6.20 1.03 20 .06 

2973.10 2-24-71 -------- 15 5 .20 .01 2 .07 

6-11-71 -------- 141 57 21.7 .96 10 .68 

7-24-71 -------- 23 7 .43 .02 2 .11 

8-10-81 -------- 9.8 3 .08 .00 7 .05 

6-18-72 -------- 99 35 9.34 .42 5 .48 

2973.20 2-24-71 -------- 1.5 4 .02 .01 2 .03 

6-11-71 -------- 4.3 69 .80 .32 42 .08 

7-24-71 -------- 1.5 7 .03 .01 10 .03 

8-10-71 -------- 1.3 128 .45 .18 42 .02 

6-18-72 -------- 2.3 10 .06 .02 4 .04 

2973.30 5-26-71 -------- 99 93 24.8 .83 12 .36 

6-22-71 -------- 135 103 9.72 .32 22 .13 

9- 2-71 -------- 7.9 1 .02 .00 7 .03 

6-14-72 -------- 105 35 9.91 .33 4 .38 

2973.40 6-11-71 -------- 368 100 99.2 1.65 20 1.12 

7-24-71 -------- 41 3 .33 .01 3 .13 

8-11-71 -------- 23 5 .31 .01 8 .07 

6- 3-72 -------- 480 388 502 8.37 36 1.46 

6-19-72 -------- 178 42 20.2 .34 6 .54 

2973.50 4-29-71 -------- 22 4 .24 .04 .41 

5-26-71 -------- 11 30 .89 .15 11 .21 

6-22-71 -------- 19 17 .87 .15 7 .36 

7-23-71 -------- 3.0 1 .01 .00 1 .06 

9- 2-71 -------- .9 1 .00 .00 6 .02 

10- 7-71 -------- .7 1 .00 .00 .01 

6- 3-72 -------- 20 813 43.8 7.30 45 .38 

6-14-72 -------- 16 30 1.29 .22 2 .30 

7-24-72 -------- 2.0 5 .03 .01 1 .04 

2973.60 5-26-71 -------- 215 60 34.8 .44 14 .47 

6-23-71 -------- 343 55 50.9 .64 19 .75 

9- 2-71 -------- 7.4 1 .02 .00 6 .02 

6- 3-72 -------- 550 605 897 11.21 55 1.20 

6-15-72 -------- 365 103 101 1.26 6 .80 

2973.80 5- 6-71 -------- 3,580 37 357 .31 .70 

6- 1-71 -------- 7,590 49 1,000 .85 20 1.48 

6-23-71 -------- 7,600 109 2,230 1.91 28 1.48 

7-22-71 -------- 3,120 3 25.2 .02 12 .61 

9- 1-71 -------- 1,180 5 15.9 .01 10 .23 
A108 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 42.~ummary of suspended sediment and turbidity data-Continued 

Water Suspended- Sediment Unit Discharge Water-data Date discharge, sediment discaarge, sediment Turbidity ratio, station No. Q concentration discharge (JTUI QIQB (f't3/sec\ (mg/1\ (tons/day\ (tonslday/mi2 \ 

13-2973.80 10- S-71 -------- 1,070 2 5.77 0.00 0.21 

6-19-72 --------- 6,560 70 1,240 1.06 6 1.28 

7-2&-72 -------- 1,950 8 42.1 .04 2 .38 

10- 4-72 -------- 980 6 15.9 .01 5 .19 

2973.84 7- 1-71 -------- 97 2 .52 .03 2 .31 

7-23-71 -------- 103 2 .56 .03 2 .33 

S-13-71 -------- 41 1 .11 .01 8 .13 

2973.88 7- 1-71 -------- 56 6 .91 .11 3 .45 

7-23-71 -------- 38 2 .21 .02 2 .31 

S-13-71 -------- 8.5 2 .05 .01 6 .07 

2973.96 &-27-71 -------- 90 26 6.31 .24 13 .41 

6-27-71 -------- 169 42 19.1 .73 11 .77 

9- 2-71 -------- 17 1 .05 .00 5 .08 

&-30-72 -------- 172 93 43.1 1.65 8 .79 

6- 1-72 -------- 180 133 64.1 2.46 16 .82 

6- 3-72 172 78 36.2 1.39 10 .79 

10- 1-72 --------- 8.1 6 .13 .00 4 .04 

2974.00 &-27-71 -------- 314 18 15.2 .20 6 .35 

6-27-71 -------- 569 19 29.1 .39 8 .64 

9- 2-71 -------- 60 0 0 .00 6 .07 

&-30-72 -------- 650 54 94.6 1.25 8 .73 

6- 1-72 -------- 900 124 301 3.98 17 1.01 

6- 3-72 -------- 760 123 252 3.34 22 .85 

7-2&-72 -------- 135 0 0 .00 0 .15 

10- 4-72 -------- 39 4 .42 .01 3 .04 

2974.04 &-27-71 -------- 128 19 6.56 .13 5 .31 

6-27-71 -------- 386 199 207 4.23 31 .94 

9- 2-71 -------- 46 1 .12 .00 6 .11 

&-30-72 -------- 390 218 229 4.68 23 .95 

6- 1-72 -------- 500 362 488 9.98 36 1.22 

6- 3-72 -------- 500 632 852 17.43 38 1.22 

10- 4-72 -------- 36 6 .58 .01 4 .09 

2974.18 6-12-71 -------- 65 110 19.3 2.97 17 .97 

7-26-71 -------- 9.3 2 .05 .01 2 .14 

S-11-71 -------- 6.6 3 .05 .01 6 .10 

&-31-72 -------- 51 378 52.0 8.00 31 .76 

6- 1-72 -------- 60 408 66.0 10.15 52 .89 

6- 3-72 -------- 44 110 13.0 2.00 17 .65 

2974.25 &- 7-71 -------- 228 9 5.53 .03 .21 

&-27-71 -------- 504 21 28.5 .17 7 .46 

6-27-71 -------- 1,300 90 315 1.93 22 1.18 

7-22-71 -------- 496 4 5.35 .03 2 .45 

9- 2-71 -------- 126 1 .34 .00 6 .11 

10- 7-71 -------- 107 1 .29 .00 .10 

6- 1-72 -------- 2,600 206 1,440 8.80 27 2.36 

6-21-72 -------- 725 36 70.4 .43 4 .66 

7-2&-72 -------- 230 3 1.86 .01 0 .21 

10- 4-72 -------- 97 5 1.31 .01 3 .09 

2974.40 6-29-71 -------- 18 1 .05 .02 1 .30 

S-31-71 -------- 4.3 1 .01 .00 6 .07 

10- &-71 -------- .9 1 .00 .00 .02 

6-20-72 -------- 27 3 .22 .08 1 .45 

7-18-72 -------- 18 1 .05 .02 1 .30 

S-29-72 -------- 3.8 4 .04 .01 1 .06 

10- 3-72 -------- 1.5 8 .03 .01 2 .03 

2974.45 6-29-71 -------- 82 4 .88 .09 1 .30 

S-31-71 -------- 16 1 .04 .00 7 .06 

10- &-71 -------- 8.1 1 .02 .00 .03 

6-20-72 -------- 104 5 1.40 .14 2 .39 

7-18-72 -------- 61 2 .33 .03 1 .23 

S-29-72 -------- 13 3 .11 .01 1 .05 

10- 3-72 -------- 6.5 4 .07 .01 3 .02 

2974.50 &- 7-71 -------- 19.1 5 .26 .01 .06 

&-27-71 -------- 55 13 1.93 .11 4 .17 
CHANNELS AND WATERS A109 

TABLE 42.-Summary of suspended sediment and turbidity data-Continued 

Water Suspended- Sediment Umt Discharge Water-data Date discharge, sediment discharge, sediment Turbidity ratio, station No. Q concentration G discharge iJTUt Q/QB ltl"isect lmg/11 I tons/day t 1 tons/day/mi 2 t 

1:>-2974.50 6-27-71 -------- 120 31 10.0 0.55 6 0.38 

7-22-71 -------- 92 8 1.98 .11 1 .29 

8-30-71 -------- 19 2 .10 .01 8 .06 

10- 6-71 ----------- 12 3 .10 .01 .04 

12- 7-81 -------- 7.6 1 .02 .00 .02 

1-17-72 -------- 7.1 2 .04 .00 .02 

2-17-72 -------- 6.9 1 .02 .00 3 .02 

:>-21-72 -------- 6.4 1 .02 .00 8 .02 

4-25-72 -------- 4.2 1 .01 .00 .01 

5-25-72 -------- 28 4 .30 .02 1 .09 

5-31-72 -------- 210 92 52.1 2.87 .67 

6- 1-72 -------- 213 113 64.9 3.58 11 .68 

6- :>-72 -------- 300 245 198 10.92 9 .95 

6-20-72 -------- 107 20 5.77 .32 5 .34 

7-17-72 -------- 66 4 .71 .04 1 .21 

8-30-72 -------- 16 5 .22 .01 2 .05 

10- 2-72 --------- 9.0 5 .12 .01 3 .03 

2974.80 6-28-71 -------- 82 13 2.87 .23 4 .44 

8-31-71 -------- 21 3 .17 .01 6 .11 

10- 6-71 -------- 6.9 2 .04 .00 .04 

6-19-72 -------- 71 16 3.06 .24 2 .38 

7-19-72 -------- 46 3 .37 .03 1 .25 

8-29-72 -------- 16 2 .09 .01 1 .09 

10- :>-72 -------- 11 5 .15 .01 2 .06 

2974.85 6-28-71 -------- 17 60 2.75 .80 12 .21 

8-31-71 -------- 3.7 7 .07 .02 9 .05 

10- 6-71 -------- 3.6 2 .02 .01 .05 

6-19-72 -------- 17 103 4.72 1.38 9 .21 

7-18-72 -------- 9.9 14 .37 .11 1 .12 

8-29-72 -------- 4.4 4 .05 .01 2 .06 

10- :>-72 -------- 3.5 15 .14 .04 3 .04 

2975.00 5-31-71 -------- 63 2,387 405 14.79 540 .29 

6-12-71 -------- 90 884 214 7.81 49 .41 

6-26-71 -------- 198 1,843 984 35.93 60 .90 

7-26-71 -------- 80 14 3.02 .11 1 .36 

9- 2-71 -------- 27 2 .15 .01 6 .12 

5-31-72 -------- 155 399 167 6.10 48 .70 

6- 1-72 -------- 210 1,331 754 27.53 65 .95 

6- :>-72 -------- 140 573 216 7.89 44 .63 

6-20-72 -------- 106 64 18.3 .67 6 .48 

7-25-72 -------- 44 8 .95 .03 1 .20 

10- 2-72 -------- 16 6 .26 .01 5 .07 

2975.30 5-31-71 -------- 25 17 1.15 .04 10 .10 

6-2:>-71 -------- 21 8 .45 .02 6 .09 

8-15-71 -------- 3.9 9 .09 .00 7 .02 

5-31-72 --------- 21 23 1.30 .05 8 .09 

6-21-72 -------- 16 11 .47 .02 3 .07 

2976.00 6- 1-71 -------- 186 89 44.6 .40 22 .32 

6-2:>-71 -------- 275 233 173 1.54 52 .47 

7-26-71 -------- 73 12 2.36 .02 10 .12 

9- 1-71 -------- 31 3 .25 .00 6 .05 

5-31-72 -------- 350 403 380 3.38 35 .60 

6- 1-72 -------- 450 320 388 3.45 20 .77 

6-15-72 -------- 200 160 86.3 .77 20 .34 

10- 4-72 -------- 26 7 .49 .00 5 .04 

2976.70 6-1:>-71 -------- 13 43 1.51 .04 12 .35 

7-20-71 -------- 4.1 22 .24 .01 15 .11 

8-11-71 -------- 3.3 26 .23 .01 19 .09 

5-31-72 -------- 4.8 86 1.11 .03 15 .13 

2976.80 6-1:>-71 -------- 3.9 82 .86 .03 14 .21 

7-20-71 -------- 1.7 230 1.05 .03 35 .09 

8-11-71 -------- .9 31 .08 .00 20 .05 

5-31-72 -------- 8.3 139 3.11 .10 20 .44 

2977.00 6- 1-71 -------- 12 153 4.95 .06 22 .14 

6-2:>-71 -------- 3.8 17 .17 .00 7 .04 

8-15-71 -------- 2.6 53 .37 .00 15 .03 
AllO HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 42.--Summary of suspended sediment and turbidity data-Continued 

Water s~:ai~~~t- Sediment Unit Discharge Water-data Date discharge, discharge, sediment Turbidity ratio, station No. Q concentration G discharge (JTUI Q!QB <fPisecl (mg/11 (tons/day) (tons/day/mi2 1 

13-2977.00 5-31-72 -------- 5.0 45 0.61 0.01 9 0.06 

6-21-72 -------- 11 28 .83 .01 4 .13 

2980.00 5- 6-71 -------- 460 78 96.7 .18 .25 

6- 1-71 -------- 1,070 52 150 .28 22 .58 

6-13-71 -------- 2,500 301 2,030 3.82 47 1.35 

6-23-71 -------- 2,670 555 4,000 7.52 62 1.44 

7-22-71 -------- 943 51 130 .24 10 .51 

~ 1-71 -----·--- 268 4 2.89 .01 6 .14 

10-- 7-71 -------- 201 1 .54 .00 .11 

5-2~72 -------- 1,380 275 1,020 1.92 34 .74 

5-30--72 -------- 1,720 341 1,580 2.97 40 .93 

5-31-72 -------- 2,250 373 2,260 4.25 55 1.21 

6- 1-72 -------- 2,700 438 3,190 6.00 61 1.45 

6- 2-72 -------- 3,170 420 3,690 6.94 65 1.71 

6- 3-72 -------- 3,200 408 3,520 6.62 59 1.72 

6- 4-72 -------- 2,450 279 1,840 3.46 46 1.32 

6-15-72 -------- 1,740 178 835 1.57 34 .94 

7-25-72 -------- 390 12 12.6 .02 2 .21 

10-- 4-72 -------- 199 6 3.22 .01 5 .11 

2983.00 6-16-72 -------- 4.0 245,300 2,645 281.98 40,600 

6-16-72 -------- 4.0 111,700 1,204 128.34 

2985.00 4-2~71 -------- 1,430 17 65.5 .04 .26 

5-26-71 -------- 4,680 56 707 .39 32 .85 

6-26-71 -------- 10,100 172 4,680 2.60 39 1.84 

7-23-71 -------- 3,700 7 69.8 .04 2 .67 

~ 1-71 -------- 1,160 2 6.25 .00 8 .21 

10-- 7-71 -------- 1,100 2 5.93 .00 .20 

5-2~72 -------- 7,200 194 3,770 2.09 20 1.31 

5-30--72 -------- 8,870 555 13,300 7.39 40 1.61 

5-31-72 -------- 10,500 372 10,500 5.83 54 1.91 

6- 1-72 -------- 12,300 641 21,300 11.83 65 2.24 

6- 2-72 -------- 13,600 583 21,400 11.88 66 2.47 

6- 3-72 -------- 13,600 465 17,000 9.44 60 2.47 

6- 4-72 -------- 12,400 349 11,700 6.50 47 2.26 

6-15-72 -------- 8,760 130 3,070 1.71 21 1.59 

7-24-72 -------- 2,020 9 49.0 .03 1 .37 

10-- 5-72 --------- 1,090 7 11.8 .01 4 .20 

TABLE 43.--Summary of regression equation data, significant major TABLE 43.--Summary of regression equation data, significant major 

ion concentration as a function of discharge ion concentration as a function of discharge-Continued 

Graph V a! ue of parameter V a! ue of parameter U.S. Geological Correlation Exponent, Graph U.S. Geological Correlation Exponent, 

plottmg Survey coefficient, or slope of plottmg St~ti~~e~o. coefficient, or slope of No. Station No. Bankfull Mean annual r relation Bankfull Mean annual No. relation (QIQB=l.O) (QtQ8 =0.25l (Q!Q8 =1.01 <QIQB=0.251 

Calcium Calcium-Continued 

1 1:>-2922.00 -0.945 -0.234 13 17 30 1:>-2974.80 ------------ -0.989 -0.359 5.0 8.3 ------------ 31 2974.85 -.972 -.215 13 17 2 2924.00 -.940 -.211 5.2 7.0 ------------ ------------ 32 2975.00 -.984 -.316 8.8 14 3 2932.00 ------------ -.962 -.165 20 25 33 2975.30 ------------

-.183 -.020 15 16 4 2934.00 -.989 -.298 12 18 ------------ ---·---------- 34 2976.00 -.954 -.136 16 19 5 2950.00 -.440 -.039 7.1 7.5 ------------ ------------ 35 2976.70 -.964 -.210 14 18 6 2956.50 -.983 -.207 6.6 8.8 ------------ ------------- 36 2976.80 -.494 -.086 35 39 7 2960.00 ------------ -.914 -.220 6.9 9.3 37 2977.00 ------------

-.771 -.165 21 26 8 2965.00 -.964 -.449 7.8 15 ------------ ------------ 38 2980.00 -.954 -.222 17 23 9 2970.00 ------------ -.991 -.485 11 21 39 2985.00 ------------ -.957 -.307 14 21 10 2971.00 ------------ -.874 -.413 9.9 18 ------------

11 2972.50 ------------ -.536 -.080 42 47 12 2973.00 ------------ -.893 -.164 16 20 Mean ______________________________ -.235 13 2973.10 -.888 -.200 6.7 8.9 ------------------------ ------------ Median -.948 -.222 14 2973.20 ------------ -.907 -.408 4.1 7.3 ---------------- ------------------------

15 2973.30 ------------ -.613 -.221 8.2 11 16 2973.40 ------------ -.953 -.213 7.7 10 Sodium 17 2973.50 ------------ -.988 -.321 12 18 18 2973.60 ------------- -.973 -.252 7.9 11 19 2973.80 ------------ -.963 -.419 11 20 1 1:>-2922.00 ------------- -0.332 -0.058 1.4 1.5 20 2973.84 ------------ -.997 -.256 7.2 10 2 2924.00 ------------ -.710 -.253 .8 1.2 21 2973.88 ------------ -.936 -.140 15 18 3 2932.00 ------------ -.743 -.300 .8 1.2 22 2973.96 ------------ -.908 -.225 15 21 4 2934.00 ------------ -.438 -.083 1.9 2.1 23 2974.00 ------------ -.937 -.268 12 18 5 2950.00 ------------ -.749 -.260 2.2 3.1 24 2974.04 ------------ -.987 -.208 16 22 6 2956.50 ------------ -.587 -.080 2.9 3.2 25 2974.18 ------------- -.755 -.120 8.0 9.4 7 2960.00 ------------ -.904 -.151 3.5 4.4 26 2974.25 ------------ -.948 -.199 16 21 8 2965.00 ------------ -.906 -.330 2.6 4.1 27 2974.40 ------------ -.741 -.128 2.2 2.6 9 2970.00 ------------ -.556 -.113 1.6 1.9 28 2974.45 ------------ -.962 -.306 4.5 6.9 10 2971.00 ------------ -.017 .002 2.3 2.3 29 2974.50 -.858 -.265 6.2 9.0 11 2972.50 ------------ -.549 -.247 3.2 4.4 
CHANNELS AND WATERS Alll 

TABLE 43.-Summary of regression equation data, significant major TABLE 43.-Summary of regression equation data, significant major 

ion concentration as a function of discharge-Continued ion concentration as a function of discharge-Continued 

V a! ue of parameter Value ofparameter 

Graph U.S. Geological Correlation Exponent, Graph U.S. Geological Correlation Exponent, 

plottmg Survey coefficient, or slope of plottmg St~~~~e~o. coefficient, or slope of No. Station No. Bankfull Mean annual relation Bankfull Mean annual No. relation rQtQ8 =1.0l rQ/Q8 =0.25l rQtQ8 =1.01 rQtQ8 =0.25l 

Sodium-Continued Bicarbonate (lab analysis)-Continued 

12 13-2973.00 ------------ -0.815 -0.211 4.8 6.4 11 13-2972.50 ------------ -0.863 -0.143 127 155 13 2973.10 ------------ -.602 -.108 3.0 3.5 12 2973.00 ------------ -.817 -.136 83 101 14 2973.20 ------------ -.998 -.903 1.0 3.6 13 2973.10 ------------ -.850 -.156 35 43 15 2973.30 ------------ -.759 -.228 3.0 4.2 14 2973.20 ------------ -.874 -.339 30 48 16 2973.40 ------------ -.835 -.151 3.6 4.4 15 2973.30 ------------ -.652 -.211 38 51 17 2973.50 ------------ -.556 -.031 4.3 4.5 16 2973.40 ------------ -.941 -.199 53 69 18 2973.60 ------------ -.834 -.119 4.1 4.9 17 2973.50 ------------ -.993 -.296 52 78 19 2973.80 ------------ -.926 -.285 2.8 4.1 18 2973.60 ------------ -.988 -.222 52 82 20 2973.84 ------------ -.941 -.265 .7 1.0 19 2973.80 ------------ -.912 -.325 46 71 21 2973.88 ------------ -.847 -.244 .8 1.1 20 2973.84 ------------ -.984 -.181 27 35 22 2973.96 ------------- -.990 -.532 1.7 3.6 21 2973.88 ------------ -.992 -.172 48 61 23 2974.00 ------------ -.975 -.455 1.7 3.1 22 2973.96 ------------ -.899 -.187 55 71 24 2974.04 ------------ -.931 -.204 1.8 2.4 23 2974.00 ------------ -.899 -.248 43 61 25 2974.18 ------------ -.943 -.233 2.8 3.9 24 2974.04 ------------ -.965 -.199 61 80. 26 2974.25 ------------ -.922 -.327 2.3 3.6 25 2974.18 ------------ -.787 -.136 42 51 27 2974.40 ------------ -.491 -.098 .6 .7 26 2974.25 ------------ -.941 -.206 58 73 28 2974.45 ------------ -.849 -.206 .8 1.1 27 2974.40 ------------ -.561 -.090 9.7 11 29 2974.50 ------------ -.755 -.245 1.4 2.0 28 2974.45 ------------ -.913 -.234 20 28 30 2974.80 ------------ -.791 -.205 .9 1.2 29 2974.50 ------------ -.771 -.209 27 36 31 2974.85 ------------ -.934 -.195 1.0 1.4 30 2974.80 ------------ -.869 -.260 21 30 32 2975.00 ------------ -.735 -.231 1.7 2.4 31 2974.85 ------------ -.912 -.200 43 56 33 2975.30 ------------ -.785 -.065 8.3 9.1 32 2975.00 ------------ -.829 -.190 34 44 34 2976.00 ------------ -.888 -.177 4.2 5.3 33 2975.30 ------------ -.507 -.089 65 74 35 2976.70 ------------ -.829 -.147 6.7 8.2 34 2976.00 ------------ -.869 -.118 77 91 36 2976.80 ------------ -.683 -.143 13 16 35 2976.70 ------------ -.974 -.228 84 116 37 2977.00 ------------ -.771 -.268 7.3 11 36 2976.80 ------------ -.482 -.105 211 244 38 2980.00 ------------ -.808 -.226 3.7 5.1 37 2977.00 ------------ -.841 -.201 113 149 39 2985.00 ------------ -.946 -.278 3.2 4.7 38 2980.00 ------------ -.896 -.200 68 90 

39 2985.00 ------------ -.950 -.260 57 81 

Mean ______________________________ -.222 ------------------------

Median -.211 ----------------- -.815 -.226 ------------------------ Mean ___ --------------------------- ------------------------ Median ---------------- -.906 -.200 ------------------------

Magnesium Sulfate 

1 13-2922.00 ------------ -0.965 -0.303 1.2 1.8 2 2924.00 ------------ -.576 -.151 .2 .3 1 13-2922.00 ------------ -0.765 -0.465 1.3 2.5 

3 2932.00 ------------ -.971 -.203 .8 1.1 2 2924.00 ------------ -.640 -.263 1.4 2.0 

4 2934.00 ------------ -.991 -.148 1.0 1.2 3 2932.00 ------------ -.526 -.131 3.7 4.4 

5 2950.00 ------------ -.197 -.070 .5 .5 4 2934.00 ------------ -.924 -.379 3.5 6.0 

6 2956.50 ------------ -.870 -.143 .8 1.0 5 2950.00 ------------ .089 .084 2.0 1.7 

7 2960.00 ------------ -.615 -.176 .7 .9 6 2956.50 ------------ .314 .143 1.3 1.0 

8 2965.00 ------------- -.809 -.365 .7 1.2 7 2960.00 ------------ -.337 -.054 3.3 3.6 

9 2970.00 ------------- -.777 -.457 .5 .9 8 2965.00 ------------ -.569 -.230 3.2 4.8 

10 2971.00 ------------ -.866 -.347 1.1 1.8 9 2970.00 ------------ .184 .076 5.3 4.7 

11 2972.50 ------------ -.648 -.129 2.8 3.4 10 2971.00 ------------ -.130 -.089 5.9 6.6 

12 2973.00 ------------ .596 .38"7 17 9.9 11 2972.50 ------------ -.209 -.072 22 25 

13 2973.10 ------------ -.967 -.297 .9 1.3 12 2973.00 ------------ -.168 -.070 8.0 8.8 

14 2973.20 ------------ -.404 -.131 1.5 1.8 13 2973.10 ------------ -.985 -.443 2.0 3.7 

15 2973.30 ------------ -.682 -.300 1.4 2.1 14 2973.20 ------------ -.983 -1.960 .0 .4 

16 2973.40 ------------ -.996 -.300 2.8 4.2 15 2973.30 ------------ -.534 -.355 4.4 7.3 

17 2973.50 ------------ -.988 -.439 2.4 4.3 16 2973.40 ------------ -.845 -.893 .6 1.9 

18 2973.60 ------------ -.973 -.272 3.0 4.4 17 2973.50 ------------ -.704 -.343 8.5 14 

19 2973.80 ------------ -.889 -.334 1.1 1.8 18 2973.60 ------------ -.743 -.227 3.4 4.7 

20 2973.84 ------------ -.749 -.236 .5 .7 19 2973.80 ------------ -.378 -.223 4.2 5.8 

21 2973.88 ------------ -.879 -.350 1.0 1.6 20 2973.84 ------------ -.992 -.441 2.3 4.2 

22 2973.96 -------------- -.656 -.175 1.4 1.7 21 2973.88 ------------ -.949 -.862 1.0 3.4 

23 2974.00 ------------ -.919 -.346 1.1 1.8 22 2973.96 ------------ -.993 -.528 5.6 12 

24 2974.04 ------------ -.852 -.271 1.2 1.7 23 2974.00 ------------ -.968 -.389 5.9 10 

25 2974.18 ------------ -.575 -.076 1.7 1.9 24 2974.04 ------------ -.883 -.440 2.1 3.9 

26 2974.25 ------------ -.908 -.206 1.7 2.2 25 2974.18 ------------ .133 .042 2.2 2.1 

27 2974.40 ------------ .262 .073 .2 .1 26 2974.25 ------------ -.942 -.452 4.5 8.4 

28 2974.45 ------------ -.390 -.128 .4 .5 27 2974.40 ------------ .068 .037 1.6 1.5 

29 2974.50 ------------ -.434 -.196 .4 .5 28 2974.45 ------------ -.911 -.323 1.6 2.5 

30 2974.80 ------------ -.772 -.252 .4 .5 29 2974.50 ------------ -.547 -.317 1.5 2.3 

31 2974.85 ------------ -.937 -.185 1.5 1.9 30 2974.80 ------------ -.982 -.516 2.1 4.4 

32 2975.00 ------------ -.311 -.110 1.2 1.4 31 2974.85 ------------ -.709 -.163 9.4 12 

33 2975.30 ------------ -.031 -.004 2.5 2.5 32 2975.00 ------------ -.332 -.283 4.2 6.2 

34 2976.00 ------------ -.824 -.116 3.8 4.5 33 2975.30 ------------ .743 .342 16 9.8 

35 2976.70 ------------ -.950 -.267 5.6 8.1 34 2976.00 ------------ -.482 -.104 5.1 5.8 

36 2976.80 ------------ -.295 -.048 20 21 35 2976.70 ------------ .097 .036 5.7 5.5 

37 2977.00 ------------ -.932 -.145 9.3 11 36 2976.80 ------------ -.724 -.186 8.4 11 

38 2980.00 ------------ -.792 -.326 2.4 3.7 37 2977.00 ------------ .145 .051 12 11 

39 2985.00 ------------ -.746 -.268 1.7 2.5 38 2980.00 ------------ -.816 -.296 6.4 9.6 

39 2985.00 ------------ -.091 -.051 4.4 4.1 

Mean ------------------ ____________ -.200 ------------------------ Median -.275 ---------------- -.809 -.236 ------------------------ Mean ------------------------------ ------------------------ Median -----· ----------- -.704 -.263 ------------------------

Bicarbonate (Lab analysis) Chloride 

1 13-2922.00 ------------ -0.976 -0.267 46 66 2 2924.00 ------------ -.947 -.189 22 29 1 13-2922.00 ------------ 0.479 0.302 0.6 0.4 

3 2932.00 ------------ -.955 -.183 67 86 2 2924.00 ------------ -.286 -.107 .3 .4 

4 2934.00 ------------ -.915 -.231 46 64 3 2932.00 ------------ .990 .578 2.0 .9 

5 2950.00 ------------ -.695 -.144 27 33 4 2934.00 ------------ .942 .528 1.1 .5 

6 2956.50 ------------ -.894 -.184 35 45 5 2950.00 ------------ -.028 -.029 .6 .7 

7 2960.00 ------------ -.897 -.182 35 43 6 2956.50 ------------ .871 .488 .8 .4 

8 2965.00 ------------ -.906 -.340 35 56 7 2960.00 ------------ .386 .151 .2 .1 

9 2970.00 ------------ -.995 -.425 40 73 8 2965.00 ------------ -.702 -.570 .3 .7 

10 2971.00 ------------ -.908 -.349 43 70 9 2970.00 ------------ -.516 -.196 .6 .8 
A112 HYDROLOGIC EVALUATION OF THE UPPER SALMON RIVER AREA, IDAHO 

TABLE 43.-Summary of regression equation data, significant major 

ion concentration as a function of discharge-Continued 

Value of parameter Gra{>h U.S. Geological Correlation Exponent. plottmg Survey coefficient. or slope of No. Station No. relation Bankfull Mean annual <Q!Q8 =1.01 <Q1Qa=0.251 

Chloride--Continued 

10 1~2971.00 -0.028 ·-0.030 0.4 0.4 11 2972.50 .370 .356 .9 .5 12 2973.00 -.427 -.177 .8 1.1 13 2973.10 .125 .060 .4 .4 14 2973.20 -.097 -.063 .8 .8 15 2973.30 -.934 -.276 .3 .4 16 2973.40 .638 .153 .9 .7 17 2973.50 -.795 -.101 .7 .8 18 2973.60 -.379 -.056 .7 .8 19 2973.80 -.553 -.559 .4 .9 20 2973.84 -.466 -.233 .4 .5 21 2973.88 -.192 -.171 .2 .3 22 2973.96 ------------- -.609 -.332 .5 .8 23 2974.00 -.762 -.537 .4 .7 24 2974.04 ------------- -.367 -.321 .5 .7 25 2974.18 -------------- .813 .430 1.4 .7 26 2974.25 -.586 -.166 .7 .9 27 2974.40 ----------- -.489 --.295 .1 .2 28 2974.45 -.245 -.114 .3 .4 29 2974.50 ----------- -.699 -.498 .2 .4 30 2974.80 -.515 -.499 .2 .3 31 2974.85 -.664 -.669 .1 .3 32 2975.00 -.353 -.156 .8 1.0 33 2975.30 -.874 -.260 .9 1.3 34 2976.00 ------------ -.903 -.186 1.1 1.3 35 2976.70 -.726 -.265 2.7 3.9 36 2976.80 ---- ---- --- -.767 -.171 7.0 8.9 37 2977.00 -.581 -.111 5.1 5.9 38 2980.00 ------ ------- -.358 -.304 1.0 1.5 39 2985.00 -------------- -.447 -.367 .7 1.1 

Mean _______ ---··------ _ . _______ --··- -.138 --------------------------

Median ------ -.553 -.171 

Total dissolved solids 

1 1~2922.00 ------------ -0.973 -0.231 49 67 2 2924.00 ------------ -.914 -.188 25 32 3 2932.00 ------------- -.966 -.156 78 97 4 2934.00 ------------ -.946 -.231 54 74 5 2950.00 -------------- -.592 -.107 39 45 6 2956.50 ------------ -.900 -.112 45 52 7 2960.00 ------------- -.929 -.132 51 61 8 2965.00 ------------ -.902 -.329 45 71 9 2970.00 ------------- -.997 -.342 50 80 10 2971.00 ------------ -.827 -.272 58 85 11 2972.50 ------------ -.569 -.099 150 172 12 2973.00 ------------ -.804 -.099 107 123 13 2973.10 ------------ -.842 -.140 49 59 14 2973.20 ------------ -.985 -.568 20 44 15 2973.30 ------------- -.649 -.193 54 71 16 2973.40 ------------ -.937 -.165 68 85 17 2973.50 ------------ -.997 -.258 70 100 18 2973.60 ------------ -.971 -.170 70 89 19 2973.80 ------------ -.910 -.276 57 84 20 2973.84 ------------ -.987 -.232 28 39 21 2973.88 ------------ -.975 -.221 45 61 22 2973.96 ------------ -.964 -.241 59 83 23 2974.00 ------------ -.935 -.285 48 72 24 2974.04 ------------ -.977 -.194 64 83 25 2974.18 ------------ -.694 -.088 56 63 26 2974.25 ------------ -.970 -.226 63 86 27 2974.40 ------------ -.768 -.106 12 14 28 2974.45 ------------ -.934 -.243 24 33 29 2974.50 ------------ -.906 -.253 29 41 30 2974.80 ------------- -.942 -.295 25 38 31 2974.85 ------------ -.754 -.321 37 58 32 2975.00 ------------ -.851 -.224 45 61 33 2975.30 ------------ -.200 -.023 98 101 34 2976.00 ------------ -.870 -.109 82 96 35 2976.70 ------------ -.983 -.189 109 141 36 2976.80 ------------ -.539 -.099 228 262 37 2977.00 ------------ -.815 -.145 145 178 39 2980.00 ------------ -.939 -.219 67 90 39 2985.00 ------------ -.936 -.186 78 101 

Mean ______________________________ -.204 ------------------------

Median ---------------- -.914 -.194 -------------------------

TABLE 44.-S ummary of regression equation data, miscellaneous 

water- quality parameters as a function of discharge 

U.S. Geological 

Survey Station No. 

1~2950.00 

2965.00 

2973.50 

2973.80 

2974.00 

2974.04 

2974.25 

2974.40 

2974.45 ---- ----- -----

2974.50 

2974.80 

2974.85 

2975.00 

2980.00 

2985.00 

Mean 

Median ------------

1~2950.00 

2965.00 

2973.50 --------------

2973.80 -------------

2974.00 ------------- ---

2974.04 --------------

2974.25 

2974.40 ---------------

2974.45 -----------------

2974.50 -------------

2974.80 -------------

2974.85 ---- ---------------

2975.00 -------------

2980.00 -------------- -- 2985.00 -----------------

Mean ---------------

Median -- ---------

Correlation Exponent, Value of parameter 

coefficient, or slope of 

relation Bankfull Mean annual 

<QIQB = l.Ol <QIQB =0.25 l 

Potassium 

0.353 0.217 0.6 0.4 -.528 -.222 .4 .6 -.408 -.0~6 .6 .7 .057 .041 .7 .7 -.970 -.450 .3 .5 -.152 -.096 .4 .5 -.581 -.295 .2 .3 -.248 -.089 .2 .2 -.397 -.208 .2 .2 .070 .035 .5 .5 -.610 -.195 .2 .2 -.144 -.061 .5 .6 -.067 -.043 .5 .5 .412 .290 .6 .4 .073 .028 .7 .7 

-.076 -------- ------ -----------------

-.353 -.089 ---------------

Fluoride 

-0.706 -0.459 0.3 0.5 -.766 -.367 .3 .5 -.586 -.234 .1 .2 -.909 -.703 .2 .5 -.993 -.832 .1 .2 -.261 -.168 .1 .1 -.691 -.401 .1 .2 -.152 -.044 .1 .1 -.530 -.290 .1 .1 -.754 -.332 .1 .1 -.367 -.184 .1 .1 -.382 -.313 .1 .1 -.444 -.441 .1 .2 -.504 -.236 .2 .2 -.828 -.475 .2 .5 

-.365 - ------- ------- -------------- -.586 -.332 -- ----------------------

Nitrite and nitrate as N 

1~2950.00 ------------- -0.422 -0.224 0.04 0.05 2965.00 ----------------- -.545 -1.238 .02 .11 2973.50 -.032 -.016 .02 .03 2973.80 ---------- ------ .438 .465 .03 .02 2974.00 ------------------ .437 .275 .02 .02 2974.04 ---- -------------- .207 .141 .02 .02 2974.25 -------- ---------- .979 .803 .06 .02 2974.40 ----------------- -.094 -.093 .05 .06 2974.45 ------------------ .420 .167 .02 .02 2974.50 ---------------- .839 .369 .o5 .o3· 2974.80 ----------------- .937 .871 .18 .05 2974.85 ---------------- .943 .554 .14 .06 2975.00 ----------------- -.496 -.899 .01 .04 2980.00 ------------------ -.495 -.513 .08 .04 2985.00 --------------------- .056 .051 .05 .04 

Mean ----------------- ------------- .117 Median -------------- .438 .167 

Orthophosphorus 

1~2950.00 ------------------ -0.376 -0.205 0.01 0.01 2965.00 --------------- .441 .240 .02 .01 2973.50 ---------------- .106 .061 .04 .03 2973.80 ---------------- .595 .387 .02 .01 2974.00 - ----------------- .000 .000 .01 .01 2974.04 ----------------- .607 .359 .02 .02 2974.25 ----------------- -.417 -.251 .01 .02 2974.40 ---------------- .000 .000 .01 .01 2974.45 ---------------- .000 .000 .01 .01 2974.50 ---------------- .977 .349 .03 .02 2974.80 ---------------- .892 .296 .02 .02 
CHANNELS AND WATERS A113 

TABLE 44.--S ummary of regression equation data, miscellaneous 

water-quality parameters as a function of discharge-Continued 

U.S. Geological 

St~ti~~e~o. 

Correlation 

coefficient, 

Exponent, 

or slope of relation 

Value of parameter 

Bankfull Mean annual (Q/QB=l.OI (Q/QB=0.251 

Orthophosphorus--Continued 

13-2974.80 2975.00 

2980.00 

2985.00 

-0.511 

.729 

.547 

.296 

-0.341 

1.100 

.297 

.212 

Mean __ __________ ____ ______________ .167 Median ______________ .441 .212 

Total phosphorus 

13-2950.00 ---------------- -0.522 2965.00 ---------------- .211 2973.50 ---------------- .223 2973.80 ---------------- .595 2974.00 ---------------- .037 2974.04 ---------------- .934 2974.25 ---------------- -.618 2974.40 ---------------- -.825 2974.45 ---------------- -.370 2974.50 ---------------- .325 2974.80 ---------------- -.458 2974.85 ---------------- .035 2975.00 ---------------- .600 

2980.00 ---------------- .663 2985.00 ---------------- .775 

Mean ------------------ ___ ----------- Median -------------- .552 

pH 

13-2950.00 ---------------- -0.057 2965.00 ---------------- -.377 2973.50 ---------·------- -.579 2973.80 ---------------- -.442 

2974.00 ---------------- .113 2974.04 ---------------- -.128 2974.25 ----------------- .246 2974.40 ---------------- -.063 2974.45 ---------------- -.198 2974.50 ---------------- -.149 2974.80 ---------------- -.392 2974.85 ------------------ -.662 2975.00 ---------------- .105 2980.00 ---------------- -.527 2985.00 ---------------- -.408 

Mean ---------------- _____________ _ Median ______________ -.246 

-0.089 .086 

.035 

.646 

.019 

.726 

-.135 

-.651 

-.082 

.142 

-.195 

.012 

1.470 

.698 

.731 

.228 

.035 

-0.002 

-.016 

-.014 

-.020 

.003 

-.004 

.008 

-.003 

-.012 

-.007 

-.026 

-.027 

.003 

-.020 

-.015 

-.010 

-.012 

Alkalinity as CaC03 

13-2950.00 ---------------- -0.716 -0.140 

2965.00 ---------------- -.900 -.333 

2973.50 ---------------- -.993 -.295 2973.80 ---------------- -.912 -.326 2974.00 ---------------- -.896 -.246 

2974.04 ---------------- -.963 -.200 

2974.25 ---------------- -.945 -.207 2974.40 ---------------- -.293 -.034 2974.45 ---------------- -.320 -.115 

2974.50 ---------------- -.967 -.318 

2974.80 ---------------- -.968 -.266 

2974.85 ---------------- -.897 -.174 2975.00 ---------------- -.849 -.205 2980.00 ---------------- -.882 -.191 

2985.00 ---------------- -.953 -.260 

Mean _____________________________ _ -.221 

Median -------------- -.900 -.207 

0.01 0.02 .15 .03 .02 .02 .02 .01 

0.03 0.04 .04 .04 .08 .07 .07 .03 .02 .02 .14 .05 .03 .04 .01 .02 .03 .04 .06 .05 .02 .03 .08 .08 .79 .10 

.17 .06 .09 .03 

7.4 

7.4 

7.4 

7.4 

7.9 

7.8 

7.9 

7.1 

6.9 

7.2 

6.9 

7.1 

7.7 

7.4 

7.5 

22 

29 

43 

37 

36 

50 

47 

8.4 

19 

16 

16 

37 

28 

57 

46 

7.4 

7.6 

7.5 

7.6 

7.8 

7.9 

7.8 

7.2 

7.1 

7.3 

7.2 

7.3 

7.7 

7.6 

7.5 

27 

46 

65 

59 

50 

66 

63 

8.8 

22 

25 

23 

47 

37 

74 

67 

TABLE 44.--Summary of regression equation data, miscellaneous 

water-quality parameters as a function of discharge-Continued 

U.S. Geological 

Survey 

Station No. 

Correlation 

coefficient, 

Exponent, 

or slope of relation 

Total hardness 

13-2950.00 ---------------- -0.833 -0.184 2965.00 ---------------- -.951 -.442 2973.50 ---------------- -.985 -.356 2973:80 ---------------- -.960 -.414 2974.00 ---------------- -.935 -.278 2974.04 ---------------- -.993 -.216 

2974.25 ---------------- -.952 -.201 

2974.40 ---------------- -.618 -.102 

2974.45 ---------------- -.954 -.296 2974.50 ---------------- -.843 -.246 

2974.80 ---------------- -.986 -.345 

2974.85 ---------------- -.977 -.206 

2975.00 ---------------- -.939 -.287 

2980.00 ---------------- -.947 -.221 

2985.00 ---------------- -.968 -.296 

Mean __ ------------------------- __ _ -.273 Median ______________ -.952 -.278 

Value of parameter· 

Bankfull Mean annual (Q/QB = 1.0 I <QIQB =0.25 I 

17 22 22 41 39 64 32 57 35 52 45 61 47 62 6.2 7.1 13 19 18 26 14 23 39 51 27 40 52 71 42 62 

INDEX 

[Italic page numbers indicate major references] 

Page 

Alkalinity ________ ------------------------ __ -------------------- ____________ 68, 90 

Alluvial deposits __ -------------- ________________________ -------------------- ____ 8 

Altitude data __ --------------------------------------------------------------____ 17 

Analysis of data _______________________ ----------------- ______ ---------------- 25, 51 

Bacteria ------------------------------------ ____________________ ------------ 80, 89 

Bankful discharge ___________________________________________ 31, 34, 36, 44, 45, 92, 93 

Beaver Creek near Stanley, Idaho ------------------------------------------------ 30 Bedload transport ________________________________________________________________ 85 

Big Boulder Creek ------------------------------------------------------ 3, 8, 78, 81 

Biological factors, related to water quality ---------------------------------------- 78 

Biota -------------------- ______________ ---------------------------- ______ 66, 77, 89 

Boulder Mountains ______ ------------------------------------------------------ 4 

Castle Peak---------------------------------------------------------- __________ 2, 5 

Challis Volcanics ------------------------------------------------------------ 6, 92 

Channel geometry-------------------------------------------------------- 34, 45, 92 

Chemical analyses ____ --------------------- _____________ ------------------------ 56 

Clayton band ______ ------------------------------------------------------------ 7 

Climate ---------------------------------------------------------------------- 8, 92 

Collection of data -------------------------------------------------- 3, 13, 25, 51, 88 

Discharge --------------------------------------------------------- 27, 30, 32, 40, 45 

related to dissolved solids -------------------------------------------- 57, 91, 92 

related to major ions -------------------------------------------------------- 61 

related to silica content ---------------------------------------------------- 63 

related to suspended sediment -------------------------------------------- 81, 91 

relation to trace elements---------------------------------------------------- 76 

Dissolved-oxygen content -------------------------------------------------------- 79 

Dissolved solids ------------------------ ____________________ ------------------ 92, 95 

related to solids runoff ------------------------------------------------------ 87 

Drainage area------------------------------------------------------------ 17, 24, 35 

Drainage density ---------------------------------------- _ --------------- 15, 16, 24 

Drainage net ---------------------------------------------------------------- 14,24 

East Fork Salmon River near Clayton, Idaho -------------------------------------- 30 Environmental interrelations _ _ __ _____ _ __ __ _ _ ___ ___ __ _ _ _ _ _ _ __ __ __ _ _ ____ __ ________ 2 

Eutrophication ___ _ __ __ __ __ __ _ _____ __ ___ _ _ ___ __ ______ __ __ __ _ _____ ___ _____ __ __ ____ 67 

Faulting __________________________________________________________ ----- __ _ _ ___ __ 4 

Flow duration ________________________________________________________ -------- 39, 50 

Flow frequency -------------------------------------------------------------- 38, 50 Folding ____ __ __ __ __ __ __ ____ _ _ __ __ ___ __ ___ __ __ ______ __ __ ____ __ __ ___ _ __ __ __ _ _____ 4 

Gaging stations---------------------------------- __________ ---------------- 3, 25, 42 

Geology ------------------------------------------------------------------ 5, 53, 92 

related to solids runoff ------------------------------------------------------ 91 Glaciation ____ _ _ _ ___ __ __ _ _ ___ ___ __ __ __ __ _ __ ___ ______ __ ___ __ ___ __ ___ _____ __ __ ___ _ 4 

Hardness ____________________________________________________________________ 68, 90 

Herd Creek ___________________________________________________________ --------- 78 

High-flow characteristics ------------------------------------------------ 42, 43, 93 

Horton analysis ____ ---------------------------------------------------------- 14, 92 

Hydraulic geometry ---------------------------------------------------------- 28, 45 

Idaho batholith________________________________________________________________ 6, 92 

Ionic concentration ---------------------------------------------------------- 61, 94 

Jim Creek above Livingston Mill ------------------------------------------------ 77 

Kinnikinic Quartzite _ _ __ __ _____ _ __ _______ ___ __ ___ ___ __ ___ __ __ ___ _____ __ _ ________ 8 

Land use------------------------------------------------------------------------ 1: 

Little Boulder Creek ------------------------------------------ 3, 8, 56, 58, 61, 65, 78 Location ________________________________________________________ ------------ __ 4, 92 

Page 

Low flow characteristics -------------------------------------------------- 42, 44, 93 

Maim Gulch ------------------------------------ ______ -------------------------- 81 Milligen Formation ______________________________________________ ------ ______ -- 7, 81 

Mineralization -------------------------------------------------------- 2, 12, 54, 92 Molybdenum _ _ _ _ _ _ _ _ _ _ __ __ ___ _ _ ___ __ _ _ _ _ _ _ __ ___ __ __ _ __ _ _ _ ___ __ ___ ___ __ ___ ___ __ __ 3 

Nutrients-------------------------------------------------------------------- 65, 78 

Organic carbon content __________ ------------------------------------------------- 80 

Particle-size distribution ___________________________________________________ --- __ 36 

Pat Hughes Creek -------------------------------------------------------------- 67 pH ___________________________________________________________________ ----------- 56 

Pollution ------------------------------------------------------------ 57, 61, 78, 80 Population _________________________________________________________________ --- _ _ 4 

Precipitation ________________________________________________________ 9, 27, 53, 59, 92 

related to suspended sediment------------------------------------------------ 83 

Previous work ____ ------------- -------------~----------------------------------- 2 

Problem stated -------------- __________ ------------------------------------------ 2 

Quality of water -------------------------------------------------- 14, 27, 52, 89, 94 

Ramshorn Slate __ -------------------------------------------------------------- 8 

Recreation-------------------------------------------------------------------- 2, 12 

Road Creek------------------------------------------------------------------ 65, 78 

Road Creek basin---------------------------------------------------------------- 46 Runoff ___________________________________________________________ ------- ___ - 27, 45 

related to silica content------------------------------------------------------ 63 

Salmon River at Challis ---------------------------------------------- 42, 61, 81, 86 

Salmon River below the Yankee Fork -----------------------------~-------------- 81 

Sampling of data ---------------------------------------------------------------- 14 

Sawtooth National Recreation Area ---------------------------------------- 3, 12, 92 Sawtooth Range ________________________________________________________ ----- _ __ 4 

Scenic beauty _____________________ ----- __ __ ____ _ ___ __ _ _ _ __ ___ _ _ __ ___ ___ __ ___ ___ 3 

Sedimentary rocks __ _ _ _ ___ __ __ __ __ _ ____ _ __ ___ __ _ _ ______ _ _ _ _ _ __ ________ __ ___ __ ___ 6 

Silica _______________________________________ ------- _____________ ----- ___ ----- __ 62 

Slate Creek------------------------------------------------------------------ 81, 89 

Slope data ------------------------------------------------------------------ 17, 25 

Solids runoff ---------------------------------------------------------------- 86, 91 

Solubility of rock ---------------------------------------------------------------- 58 Specific conductance _______________________________________________________ ----- 56 

Stanley Basin ________________________________________________________ 4, 8, 12, 13, 61 

Stream channel network -------------------------------------------------------- 13 Stream length __________________ ------ ______________________________ -- __ ------ __ 24 

Stream order _______________________________________________________________ ----- 14 

Stream runoff ______________________________________________________________ ---- 93 

Streamflow measurement ---------------------------------------------------- 14,26 

Study area ____ ----- ______ ------- ____________ --- _ ------- _________ ----- __ -------- _ 4 

Summary of findings ------------------------------------------------------------ 92 

Suspended sediment -------------------------------------------------- 14, 80, 91, 95 

related to solids runoff ------------------------------------------------------- 87 

related to turbidity ---------------------------------------------------------- 85 

Temperature (air) ------------------------------------------------------------ 9, 14 Temperature (water) __________________________________________ ------- _____ ------ 54 

Thompson Creek ------- ____________________________________ ----- __ __ ___ ___ __ __ __ 12 

Timbering _____ _ __ __ __ _______ ___ _____ __ _____ __ _____ ___ __ __ _____ _____ __ ______ __ __ 12 

Topography ____________________________ ----- _________________ ---------------- 4, 92 

Trace elements-------------------------------------------------------- 14, 73, 89, 95 Tree species ___________________________ ----- ______________ ------------------ __ __ 9 

Tributary drainage _ ___ __ __ _____ ___ __ __ ___ _________ __ ___ ___ __ __ ____ ______ ____ _ ___ 15 

Turbidity _____________________________ --------- _____________ ----------------- __ 83 

Use of water ---------------------------------------------------------------- 89, 95 

Al15 
A116 INDEX 

Page 

Valley Creek____________________________________________________________________ 13 

Volcanic rocks _______________________________ ----------------------------------- 6 

Warm Springs Creek ------------------------------------------------------------ 13 

Water-data stations __________________________________________________________ 13, 27 

Page 

Weather stations _______ --------------------------------------------------- ______ 9 

White Cloud Peaks ------------------------------------------------------------ 2, 4 

Wood River Formation ---------------------------------------------------------- 7 

Yankee Fork ---------------------------------------------------------------- 12, 13 

*U.S. GOVERNMENT PRINTING OFFICE: 1975~0-690-036/17