The Hydrology of Four Streams 

in Western Washington 

as Related to Several 

Pacific Salmon Species

By M. R. COLLINGS, RONALD W. SMITH, and G. T. HIGGINS

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1968

Prepared in cooperation with the 

Washington State Department of 

Fisheries

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1972
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS G. B. MORTON, Secretary

GEOLOGICAL SURVEY 

W. A. Radlinski, Acting Director

Library of Congress catalog-card No. 76-179676

For sale by the Superintendent of Documents, U.S. Government Printing Office

Washington, D.C. 204412 - Price 55 cents (paper cover)

Stock Number 2491-1189
CONTENTS

	Page

Abstract ___ __ 1

Introduction _ ________ 2

Purpose and scope _____ _ ____________ 3

Acknowledgments __________________________ 3

Approach ___ _ ______ ____________________ 4

Selection of sites __________________ 4

Hydraulic criteria _ ____ _ ______________ 5

Streambed gravels _____________________________ 8

Water temperatures ____________________________ 9

Salmon and spawning ___________________________ 9

Dewatto River __________________________________ 11

Dewatto River reach A __________________________ 13

Dewatto River reach A-l _________________________ 20

Dewatto River reach B __________________________ 23

Cedar River ____________________________________ 30

Cedar River reach A ____________________________ 33

Cedar River reach B ____________________________ 37

Cedar River reach C ____________________________ 43

Kalama River _________________________________ 47

Kalama River reach A __________________________ 53

Kalama River reach B __________________________ 56

Kalama River reach C ___________________________ 66

North Fork Nooksack River __________________________ 74

North Fork Nooksack River reach A __________________ 80

North Fork Nooksack River reach B __________________ 87

North Fork Nooksack River reach C __________________ 91

Generalization of peak preferred spawning discharges __________ 101

Conclusions ____________________________________ 103

References ____________________________________ 108

ILLUSTRATIONS

Page

FIGURE 1. Map of western Washington showing location of streams

studied ____________________________ 4

2. Hydrograph showing mean monthly discharge and maximum and minimum monthly mean discharges, Dewatto 

River near Dewatto ____________________ 11

3. Graph showing maximum, minimum, and mean daily

water temperatures, Dewatto River near Dewatto.__ 12

4. Map showing study reaches on Dewatto River ______ 13

5. Graph showing curves for average grading of several 

samples of gravel found on natural spawning grounds 

on Dewatto River ____________________ 14

in
IV CONTENTS

Page

FIGURE 6. Graphs showing relation of preferred spawning conditions to discharge, Dewatto River reach A._______ 15 

7. Sketches showing areas of preferred spawning, Dewatto

River reach A _________________________ 16 

8-11. Graphs showing 

8. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Dewatto River reach A.______ ________ 17

9. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Dewatto River reach A ___________ 18

10. Monthly and annual flow durations, Dewatto

River reach A ___________ ______ 19

11. Relation of preferred spawning conditions to discharge, Dewatto River reach A-l._______ 22 

12. Sketches showing areas of preferred spawning, Dewatto

River reach A-l.________________________ 23 

13-15. Graphs showing 

13. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Dewatto River reach A-l.__________ 24

14. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Dewatto River reach A-l __________ 25

15. Relation of preferred spawning conditions to discharge, Dewatto River reach B ________ 26

16. Sketches showing areas of preferred spawning, Dewatto

River reach B __________________________ 27 

17-22. Graphs showing 

17. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Dewatto River reach B _____________ 28

18. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Dewatto River reach B ____________ 29

19. Monthly and annual flow durations, Dewatto

River reach B ___________________ 30

20. Mean monthly discharge and maximum and minimum monthly mean discharges of Cedar River 

at Renton __________ __________ 32

21. Monthly and annual flow durations, Cedar River

at Renton __________________ 33

22. Water temperatures, Cedar River near Landsburg 34

23. Map showing study reaches on Cedar River _______ _ 34

24. Graph showing curves for average grading of several 

samples of gravels found on natural spawning grounds 

of Cedar River _______________________ 35

25. Sketches showing areas of preferred spawning, Cedar

River reach A _ _ _ __ 36
CONTENTS V

Page

FIGURES 26-29. Graphs showing 

26. Relation of preferred spawning conditions to discharge, Cedar River reach A __________ 38

27. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Cedar River reach A _______________ 39

28. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Cedar River reach A ___ _________ 40

29. Monthly and annual flow durations, Cedar River

reach A _______________________ 41

30. Sketches showing areas of preferred spawning, Cedar

River reach B ____________________ 42

31-34. Graphs showing 

31. Relation of preferred spawning conditions to discharge, Cedar River reach B ___________ 44

32. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Cedar River reach B _____________ ______ 45

33. Family of curves for relation between velocity, 

discharge and percentage of bankfull area, 

Cedar River reach B _____________ 46

34. Monthly and annual flow durations, Cedar River

reach B ________________________ 47 

35. Sketches showing areas of preferred spawning, Cedar

River reach C _______________________ 48 

36-38. Graphs showing 

36. Relation of preferred spawning conditions to discharge, Cedar River reach C ___________ 50

37. Monthly and annual flow durations, Cedar River

reach C ____________________ 51

38. Mean monthly discharge and maximum and minimum monthly mean discharges of Kalama 

River below Italian Creek, near Kalama .___ 52 

39. Map showing study reaches on Kalama River ______ 53 

40-42. Graphs showing 

40. Water temperatures, Kalama River below Italian

Creek, near Kalama ______-_______ 54

41. Average grading of several samples of gravels 

found on natural spawning grounds of Kalama 

River _____________________ 55

42. Relation of preferred spawning conditions to discharge, Kalama River reach A ________ 57 

43. Sketches showing areas of preferred spawning, Kalama

River reach A __________________________ 58 

44-47. Graphs showing 

44. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Kalama River reach A _____________ 60
VI CONTENTS

Page

FIGURES 44-47. Graphs showing Continued

45. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Kalama River reach A ______________ 61

46. Monthly and annual flow durations, Kalama

River reach A ________________ 62

47. Relation of preferred spawning conditions to discharge, Kalama River reach B _ 62 

48. Sketches showing areas of preferred spawning, Kalama

River reach B _______________________ 64 

49-51. Graphs showing 

49. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Kalama River reach B _____________ 67

50. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Kalama River reach B _____________ 68

51. Relation of preferred spawning conditions to discharge, Kalama River reach C ________ 69 

52. Sketches showing areas of preferred spawning, Kalama

River reach C _______________________ 70 

53-55. Graphs showing 

53. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

Kalama River reach C ___________ 72

54. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

Kalama River reach C ___________ 73

55. Monthly and annual flow durations, Kalama

River reach C ___________________ 75

56. Map showing study reaches on North Fork Nooksaek

River ______________________________ 76 

57-60. Graphs showing 

57. Average grading of several samples of gravels 

found on natural spawning grounds of North 

Fork Nooksaek River ______________ 77

58. Mean monthly discharge and maximum and minimum monthly mean discharges, North Fork 

Nooksaek River below Cascade Creek near 

Glacier and mean monthly discharge, North 

Fork Nooksaek River near Deming ______ 78

59. Daily water temperatures, North Fork Nooksaek

River near Deming _______________ 79

60. Relation of preferred spawning conditions to discharge, North Fork Nooksaek River reach A_ 81 

61. Sketches showing areas of preferred spawning, North

Fork Nooksaek River reach A __ ___________ 82 

62-65. Graphs showing 

62. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

North Fork Nooksaek River reach A._____ 84
CONTENTS VII

Page

FIGURES 62-65. Graphs showing Continued

63. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

North Fork Nooksack River reach A._____ 85

64. Monthly and annual flow durations, North Fork

Nooksack River reach A _ ___ _ _ ______ 86

65. Relation of preferred spawning conditions to discharge, North Fork Nooksack River reach B_ 88 

66. Sketches showing areas of preferred spawning, North

Fork Nooksack River reach B.______________ 90 

67-70. Graphs showing 

67. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

North Fork Nooksack River reach B ______ 92

68. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

North Fork Nooksack River reach B._____ 93

69. Monthly and annual flow durations, North Fork

Nooksack River reach B __________ 94

70. Relation of preferred spawning conditions to discharge, North Fork Nooksack River reach Cgg 

71. Sketches showing areas of preferred spawning, North

Fork Nooksack River reach C _ ________ 96 

72-75. Graphs showing 

72. Wetted perimeter versus discharge and percentage of bankfull area wetted versus discharge, 

North Fork Nooksack River reach C._____ 98

73. Family of curves for relation between velocity, 

discharge, and percentage of bankfull area, 

North Fork Nooksack River reach C._____ 99

74. Monthly and annual flow durations, North Fork

Nooksack River reach C ____________ 100

75. Relations between selected percentage reductions 

in discharge from the peak preferred discharge 

and comparable percentage reductions of 

spawnable area 107

TABLES

Page

TABLE 1. Preferred depth and velocity criteria for salmon spawning 5 

2. Comparison of spawnable areas and of variations of discharges for adjacent reaches on the Cedar River._ 7 

3-14. Characteristics of water quality:

3. Dewatto River reach A __ _ 20

4. Dewatto River reach A 1 _ __ 21

5. Dewatto River reach B _ _ 31

6. Cedar River reach A _ ______ 40

7. Cedar River reach B __________________ 45
VIII CONTENTS

Page

TABLES 3-14. Characteristics of water supply Continued

8. Cedar River reach C __________________ 48

9. Kalama River reach A _______________ 56

10. Kalama River reach B _________________ 66

11. Kalama River reach C _________________ 74

12. North Fork Nooksack River reach A ________ 87

13. North Fork Nooksack River reach B ________ 93

14. North Fork Nooksack River reach C ________ 101

15. Summary of peak preferred spawning areas and discharges and of corresponding selected reductions.___ 104

16. Percentage reductions of spawnable area for selected

reductions of the peak spawning discharge._______ 106
THE HYDROLOGY OF FOUR STREAMS

IN WESTERN WASHINGTON

AS RELATED TO SEVERAL PACIFIC

SALMON SPECIES

By M. R. COLLINGS, RONALD W. SMITH, and G. T. HIGGINS

ABSTRACT

Enhancement or possibly even preservation of the Pacific salmon hinges 

on the careful planning and proper management of the streamflow upon which 

they depend for spawning. Most spawning activity occurs on reaches of streams 

where specific hydraulic conditions exist and where stream-channel characteristics and water-quality criteria are met. The present report is the first of a 

series and is used to present the method of determining preferred spawning 

conditions and results of the investiagtion of 129 measurements on 14 study 

reaches of the Dewatto, Cedar, Kalama, and North 'Fork Nooksack Rivers. 

Subsequent reports, using the same method will present analyses and preferred 

spawning and rearing discharges for other streams used by salmon.

The method consists of measuring water depth and velocities to designate, 

from area (spawnable) discharge curves, peak, preferred spawning discharges for fall chinook, spring chinook, sockeye, and coho salmon at each 

reach on each river. Also, streambed gravels, water temperature, suspended 

sediment, dissolved oxygen, and specific conductance are used to help evaluate 

river conditions during spawning.

In examining the repeatability of the method, tested by analyzing independently each of selected pairs of adjacent reaches on the Cedar River, it was 

found that the preferred peak discharges from the comparisons varied 4.6 

percent for the average of four species and two pairs of reaches.

Peak spawning discharges ranged, for the four salmon species on each of 

the three study reaches of each river, from 50 to 140 cfs (cubic feet per second) 

on Dewatto River, from 230 to 510 cfs on Cedar River, from 245 to 800 cfs on 

Kalama River, and from 195 to 710 cfs on North Fork Nooksack River.

The results indicate that the methods used and the probable discharge 

values determined are reasonable and, if economically justified, may be used 

to select discharges, for salmon spawning and rearing.
2 HYDROLOGY AS RELATED TO PACIFIC SALMON

INTRODUCTION

The Pacific salmon is an anadromous fish, living in the sea and 

ascending rivers and streams for spawning, incubation, and early 

rearing. Five salmon species of Pacific salmon frequenting the 

Washington streams are sockeye (Oncorhynchus nerka), chinook 

(O. tsawytscha), coho (O. Kisutch), pink (O. gorbuscha), and chum 

O. keta). Sockeye, coho, and the spring and fall chinook were investigated in this study; for simplicity, in the rest of this report these 

three salmon species (with two races of one species) will be referred 

to as four species.

The Pacific salmon utilizes most of the streams in western Washington for spawning and rearing. The most productive spawning 

activity occurs on reaches of streams where specific hydraulic conditions exist and where certain stream-channel characteristics and 

water-quality criteria are met. Each salmon species has specific 

hydraulic prerequisities ranges of water depths and bottom velocities for spawning. The critical channel characteristics include 

streambed composition and compactness infiltration of water 

through the gravels, cover and concealment, and the amount of 

habitation along the streambanks (Royce, 1959). Some factors of 

water quality which influence spawning are water temperature, 

suspended sediment, dissolved oxygen, and dissolved-solids concentration.

Anadromous fish usually spawn in pool-riffle streams, where the 

water slope alternates between comparatively level reaches (pools) 

and comparatively steep segments (riffles). Sand is the predominant 

bed material in the pools, whereas the bed material of the riffles, 

where the salmon form their redds (nests), is generally much 

coarser. Smolt production is highest in stream channels composed 

of 50-percent riffles and 50-percent pools (Ruggles, 1966). The pools, 

with proper food production and volume of water, serve as rearing 

areas for the fry and fingerlings of some salmon species. Riffles also 

serve as food-production and rearing areas.

At present, the streams of western Washington have an abundant 

supply of water; however, the increasing population and industrial 

growth is accompanied by an ever-growing demand for water for 

hydroelectric power generation and other beneficial uses, such as 

irrigation and municipal supply. Therefore, if the Pacific salmon 

is to be enhanced or even preserved, the allocation of streamflow, 

careful planning, and proper management will be necessary.
INTRODUCTION 3

PURPOSE AND SCOPE

The major purpose of this study was to develop a suitable method 

for designating the most desirable streamflow or flows for spawning and rearing of various salmon species in the major salmonproducing streams in Washington. The preferred rates of streamflow are based on optimum salmon propagation at the minimum 

suitable flow. The ultimate objective of the study, after a sufficient 

sample is obtained, is regionalization which will allow a determination of the minimum acceptable flow at any desired location on a 

river. The relationships developed minimum acceptable discharge 

versus easily obtained significant basin and channel parameters 

may provide a basis for future "allocation of water for salmon.

The present report is the first of a series on a study of streams 

used by salmon. On four streams (fig. 1) the Dewatto, Cedar, 

Kalama, and North Fork Nooksack Rivers at 14 sites, 129 determinations of velocity, depth, discharge and water-quality parameters have been made. These data are used to determine rearing 

and spawning discharges for sockeye, coho, spring chinook, and fall 

chinook salmon, species for which the preferred spawning depths 

and velocities are known. Spring and fall chinook are races of the 

species Oncorhynchus tshawytscha. Each stream and each site is 

discussed independently, each having varying degrees of analysis, 

depending on the amount of data available at this time (1969).

ACKNOWLEDGMENTS

This study was made under a cooperative agreement between the 

U.S. Geological Survey and the Washington State Department of 

Fisheries. The assistance of biologists from the Department of 

Fisheries in selecting river study reaches is gratefully acknowledged. The constructive criticism and suggestions from colleagues 

Prof. Milo C. Bell of the Fisheries Center, University of Washington, M. A. Benson and S. E. Rantz of the Geological Survey, and 

Stanley G. Jewett, Jr., of the U.S. Fish and Wildlife Service were of 

benefit to the final report.

APPROACH

The methods used for collection and analysis of these data are, 

with a few modifications, a combination of the methods used by
HYDROLOGY AS RELATED TO PACIFIC SALMON

FIGURE 1. Location of streams studied in western Washington: (1) Dewatto 

River, (2) Cedar River, (3) Kalama River, and (4) North Fork Nooksack 

River.

Rantz (1964), Westgate (1958), and the Washington State Department of Fisheries (Deschamps and others, 1966).

SELECTION OF SITES

Three major factors were considered in the selection of streams 

for this study: (1) The streams must have known salmon-spawning 

areas; (2) because obviously not all streams can be studied, streams 

must be selected on the basis of being representative of varying 

geographic locations, such as highland or lowland streams, and of
APPROACH 5

differing runoff characteristics; and (3) a priority must be given to 

streams where future water development projects are imminent. 

Three to five reaches were selected on each river to obtain replications of the sample in order to analyze the variance of the sample 

within a particular river or for error evaluation. Selection of the 

reaches was based on the following criteria: (1) The reach must 

exhibit observable spawning activity, and (2) the reach must have 

a fairly stable streambed to enable sampling of a range of flows 

without major channel shifting. At each reach four cross sections 

were established, the reach was mapped by planetable methods, and 

a river-stage reference point or gage was established.

HYDRAULIC CRITERIA

To obtain a sample, the discharge was measured, the river stage 

noted, and the depth and bottom velocity were measured at 10-25 

points on each cross section. The bottom velocity was measured at 

a distance of 0.4 foot above the streambed (Chambers and others, 

1955, p. 43). After a number of samples were obtained, the stagedischarge relation was established and used to detect any major 

streambed shifting. The cross-sectional depth and bottom-velocity 

data for each discharge were plotted on the planetable map of the 

reach, and lines of equal depth and velocity were drawn.

Chambers and others (1955) have supplied ranges of "preferred" 

depth and bottom velocity of the water for spawning of fall chinook, 

spring chinook, sockeye, and coho salmon, which are given in table 

1. The table shows a range of water velocities from 1.75 to 1.8 fps 

(feet per second) for sockeye spawning. Chambers gives the preferred water velocity for sockeye as 1.75 fps, and Clay (1961, p. 232) 

presents the velocity range from 1.75 to 1.8 fps. For purposes of 

analyses, to define an area of spawning, Clay's range of preferred 

velocity for sockeye spawning is used. No preferred water-depth

TABLE 1. Preferred depth and velocity criteria for salmon spawning 

from Chambers and others, 1955

Salmon 

species

Fall chinook _ __ _ _ _

Sockeye _ __ _ ____

Coho __ _ ____ __,

Depth 

(feet)

_ _ _ __ 1.0-1.5

1.5-1.75

. ____ 1.0-1.5

_ _ _ _ 1.0-1.25

Velocity 1 

(feet per second)

1.0 2.25

1.75-2.25

1.75-1.8

1.20-1.80

1 Measured 0.4 ft above streambed
6 HYDROLOGY AS RELATED TO PACIFIC SALMON

and water-velocity values have yet been determined for chum and 

pink salmon.

On the depth and velocity maps for a particular discharge, and 

using the preferred velocity and depth criteria from table 1, the 

areas of preferred velocity, preferred depth, and preferred spawning (where overlapping occurs), are delineated and measured for 

each of the salmon species investigated. After determination of preferred areas (expressed in square feet), the relation of discharge 

versus preferred area is plotted, a trend analysis using a threepoint moving average is made, and a curve is fitted to the data.

The curves of the original data, as plotted, are jagged because, 

as discharge in the low-water channel increases beyond an optimum value, the velocity-depth criteria are exceeded and preferred 

area begins to decrease. When water depth increases sufficiently 

to just cover a medium-stage berm, the preferred area increases 

sharply. This sequence may be repeated as the depth continues to 

increase, depending on the number of berms that progressively become submerged. In a long reach, however, not all berms would be 

simultaneously submerged, and the pattern of increasing or decreasing favorable area would not be uniform throughout the reach. 

Consequently, the tendency would be for a smoother area-discharge 

curve. The authors obtained this smoothing effect by using moving 

averages.

From the highest point on the area-discharge curve, or the point 

where the spawnable area (determined from the preferred criteria 

in table 1) is greatest, the most preferred discharge for salmon 

spawning will occur. This point is referred to as the "peak preferred 

discharge." Most preferred area-discharge curves have a plateau 

rather than a peak because the discharge is diminishing at a faster 

rate than the area preferred for spawning. Thus, possibly at some 

point below the peak preferred discharge, there may be only a small 

decrease in spawning area, although the discharge is appreciably 

smaller than the peak.

To investigate the shape of the curves and determine the breaking or inflection point on the lower side of the peak, the peak spawning discharge is reduced by selected percentages of 5, 10, 15, and 

25 percent. Using these reduced discharges the comparable reduction in spawnable area is picked from the area-discharge relations. 

These discharge and area values are given in table 15.

The repeatability of the method used to determine the preferred 

spawning discharges was investigated by selecting adjacent reaches 

on the Cedar River; that is, the riffle about 250 feet below reach B, 

referred to as reach Bl and the riffle about 200 feet above reach C,
APPROACH <

referred to as Cl, were sampled and analyzed independent of 

reaches B and C and the results were compared. The period of 

sampling for reaches B and C extended from April 1968 through 

October 1968, and that of reaches Bl and Cl extended from September 1968 through August 1969. The comparisons of the five 

selected area-reduction points and comparable discharges from 

each of the four discharge-preferred-area curves are shown in 

table 2.

TABLE 2. Comparison of spawnable areas and of variations of discharges for 

adjacent reaches on the Cedar River

[Numbers in parentheses are values obtained by extrapolation. All areas in square feet. 

All discharges in cubic feet per second]

Salmon species

Fall chinook

PreReach ferred 

parameter

B.. 

Bl. 

C..

Cl.

. Area ..... 

Discharge .

Discharge . 

. Area ..... 

Discharge .

Discharge .

Percentage reductions of spawable 

area from the peak

Peak

.1,050 

275 

4,080 

250 

. 960 

320 

. 1,920

290

2

1,029 

250 

3,998 

230 

941 

(310) 

1,882 

270

5

998 

230 

3,876 

220 

912 

(300) 

1,824 

250

10

945 

210 

3,672 

(210) 

864 

(290) 

1,728 

(230)

15

8.92 

190 

3,468 

(200) 

816 

(280) 

1,632 

(210)

Spring chinook

Percentage reductions of spawnable 

area from the peak

Peak

170 

510 

525 

480 

420 

420 

630 

420

2

167 

500 

514 

440 

412 

400 

617 

400

5

162 

490 

499 

430 

399 

380 

598 

360

10

153 

460 

472 

(390) 

378 

365 

567 

(340)

15

144 

440 

446 

(370) 

357 

360 

536 

(320)

Percentage differences in discharges

B/B1 ..........

C/C1 ..........

+10.0 

+10.3

+8.7 +4.5 0 5.0 +6.2 +13.6 +14.0 +18.0 +18.9 

+14.8 +20.0 +26.1 +33.3 0 0 +5.6 +7.4 +12.5

Salmon species

Preferred 

Reach parameter

Discharge .

Discharge . 

C . . Area ..... 

Discharge . 

Cl. Area .....

Discharge .

Coho Sockeye

Percentage reductions of spawnable Percentage reductions of spawnable 

area from the peak area from the peak

Peak

320 

270 

. 767 

285 

. 360 

450 

. 285

450

2 5 10 15 Peak 2 5 10 15

314 304 288 272 255 250 242 230 217 

255 235 220 205 440 420 400 330 290 

752 729 690 652 275 270 261 248 234 

260 250 (240) (230) 430 410 400 (385) (370) 

353 342 324 306 170 167 162 153 144 

440 430 410 (300) 510 500 485 465 450 

279 271 256 242 130 127 124 117 110 

430 390 (370) (350) 490 460 440 (420) (400)

Percentage differences in discharges

B/B1

C/C1

 5.3 1.9 6.0 8.3 10.9 +2.3 +2.4 0 14.3 21.6 

0 +2.3 +10.2 +10.8 14.3 +4.1 +8.7 +10.2 +10.7 +12.5

Table 2 also shows that, at all discharges used in calculations, 

the areas spawnable are greater for reach Bl than for reach B. The 

same is true for reach Cl compared to reach C, except for the sockeye and coho salmon, where reach C has slightly greater spawning 

areas than reach Cl.
8 HYDROLOGY AS RELATED TO PACIFIC SALMON

The lower part of table 2 shows the ratios of discharges, expressed as percentages, of reaches B divided by Bl and reaches C 

divided by Cl for each species at the peak and the four reductions 

of discharge. These percentage ratios may be used to show the consistency of the method used to determine preferred discharges. 

Some of the errors involved in the discharge percentages would 

result from measuring discharge, plotting of the hydraulic criteria, 

measuring the areas preferred for spawning, and slight shifts in 

streambed configuration. The peak spawning discharges between 

compared reaches for the four salmon species vary as much as 10.3 

percent, are as small as 0.0 percent, and average 4.6 percent for all 

points on both reaches.

Flows for rearing are determined from curves (for example, 

fig. 8A) showing how the perimeter of the average study reach 

that is wetted increases as the discharge increases. This relationship is shown by wetted-perimeter-discharge curves. At lower discharges the typical curve is steep, indicating that wetted perimeter 

increases at a rate equal to, or greater than, the increase in flow. 

Where the curve breaks, or at the point where, for a unit increase 

in discharge the wetted perimeter increases considerably less than 

a unit, the greatest perimeter of the stream would be covered by 

water at the lowest discharge. Above the break the wetted perimeter 

increases very little with increasing discharge. This point is picked 

as representing the rearing discharge. To aid in determining this 

breaking point a second curve (see fig. SB) is drawn showing the 

percentage of bankfull area wetted versus the discharge. The bankfull area was defined along each particular study reach as the last 

definite change in slope of either bank of the river beginning at 

the lowest point in stream cross section. The bankfull area, as defined, is generally very discernible from aerial photographs. The 

curves of percentage of bankfull area wetted versus discharge and 

that of wetted perimeter versus discharge generally break at 

nearly the same discharge.

STREAMBED GRAVELS

The bed material of spawning areas must consist of gravel of 

such size that the salmon which is ready to spawn can excavate 

redds in which their eggs may be deposited, fertilized, and hatched.

Gravel size and stream velocity are interrelated. Spawning 

salmon prefer specific gravel sizes as well as hydraulic criteria. The 

excess fines, to a certain extent, may be washed out during the 

course of spawning by the action of the fish. The water velocities 

also may be important to ensure covering of the eggs by hydraulic
APPROACH 9

action on the gravel during spawning and in determining the size 

of the gravel present at a particular location.

In each of the 14 reaches selected for this study spawning salmon 

were observed, indicating that the gravels for the observed species 

must have been acceptable. No attempt was made to establish 

criteria for streambed composition preferred by the various species. However, gravel samples were taken within the preferred 

spawning areas, and curves of the percentage by weight of gravel 

passing a range of sieve sizes are shown for each reach.

The streambed samples were obtained with a cylindrical toothedged "cookie cutter" that was 2 feet in length and 14 inches in 

diameter (patterned after Rantz, 1964, p. AA5). The cylinder was 

forced into the streambed as far as possible (usually 1 ft), the material within was removed by hand, sorted in sieves, and each fraction weighed. Four to five samples were obtained on each reach.

WATER TEMPERATURE

The temperature of the stream influences the rate of production 

of aquatic life (food for the rearing salmon), the amount of dissolved oxygen in the water, and the length of time for salmon egg 

incubation. Fish affected by a rise of water temperature respond 

by increased metabolic rates, higher oxygen requirements, greater 

sensitivity to toxic materials, and reduced swimming speed.

For maximum productivity of the Pacific salmon the fresh-water 

temperature requirements range from 7.2° to 15.6°C (45°-60°F) 

for upstream migration, from 5.8° to 12.8°C (42.5°-55°F) for maximum survival at spawning, from 0° to 12.8°C (32°-55°F) for egg 

incubation, and from 10° to 15.6°C (50°-60°F) for the fingerling 

salmon development (Burrows, 1963). The four rivers investigated 

in this report are covered by thermograph records that have been 

analyzed; these data are presented with the discussion and analysis 

of each river.

SALMON AND SPAWNING

When spawning, the salmon excavates a pit in the bottom of the 

streambed in which ova are deposited. This pit and the resulting 

downstream pile of disturbed gravel is called a redd. The two major 

parts of a redd are the "pot," or excavated pit, and the "tail spill," 

or the downstream gravel (Burner, 1951, fig. 4, p. 101). Where mass 

spawning of salmon occurs, however, the outlines of the individual 

redds are completely obliterated because of the close proximity in 

which the salmon spawn. After spawning, the territorial behavior
10 HYDROLOGY AS RELATED TO PACIFIC SALMON

of the individual salmon, in the vicinity of the redd, forces other 

salmon to spawn at other locations in the reach. At times, where 

preferred areas are limited or mass spawning occurs, spawning 

may take place in locations within the reach, which may not meet 

the preferred hydraulic criteria. The average sizes of redds for the 

four salmon species of this study are fall chinook, 6.1 sq yd (square 

yards); spring chinook, 3.9 sq yd; coho, 3.4 sq yd; and sockeye, 2.1 

sq yd (Burner, 1951, p. 110).

Certain streams are noted for their production of a particular 

salmon species (discussed under the analysis of each stream) generally, the Cedar River is noted for sockeye; the Nooksack River, 

for pink; the Dewatto River, for chum; and the Kalama River, for 

coho and chinook. Some of the other salmon species also spawn to a 

lesser degree in these rivers, but, conversely, not all species spawn 

in significant numbers in any one of these rivers. Each reach analysis in this report was made from preferred hydaulic criteria for the 

four species given in table 1, even though some of these species and 

races do not frequent that particular stream.

Among the many reasons that all salmon species do not spawn 

in a particular river, where one, two, or three species now spawn, 

are (1) the flow may not be acceptable for spawning and (or) rearing 

during the desirable interval of time, (2) the streambed materials 

may not be satisfactory, (3) the strength or size of the members of 

a species may limit their upstream migration, (4) nonavailability 

of rearing areas or the rearing habits of a species may render the 

stream unacceptable, (5) sea-migration patterns may not be compatible with the location of the river, and (or) (6) susceptibility to 

certain water-quality characteristics may be prohibitive to some 

species. Some of these conditions have only minor or negligible 

relation to the hydraulics (depth and velocity) of a reach of a river; 

others have no relation at all. For the purposes of this report the 

assumption is made that the reach hydraulics, from which the discharge-preferred spawning-condition relation is obtained, would 

theoretically be acceptable for spawning by all species if the other 

criteria were met. Therefore, the same hydraulic parameters are 

used for all species studied and for all stream reaches, regardless of 

whether fish are present or not. The hydraulic criteria are applied 

as independent variables that can be considered even though the 

total environment might not support a specific species or fish life 

at all. In this context, they would be considered, for example, for a 

reach of river upstream from a dam or high waterfall, even though 

the downstream barrier might effectively prevent fish from ever 

entering the study reach.
HYDROLOGY AS RELATED TO PACIFIC SALMON 11

DEWATTO RIVER

The Dewatto River is on the southwestern lobe of the Kitsap 

Peninsula and drains into Hood Canal (fig. 1). The basin lithology 

consists of unconsolidated sand and gravel of varying thicknesses 

underlain by sandy clay. Swamp deposits (peat) also are found in 

abundance in the upper parts of the basin.

The Dewatto River, with a source altitude of 360 feet, may be 

classified as a lowland stream. The flow of the river reflects the 

precipitation of the area (fig. 2), high during the wet winter months 

and low during the late summer and early fall months when rainfall 

is least. September is generally the month with the lowest mean 

monthly discharge, and January has the highest discharges. Winter 

snowfall is negligible, and there is little, if any, effect on the streamflow from snowmelt; however, a small amount of ground-water 

storage is provided by the permeable nature of the sand and gravels 

and the water-holding capacity of the clay and swamp materials. 

This storage helps maintain stream flows during the dry season.

A thermograph was installed on the stream near reach A. Daily 

stream temperature maximums, means, and minimums were evaluated for the 1968 calendar year using a harmonic fitting (Collings, 

1969). The resulting curves (fig. 3) have 91, 93, and 92 percent of

500

h 100

Maximum monthly mean

Minimum monthly mean

I_____I_____I_____I_____I_____I_____I_____I_____I_____I_____I

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

FIGURE 2. Mean monthly discharge and maximum and minimum monthly mean 

discharges. Dewatto River near Dewatto, 1947-54 and 1958-67.
12 HYDROLOGY AS RELATED TO PACIFIC SALMON

their variance denned, and the standard errors of estimate are 1.1°, 

0.9° 0.9°C (degrees Celsius) for maximum, mean, and minimum 

temperatures, respectively. The temperature of the stream generally reflects the season, being high during the summer and low in 

the winter, which is the inverse of the flow hydrograph (fig. 2).

Maximum daily

Mean daily

Minimum daily

- -55

V-40

50

--45

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

32

FIGURE 3. Maximum, minimum, and mean daily water temperatures, Dewatto 

River near Dewatto. Data from harmonic fitting of thermograph record 

for 1968.

The major salmon species that frequent Dewatto River are coho 

and two races of chum. The period of spawning for these species, 

depending on various factors which include flow conditions, will 

range from September through January. After hatching, the chum 

go almost immediately to salt water, but the coho will rear for about 

1 year in the stream before migrating to salt water.

Three reaches were selected for study on the Dewatto River (fig. 

4). The average grading of the gravels in the three reaches is shown 

in figure 5. The curves are best explained by an example: 40 percent of the gravels of reach A are less than 1 inch in size (40 percent 

by weight will pass the 1-in. sieve). Also, 51 percent of reach B 

gravels and 43 percent of reach A-l gravels will pass the 1-inch 

sieve. Generally, as seen by the curves, reach A has gravels that 

are slightly coarser than those of reach B. Reach A-l has gravel of 

sizes more or less between those of reaches A and B.
DEWATTO RIVER

DEWATTO RIVER REACH A

13

The Geological Survey gaging station (Dewatto River near 

Dewatto) is just above reach A. This gage was used for the riverstage reference and also for discharge determinations. The stream 

above reach A drains 18.4 square miles and has a main-stem length 

of 7.6 miles. The altitude at the gage is 55 feet, and the mean basin 

altitude is 376 feet; the channel slope above the reach is 36 feet per 

mile. The reach has a surface area of 7,690 square feet at bankfull 

stage.

On reach A, 14 measurements of depth and bottom velocity were 

made at each cross section, with flows ranging from 19 to 225 cfs.

123°05' 123°00'

FIGURE 4. Study reaches on Dewatto River.
14 HYDROLOGY AS RELATED TO PACIFIC SALMON

'SIEVE SIZE. IN MILLIMETERS

200

I

s- Reach B

/ Reach Al

/ Reach A

2.0 1.0 OJ5

SIEVE SIZE, IN INCHES

FIGURE 5. Curves showing average grading of several samples of gravel 

found on natural spawning grounds on Dewatto River.

The relation between preferred depth, velocity and spawnable area 

(the area where both preferred depth and velocity criteria are met) 

versus discharge, for each salmon species is shown in figure 6. Also, 

a trend-fitted curve of the data was obtained by using a three-point 

moving average.

The peaks (from fig. 6), the spawning-discharge values for the 

selected reductions of 5,10,15, and 25 percent, and the comparable 

spawnable areas are given in table 15.

Table 15 shows that at the 10-percent discharge reduction (from 

87 to 78 cfs) the spawnable area for fall chinook is only 1 percent 

less than the spawnable area at the peak (from 1,440 to 1,420 sq ft). 

The spawnable area for spring chinook decreases at a greater rate 

than the discharge at the 15-percent discharge reduction (table 16), 

and the 25-percent discharge reduction shows a 35-percent reduction in area. Compared with the other species, sockeye has the least 

amount of spawnable area, 140 square feet at a peak preferred 

discharge of 50 cfs.
DEWATTO RIVER 15

FALL CHINOOK 

NAL ______ TREND FITT

« ! V1*-.

III 

D FITTED

\

EXPLANATION

 - Preferred velocity

 Pr«f«rr«d depth V

I i I I I I

10 20 SO 100 200 20

50 100 200 

DISCHARGE, IN CUBIC FEET PER SECOND

50 100 200

20 50 100 200

5000 .-

10 20 50 100 200 20 50 IOO 2OO

20 50 IOO 20O 20 50 100 ZOO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 6. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Dewatto River reach A. Curves show the original and the trend-fitted data 

based on a three-point moving average. Total area of the reach is 7,690 

square feet.
16 HYDROLOGY AS RELATED TO PACIFIC SALMON

SECTION I .SECTIONS I SECTION 3

Species: Fall Chinook

Discharge: 68 cfs

Percentage preferred spawning: 17.1

Percentage preferred velocity: 39.8

Percentage preferred depth: 30.9

Species: Sockeye

Discharge: 68 cfs

Percentage preferred spawning: 1.6

Percentage preferred velocity: 3.7

Percentage preferred depth: 30.9

Species: Spring Chinook 

Discharge: 98 cfs

Percentage preferred spawning: 5.9 

Percentage preferred velocity: 22.7 

Percentage preferred depth: 18.3

Species: Coho

Discharge: 52 cfs

Percentage preferred spawning: 6.0

Percentage preferred velocity: 21.0

Percentage preferred depth: 14.3

FIGURE 7. Plain-view locations of cross sections and preferred spawning areas 

for each of four salmon species studied at selected discharges, Dewatto 

River reach A.

The areas within the reach which would be preferred for spawning are shown in figure 7 for the four salmon species. The data for 

figure 7 were obtained from flows selected near the peak spawning 

conditions shown by the curves in figure 6. The most preferred 

areas (fig. 7) tend to be in the same general locations in the reach 

because of the general overlap of the preferred data of table 1.

Obviously, the most important criteria for salmon rearing in a 

stream is that water has to be present during the period of rearing,
DEWATTO RIVER 17

40 8O 120 160 2OO 240 280

DISCHARGE, IN CUBIC FEET PER SECOND

A

320 360

Q 100

9O

80

70

60

50

40 80 120 160 200 240 280

DISCHARGE, IN CUBIC FEET PER SECOND

B

320 360

FIGURE 8. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge 

(graph B), Dewatto River reach A. The point at which the curve in A 

changes slope indicates the most advantageous discharge for rearing. The 

curve in B is used in conjunction with figure 9.

but other important rearing criteria are stream temperature, area 

of pools, water velocity, and food production. The curves of figure 8 

show how the wetted perimeter and wetted reach area increase with 

increasing discharges. After the first break in the curves, at about
18 HYDROLOGY AS RELATED TO PACIFIC SALMON

20 cfs (fig. SA), the wetted perimeter increases relatively little with 

increasing discharge.

By joint use of figure SB and figure 9, we can determine areavelocity relations in the study reach, and from those relations, select optimal discharge for rearing in the reach. For example, at a 

discharge of 20 cfs, 20 percent of the area of reach A will be covered by water moving at a velocity of 1.2 fps or more. At the same 

discharge, 30 percent of the area is dry (fig. 8B). Over the remaining 50 percent of the area of reach A 3,845 square feet of the total 

7,690 square feet the velocity of the water will be equal to or less 

than 1.2 fps. The curves in figure 9 are linear only in the part shown, 

and they should not be extrapolated for higher or lower discharges 

without further data.

Stream velocity is an important factor influencing rearing potential. Food production as well as the capability of fry and fingerlings 

to exist in a stream is partly dependent upon the velocity. A study 

made by the Bureau of Sport Fisheries and Wildlife (Kennedy,

3.0

10 2O 3O 40 50 100

DISCHARGE, IN CUBIC FEET PER SECOND

200

FIGURE 9. Family of curves showing relation between velocity, discharge, and 

percentage of bankfull area, Dewatto River reach A. Shows selected percentages of reach which have velocities equal to or less than that indicated at 

a selected discharge.
DEWATTO RIVER 19

1967) discloses that the greatest concentration of food organisms 

occurs at velocities from 1.0 to 1.2 fps, with the majority (79 percent) occurring in the range 1.0-1.7 fps. The optimal depth is in the 

3-6-inch range.

The occurrence of sufficient discharges at the desired time of the 

year is one criterion for determining whether a salmon species is 

able to frequent a particular stream or reach of a stream for spawning and rearing. The hydrographs (fig. 2) indicate when high and 

low streamflows occur on the average; however, a more useful 

evaluation of occurrence of flows is presented by the monthly and 

annual flow-duration curves (fig. 10). These curves are computed

1000

I_ I _1__1_ I

500

I_ I I I I

10 30 50 70 90 10 30 50 70 9O

0 IOOO

10 30 50 70 9O 99 I IO 30 50 70 90

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 10. Monthly and annual flow durations, Dewatto River reach A.
20 HYDROLOGY AS RELATED TO PACIFIC SALMON

from mean daily discharges for Dewatto River near Dewatto for 

the period 1948-66 and indicate the percentage of time a selected 

discharge can be expected to be equaled or exceeded. For example, 

using the peak preferred spawning discharge of 51 cfs for coho, a 

discharge of 51 cfs will be exceeded 15 percent of the time in October, 66 percent during the November-December period, and 86 

percent in January (fig. 10). Inversely, this means that during 85 

percent of the time in October the discharge will be below 51 cfs.

Similar computations show that the rearing discharge of 20 cfs 

is exceeded 72 percent of the time annually (fig. 10).

Some water-quality characteristics of reach A are given in table 

3. The dissolved-oxygen content was derived from a relation with 

stream temperature, assuming 100-percent saturation which was 

checked by taking dissolved-oxygen samples. The suspended sediment, for the few samples taken, was very low, the largest concentration being 14 mg/1 (milligrams per liter) at 20 cfs.

TABLE 3. Characteristics of water quality, Dewatto River reach A, 

March-December 1968

Temperature

Date

Mar. 

Apr.

May

July 

Sept. 

Oct.

Nov. 

Dec.

14

2

9__ _

17 ___.

29 __

15 _

31 __ .

8

16 _

10

18 __

13 __ _

26 _ .

13 ___.

Discharge

225

98

68

52

43

32

27

20

19

26

35

101

76

._ 134

(°C)

7.2 

8.9

6.7 

8.9 

10.0 

10.0 

13.9 

11.7 

8.9 

8.0 

6.9 

7.8 

5.3

(°F)

45 

48

44 

48 

50 

50 

57 

53 

48 

46.5 

44.5 

46 

41.5

Dissolved 

oxygen 

(mg/1)

11.7

11.2

11.8 

11.2 

11.0 

10.9 

10.0 

10.5 

11.2 

11.4 

11.7 

11.5 

12.2

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

 

6

7

14

0

1 

0 

0

 

 

45 

30

DEWATTO RIVER REACH A-l

Reach A-l on the Dewatto River is between reaches A and B (fig. 

4), and encompasses 2,920 square feet. Above this reach, which has 

an altitude of 40 feet, the stream is 8.1 miles long, has a drainage 

area of 19.1 square miles, and a channel slope of 32.9 feet per mile. 

For the analysis of this reach, nine streamflow measurements were 

made with discharges ranging from 19 to 247 cfs. A stage discharge 

relation was established from a staff gage, near the downstream end 

of the reach, at the time of each discharge measurement. No major 

shifting in the reach was evident over the period of measurements.
DEWATTO RIVER 21

The analyses conducted on reach A data also were conducted on 

reach A-l data, except for determination of the flow-duration 

curves (fig. 10). A regression analysis of discharge at reach A-l 

versus that at reach A shows a relation defined by

QA-i = 0.99(QA)'-""

where QA1 is the discharge at reach A-l and QA is the discharge at 

reach A. The standard error of estimate of the relation is ±1.4 percent. The regression constant is not significantly different from 1.0, 

at the 95-percent significance level; therefore, the discharges of the 

two reaches are not significantly different (QAI^QA), and the flowduration curves of figure 10 apply to both reaches.

The curves of figure 11 show the relations between discharge and 

spawnable area for the four species groups. The discharges for the 

peak and the four defined discharge reductions and comparable 

areas are given in table 15. The preferred-velocity curves for coho 

and fall chinook are open ended at the lower discharges, indicating 

a general maintenance of a minimum velocity (about 1 fps), governed by the channel slope.

The plan views (fig. 12) of reach A-l show the preferred areas of 

spawning for the four species. The spawning areas are well distributed over the entire reach. Figure 13 shows the relation between 

the curve for the wetted perimeter versus discharge and the curve 

for the percentage of bankfull area wetted versus discharge. This 

latter curve may be used in conjunction with figure 14 to obtain 

information on the rearing conditions of the reach. The preferred 

rearing discharge occurs at the break in the wetted perimeter versus 

discharge curve (fig. 13A), or at about 20 cfs.

The water-quality characteristics of reach A-l are given in 

table 4.

TABLE 4. Characteristics of water quality, Dcwatto River reach A-l 

September-December 1968

Temperature

Date

Sept. 

Oct.

Nov.

Dec.

16

25 __ _.

10 __ . 18- _.

15

26_

11 __

Discharge

19

19

26

34

__ 101

65

76

247

._ 134

CO

11.7

~~9~4 

8.9 

7.2 

6.1 

7.8 

6.7 

5.3

CF)

53

~~49 

48 

45 

43 

46 

44 

41.5

Dissolved 

oxygen 

(mg/1)

10.5

11.2 

11.7 

12.0 

11.5 

11.8 

12.2

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

0

"" 6

0

i

2 

0

 

46 

33 

30
22 HYDROLOGY AS RELATED TO PACIFIC SALMON

I I I I 11 III I I I 11

EXPLANATION '

 Pr«t«rr«d dtpth ond velocity

 - Pr«f«rr«d velocity

 Pr«f«rr«d dapth SOCKEYE

TREND FITTED

\

\

I

.

10 20 90 100 ZOO 20 90 100 ZOO

90 100 ZOO 20

DISCHARGE, IN CUBIC FEET PER SECOND

90 IOO ZOO

I I | I I II |

EXPLANATION

Prtftrrtd dtpth and velocity 

---. Pr«f«rr«d velocity 

- Pr«f«rr«d d«pth

10 20 SO 100 ZOO 20 90 100 ZOO

20 90 100 ZOO 20 90 100 ZOO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 11. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Dewatto River reach A-1. Curves show the original and the trend-fitted data 

based on a three point moving average. Bankfull area of reach covers 2,920 

square feet.
DEWATTO RIVER 23

Species: Fall Chinook

Discharge: 65 cfs

Percentage preferred spawning: 31.0

Percentage preferred velocity: 44.5

Percentage preferred depth: 59.5

Species: Sockeye

Discharge: 65 cfs

Percentage preferred spawning: 3.1

Percentage preferred velocity: 4.0

Percentage preferred depth: 59.0

Species: Spring Chinook 

Discharge: 101 cfs 

Percentage preferred spawning: 5.7 

Percentage preferred velocity: 13.1 

Percentage preferred depth: 20.7

Species: Coho

Discharge: 65 cfs

Percentage preferred spawning: 8.0

Percentage preferred velocity: 18.9

Percentage preferred depth: 45.6

FIGURE 12. Plan-view locations of cross sections and preferred spawning areas 

for each of four salmon species studied at selected discharges, Dewatto River 

reach A 1.

DEWATTO RIVER REACH B

Dewatto River reach B is the lowest study reach on the river 

(fig. 4), having an altitude of 10 feet. Above the reach the stream is 

9.0 miles long, and has a drainage area of 21.7 square miles and a 

channel slope of 32.6 feet per mile. Fourteen flow measurements, 

ranging from 22 to 274 cfs, were used to analyze the reach.
24 HYDROLOGY AS RELATED TO PACIFIC SALMON

40

30

20

10

40 80 120 160 200 240 

DISCHARGE, IN CUBIC FEET PER SECOND

A

280 320

100

E 0 40 80 120 160 200 240 280 320

DISCHARGE, IN CUBIC FEET PER SECOND

B

FIGURE 13. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge 

(graph B), Uewatto River reach A-l. The inflection point of the curve on 

graph A, where it begins to flatten, denotes the most advantageous rearing 

discharge. Curve on graph B, which is similar in shape to that in graph A, 

is used in conjunction with figure 14.

Reach B, which covers 8,250 square feet, is above a section of the 

river where the stream divides into two channels at flows greater 

than 45 cfs. During low discharges about 25 cfs, and discharges 

above 45 cfs, the riffle area extends over parts of the entire reach.
DEWATTO RIVER 25

10 20 30 40 50 100

DISCHARGE, IN CUBIC FEET PER SECOND

200

FIGURE 14. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, Dewatto River reach A-l. Shows selected 

percentages of reach which have velocities equal to or less than that indicated at a selected discharge.

For discharges between 25 and 45 cfs, the riffle is confined mainly 

to an area in the vicinity of cross section 3. The area of the reach 

having preferred spawning versus discharge for each of the species 

is shown in figure 15. The trend-fitted preferred-velocity curves 

have a tendency toward double peaks. One peak occurs near the 

discharge where the stream splits and the riffle area lengthens, and 

another peak occurs at a lower flow. The trend-fitted curves for 

preferred depth versus discharge have either an open end or peak 

at the higher discharges, indicating only slight increases in depth 

as discharge increases, again because of the splitting channel control. However, the preferred depth and velocity combine to produce 

well-defined peaks for the preferred spawning versus discharge 

curves. The areas and discharges for the peak and the four selected
26 HYDROLOGY AS RELATED TO PACIFIC SALMON

10,000

20 so no 200 20 so 100 200

20 SO 100 200 20 50 100 200

DISCHARGE. IN CUBIC FEET PER SECOND

III | I I I I I I 1 

SPRIH6 CHINOOK

TREND FITTED TREND FITTED

\/ /

\

ti\ \

EXPLANATION

I I I I I I-L

IO 20 90 100 20O 20 SO KX> 200

2O SO 100 200 20 SO IOO ZOO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 15. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Dewatto River reach B. Curves show the original and the trend-fitted data 

based on a three-point moving average. Bankfull area of reach covers 

8,250 square feet.
DEWATTO RIVER 27

percentage discharge reductions for each of the four salmon species 

are given in table 15. The higher preferred depth and velocity 

ranges (table 1) may be the cause of the higher peak discharges for 

spring chinook.

Species: Fall Chinook

Discharge: 76cfs

Percentage preferred spawning: 26.0

Percentage preferred velocity: 47.9

Percentage preferred depth: 29.4

Species: Sockeye

Discharge: 76cfs

Percentage preferred spawning: 2.6

Percentage preferred velocity: 4.3

Percentage preferred depth: 29.5

Species: Spring Chinook 

Discharge: 116cfs 

Percentage preferred spawning: 5.4 

Percentage preferred velocity: 23.6 

Percentage preferred depth: 12.1

Species: Coho

Discharge: 41cfs

Percentage preferred spawning: 8.3

Percentage preferred velocity: 26.9

Percentage preferred depth: 17.1

FIGURE 16. Plan-view locations of cross sections and preferred spawning areas 

for each of four salmon species studied at selected discharges, Dewatto River 

reach B.

The plan views (fig. 16) show the areas of preferred spawning, at 

selected discharges, for each salmon species studied. Shallow pool 

areas occur on the left side of section 2 and on the right side of
28 HYDROLOGY AS RELATED TO PACIFIC SALMON

60

50

40

S 30

2Q

40 80 120 160 200 240 280

DISCHARGE, IN CUBIC FEET PER SECOND

A

320 360

Q 100

90

80

40 80 120 160 200 240 280

DISCHARGE, IN CUBIC FEET PER SECOND

B

320 360

FIGURE 17. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge (graph B), Dewatto River reach B.

section 4. The shallow pools act as resting areas for salmon migrating upstream and also as possible rearing areas.

Figure 17 shows the relation between the curve for the wetted 

perimeter versus discharge and the curve for the percentage of 

bankfull area wetted versus discharge. The break in the wetted 

perimeter discharge curve (fig. 17A) occurs at about 40 cfs. Figure 

18 shows the relation between the velocity, discharge, and percentage of bankfull area for reach B.
DEWATTO RIVER 29

10 20 30 40 50 100

DISCHARGE, IN CUBIC FEET PER SECOND

200 300

FIGURE 18. Family of curves showing relation between velocity, discharge, and 

percentage of bankfull area, Dewatto River reach B. Shows selected percentages of reach which have velocities equal to or less than that indicated at a 

selected discharge.

Flow-duration curves (fig. 19) for reach B were obtained from an 

analysis of discharge at reach B (QB) versus discharge at reach A 

(QA), which is at the gaging station Dewatto River near Dewatto. 

The relation is shown by the equation

QB = 1.8a(QA) 0 -97

and has a standard error of estimate of ±4.5 percent. The regression coefficient and constant are significantly different from 1.0 at 

the 95-percent testing level.

The peak spawning discharge for coho is 50 cfs and has an 

exceedance percentage from the flow-duration curves (fig. 19) of 20 

percent for October, 72 percent for the November-December period, 

and 92 percent for January. The rearing discharge of 40 cfs has 

an annual exceedance percentage (fig. 19) of 53 percent.
30 HYDROLOGY AS RELATED TO PACIFIC SALMON

500

SO

u 10

10 30 50 TO 90 99 I 10 30 50 70 90

J__j_ _I

I 10 30 50 70 90 99 I 10 30 5O 70 90

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 19. Monthly and annual flow duration, Dewatto River reach B.

The water-quality characteristics of reach B are given in table 5 

and show uniformity with upstream reaches A and A-l.

CEDAR RIVER

The Cedar River, with a drainage that heads in the west Cascade 

foothills at an altitude of 3,600 feet, flows across the Puget Sound 

lowland and empties into Lake Washington. The mean annual precipitation ranges from more than 100 inches in the uppermost parts 

of the basin to about 32 inches near the mouth of the river.
CEDAR RIVER 31

TABLE 5. Characteristics of water quality, Dewatto River reach B, 

April-December 1968

Da

Apr.

May

July

Sept.

Oct.

Nov.

Dec.

te

2

9_ __.

17 _ _.

29 __ .

15 __ .

31 __ .

8

16

10 __ _.

18

13 __

26 _ _ .

11 _ .

13 __ .

Discharge

._ 107

76

61

52

40

35

23

22

31

41

116

94

._ 274

156

Tempi

(°C)

8.3

7.8 Q 4

9.4

10.6

12.8

11.7

10.0

8.3

7.2

7.5

6.4

5.3

erature

(°F)

47

46

49

49

51

55

53

50

47

45

45.5

43.5

41.5

oxygen 

(mg/1)

11.4

11.5 11.1 11.1

10.8

10.3

10.5

11.0

11.4

11.7

11.6

11.9

12.2

sediment ( 

(mg/1)

4

16

10

2

4

1

1

1

1

Specific

micromhos per 

cmat25°C)

50

35

40

The flow of the river is regulated both by powerplant operation 

at Chester Morse Lake and by continuous diversion of between 200 

and 300 cfs farther downstream by the city of Seattle. The hydrograph of streamflow of the Cedar River at Renton (fig. 20), which 

is below the study reaches, shows high flows during the winter and 

low flows in late summer, typical characteristics of a lowland 

stream. However, in the spring months some snowmelt runoff does 

occur. The flow-duration curves (fig. 21), based on records for 1946- 

67, show the effect of the city of Seattle's diversion by the very 

steep lower end on the summer-month curves; also shown is the 

small effect of snowmelt by the general flatness of the upper parts 

of the April-May curve. Flow-duration curves for the long-term 

gage, Cedar River at Renton, are related to each of the study reaches 

on the Cedar River by regression methods.

Stream temperatures were determined by analysis of thermograph records from the Cedar River near Landsburg gaging station, for the years 1954-66. The median temperature and the 95- 

percent-probability extremes of maximum and minimum temperatures were fitted by harmonic curves (fig. 22). The fitted curves 

define 90 percent of the temperature variance and have a standard 

error of estimate of 0.4°C. Stream temperatures will be within the 

outer two curves 90 percent of the time, and there is a 95-percent 

chance that the minimum stream temperature in January will exceed 2.2°C and the maximum stream temperature in July will be 

less than 17.6°C.

As an aid in determining potential rearing and possible spawning 

areas, stereo pairs of aerial photographs were obtained for the
32 HYDROLOGY AS RELATED TO PACIFIC SALMON

Cedar River from Landsburg to the mouth, a distance of 20.9 miles. 

From these photographs, the pool-and-riffle relation was established 

*by delineating areas of each, then planimetering each area to 

determine the total area of riffles and of pools. The discharge when 

the photographs were taken was 185 cfs at the lower study reach 

(reach C, fig. 23). The stretch of river photographed showed 57.8 

percent about 2.4X105 sq ft per mi) as pool area and 42.2 percent 

(about l.TxlO5 sq ft per mi) as riffle area.

Five study reaches were selected on the Cedar River. Reaches Bl 

and Cl (fig. 23) were established to supplement data collected at 

reaches B and C and to evaluate repeatability of the methods and 

the sampling error by comparison with reaches B and C, respectively. This comparison is evaluated on page 6.

The major spawning areas in the Cedar River extend from Maple 

Valley to below reach C (fig. 23). The major salmon species which 

frequent the Cedar River are sockeye and fall chinook. The sockeye 

rear in Lake Washington for about a year, whereas the fall chinook 

return to salt water in the spring.

A

Moximum monthly meon /

/

Minimum monthly nneon

J____L

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

FIGURE 20. Mean monthly discharge and maximum and minimum monthly 

mean discharges of Cedar River at Renton, 1950-67.
CEDAR RIVER 33

Figure 24 shows curves of the average grading of gravels for the 

five study reaches. Reach Bl has a greater amount of fines than the 

other reaches. Reaches A, B, C, and Cl have a similar grading of 

gravels, with 35-40 percent by weight passing the 1-inch sieve. Only 

8 percent or less of the gravels pass the 0.1-inch sieve on all reaches.

CEDAR RIVER REACH A

Study reach A is a typical Cedar River spawning area. Above the 

reach, which is at an altitude of 260 feet, the mean basin altitude is 

2,010 feet. The river is 41.4 miles long, drains an area of 160 square

10 30 5O 70 90 95 99 I 10 30 50 70 90 95 99

5000

10 30 50 70 90 95 99 I 10 30 50 70 90 95 99 

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 21. Monthly and annual flow durations, Cedar River at Renton. Upstream diversions account for the steepness of the lower end of the summermonth curves.
34 HYDROLOGY AS RELATED TO PACIFIC SALMON

OT |4

5 10

95-percent probability that maximum 

temperature will be equal to or less^ 

than this line

'95-percent probability that minimum temperature 

will equal or exceed this line

60 t50

45

40

35

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

FIGURE 22. The 90-percent probability range of stream temperatures, Cedar 

River near Landsburg, 1954-66.

FIGURE 23. Study reaches on Cedar River.
CEDAR RIVER 35

SIEVE SIZE. IN MILLIMETERS

tOO 50 20

I I I I I I____I______I____I

TTT I I I I

i I J 1

IO.O 2.O 1.0 O.S 

SIEVE SIZE, IN INCHES

FIGURE 24. Curves showing average grading of several samples of gravels 

found on natural spawning grounds of Cedar River.

miles, and has a channel slope of 50 feet per mile. Reach A, which 

covers 22,240 square feet at bankfull stage, is located just upstream 

from a bridge on State Highway 169, a little less than 1 mile below 

Maple Valley. The main channel of reach A is just left of center 

and spawning tends to be heaviest on the right bank (fig. 25).

Figure 26 shows plots of the original and the trend-fitted data 

for discharge versus spawning area preferred for each of the four 

salmon species studied. The curves tend toward double peaks, since 

powerplant regulation has established two fairly well defined gradational terraces by releasing relatively constant flows for long 

periods of time. At the lower flows, one terrace is inundated. As the 

river stage increases, water overflows onto the second terrace, thus 

establishing a second preferred spawning area at the higher discharge. Ten discharge measurements ranging from 76 to 1,050 cfs 

were made for the analysis. The preferred spawning discharges 

and areas for the peaks and the discharges and areas for the four 

percentage discharge reductions for the species studied are given 

in table 15. The discharges for the peaks are uniform for the four 

species, varying only 10 cfs (230-240 cfs).
36 HYDROLOGY AS RELATED TO PACIFIC SALMON

Species: Fall Chinook 

Discharge: 310 cfs 

Percentage preferred spawning: 9.6 

Percentage preferred velocity: 17.5 

Percentage preferred depth: 10.9

Species: Sockeye

Discharge: 282 cfs

Percentage preferred spawning: 1.3

Percentage prefered velocity: 2.7

Percentage preferred depth: 11.4

FIGURE 25. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Cedar 

River reach A. The bankfull area of the reach covers 22,240 square feet.

Rearing potential at reach A may be examined by referring to 

figures 27 and 28 and using them in the same way that the preferred 

relations of wetted perimeter versus discharge, wetted area versus 

discharge, and velocity versus discharge versus percent area were 

used on the Dewatto River reaches (p. 18). Figure 27 shows the 

double-terrace effect by the slight double break in the curve. The 

first break in the wetted perimeter curve occurs at about 75 cfs; 

this may be referred to as the rearing discharge.

The duration of flows was determined at reach A by relating discharges at reach A (QA) to equivalent discharges at the gaging 

station, Cedar River at Renton (QR). The relation is shown by the 

equation
CEDAR RIVER 37

Species: Spring Chinook 

Discharge: 282 cfs 

Percentage preferred spawning: 2.5 

Percentage preferred velocity: 7.9 

Percentage preferred depth: 11.4

Species: Coho

Discharge: 282 cfs

Percentage preferred spawning: 2.5

Percentage preferred velocity: 9.1

Percentage preferred depth: 4.9

FIGURE 25. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Cedar 

River reach A. The bankfull area of the reach covers 22,240 square feet Con.

and has a standard error of estimate of ±8.2 percent. The above 

equation was used to reconstruct flow-duration curves (fig. 29) from 

the gaging-station records.

Water-quality parameters obtained at reach A are given in table 

6. The dissolved-oxygen content given is from a relation with stream 

temperature which was checked by sampling. Oxygen saturation of 

the water exists at or near 100 percent most of the time.

CEDAR RIVER REACH B

Reach B of the Cedar River is downstream from a highway 

bridge and just below a river channel island. Above the reach, which 

is at an altitude of 225 feet, the river is 43.5 miles long, drains an
38 HYDROLOGY AS RELATED TO PACIFIC SALMON

I I I I

SPRING CHINOOK 

ORIGINAL TREND FITTED

V V;--- fc' 3$

V

EXPLANATION

- Pr«f«rr«d dtpth and velocity

* Pr«f«rr«d dtpth

I I M I

so 100 200 SO IOO 2OO 

SOO IOOO 

DISCHARGE, IN CUBIC FEET PER SECOND

-MM | I I | I I I l| I I I M I I 

I ' FALL CHINOOK ' I

TREND FITTED

EXPLANATION

. . pr.ftrrtd vtlacity 

 Pr«f«rr«d dtpth

I__i_ I I 1 I

I I I I I I \> ITTT 1 T TTl + 

I ' SOCKfYf I I

ORIGINAL TREND FITTED

so too zoo 500 looo so 100 zoo soo 1000 loo 200 soo 1000 too 200 soo 1000

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 26. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Cedar River reach A. Curves show the original and the trend-fitted data 

based on a three-point moving average. The bankfull area of the reach 

contains 22,240 square feet.
CEDAR RIVER 39

too

200 4OO 600 800

DISCHARGE, IN CUBIC FEET PER SECOND

IOOO 1100

80

7°

60

50

40

a. 30

200 400 600 800 

DISCHARGE, IN CUBIC FEET PER SECOND

IOOO 1100

B

FIGURE 27. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge (graph B), Cedar River reach A. The first break in the curve of 

graph A denotes the most advantageous rearing discharge, whereas the 

second break is caused by the high terrace of the channel. The curve in 

graph B is used in conjunction with figure 28.

area of 169 square miles, and has a channel slope of 48 feet per 

mile. Reach B covers 23,420 square feet. The main channel flow is 

centered in the upper sections but veers to the right at the lower 

end of the reach. Both banks have been stabilized by rock riprap. 

The preferred spawning areas occur just below and to the left of the 

upstream channel island and under overhanging bushes on the 

right bank (fig. 30).
40 HYDROLOGY AS RELATED TO PACIFIC SALMON

VELOCITY, FEET PER INSECOND

-IIM 01 b uP <

^"^

s

^

'

^

^

^

/

LX

/

/

\

Percen 

bankfi

^

/

/

/

/

1 

tage of 

ill area

^

X

/

1

1

3

,*'

A

/

,*'

\

^

/

/

/

>

/

0 100 200 500 IOC

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 28. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, Cedar River reach A. Shows selected 

percentages of reach which have velocities equal to or less than that indicated at a selected discharge.

TABLE 6. Characteristics of water quality, Cedar River reach A, 

April-October 1968

Temperature

Date

Apr. 

May

June 

July

Aug. 

Sept. 

Oct.

11__ .

22 _ .

1

29__ .

5

2 __.

10 .

30 __.

30 _.

16 _ .

Discharge

1,050

._ 1,050

394

370

459

183

76

.__ 282

.__ 310

.__ 584

<°C)

9.4 

8.3 

11.1 

11.1 

18.3 

14.7 

12.8 

11.7 

9.4

(°F)

49 

47 

52 

52 

65 

58.5 

55 

53 

49

Dissolved 

oxygen 

(mg/1)

11.1 

11.4 

10.7 

10.7 

9.1 

9.9 

10.3 

10.5 

11.1

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

4 

19 

10 

2

0 

2

6

 
CEDAR RIVER 41

1

-

-

___ I

^

\

1

1

\

1

1

v

\

\

-

-

-

1 I

- NS,

-

-

1

V

\

1

^.

1

\

1

1

V

V

\

1 1 -

\ ^^

% "

^ ,

10 30 5O 70 90 99 1 10 30 50 70 90 9'

I 10 30 50 70 90 99 I 10 30 50 70 90

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 29. Monthly and annual flow durations, Cedar River reach A.

The double terracing of the channel at reach B is not so well 

developed as it is at reach A, as indicated by the curves in figure 31. 

The lower peak (fig. 31) is much more definite, probably because of 

the bank riprap. The peak preferred spawning discharges and 

areas, and discharges and areas for the selected percentage reductions in discharge for the four salmon species are given in table 15. 

Using table 15 with the above discharges it may be noted that on 

reach B for a reduction in sockeye spawning discharge of 25 percent 

from the peak (from 440-330 cfs) the spawnable area decreases only 

8 percent (from 255-235 sq ft). Similar evaluations may be made 

for the other species. Ten discharge measurements, ranging from 

89 to 1,540 cfs, were available for this analysis.

Figures 32 and 33 are used to evaluate the hydraulics of rearing 

conditions on reach B. The double-terrace effect is evidenced in 

graph A of figure 32 by the double break in the curve. The lower 

break, used to indicate the rearing discharge, occurs at about 90 cfs.

Flow-duration curves for discharges of Cedar River reach B (QB) 

were obtained by relating QB to the discharge of the Cedar River
42 HYDROLOGY AS RELATED TO PACIFIC SALMON

0510 ao jo <o x eorarr

Species: Fall Chinook 

Discharge: 283 cfs 

Percentage preferred spawning: 4.5 

Percentage preferred velocity: 21.7 

Percentage preferred depth: 17.8

Species: Sockeye

Discharge: 443 cfs

Percentage preferred spawning: 1.4

Percentage preferred velocity: 5.2

Percentage preferred depth: 18.2

FIGURE 30. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Cedar 

River reach B.

at the Renton gaging station (QR), after adjustment of discharge for 

time of travel between the two sites. The relation is shown by the 

equation

Qs = 0.59 (QR) 1-07,

which has a standard error of estimate of ±3.5 percent. The flowduration curves obtained from this relation are shown in figure 34. 

The water-quality characteristics of reach B (table 7) are not 

significantly different from those for reach A (table 6).
CEDAR RIVER 43

Species: Spring Chinook 

Discharge: 443 cfs 

Percentage preferred spawning: 1.2 

Percentage preferred velocity: 11.6 

Percentage preferred depth: 9.9

Species: Coho

Discharge: 283 cfs

Percentage preferred spawning: 1.6

Percentage preferred velocity: 9.3

Percentage preferred depth: 9.6

FIGURE 30. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Cedar 

River reach B Continued.

CEDAR RIVER REACH C

Cedar River reach C (alt 90 ft) is the lowest site studied on the 

river. The river above the reach is 49.4 miles long, drains an area 

of 177 square miles, and has a channel slope of 44 feet per mile. The 

bankfull area of the reach encompasses 17,620 square feet. The 

left bank is stabilized by riprap, and the main flow is also on the left 

side of the channel. The preferred spawning area is on the right 

side of the channel (fig. 35).
44 HYDROLOGY AS RELATED TO PACIFIC SALMON

5000

S 

w 20OO

K 

4

* IOOO

2 so° 

1

2OO

X

4

" IOO 

&

£ so

20 

"t

10,000

sooo

fc

£| 2000

a: 

4 

§ IOOO

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J SOO

i

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£ IOO 

O 

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1O

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 Pr«f«rr<

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ITION 

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0 IOO 200 SOO IOOO IOO ZOO SOO IOOO

too aoo soo 1000 100 aoo 500 1000 201

DISCHARGE, IN CUBIC FEET PER SECOND

|

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:

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t

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RI6INAL

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6O IOO ZOO SOO IOOO IOO ZOO SOO IOOO

IOO ZOO SOO IOOO IOO 2OO SOO IOOO 20OO

DISCHARGE. IN CUBIC FEET PER SECOND

FIGURE 31. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, Cedar 

River reach B. Curves show the original and the trend-fitted data based on a 

three-point moving average. The bankfull area of the reach covers 23,420 

square feet.
CEDAR RIVER 45

400 600 600 1000 

DISCHARGE, IN CUBIC FEET PER SECOND

1200 1300

PERCENT BANKFULL O

WETTED AREA 

JJ -<l CD 1C0) 3 CO 

-

-

- r

i

^

i

^*^- ^~

i

^^*

i

i

~~~-~-

1

i

 

i

'

 

i

,

i

i

 

i i

1

-

-

1

400 600 600 1000 

DISCHARGE, IN CUBIC FEET PER SECOND

B

FIGURE 32. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge 

(graph B), Cedai* River reach B.

TABLE 7. Characteristics of water quality, Cedar River reach B, 

April 1968-August 1969

Temperature

Date

Apr. 

May

June 

July

Aug. 

Sept. 

Oct. 

Nov. 

Mar. 

Auer.

15 _ .

22 _.

1 _ .

29 __.

5

2

10 _ .

30 _ .

30

16

3 __ .

21

1 _.

Discharge

. _ 1,540

.__ 365

._ 1,240

443

474

212

89

283

319

.__ 607

306

.__ 452

. _ 170

CO

6.4 

9.4 

9.4 

11.1 

13.9 

15.6 

16.4 

15.6 

12.2 

9.4 

9.2 

8.3 

12.8

(°F)

43 

49 

49 

52 

57 

60 

61.5 

60 

54 

49 

48.5 

47 

55

Dissolved 

oxygen 

(mg/1)

12.0 

11.1 

11.1 

10.7 

10.2 

9.7 

9.5 

9.7 

10.4 

11.1 

11.5 

11.4 

10.3

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

6 

18 

10 

4 

0 

1 

2

5

2

 

 

59 

66
46 HYDROLOGY AS RELATED TO PACIFIC SALMON

03.0

UJ 

(0

UJ

£2.0

o 

o

ui

Percentage of 

bankfutl

50 100 

DISCHARGE, IN

200 

CUBIC

300 

FEET

400 500 

PER SECOND

1000

FIGURE 33. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, Cedar River reach B. Shows selected percentages of reach which have velocities equal to or less than that indicated 

at a selected discharge.

Seven discharge measurements, ranging from 290 to 900 cfs, 

were made during the period of investigation. At the time of low 

flows, a temporary unauthorized rock dam was constructed below 

the study reach and was used to impound water for swimming. 

Therefore, the lower end of the discharge curves for preferred 

spawning conditions (fig. 36) for fall chinook could not be defined 

properly. However, the preferred discharges and areas for the 

peaks and for the selected percentage reductions in discharge for 

the four salmon species are given in table 15. The spawnable area 

values in parenthesis were extrapolated by using the original and 

trend-fitted depth, velocity, and depth and velocity curves (fig. 36) 

as guides.

In order to evaluate the flow duration at reach C relations were 

determined between discharges at reach C (Qc) and discharges at
KALAMA RIVER 47

500

Q

Z

o 

o

<n

J5 100 o1

-

,

' v

1

N

V

\

1

\1

1 l_

_

, ,

10 30 50 70 90 9

1000

"I 10 30 50 70 90 99 "I 10 30 SO 70 90 

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 34. Monthly and annual flow durations, Cedar River reach B.

the long-term recording gage, Cedar River at Renton (QR). The discharges of the Cedar River at Renton were adjusted for discharge 

time of travel between the two sites. The relation is shown by the 

equation

Q0 = 0.78 (QR) i-03,

which has a standard error of estimate of ±2.5 percent and at the 

Renton gage is valid only over a discharge range from 200 to 900 

cfs. By use of the equation, the flow-duration curves in figure 37 

were constructed.

Table 8 gives the water-quality measurements on reach C.

KALAMA RIVER

The Kalama River drains a part of the western foothills (source 

alt 2,900 ft) of Mount St. Helens and flows westward into the lower 

Columbia River. The river receives flow from snowmelt during the 

spring; however, most peak flows occur because of the winter rains. 

The low flows of late summer are maintained largely by considerable ground-water inflow from alluvium and from permeable vol-
48 HYDROLOGY AS RELATED TO PACIFIC SALMON

OSIO20304O9OCO FEET

Species: Fall Chinook 

Discharge: 443 cfs 

Percentage preferred spawning: 6.0 

Percentage preferred velocity: 9.5 

Percentage preferred depth: 6.1

Species: Sockeye

Discharge: 489 cfs

Percentage preferred spawning: 1.5

Percentage prefered velocity: 1.5

Percentage preferred depth: 3.2

FIGURE 35. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Cedar 

River reach C.

canic rocks predominantly basalt flows and flow breccia which 

include some pyroclastics and andesitic rocks (Huntting and 

others, 1961). The mean monthly hydrograph of discharge (fig. 38) 

shows that the streamflow diminishes continuously from January

TABLE 8. Characteristics of water quality, Cedar River reach C, 

April 1968-March 1969

Temperature

Date

Apr. 

May

June 

Aug. 

Sept. 

Oct. 

Nov. 

Mar.

22

13 _ . 28 __

4

26_ . 24

16 _

3 _

21

Discharge

.__ 571

.__ 489

443

900

327

290

657

.__ 327

537

CO

7.8 

9.4 

14.7 

11.7 

13.3 

13.9 

8.6 

8.9 

7.2

CF)

46 

49 

58.5 

53 

56 

57 

47.5 

48 

45

Dissolved 

oxygen 

(mg/1)

11.5 

11.1 

9.9 

10.6 

10.2 

10.0 

11.3 

11.2 

11.7

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

4 

8

7

6 

4

 

____

~~63
KALAMA RIVER 49

Species: Spring Chinook 

Discharge: 465 cfs 

Percentage preferred spawning: 2.7 

Percentage preferred velocity: 6.2 

Percentage preferred depth: 2.9

Species: Coho

Discharge: 489 cfs

Percentage preferred spawning: 2.9

Percentage preferred velocity: 5.2

Percentage preferred depth: 3.3

FIGURE 35. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Cedar 

River reach C Continued.

to August. Flow stabilization occurs during the base-flow period in 

August and September; then discharge increases as the winter 

rains begin.

The majority of the salmon that frequent the Kalama River are 

coho, spring chinook, and fall chinook. The study reaches (fig. 39) 

are above two hatcheries of the Washington State Department of 

Fisheries. These hatcheries collect fall chinook and coho for their 

operations.

A thermograph has been operated since 1955 in the gaging station (Kalama River below Italian Creek, near Palama) located below the study reaches. The thermograph records were analyzed and 

time-temperature relations computed and drawn (fig. 40). The fitted 

curves show the median temperature and the 95-percent probability 

extremes of maximum and minimum temperatures. The outer 

curves indicate that for the average year, at the end of July, there 

is a 90-percent chance that the maximum temperature will not
50 HYDROLOGY AS RELATED TO PACIFIC SALMON

sooo

>. 2000 

IOOO 

u SOO

> 2OO 

: IOO 

SO

20

1C

K 

< 

3 

O

Z

SPAWNABL S i

X 

<

:

-

~:

-

:

-

i i

ORIGIN/

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-i

FAL

kL

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A\

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L CH

1

1 1

NOOK 

REND F

X

"A

EXPLANATION

1 1

(erred epth

1 1

MM

TTED

 

MM

1 1

ORI

.

1

\

d »-.-j

1 1 1

GINAL

A.

f

\'''

MM

SOCKt.

1 1

re

TREND

\

\

\ 

\

-J1 1

MM

FITT

^

-^.

MM

00 ZOO SOO IOOO IOO 2OO SOO IOOO 

IOO ZOO SOO IOOO IOO ZOO SOO 

DISCHARGE. IN CUBIC FEET PER SECOND

5

-

-

-

2

-

1 1

ORIGINAL

. \ /

/\v

N

MM

spun

\

rx

^-

1 1 1 1

6 CHI

TR

1 1

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END Fll

V

-^

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1 1 M

TED

 \

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*

ORIGIN

\

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EXPLANATIO^

 Pr*

1 I

f«rred

1 1 1 1

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TR

itpth

1 1

END FIT

~\

\

-

1 1

MM

TED

-

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:o

000 2000

2

~-

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-

-

-

100 ZOO 5OO IDOO IOO ZOO 900 IOOO

100 200 500 IOOO IOO ZOO SOO IOOO 2OOO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 36. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of the four salmon species, 

Cedar River reach C. Curves show the original and the trend-fitted data 

based on a three-point moving average. The bankfull area of the reach covers 

17,620 square feet.
KALAMA RIVER 51

500

IOO

-

-

.

1

1 >

1

1

1

1

\

1 \1

1 l_

-

V i i

I 10 30 SO 70 90 99 I 10 30 SO 70 90 99

1000

SOO

I 10 30 SO 70 90 99 I 10 30 SO 70

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 37. Monthly and annual flow durations, Cedar River reach C.

exceed 19.2 °C (about 66 °F) and that the minimum temperature at 

the end of January will not be less than 0.9°C (about 33°F). The 

fitted curves in figure 40 define an average of 86 percent of the 

stream-temperature variance; the standard error of estimate of the 

fittings is 1.1°C.

Aerial photographs of the Kalama River were obtained during a 

discharge of about 400 cfs at the gaging station. From the stereo 

pairs of photographs, the pool-and-riffle areas from Pigeon Springs 

(fig. 39) to the river mouth were delineated and planimetered. Of 

the 21.1 miles of river photographed, 29.7 percent (1.928xl05 sq ft 

per mi) of the stream is riffle area, and 70.3 percent (6.485xl05 sq 

ft per mi) is pool area. The lower 3 miles of the Kalama River is 

mainly pool area, being on the reentrant flood plain of the Columbia 

River.

To investigate the section of upper river where the study reaches 

are located, relations were established between the pools and riffles 

of the reaches. The percentage of area of pools and riffles was 

determined over a length of stream extending from halfway between reaches A and B to an equidistant point above reach A, 

which is within the photographed part of the river. This length of
52 HYDROLOGY AS RELATED TO PACIFIC SALMON

1000

500

I T I I I I I

NN .> Maximum monthly mean

Minimum monthly mean

Mean / 

monthly /

J_____1

JAN FEB MAR APR MAY JUNE JULY AU6 SEPT OCT NOV DEC

FIGURE 38. Mean monthly discharge and maximum and minimum monthly 

mean discharge of Kalama River (Kalama River below Italian Creek, near 

Kalama), 1950-67.

stream through reach A contained 54.1 percent riffle area; the slope 

of the channel here is 113 feet per mile. The next stretch of river 

examined was from a point halfway between reaches A and B to a 

point halfway between reaches B and C. This length of stream 

through reach B had 37.6 percent riffle area; the channel slope to 

this point has decreased to 102 feet per mile. The third stretch of 

river examined was from a point halfway between reaches B and C 

to an equidistant point below reach C. This length of river through 

reach C had 42.7 percent riffle area, the channel slope being 94 feet 

per mile. The riffle areas over the three study reaches averaged 44.8 

percent of their lengths.

The average grading of gravels on the three Kalama River study 

reaches is shown by the curve in figure 41. Compared to other 

streams studied in this report, the gravels on the three reaches are 

fairly coarse, with from 20 to 26 percent of the gravels passing 

through the 1-inch screen. The three reaches have generally similar 

gravels, and the difference in curve shapes and spread between 

curves is small.
KALAMA RIVER 53

FIGURE 39. Study reaches on Kalama River.

KALAMA RIVER REACH A

The Kalama River above reach A is 29.0 miles long, has a mean 

basin altitude of 2,350 feet, and drains 142 square miles. Reach A, 

at an altitude of 400 feet, is on a straight channel of the river and 

encompasses 23,140 square feet at the upstream part of a riffle. 

Water is distributed over the entire width of the reach, but the 

main flow at lower stages is near the left bank, especially in the 

lower part of the reach. Slightly upstream from the uppermost part 

of the reach, and on the right side of the channel, bedrock is exposed and the channel is deeper; also evident is a higher percentage 

of fine material (sand) in the streambed.

Discharge measurements, covering a range of 270 to 1,280 cfs, 

have been used in the analysis. The curves in figure 42 show hydraulic relations in the reach for preferred conditions for spawning. 

The peak preferred spawning discharges and areas and the discharge reductions and areas for each species are given in table 15.
54 HYDROLOGY AS RELATED TO PACIFIC SALMON

95-percent probability that maximum

temperature will be equal to or less

 than this li

Median temperature

ercent probability that minimum temperat re 

will equal or exceed this line

O)o 

EI

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

<fO D

4k(ji

£5 T

(11(ji

(11 IM

FIGURE 40. The 90-percent probability range of stream temperatures, at 

station Kalama River below Italian Creek, near Kalama, 1955-66.

Under favorable discharge conditions, the preferred spawning 

areas are near the lower three sections (fig. 43), tending toward the 

left bank at section 2. The small tributary from the right bank (fig. 

43), between sections 1 and 2, drains logged areas and unpaved 

roadways and carries some sediment during rainstorms. The hydraulic criterion of spawning depth, and probably the physical 

criterion of suspended sediment, are the major reasons for the lack 

of spawning on the right side of the channel between sections 1 and 

2, which indicates that hydraulic and physical criteria are related.
KALAMA RIVER 55

200

I

SIEVE SIZE, IN MILLIMETERS 

90 20 9 

I I

n i i i i

Reach A 

Reach B

1.0

SIEVE SIZE. IN INCHES

T 0.l

FIGURE 41. Curves showing average grading of several samples of gravels 

found on natural spawning grounds of Kalama River.

Data on rearing capacity at reach A may be obtained by using 

the wetted perimeter versus discharge relation, the percentage 

wetted area versus discharge relation (fig. 44 A, B, respectively), 

and the velocity versus discharge versus percentage of bankfull 

reach curves (fig. 45) in the same way as figures 8 and 9 were used 

on the Dewatto River reach A. For instance, the curve in figure 44A 

tends to flatten at about 350 cfs, the minimum discharge for maximum rearing area. At this discharge, about 99 percent (fig. 44£) of 

the bankfull area is wetted or 1 percent is dry. As shown in figure
56 HYDROLOGY AS RELATED TO PACIFIC SALMON

45, a velocity of 1.2 fps and a discharge of 350 cfs intersect at the 

50 percent bankfull area curve. However, 1 percent of the bankfull 

area is dry (fig. 44B) and, therefore, 49 percent, or 11,340 square 

feet, of the bankfull area of the reach is wetted.

Flow-duration curves for reach A (fig. 46) were obtained by computing the relation between reach A discharge (QA) and the discharge (QG) at the long-term (1947-66) gaging station Kalama 

River below Italian Creek, near Kalama, which is downstream. The 

relation is shown by the equation

QA =1.59(Q0)»-" f

which has a standard error of estimate of ±7.8 percent.

Both coho and spring chinook rear in the river for a little more 

than 1 year after hatching. From the annual flow-duration curve 

(fig. 46), the rearing discharge of 350 cfs (fig. 44A) will be equaled 

or exceeded 80 percent of the time or during 20 percent of the 

time, discharges will be less than the most advantageous rearing 

discharge for the species.

Data on discharge, water temperature, dissolved-oxygen content, 

and suspended-sediment concentration for reach A are given in 

table 9.

TABLE 9. Characteristics of water quality, Kalama River reach A, 

June 1968-August 1969

Temperature

Date

June 

July 

Aug.

Sept. 

Oct. 

Aug.

19 _ .

17

15

29

3

29 __ .

8

Discharge

.__ 555

352

270

._ 1,280

528

.__ 754

297

CO

10.6 

12.2 

11.1 

9.4 

10.0 

9.4 

10.6

CF)

51 

54 

52 

49 

50 

49 

51

Dissolved 

oxygen 

(mg/1)

10.8 

10.4

10.7

11.1

11.0 

11.1 

10.8

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

2 

2

1

4 

2

52

KALAMA RIVER REACH B

Study reach B is at an altitude of 330 feet and about a quarter of 

a mile below the confluence of the Kalama River with Summers 

Creek (fig. 39). Above reach B the river is 31.0 miles long and drains 

an area of 154 square miles.

The surface area of reach B encompasses 16,800 square feet. Just 

above the reach the streambed is bedrock, and just below the reach
KALAMA RIVER 57

IO.OOO 

9000

200O

BO

~

SPRING CHINOOK 

ORIGINAL TREND

:v\

/

/

/

//

' /

- /

- j

1

1

;

i i

'/\

V \

^

\

\

\

1

1 1 1 1

^

\

\

\

..._^

/

1

 h -t

EX PL A

1 1 1 1

FITTED

^

^

\

\

\

\

NATION

1 1

ORIGINAL 

/^^T*V

-4

-x\

.A \

A

 Pr»f»rr»d d»pth and vtlaelly v~ - Pr»f»rr»d vtlocity _,

\

 Pr«f«r

1 i

r»d dtp

I 1 1 1

h

^

i i

\ 

\

i

|V

1

\

,u

COHO

\

\

''

1

TREND

s

/--^\

\

^

i i

i i 1 1

FITTED x

\

\V

^

1 1 1 1

-

_

_

_

5

-

-

E

500 1000 200O 200 SOO WOO 2000

200 900 1000 2000 ZOO

DISCHARGE, IN CUBIC FEET PER SECOND

900 tOOO 2000

50,000

20,000

10,000

'

8 9000

FALL CHINOOK 

ORIGINAL TREND FITTED

EXPLANATION 

Pr«f«rr«d depth and velocity

TREND FITTED

IV

! A

r

SOO IOOO 20OO 200 900 IOOO 2000

20O 900 IOOO 200O 200

DISCHARGE, IN CUBIC FEET PER SECOND

SOO IOOO 2000

FIGURE 42. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Kalama River reach A. Curves show the original and the trend-fitted data 

based on a three-point moving average. The bankfull area of reach covers 

23,140 square feet.
58 HYDROLOGY AS RELATED TO PACIFIC SALMON

0 10 20 30 40 50 60 FEET SECTION 3

SECTION 4

FLOW

Species: Fall Chinook

Discharge: 270 cfs

Percentage preferred spawning:30.3

Percentage preferred velocity: 55.0

Percentage preferred depth: 39.8

Species: Sockeye

Discharge: 528 cfs

Percentage preferred spawning: 2.3

Percentage preferred velocity: 11.3

Percentage preferred depth: 19.6

FIGURE 43. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Kalama 

River reach A.

the channel splits into two channels, the main flow being on the left 

side. The pool above the riffle at reach B is considerably smaller in 

volume than the pool at reach A, but it has higher velocities and is 

slightly deeper. The channel bank on the left side of reach B is steep,
KALAMA RIVER 59

Species: Spring Chinook 

Discharge: 528 cfs 

Percentage preferred spawning: 10.0 

Percentage preferred velocity: 26.5 

Percentage preferred depth: 21.8

Species: Coho

Discharge: 352 cfs

Percentage preferred spawning: 9.6

Percentage preferred velocity: 49.7

Percentage preferred depth: 14.9

FIGURE 43. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Kalama 

River reach A Continued.

but on the right side a poorly defined flood plain exists; this plain 

is inundated by high flows that build up behind the downstream 

channel island. At lower flows the riffle area extends well into the 

study area.
60 HYDROLOGY AS RELATED TO PACIFIC SALMON

200 400 600

DISCHARGE, IN CUBIC FEET PER SECOND

A

800 900

'ERCENTAGE OFBANKFULL AREA WETTEC

<o ? o

-4 <o±a>no 

I

-

-

-

I

1

/

I

1

/

/

1

I

X"

1

1

S

^

1

X"

1

1

^ 

1

1

1

1

-

-

-

1

200 400 600

DISCHARGE, IN CUBIC FEET PER SECOND

B

800 900

FIGURE 44. Relation between curve of wetted perimeter versus discharge 

(graph A)and curve of percentage of bankfull area wetted versus discharge 

(graph B), Kalama River reach A.
KALAMA RIVER 61

Percentage of 

bankfull area

150 200 300 400 500

DISCHARGE, IN CUBIC FEET PER SECOND

1000

FIGURE 45. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, Kalama River reach A. Shows selected 

percentages of reach which have velocities equal to or less than that indicated at a selected discharge.

Discharge measurements covering the range 287-1,690 cfs were 

used in the analysis. The curves of preferred spawning parameters 

versus discharge are shown in figure 47. The spawning discharges 

and areas for the trend-fitted peaks and the selected discharge reductions for the four species are given in table 15.

The preferred spawning areas of reach B (fig. 48) occur mainly 

on the left side of sections 2 through 4 and on the right side of the 

channel over sections 3 and 4. The greater depth and, for most discharges, the higher velocities in midchannel limit spawning at section 1.

A discharge of about 400 cfs (fig. 49A) is the most advantageous 

discharge for rearing on reach B. The relation between wetted 

perimeter and discharge shows the effect of the branching channel 

by the break in the curve at about 450 cfs. As would be expected, 

the channel branching also causes a break in the relation between 

percentage of bankfull area wetted and discharge, shown in figure 

495. This graph is used in conjunction with the velocity versus 

discharge versus percentage of bankfull area curves (fig. 50) for
62 HYDROLOGY AS RELATED TO PACIFIC SALMON

10,000

5000

I__ I I I__I

10,000

10 30 50 70 90 95 99 I

10,000 \Of>OQ

5000

1000

10 30 50 70 90 95 99

10 30 50 70 90 95 99 I 10 30 50 70 90 95 99 

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 46. Monthly and annual flow durations, Kalama River reach A.

determining the area of the reach with velocities equal to or less 

than a certain magnitude at a specified discharge. For the rearing 

discharge of 400 cfs, 96 percent of the bankfull area is wetted (fig. 

495), or 4 percent is dry. Also at 400 cfs, 50 percent of the reach 

has velocities equal to or less than 1.5 fps (fig. 50), but since 4 perFIGURE 47. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Kalama River reach B. Curves show the original and the trend-fitted data 

based on a three-point moving average. The bankfull area of the reach is 

16,800 square feet.
KALAMA RIVER 63

10,000

5000

2000 

IOOO 

500

200 

100 

50

20

10

1 1

ORIG

: X"

" A

rf

1 )

\ 1

F 

NAL

\

\ 

\

k

Y

ALL C

\

\ 

\_

\

\

-1

J

1 , _

II 1 1 1 1

l i

HINOOK 

TREN

/

/

/

D FITT

X 

X

k\

\

ED

EXPLANATION

 - Pref«rr«d velocity

1 1

 

ORIGIN/

A

/ /

/

i i 

i

i I

J

;

/ 

i i

!r

i i

so

IL

N\ \ \

X

\ \

^ ^ t

^

1 1 1 1

CKEYE

\

x \

N

\

TREND

/ 

/ 

/

/

/"""

1 1

FITTED

\

\

\ '

\

N

1 1 1 1

':

;

I

~

200 500 1000 2000 ZOO 5OO IOOO 20OO

200 5OO IOOO 20OO ZOO

DISCHARGE, IN CUBIC FEET PER SECOND

500 IOOO 20OO

10,000

T ' I* SPRING CHINOOK ' ' ' ' ' I 

ORIGINAL TREND FITTED

I I I 111

T ' ' " I CO HO ' ' ' ' '"I 

ORIGINAL TREND FITTED

\

EXPLANATION 

ond velocity

:ity -

I I I I 11

200 500 IOOO 2000 200 SOO IOOO 2000

200 500 IOOO 20OO 200

DISCHARGE, IN CUBIC FEET PER SECOND

500 IOOO 2000
64 HYDROLOGY AS RELATED TO PACIFIC SALMON

O IO 2O SO 4O 5O 6OFEET

ISECTION I SECTION 2 I

Species: Fall Chinook 

Discharge: 355 cfs 

Percentage preferred spawning: 9.1 

Percentage preferred velocity: 55.7 

Percentage preferred depth: 16.6

Species: Spring Chinook 

Discharge: 355 cfs 

Percentage preferred spawning: 5.9 

Percentage preferred velocity: 14.3 

Percentage preferred depth: 19.6

FIGURE 48. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Kalama 

River reach B.

cent of the 50 percent bankf ull area is dry, 46 percent of the bankf ull 

area of the reach is wetted and has velocities less than or equal to 

1.5 fps. It must be remembered that the error involved in this 

determination is at least equal to the sum of the errors of each of 

the curves used to derive the values.

Flow-duration curves for reach B were determined by relating 

discharges at reach B (QB) to discharges at the gaging station 

Kalama River below Italian Creek, near Kalama (QG). The relation
KALAMA RIVER 65

Species: Sockeye

Discharge: 355 cfs

Percentage preferred spawning: 0.6

Percentage preferred velocity: 4.9

Percentage preferred depth: 16.6

Species: Coho

Discharge: 565 cfs

Percentage preferred spawning: 2.9

Percentage preferred velocity: 32.4

Percentage preferred depth: 6.4

FIGURE 48. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Kalama 

River reach B Continued.

is shown by the equation

= l.ll(Qo) 0-97 ,

which has a standard error of estimate of ±7.8 percent. The relation is not significantly different (tested at the 95-percent confidence level) from the relation between reach A and the gaging 

station ; therefore, the duration curves of reach A (fig. 46) also may 

be used for discharges at reach B. For the most advantageous rear-
66 HYDROLOGY AS RELATED TO PACIFIC SALMON

ing discharge at reach B (fig. 49A), the annual duration curves (fig. 

46) show that 400 cf s will be equaled or exceeded 72 percent of the 

time.

The water-quality characteristics at reach B (table 10) are similar to those at reach A (table 9).

TABLE 10. Characteristics of water quality, Kalama River reach B, 

June 1968-August 1969

Temperature

Date Discharge

Dissolved 

oxygen

Specific

Suspended conductance

sediment (micromhos per

(mgr/1) cmat25°C)

July

Aug.

Sept.

Oct.

Aug.

19 _ .

17

16 _ _.

28- _.

3 _ .

29 . _.

8 __ .

. _ 546

.__ 355

.__ 287

.__ 1,690

.__ 518

.__ 790

.__ 329

10.6

11.7

11.1

10.6

11.7

8.9

12.2

51

53

52

51

53

48

54

10.8

10.5

10.7

10.8

10.5

11.2

10.4

3

1

1

5

1

5

51

KALAMA RIVER REACH C

Reach C is the lowest study site (alt is 260 ft) on the Kalama 

River (fig. 39). Above reach C, the river is 33.0 miles long and drains 

157 square miles. Reach C, which covers an area of 22,090 square 

feet, differs from reaches A and B in that the latter two encompass 

riffle areas, whereas reach C does not. Reach C is located above a 

slight bend and also above a bedrock outcrop. Behind the outcrop 

and mainly on the inside of the bend (left bank) gravel has been 

deposited. The water flows through the gravel behind the bedrock 

and emerges at the impermeable rock barrier. Thus, the gravel in 

the bar is well oxygenated and provides an acceptable spawning 

area for salmon.

From the measurements of depth and velocity for a range of discharges (264-1,660 cfs), the curves showing preferred spawning 

hydraulic parameters versus discharge were fitted for each of the 

salmon species studied (fig. 51). These plots show peaks for the 

original as well as for the trend-fitted data. The spawning discharges and areas for the trend-fitted peaks (fig. 51) and the four 

discharge reductions and areas for the four species are given in 

table 15.
KALAMA RIVER 67

PERIMETER, IN FEET

O - 

O 4to00

2 106

H 

LU 

£

104

102 

10

1

-

-

-

-

J

1

/

/

/

1

X

/

1

^

1

/>

1

^

1

1

^*

1

1

- -~-~

1

1

 i =

-

-

_

-

1

0 200 400 600 800 IOC

DISCHARGE, IN CUBIC FEET PER SECOND 

A

»»

IRCENTAGE OF BANKULL AREA WETTED

U> (0 <0-fc O> 01CD-J

0.

09

1

-

-

-

-

-

1

1

|

1

/

/

|

1

1

1

/

'

1

1

^

1

1

^^>

1

1

^ 

1

1

-

-

-

-

1

100 200 400 600 800 1000 

DISCHARGE, IN CUBIC FEET PER SECOND

B

FIGURE 49. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge 

(graph B), Kalama River reach B.
68 HYDROLOGY AS BELATED TO PACIFIC SALMON

3.5

3.0

o 

o

LJ 

V)

cc

£ 2.0

UJ 

LJ

O

° 1.0

I I I 1 T

Percentage of 

bankfull Area -r

II i

XX

I50 200 300 400 500

DISCHARGE, IN CUBIC FEET PER SECOND

1000

FIGURE 50. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, Kalama River reach B. Shows selected percentages of reach which have velocities equal to or less than that indicated 

at a selected discharge.

From the curves in figure 51, measured discharges in the vicinity 

of the preferred discharge were selected, and the preferred spawning areas (areas where preferred depth overlaps preferred velocity.) 

were delineated on maps of the reach (fig. 52). The map plots (fig. 52) 

show that the major preferred spawning area is on the left side of 

the channel which, as mentioned on page 66, is also preferred for 

spawning because of the flow through the gravel.

Because of the nearly vertical banks, which are 2-3 feet and 

higher, on either side of the study reach channel, the bankfull area 

(fig. 52) is covered by water for discharges greater than 300 cfs. At 

a discharge of 300 cfs, an inflection in the wetted perimeter versus 

discharge curve (fig. 53A) also occurs. Thus, the most advantageous 

discharge for rearing is at 300 cfs, above which the wetted perimeter increases only a small amount with increases in discharge.

For the rearing discharge of 300 cfs, 75 percent of the bankfull 

area of the reach has velocities of 1.2 fps or less (fig. 54). However,
KALAMA RIVER 69

~1 I MIN I I M Ml

FALL CHINOOK 

ORIGINAL TREND FITTED

I 111

EXPLANATION

I I I I

200 500 1000 2000 2OO 5OO 1000 20OO

20O 500 1000 2OOO 200

DISCHARGE, IN CUBIC FEET PER SECOND

500 IOOO 2OOO

10,000

~1 I I I I 111 p

EXPLANATION

----- Preferred velocity

 Preferred depth

SPRING CHINOOK

TREND FITTED

ORIGINAL 

/\

 | I I I II I I 

COHO

TREND FITTED

200

500 IOOO 20OO 

DISCHARGE, IN CUBIC FEET PER SECOND

500 IOOO 2000

FIGURE 51. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

Kalama River reach C. Curves show the original and the trend-fitted data 

based on a three-point moving average. The bankfull area of the reach 

covers 22,090 square feet.
70 HYDROLOGY AS RELATED TO PACIFIC SALMON

10 20 30 40 90 60 FEET

Species: Fall Chinook

Discharge: 583 cfs

Percentage preferred spawning: 18.5

Percentage preferred velocity: 17.1

Percentage preferred depth: 26.1

Species: Sockeye

Discharge: 528 cfs

Percentage preferred spawning: 1.3

Percentage preferred velocity: 8.1

Percentage preferred depth: 23.8

FIGURE 52. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Kalama 

River reach C.
KALAMA RIVER 71

Species: Spring Chinook 

Discharge: 822 cfs 

Percentage preferred spawning: 2.06 

Percentage preferred velocity: 18.6 

Percentage preferred depth: 11.8

Species: Coho

Discharge: 822 cfs

Percentage preferred spawning: 8.2

Percentage preferred velocity: 27.8

Percentage preferred depth: 11.8

FIGURE 52. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, Kalama 

River reach C Continued.
72 HYDROLOGY AS RELATED TO PACIFIC SALMON

153

145

100 300 500 700 900

DISCHARGE, IN CUBIC FEET PER SECOND

A

MOO

-ENTAGE OFBANKULL AREAWETTED 

3 0 U> <0§ o2o> <o>i 

1

-

-

1

1

^

/

\

I

*^- 

1

1

 

1

1

,

1

1

,

I

1

- 

1

1

i

1

I

1

-

-

i

100 300 500 700 900 MOO LU

°" DISCHARGE, IN CUBIC FEET PER SECOND

B

FIGURE 53. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge 

(graph B), Kalama River reach C.

99 percent of the bankfull areas is wetted and 1 percent is dry (fig. 

53#); therefore, 74 percent of the wetted area (16,350 sq ft) has 

velocities less than 1.2 fps.

The flow-duration curves for reach C (fig. 55) were determined by 

relating the discharge at reach C (Qc) to the discharge downstream
KALAMA RIVER 73

2.o

I.O

1 | 1 | 1 

Percentage of 

bankfull area

i i i _i

150 200 300 400 500

DISCHARGE. IN CUBIC FEET PER SECOND

1000

FIGURE 54. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, Kalama River reach C. Shows selected percentages of reach which have velocities equal to or less than that indicated 

at a selected discharge.

(Qo), gaging station Kalama River below Italian Creek, near 

Kalama. The relation was found to be

Qc = 1.08 (QG) o.98

and had a standard error of estimate of ±6.8 percent. From the 

flow-duration curves (fig. 55), the occurrence of 800 cfs, the peak 

spawning flow for spring chinook (fig. 51), will be equaled or 

exceeded 3 percent of the time in September, 30 percent in October, 

and 76 percent of the time for the November-December period. 

The rearing discharge of 300 cfs (from fig. 53A) will be equaled or 

exceeded 85 percent of the time annually (fig. 55).
74 HYDROLOGY AS RELATED TO PACIFIC SALMON

Table 11 gives water-quality measurements obtained over a 

range of discharges in the summer and fall of 1968. The suspendedsediment-concentration average is slightly higher for reach C 

(7 mg/1) than for reach A (2 mg/1) and reach B (3 mg/1), but it is 

not excessive at any reach.

TABLE 11. Characteristics of water quality, Kalama River reach C, 

June 1968-August 1969

Temperature

Date

June 

July 

Aug.

Sept. 

Oct. 

Aug.

19 _

17 __

15- _

28

4_

29 _ _

8

Discharge

_ 583

358

264

1,660

528

.__ 822

__ 320

CO

11.4 

12.8 

12.2 

10.6 

11.1 

8.9 

13.3

CP)

52.5 

55 

54 

51 

52 

48 

56

Dissolved 

oxygen 

(mg/1)

10.6 

10.2 

10.4 

10.8 

10.7 

11.2 

10.2

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

11 

1

1

8 

5 

18

 

 

~~52

NORTH FORK NOOKSACK RIVER

The Nooksack River basin is in the northwestern part of the 

State. Streamflow originates on the western slope of the northern 

Cascade Range and terminates in Lummi Bay on the Strait of 

Georgia, west of Bellingham.

The salmon study was conducted on the North Fork Nooksack 

River (fig. 1). Some of the tributaries in the headwaters have their 

source at altitudes of about 6,500 feet. The main-stem source altitude is about 3,600 feet. During melting periods several large 

glaciers on Mounts Baker and Shuksan contribute to the flow of the 

river. The bed of the North Fork Nooksack River is heavily charged 

with gravel, and in many places the stream has numerous small 

interlacing, or braided, channels. The braiding of the stream is 

caused by the waters passing through the streambed gravels and 

subsequently dropping their load, which clogs the channel. The 

gravel-bar dams that are constantly being deposited force frequent 

position changes in the channel by splitting it into anabranches 

which reunite downstream with the main stem. Other reaches of 

the channel are controlled by bedrock and have little or no definite 

flood plain. At these places, if the channel slope is steep enough, 

rapids are present; if the channel slope is not steep, there is one 

gravel-filled channel generally a riffle. The three reaches selected 

for study on the Nooksack (fig. 56) experienced shifting of bed 

material during the investigation period, but they are probably as 

stable, or more stable, than any other spawned section that could 

be chosen on this river.
10,000

NORTH FORK NOOKSACK RIVER

10,000, 

5OOO

I__ I I i I I I

75

I IO 3O SO 7O 90 95 99 I IO 30 SO 70 90 95 99

10,000 p

< 5000

3 lOjOOO

' I 10 30 50 70 90 95 99 '"I IO 30 50 70 90 95 99 

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 55. Monthly and annual flow durations, Kalama River reach C.

Curves of average grading of gravels on study reaches of the 

North Fork Nooksack River are shown in figure 57. Reach B gravel 

sizes are similar to those of the Dewatto and Cedar River study 

reaches, but gravels of reaches A and C approximate those of the 

study reaches on the Kalama River.

Aerial photographs were taken of the North Fork Nooksack River 

from the powerplant at Excelsior, about 1.5- miles above reach A 

(fig. 56), to the confluence with the South Fork a distance of 33 

river miles with 28.3x10" square feet of river surface (8.54xl05 

sq ft per mi). From the stereo pairs of aerial photographs, the areas 

of pools and riffles were delineated and measured. Examination
122° 05' 

FIGURE 56. Study reaches on North Fork Nooksac
NORTH FORK NOOKSACK RIVER 77

shows that the photographed part has 52.5-percent pool area and 

47.5-percent riffle area.

The percentage of riffle area was determined for reach A by using 

the distance from the powerplant at Excelsior to a point midway 

between reaches A and B; for reach B, by using the distance from 

the point midway between reaches A and B to a point midway between reaches B and C; and for reach C, by using the distance from 

the midway point between B and C to the confluence with the South 

Fork. Reach A contains 64.2 percent riffles, and the channel slope 

for the total main stem above A is 106 feet per mile; reach B has 

56.7 percent riffle area with the slope of the total main stem above 

B being 97 feet per mile; and reach C has 26.1 percent riffles, with 

the slope of the main stem above having decreased to 71 feet per 

mile.

Flows of the river during the winter-early spring period (fig. 58) 

are typical of a glacier-fed stream; however, at these low flows 

there is some minor regulation from the operation of a powerplant 

at Excelsior. During the winter, the glacier flow will decrease because of freezing, and the lowest discharges of the year occur at

SIEVE SIZE. IN MILLIMETERS 

20 10 53

I I I I i I____I

SIEVE SIZE. IN INCHES

FIGURE 57. Curves showing average grading of several samples of gravels 

found on natural spawning grounds of North Fork Nooksack River.
78 HYDROLOGY AS RELATED TO PACIFIC SALMON

this time. With spring snowmelt and increased flow from the 

glaciers as the air temperature rises, the river stage rises to a peak 

in June. Streamflow at the upper station, North Fork Nooksack 

River below Cascade Creek near Glacier (fig. 58A), the site of reach 

A, does not reflect the winter rains (October through January) as 

much as the discharge at the lower station, North Fork Nooksack 

River near Deming, the site of reach C (fig. 585), because precipitation above reach A occurs more often as snow.

The annual cycle of river temperatures (fig. 59) reflects the seasonal climate; lows occur in February and highs occur in July. The 

curves in figure 59 were computed from 365 values each for maxi3000

1000

i i i i i r i

500

Minimum monthly m*an

z 100

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

A

3OOO

I OCX)

5OO

I I T I I I I I I I I I

M*an monthly

JAN FEB MAR APR JUNE JULY

B

AUG SEPT OCT NOV DEC

FIGURE 58. Mean monthly discharge and maximum and minimum monthly 

mean discharges, North Fork Nooksack River below Cascade Creek near 

Glacier, 1950-67 (graph A), and mean monthly discharge, North Fork 

Nooksack River near Deming, 1965-67 (graph B).
NORTH FORK NOOKSACK RIVER 79

mum, mean, and minimum water temperatures in the calendar year 

1968. The curve fitting the maximum daily water temperatures defines 84 percent of the variance of the data and has a standard 

error of estimate of ±1.4°C. The mean daily water-temperature 

curve defines 89 percent of the variance of the data and has a standard error of estimate of 1.0 °C. The curve defining the minimum 

daily temperatures accounts for 89 percent of the variance and has 

a standard error of estimate of 0.9 °C.

The diurnal fluctuations of stream temperature during the summer months, at times, amount to as much as 6°C (11.0°F). These 

diurnal fluctuations are clue to a larger contribution of cooler melt 

waters from glaciers during the daylight hours and to the reduction of this colder-water flow at night, when most of the streamflow 

is from lower-altitude snowmelt and ground-water inflow. Although the lower-altitude snowmelt water is at about the same 

temperature as the glacier melt water, the latter occurs at the 

sources of the streams, whereas snow after melting generally becomes overground runoff, which is warmed before it enters the 

stream.

The major salmon species frequenting the North Fork Nooksack 

River and its tributaries are the coho, chum, pink, and fall chinook. 

Typically, spawning occurs later (about December-March) in the 

North Fork than in non-glacier-fed streams. The winter and early

(012

lulO

E 6

Maximum daily 

t«mp«ratura _

M«an daily 

t«mp«rotura /y

Minimum daily 

tamp«ratur*

- 60

vV ~

50

45

40

JAN FEB MAR APR MAY JUNE JULY AIM SEPT OCT NOV DEC

FIGURE 59. Maximum, minimum and mean daily water temperatures, North 

Fork Nooksack River near Deming. Data from harmonic fitting of thermograph record for 1968.
80 HYDROLOGY AS RELATED TO PACIFIC SALMON

spring months are the low-flow period (fig. 58). Discharges are low 

because pre'cipitation is in the form of snow and the glaciers are 

contributing little or no water, resulting in clearer water (without 

"glacier flour") and a more stable streambed. Also, the water temperature begins to rise in March (fig. 59), facilitating hatching and 

food growth for later rearing.

NORTH FORK NOOKSACK RIVER REACH A

Reach A is located (fig. 56) just below the gaging station (North 

Fork Nooksack River below Cascade Creek, near Glacier) and encompasses 13,880 square feet. Reach A is the highest study reach on 

the river, having an altitude of 1,245 feet. Above reach A, the main 

river stem is 17.6 miles long and drains a 105-square-mile area that 

has a mean altitude of 4,300 feet.

Bedrock is exposed in the channel just above the study reach, 

and large boulders are randomly distributed in the channel below 

the reach. The right bank of the reach is very steep and rises more 

than 15 feet above the channel bed. The left side of the reach has a 

shallow cross-sectional gradient for a short distance, then rises 

about 4 feet and flattens toward a Forest Service picnic ground 

away from the reach.

The peaks for spawnable areas and discharges and the values for 

the selected percentages of reduction of discharge and area are 

given in table 15. These discharge values were obtained from the 

trend-fitted curves in figure 60. In two of the four plots, the trendfitted curves are not well defined on the low discharge side; however, by extrapolating between the original curves and the trendfitted velocity and depth curves, the breakover is estimated (estimated values in table 15 are given in parentheses). Also, the 

exceedance percentage of the peaking discharge (fig. 64) is very 

high, indicating that preferred spawning discharges will be available most of the time under natural conditions.

The preferred spawning areas within reach A (fig. 61) tend to be 

located on the left side of the reach. This probably is due to the midstream velocities being slowed by the upstream bedrock outcrop; 

also, the river bends to the left below the reach, and its greatest 

flow is forced onto the steep right bank. The streambed lithology 

also is more desirable on the left side of the river because it consists 

of more gravel and fewer large rocks.

The curve for the relation of wetted perimeter versus discharge 

(fig. 62A) is representative mainly of the left side of the channel, 

the right side being very steep. Two breaks in the curve are noted;
NORTH FORK NOOKSACK RIVER 81

100 ZOO 90O 1000 IOO 200 900 IOOO

100 ZOO 5OO IOOO 100 ZOO SOO IOOO 2OOO

DISCHARGE, IN CUBIC FEET PER SECOND

900 IOOO 100 ZOO SOO IOOO

100 ZOO 900 IOOO 100 ZOO 900 IOOO ZOOO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 60. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

North Fork Nooksack River reach A. Curves show the original and the trendfitted data based on a three-point moving average. The bankfull area of 

reach covers 13,880 square feet.
82 HYDROLOGY AS RELATED TO PACIFIC SALMON

10 20 so 40 »o «o MEET

EDOE OF 

WATER

FLOW

Species: Fall Chinook

Discharge: 288 cfs

Percentage preferred spawning: 12.3

Percentage preferred velocity: 32.4

Percentage preferred depth: 22.7

Species: Sockeye

Discharge: 288 cfs

Percentage preferred spawning: 1.2

Percentage preferred velocity: 2.5

Percentage preferred depth: 22.3

FIGURE 61. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, North 

Fork Nooksack River reach A.

one break occurring at a little less than 200 cfs (near the minimum 

preferred spawning discharge) and the other more definite break 

occurring at about 750 cfs. The wetted perimeter increases 35 feet, 

from 95 feet at 200 cfs to 130 feet at 750 cfs. Either of these curve
NORTH FORK NOOKSACK RIVER 83

Sp«ci«s: Spring Chinook 

Discharge: 288 cfs 

Percentage preferred spawning: 4.8 

Percentage preferred velocity: 20.4 

Percentage preferred depth: 23.8

Species: Coho

Discharge: 288 cfs

Percentage preferred spawning: 1.6

Percentage preferred velocity;, 9.4

Percentage preferred depth: 7.6

FIGURE 61. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, North 

Fork Nooksack River reach A Continued.

breaks could be considered the point for the preferred rearing discharge ; as would be expected, however, the exceedance percentage 

of the lower discharge is much greater than that of the upper flow 

(fig. 64).
PERCENTAGE OF BANKFULL AREA WETTED 

ov

O 4008OOI2OO 1600

DISCHARGE, INCUBIC FEETPER SECOND

> ->4 00 tp r 

> O O O c

' I "

-

-

-

-

-

-

|

1

\

\

1

1

\

\

1

1

-

-

-

\ -

\ ~

-

1

00

o

o 

c

2 oo 

o O

0>
NORTH FORK NOOKSACK RIVER 85

Figure Q2B shows the percentage of bankf ull area wetted versus 

discharge. This percentage was used in conjunction with the percentage of bankfull area versus velocity versus discharge curves 

(fig. 63) to evaluate the velocities over the reach at the preferred 

rearing flows.

Duration curves showing the percentage of time that annual and 

monthly discharges are equaled or exceeded at reach A (fig. 64) were

Percentage of 

bankfull area

200 500 IOOO

DISCHARGE. IN CUBIC FEET PER SECOND

2000

FIGURE 63. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, North Fork Nooksack River reach A. 

Shows selected percentages of reach which have velocities equal to or less 

than that indicated at a selected discharge.
86 HYDROLOGY AS RELATED TO PACIFIC SALMON

500

50

1000

1 III I

1000

500

100

50

I 10 30 50 70 9O 99 I 10 3O SO 70 90 99

1000

I 10 30 50 70 9O 99 I 10 3O SO 70 90 99

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 64. Monthly and annual flow durations, North Fork Nooksack River

reach A.

computed from records of the North Fork Nooksack River above 

Cascade Creek for the period 1938-66. The preferred spawning discharges at the peak (fig. 60) for all species except sockeye are within 

the 180-200 cfs range. A discharge of 190 cfs will be equaled or 

exceeded 98 percent of the time in the November-December period, 

91 percent of the time in January, 82 percent of the time in February, and 85 percent of the time in March. As seen by the exceedance percentages, a discharge of 190 cfs could be realistically 

maintained by the natural discharge of the stream during the 

spawning period.
NORTH FORK NOOKSACK RIVER 87

The lowest rearing flow (200 cfs), will be exceeded annually 96 

percent of the time (fig. 64), but the higher rearing discharge (750 

cfs) will be exceeded annually only 37 percent of the time. Thus, the 

chances of obtaining the lowest rearing discharge (200 cfs) are 

much more favorable, even though there is 35 feet less wetted perimeter for the lower discharge than for the higher rearing discharge.

Water-quality parameters collected at reach A are listed in table 

12. As would be expected for glacial streams, both the suspendedsediment concentration and specific conductivity are higher than 

for the other streams studied. However, for the measurements 

made, neither is excessive and, by observation, does not seem to be 

detrimental to fish life.

TABLE 12. Characteristics of water quality, North Fork Nooksack River 

reach A, April 1968-October 1969

Temperature

Date

Apr. 

May

June 

Oct. 

Dec. 

Feb.

Oct.

4_ .

18 __ .

3 _.

27 _.

24 _.

9 _.

23 _.

5__ .

18 _ .

25

8 __ .

Discharge

370

288

570

1,010

1,270

.__ 397

.__ 360

200

213

185

.__ 1,800

<°C)

4.4 

4.4 

4.4 

5.8 

8.9 

5.6 

2.8 

.8 

1.9 

2.2 

6.7

(°F)

40 

40 

40 

42.5 

48 

42 

37 

33.5 

35.5 

36 

44

Dissolved 

oxygen 

(msr/1)

12.5 

12.5 

12.5 

12.1 

11.3 

12.2 

13.1 

13.8 

13.4 

13.3 

11.9

Specific 

Suspended conductance 

sediment (micromhos per 

(mg/1) cmat25°C)

 

'7 

30 

30 

0

3 

0 

1

 

 

91 

85 

97 

98 

46

NORTH FORK NOOKSACK RIVER REACH B

The middle study reach on the North Fork Nooksack River is denoted as reach B and is located about a quarter of a mile below the 

inflow of Canyon Creek (fig. 56). Above reach B (alt 720 ft), the 

main river is 25.5 miles long and drains an area of 193 square miles.

Reach B covers a surface area of 28,750 square feet. At flows 

greater than 2,500 cfs, the stream below the reach is divided into 

two channels. At lower discharges, the main flow is on the right at 

the upper end of the reach and moves to the left at the lower end. 

The right bank is riprapped with large boulders near the upper end 

of the reach, and abandoned railroad-bridge abutments stand on 

both banks near the center of the reach.

The relations between discharge and area of reach with preferred spawning conditions (fig. 65) were trend fitted to smooth out 

any peaks or outlier measurements (one-point peaks) which do not
88 HYDROLOGY AS RELATED TO PACIFIC SALMON

1C 

20,000 

IO.OOO

y 5OOO

u.

UJ

K 

4

g 2000

z

uj IOOO

0

4

< SOO 

en

r

4 

K 2OO 

fc

4

4 

SO

?o

5

-

:

:

-

~

\

A

y\

 

i

X> 200

:

-

:

~

-

-

-

FALL

1N/

/

^-~

EX

I i

500

O

;

.

/

v

|

CHINO

/ \

A

^

/

PLANAT

yx

TREND

' 

\

ON

1 1

F TTED

/"'\_^-

/^ '

1 1 1 1

* -~~.

i

N \ 

S

\N

 '

I

\

\

RIGINAI

i

I

v

f

MIL

SOCK

/A

/'\

A

/\

\

Frf

x_-

I

i i

FITTE

^X _

'A /

\j

1 1 1 1

-

/ 

:

* - 

:

-

IOOO 2000 200 500 OOO 2OOO 

20O SOO IOOO 2OOO 2OO SOO IOOO 2OOC 

DISCHARGE, IN CUBIC FEET PER SECOND

i i H

IOINAL

^x. 

A

7

......

i

u

EX

SPftIN

i \ 

1

'f

/'

/

CHIN I 

TRE

\x

k.

F PLANATION

1OK

ND FIT

^N/

 Preferrod v«locity

1 1 i

 ED

.^

V

A

/ 

1 1

ORIGIN

/N

j

V

1

/

F---

1 1

AL

t

s\ "\

i i

 OHO 

TR

v^

/

1

1

1 1 1 1

ND Fl

\ s~

X1 1 1

TTED ~

~

^

5

" 

_

-

-

IOO 200 SOO IOOO 2000 2OO SOO IOOO 20OO

2OO SOO IOOO 2OOO 200 SOO IOOO 2OOO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 65. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

North Fork Nooksack River reach B. Curves show the original and the trendfitted data based on a three-point moving average. Bankfull area of reach 

covers 28,750 square feet.
NORTH FORK NOOKSACK RIVER 89

have enough data to be substantiated or do not conform to the 

trend. The original plots (fig. 65) show several peaks, in most places, 

three; but after trend fitting, one peak is defined and another, at a 

higher discharge, is open ended. This higher discharge peak is the 

result of the gravel bar on the left side of sections 1 and 2 being 

inundated at higher stages. The peak spawnable areas and discharges for the lowest peak of the preferred spawning curves (fig. 

65), and the areas and discharges for the percentage discharge reductions are given in table 15.

The preferred spawning areas in reach B (fig. 66) tend to be 

located near the left side of the channel between sections 2 and 4 

and on the right side of the channel between sections 3 and 4. The 

area on the right side between sections 1 and 2 is too deep and fast 

for spawning, and the left side between sections 1 and 2 is generally 

too shallow for spawning. Also, the boulder riprap on the right bank 

at the upper end of the reach makes this section undesirable for 

spawning.

The curve showing the relation between wetted perimeter and 

discharge (fig. 67A) is used to determine the preferred rearing discharge. The preferred rearing discharge was selected at the first 

break in the wetted perimeter curve, which occurs at a discharge of 

560 cfs. Figure Q7B, showing percentage of bankfull area wetted 

versus discharge, is used in conjunction with figure 68 to evaluate 

the velocity over the reach for the preferred rearing discharge. For 

example, at 560 cfs, 64 percent of the bankfull area is wetted (fig. 

67Z?), or 36 percent is dry. Also, at this discharge, 60 percent of 

the bankfull area has velocities equal to or less than 1.3 fps; thus, 

24 percent (60 36) of the bankfull area of the reach is wetted and 

has velocities less than 1.3 fps.

The annual and monthly flow-duration curves (fig. 69) were 

determined by relating the discharges of reach B (QB) to the discharges (QA) at the long term gaging station (North Fork Nooksack 

River above Cascade Creek, near Glacier). The relation is shown by 

the equation

QB = 4.84 (QA) 0^,

which has a standard error of estimate of ±4 percent. The peak 

preferred spawning discharge for fall chinook (620 cfs) will be 

equaled or exceeded 87 percent of the time during the NovemberDecember period, 61 percent of the time in January, and 55 percent 

of the time in February. The preferred rearing discharge of 560 cfs 

will be equaled or exceeded annually 88 percent of the time.
90 HYDROLOGY AS RELATED TO PACIFIC SALMON

Species: Fall Chinook 

Discharge: 1770 cfs 

Percentage preferred spawning: 8.1 

Percentage preferred velocity: 28.9 

Percentage preferred depth: 12.0

Species: Sockeye

Discharge: 1770 cfs

Percentage preferred spawning: 0.9

Percentage preferred velocity: 3.5

Percentage preferred depth: 12.2

FIGURE 66. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, North 

Fork Nooksack River reach B.

The water-quality characteristics of reach B that were measured 

are given in table 13. They do not vary substantially from those at 

reach A, except the specific conductivity (a function of dissolved 

solids in the water) seems to have increased slightly. The average 

conductivity at reach A is 93 micromhos per centimeter, and the 

average at reach B is 107 micromhos per centimeter. The samples 

were taken during the same time period.
NORTH FORK NOOKSACK RIVER 91

Species: Spring Chinook 

Discharge: 1770 cfs 

Percentage preferred spawning: 2.4 

Percentage preferred velocity: 12.4 

Percentage preferred depth: 7.4

Species: Coho

Discharge: 1770 cfs

Percentage preferred spawning: 2.1

Percentage preferred velocity: 14.2

Percentage preferred depth: 6.4

FIGURE 66. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, North 

Fork Nooksack River reach B Continued.

NORTH FORK NOOKSACK RIVER REACH C

Reach C, at an altitude of 345 feet, is the lowest study reach on 

the river (fig. 56). Above the reach the main river is 36.7 miles long 

and has a drainage area of 282 square miles.

Reach C covers 54,940 square feet and has a channel which, for 

the most part, is wide and uniform, and which virtually exhibits no
92 HYDROLOGY AS RELATED TO PACIFIC SALMON

130

120

z 110

5 100

90

80

70

200 600 8OO IOOO 1200 I4OO 1600 1800 200O 22OO 

DISCHARGE, IN CUBIC FEET PER SECOND

90

< 80

70

60

o 50

20O 400 6OO 800 IOOO I20O 1400 1600 

DISCHARGE, IN CUBIC FEET PER SECOND

1800 2000 2200

B

FIGURE 67. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge (graph B), North Fork Nooksack River reach B.

flood plain. Gravel bars migrate through the reach, but the water 

depth at any one section remains fairly uniform. About 100 yards 

above the reach is a bend where the river narrows from a braided 

stream into one channel; about 100 yards below the reach, the 

channel again becomes braided.
NOETH FOEK NOOKSACK EIVEE 93

8 2

UJ 

V)

IT 

UJ 

0.

Percentage of 

bankfull area

300 500 1000

DISCHARGE. IN CUBIC FEET PER SECOND

2000 3000

FIGURE 68. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, North Fork Nooksack Eiver reach B. 

Shows selected percentages of reach which have velocities equal to or less 

than that indicated at a selected discharge.

TABLE 13. Characteristics of water quality, North Fork Nooksack River 

reach B, April 1968-October 1969

Temperature

Date

Apr.

May

June 

Oct. 

Dec. 

Feb.

Oct.

4_ .

18 _.

2 _ .

27 _ .

24

9

23 _ .

5

18 _ .

25 __ .

8_ .

Discharge

.__ 767

620

1,050

1,770

 2,160

754

.__ 730

. _ 365

392

342

(°C)

5.0 

5.6 

8.9 

7.2 

10.6 

5.6

1.1 

3.3 

3.6 

7.2

(°F)

41 

42 

48 

45 

51 

42

34 

38 

38.5 

45

Dissolved 

oxygen

(mg/1)

12.3 

 12.2 

11.2 

11.7 

10.8 

12.2

13.7 

12.9 

12.8 

11.7

Specific 

Suspended conductance 

sediment (micromhos per 

(mgr/1) cmat25°C)

6 

6 

39

7

1 

1 

2

 

100 

109 

109 

112 

42
94 HYDROLOGY AS RELATED TO PACIFIC SALMON

10 30 50 TO 90 95 99 I 10 30 50 70 90 95 99

0 5000 5000

10 30 50 TO 90 95 99 I 10 30 50 TO 90 95 99

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 69. Monthly and annual flow durations, North Fork Nooksack River

reach B.

The peaks for spawning discharges and areas (fig. 70) and the 

values for the selected percentages of reduction of discharge are 

given in table 15. The original and the trend-fitted curves for depth, 

velocity, and depth and velocity (fig. 70) were used as guides to 

extrapolate the spawnable area values (shown in parentheses).

The locations within the reach of preferred spawning areas, generally, are confined to edges of the channel with no spawning occurring in midchannel (fig. 71). At discharges near the preferred 

discharge, the center of the channel has depths slightly greater
NORTH FORK NOOKSACK RIVER 95

100 200 500 IOOO 2OOO 5OO IOOO 2OOO

500 IOOO 2000 500 IOOO 2OOO

DISCHARGE, IN CUBIC FEET PER SECOND

jjj 5000

| 

g 2OOO

z

a

8

«= 200

fc

g

I

-

_

_

I

-

1 1 1 1 1

ORIG

)(/

|/\l r-\

\

SPR

NAL

WA>

v\

\ j \/

TTk

A

i i 1 1 1 1

INS CHINOOK

^

X

1 -

REND

N

' S

 ITTED

I 

V

\

\

1 1

EXPLANATION 

 ' Prifimd dipth on 

 - . Priflrrld v«locltv

1 1 III | II

1 COHO

ORIGIh

\J\ ;

/^

\

d vilocl

 1 J J i^ "

1 1 1 1 1 1 1 1 1 1 1 1

AL

L

\ ^

i

i

TR

\

\

1 1

1 1 1 1

END F

V^»

A

\

MM

TTED

-_

\ '

V\

N ~ V

I

-

100 20O 500 IOOO 2000 5OOO 2OO SOO IOOO 2000 BOOO

500 IOOO 500 IOOO 20OO

DISCHARGE, IN CUBIC FEET PER SECOND

FIGURE 70. Relations between area of reach and discharge, for preferred 

velocity, depth, and depth and velocity, for each of four salmon species, 

North Fork Nooksack River reach C. Curves show the original and the trendfitted data based on a three-point moving average. Bankfull area of reach 

covers 54,940 square feet.
96 HYDROLOGY AS RELATED TO PACIFIC SALMON

Species: Fall Chinook

Discharge: 720 cfs

Percentage preferred spawning: 14.7

Percentage preferred velocity: 34.2

Percentage preferred depth: 19.3

Species: Sockeye

Discharge: 720 cfs

Percentage preferred spawning: 1.2

Percentage preferred velocity: 2.3

Percentage preferred depth: 19.3

FIGURE 71. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, North 

Fork Nooksack River reach C.

than those preferred for spawning, and the velocities are generally 

much too great.

The preferred rearing discharge in reach C (570 cfs) was determined from the first break in the curve of wetted perimeter versus
NORTH FORK NOOKSACK RIVER 97

Species: Spring Chinook 

Discharge: 970 cfs 

Percentage preferred spawning: 3.1 

Percentage preferred velocity: 13.1 

Percentage preferred depth: 7.9

Species: Coho

Discharge: 720 cfs

Percentage preferred spawning: 3.3

Percentage preferred velocity: 12.5

Percentage preferred depth: 8.8

FIGURE 71. Plan-view locations of cross sections and preferred spawning 

areas for each of four salmon species studied at selected discharges, North 

Fork Nooksack River reach C Continued.

discharge (fig. 72A). At 570 cfs, 76 percent of the bankfull area is 

wetted (fig. 72B), and 24 percent is dry. From the relations of percentage of bankfull area versus velocity versus discharge (fig. 73) it 

was determined that, at 570 cfs, there is 40 percent of the bankfull
98 HYDROLOGY AS RELATED TO PACIFIC SALMON

200

I9O

I8O

I7O

160

ISO

O ZOO 4OO 6OO BOO IOOO 1200 1400 I60O I8OO 2OOO 22OO

DISCHARGE, IN CUBIC FEET PER SECOND

Q IOO

9O

80

7O

6O

50

O 2OO 4OO 600 BOO IOOO I2OO 1400 I6OO I8OO 20OO 22OO

DISCHARGE, IN CUBIC FEET PER SECOND

B

FIGURE 72. Relation between curve of wetted perimeter versus discharge 

(graph A) and curve of percentage of bankfull area wetted versus discharge (graph B), North Fork Nooksack River reach C.

area or 16 percent (40 24) of the wetted bankfull area with 

velocities equal to or less than 1.2 fps. In reach C, 16 percent of the 

wetted area encompasses 8,790 square feet.

The annual and monthly flow-duration curves (fig. 74) were 

determined by relating mean daily discharges from reach C (Qc), 

the site of the gaging station, North Fork Nooksack River, near 

Deming, to the flows at reach A (QA), North Fork Nooksack River 

below Cascade Creek, near Glacier. Reach A has 30 years of flow 

data, whereas reach C has only 3 years of data. The relation is 

shown by the equation

Qc = 22.0 (QA) 0-^,
NORTH FORK NOOKSACK RIVER 99

Q

§ 3

O

ui

2

Percentage of 

bankfull areaI I I

500 1000 2000 

DISCHARGE, IN CUBIC FEET PER SECOND

4000

FIGURE 73. Family of curves showing relation between velocity, discharge, 

and percentage of bankfull area, North Fork Nooksack River reach C. 

Shows selected percentages of reach which have velocities equal to or 

less than that indicated at a selected discharge.
100 HYDROLOGY AS RELATED TO PACIFIC SALMON

1000

10 30 50 70 9O 99 I 10 30 50 70 90 99

o 5000, 5000

1000

10 30 50 70 90 99 I 10 30 50 70 90 99

PERCENTAGE OF TIME INDICATED DISCHARGE WAS EQUALED OR EXCEEDED

FIGURE 74. Monthly and annual flow durations, North Fork Nooksack River

reach C.

which has a standard error of estimate of ±30 percent. The standard error is very large and, above a discharge of 1,700 cfs at reach 

C, the curve breaks and the equation does not hold. However, the 

lower discharges for spawning and rearing are the major concern 

of this analysis, and the equation is valid over this range. The 

large magnitude of the standard error is probably caused by the 

difference in elevation between reaches A and reach C, the latter 

being 900 feet lower. Much of the fall, winter, and spring precipitation occurs as snow at reach A and as rain at reach C.

From the flow-duration curves (fig. 74), the peak preferred 

spawning discharge of 680 cfs for fall chinook is equaled or ex-
NORTH FORK NOOKSACK RIVER 101

ceeded 96 percent of the time in the November-December period, 

91 percent of the time in January, and 80 percent of the time in 

February. The preferred rearing discharge (570 cfs) is equaled or 

exceeded 98 percent of the time annually or only 2 percent of the 

time will the discharge be less than the preferred rearing discharge. 

The flow-duration curves (fig. 74) are no better than the relation 

from which they were derived, which has a standard error of ±30 

percent.

The water-quality characteristics for reach C are given in table 

14. The specific conductivity shows, as it did between reaches A 

and B, a downstream increase; the average conductivity for reach 

C is 115 micromhos per centimeter. Thus, between reaches A and 

C there is an increase of 22 micromhos per centimeter in specific 

conductivity. This is a relatively small amount, however, and by no 

means would it be detrimental to aquatic life at any of the reaches.

TABLE 14. Characteristics of water quality, North Fork Nooksack River 

reach C, April 1968-October 1969

Temperature

Date

Apr. 

May

June 

Oct. 

Dec. 

Jan. 

Feb.

Oct.

3 _.

18

2

28 __ .

25 __ .

9

23 _ .

22 _ .

18 __ .

26 __ .

8 _ .

Discharge

1,080

900

. _ 1,260

. _ 1,730

2,320

970

._ 1,040

720

710

585

 2,700

<°C)

7.8 

6.1 

8.9 

7.8 

9.4 

6.9 

3.3 

.6 

5.0 

3.3 

8.3

(°F)

46 

43 

48 

46 

49 

44.5 

38 

33 

41 

38 

47

Dissolved 

oxygen

(mg/1)

11.5 

12.0 

11.2 

11.5 

11.1 

11.8 

12.9 

13.9 

12.3 

12.9 

11.4

Specific 

Suspended conductance 

sediment (micromhos per 

(mgr/1) cmat25°C)

 -

~~32 

71 

6

3 

1 

13

 

104 

122 

115 

120 

47

GENERALIZATION OF PEAK PREFERRED 

SPAWNING DISCHARGES

One of the principal objectives of the study is the generalized 

definition of spawning discharges in all salmon-producing streams 

in Washington, whether or not the streams have field determination of spawning discharges. This generalization of preferred 

spawning discharges would enable allocation of streamflows for 

salmon spawning and thus would aid the designer in making economic feasibility studies on rivers where projects for diversion or 

storage are planned.

There are many possible ways of generalizing preferred spawning discharges, starting with the determination by sampling at
102 HYDROLOGY AS RELATED TO PACIFIC SALMON

specific sites. All the known hydrologic techniques of generalization 

were examined, and it was concluded that the most promising 

method was by statistical correlation of spawning discharges with 

basin and stream-channel characteristics.

Only a relatively small sampling of spawning discharges are 

available or will be available, and definition of spawning discharge 

at any desired site, requires a method of transferring and extending available discharge information. The transfer methods range 

from simple extrapolation or interpolation at two sites to complex 

statistical methods that simultaneously consider a population of 

discharges and related environmental characteristics. The selected 

multiple-regression technique seems to be the most effective.

A study was made, using the data in this report, for the purpose 

of testing the feasibility of using the multiple-regression method 

for a spawning-discharge generalization. Peak preferred spawning 

discharge were related to several easily measured stream-channel 

and basin parameters individually, as well as in combinations and 

ratios with each other. Some of the parameters tested were stream 

length, in miles, from the source to the sampling site; channel slope, 

in feet per mile, of the river upstream from the site; mean altitude 

of the drainage basin, in feet; the drainage area, in square miles; 

and the average width and depth of the stream channel for the 

bankfull stage at the study reach.

Even though there are 12 samples (four rivers each with three 

reaches) only four data sets, with the reaches as replications, could 

be used in this preliminary investigation, because of the interrelation of reaches on a given river. Also, no more than three parameters could be related to spawning discharges in any one regression because of the small sample size and the loss of one degree of 

freedom for each parameter used. Several of the regressions were 

not significant when only two parameters were used.

There are 24 or 16 possible combinations of relations between the 

spawning discharges of three reaches on each of the four rivers and 

the basin and channel parameters. To expedite this preliminary 

generalization, however, relations were developed using spawning 

discharges from the upper reach, the middle reach, and the lower 

reach of each of the four rivers. Thus, regressions were computed 

and tested using upper-reach spawning discharges versus basin 

and channel parameters; then, the same regressions were computed 

for the spawning discharges from the middle reaches; and, finally, 

the lower-reach spawning discharges were used to derive the regressions. Coefficients of correlation were high, and all three sets of 

regressions showed the same general tendency for the most sig-
CONCLUSIONS 103

nificant parameters to be (1) drainage area, (2) channel slope, and 

(3) stream width and depth. Also, regression coefficients were found 

to be similar on each of the parameters. The standard errors of 

estimate of the relations (before adjustment for sample size) ranged 

from ±18 to ±42 percent. After adjustment for sample size the 

error range increased considerably, ranging from ±28 to ±62 percent, which shows the need for an increased sample size. The resultant equations of this generalization are of only academic interest 

with little usable value, because of the small sample size, and are 

therefore not shown. At present, other study reaches on additional 

streams are being sampled and the spawning discharges determined 

so that the generalization method herein presented may be refined 

and more reliable relations obtained.

In summary, this initial attempt by generalization of spawning 

discharges shows that 

(1) Multiple-regression methods may lead to reasonably accurate 

relations for predicting peak preferred spawning discharges 

from basin and channel characteristics.

(2) The most significant basin and channel characteristics of those 

investigated were drainage area, channel slope, and stream 

width and depth.

(3) A larger sample of spawning discharges is needed in order to 

investigate interrelations between the physical characteristics and improve the standard error of estimate of the 

relations.

(4) Even though results from this generalization produce only 

rough estimates of peak preferred spawning discharges, 

data being collected in the present continuing program seem 

to follow the trends and relations indicated by this initial 

study.

CONCLUSIONS

The curves, graphs, and values in this report are all subject to a 

certain amount of error inherent in field measuring, streambed 

shifts, manmade controls of flow, plotting of maps, and fitting of 

curves. Wherever feasible, the errors involved are stated as errors 

or a confidence interval is shown. However, some errors were not 

evaluated because time limited obtaining replications of samples, 

which would have enabled definition of the sampling errors.

Table 15 gives the preferred spawning areas and discharges, for 

the four salmon species studied, at the maximum or peak condition 

and at each of the 5-, 10- 15-, and 25-percent discharge-reduction 

levels for the 14 study reaches on the four rivers investigated.
104 HYDROLOGY AS RELATED TO PACIFIC SALMON

Table 16 gives the percentage reductions of spawning area for 

each of the four salmon species, at the four percentage reductions 

from the peak spawning discharge, for the 14 river study reaches. 

For example, table 16 shows that for fall chinook on the Dewatto 

River reach A, for a 25-percent reduction from the peak in spawning discharge, there is only a 6-percent reduction from the peak in 

spawning area.

A more general presentation of table 16 is obtained by a plot of 

the reduction data as shown in figure 75. Here, the regression line 

for a river is indicative of the average of the study reaches and of 

the salmon species. Three of the regression lines (for the Dewatto, 

Cedar, and Kalama Rivers) shows that for a selected percentage 

reduction of spawning area the percentage reduction in discharge

TABLE 15. Summary of peak preferred, 

corresponding reductions of spawnable areas

[Numbers in parentheses are values obtained by extrapolation.

Salmon Species

Fall chinook

River

Dewatto

Cedar. .....

Kalama. . . .

North Fork 

Nooksack

Preferred 

Reach parameter

.A. .

Al.

B. .

.A..

B. .

Bl.

C...

01.

.A..

B..

C..

A..

B. .

C. .

Discharge . .

Discharge . .

. .Area ......

Discharge . .

. . Area ......

Discharge .

Discharge . .

. .Area ......

Discharge . .

, . Area ......

Discharge . .

. . Area ......

Discharge . .

. . Area ......

Discharge . .

. .Area ......

Discharge . .

Discharge . .

Discharge . .

. .Area ......

Discharge . . 

. .Area ......

Discharge . .

Percentage reduction 

from peak spawning 

discharge

Peak

. 1,440 

87 

640 

74

. 2,100

92

. 1,900

230 

. 1,050 

275

. 4,080

250

960

320

. 1,920

290

. 6,100

260

. 1,560

520 

. 4,100 

650 

. 2,050 

195

. 1,250

620 

. 7,400 

680

5

1,440 

83 

630 

70

2,100

87

1,900

218 

1,040 

261

4,050

238

(920)

304

1,900

276

6,100

246

1,520

495 

4,100 

617 

2,000 

185

1,250

589 

7,300 

646

10

1,420 

78 

625 

67

1,950

83

1,900

207 

1,030 

248

3,950

225

(860)

288

1,850

261

6,000

234

1,450

468 

4,050 

585 

1,950 

175

1,220

557 

6,000 

612

15

1,400 

74 

620 

63

1,900

78

1,870

196 

1,010 

234

(3,700)

212

(780)

272

(1,800)

246

5,900

221

1,380

442 

4,000 

552

166

1,150

527 

(4,700) 

578

25

1,350 

65 

590 

56

1,800

69

1,800

172 

930 

206

(3,300)

188

(650)

240

(1,650)

218

4,700

195

1,200

390 

3,450 

487

146

1,040

465 

510

Peak

460 

77 

80 

83

440

140

680

240 

170 

510

525

480

420

420

630

420

1,640

580

510

375 

160 

800 

960 

200

360

370 

1,720 

670

Spring chinook

Percentage 

reduction from 

peak spawning' 

discharge

5

450 

73 

79 

79

440

135

660

228 

160 

484

520

456

410

399

620

399

1,620

504

500

356 

160 

760 

950 

190

360

352 

1,700 

636

10

420 

69 

72 

75

435

125

640

216 

150 

459

505

432

400

378

610

378

1,610

476

490

338 

155 

720 

900 

180

350

333 

1,690 

603
CONCLUSIONS 105

is greater. This is indicated by the relative positions of the "average" line and the line of equal reduction. The North Fork Nooksack 

River average line intersects the equal reduction line at about 23- 

percent reduction in area and discharge. Below this intersection, 

reduction in area is less than the reduction in discharge; above 23 

percent, the inverse is true. In figure 75 the average line slope for 

the North Fork Nooksack is greater than 1.0 indicating a steep 

recession on the area-discharge relations (for example, see fig. 65 

for sockeye). The assumption of linearity for the average lines of 

figure 75 should not be extended beyond the ranges shown.

The standard error of estimate (fig. 75) is not an error term, but 

an index of the deviation of the data about the average line for the 

river; in essence, it indicates the magnitude of differences between

spawning areas and discharges and of

at 5,10,15, and 25 percent reduction of discharge

All areas in square feet. All discharges in cubic feet per second]

Salmon species Continued

Spring chinook Con.

Percentage 

reduction from 

peak spawning 

Discharge 

Continued

15

390

66

60

71

420

120

620

204

140

434

(485)

408

350

357

(595)

357

1,550

450

410

318

150

680

(800)

170

(310)

315

(1,550)

568

25

300

58

36

62

410

105

530

180

115

382

(440)

360

(280)

315

(530)

315

1,250

398

210

281

100

600

150

278

502

Coho

Percentage reduction from 

peak spawning discharge

Peak

460

51

170

70

550

50

520

235

320

270

767

285

360

450

285

450

2,130

245

430

540

1,140

725

460

180

405

515

1,400

660

5

450

48

170

66

550

48

515

223

315

256

760

271

340

428

280

428

2,110

232

425

512

1,100

688

440

171

400

490

1,350

626

10

430

46

165

63

540

45

510

212

310

243

750

256

320

405

275

405

2,090

220

410

485

1,060

652

(380)

162

385

464

(1,150)

594

15

390

43

160

60

480

42

500

200

300

230

(700)

242

315

382

(265)

382

2,010

208

400

468

1,010

615

(340)

153

365

438

(1,000)

560

25

320

38

150

52

380

38

460

176

260

202

(440)

214

315

338

(225)

338

1,800

183

280

405

870

544

135

315

386

495

Peak

140

50

62

65

150

88

370

240

255

440

275

430

170

510

130

490

390

420

86

390

115

570

130

300

135

570

690

710

Sockeye

Percentage reduction from 

peak spawning discharge

5

135

48

60

62

150

84

370

228

250

418

265

408

160

484

125

466

380

398

84

370

115

542

130

285

130

541

670

674

10

130

45

58

58

140

79

360

216

240

396

250

387

150

459

120

441

370

378

83

351

113

514

125

270

125

512

600

639

15

130

42

57

55

135

75

355

204

235

374

(230)

366

125

434

(115)

416

365

366

82

332

110

485

120

255

95

485

(550)

604

25

120

38

55

49

130

66

335

180

235

330

(185)

322

95

382

(95)

368

320

315

73

292

100

428

100

225

87

427

532
106 HYDROLOGY AS RELATED TO PACIFIC SALMON

TABLE 16. Percentage reductions of spawnable area for selected reductions of 

the peak spawning discharge

[Numbers in parentheses are values obtained by extrapolation]

Salmon species 

Fall chinook Spring chinook Coho Sockeye

Reach Selected percentage reductions of peak spawning discharge 

_______5 10 15 25 5 10 15 25 5 10 15 25 5 10 IB 25

Dewatto River, percentage reductions of spawnable area

A ...

Al ..,

B ...

... 0

... 2

... 0

2

1

3

3

2

6

8

3

?,

1

0

10

1

IB

25

4

35

45

7

0

0

6

3

?,

15

6

13

30

12

31

4

3

0

7

6

7

7

8

10

14

11

13

Cedar River, percentage reduction of spawnable area

A ..

B ..

Bl . 

C .

Cl .

.... 0

.... 1

.... 1

.... 1

0

2

3

(10)

4

2 5

4 11

(9) (19

S1Q\ fQ9

(6) (14

3 6

6 12

1 4 

2 5

2 3

g

18

(8)

17

/fi\

99 1

32 2

(16) 1 

(33) 6

(16) 2

3

2 

11

4

4

6

(9) 

12

(7)

19

19

(43) 

12

/91 \

0

0

2 6

4 9 

6 12

4

0

4 10

8 8

(16) (33) 

26 44

/ to) /97\

Kalama River, percentage reductions of spawnable area

A ...

B ...

C ...

... 0

... 2

... 0

2

7

1

3

11

2

23

23

16

1

?,

0

?,

4

3

5

20

6

24

59

38

1

1

3

?,

4

7

B

7

11

15

35

84

?,

?,

0

5

4

?,

6

5

4

18

15

13

North Fork Nooksack River, percentage reductions of spawnable area

A......2 5 .. .. 1 6 (17) .. 4 (17) (26) ..04 8 23

B ...... 0 2 8 17 01 (4) .. 1 5 10 22 4 7 30 35

C ...... 1 19 (36) .. 12 (10) 4 18 28 3 13 (20)

species and between reaches. The standard error should not be 

used as an index between streams because of the differences in 

sizes of peak spawning flows and spawnable areas between rivers. 

For example, a reduction of 5 cf s will be 50 percent if the reduction 

is from 10 to 5 cf s but only 5 percent with a reduction from 100 to 

95 cf s.

By using table 15 in conjunction with table 16, it is possible to 

select reasonable discharge to allocate for salmon spawning at the 

reaches studied.

The timing of discharges, as shown by the hydrographs of 

streamflows, plays an important part in the survival of anadromous 

fish, not only for spawning discharges but for egg incubation, rearing, and up-and-down stream migration. Unnatural changes in discharge, and shifts in timing or movement of water in a river system 

may have an adverse effect on velocity which could cause warming 

or cooling of certain water areas.

In the future, after a sampling of rivers deemed large enough for 

reliable analysis, a regionalization will be attempted by testing and 

then relating the most significant basin and channel parameters to 

the preferred discharges. Then, if the attempt succeeds, at river lo-
CONCLUSIONS 107

A' DEWATTO 

' RIVER

10 2O 30

^ 60

50

40

30

20

10

EXAMPLE: If di*chorgt is rtductd 20 

ptrctnt from tht ptok spawning 

discharge, ths spawnablt orso will 

bt reduced bttwttn 8 ptrctnt and 

19 percent, avtraglng 13 ptrctnt from 

ptak spawnablt arta

,' KALAMA 

RIVER

EXPLANATION

. Fall Chinook 

O Spring Chinook 

0 Coho 

A Socktyt______

"LINE~OF EQUAL REDUCTION

AVERAGE

STANDARD ERROR 

OF ESTIMATE

NORTH FORK 

NOOKSACK 

RIVER

___I

10 20 30 

PERCENTAGE REDUCTION

0 10 20 

OF DISCHARGE

30

FIGURE 75. Relations between selected percentage reductions of the peak 

spawning discharge and comparable percentage reductions of spawnable 

area. The assumption of linearity for the average line should not be extended 

beyond the ranges shown.

cations where the preferred spawning discharge is desired, the 

specified parameters can be obtained and the preferred discharge 

computed. The parameters used to derive the regionalized equation 

must be pertinent as well as related to the dependent variable. These 

parameters also must be easily obtained to expedite derivation
108 HYDROLOGY AS RELATED TO PACIFIC SALMON

of the relation; they may be used for predicting the preferred discharge in practical applications. If the parameters are more difficult 

to determine than the preferred discharge, the relation has lost its 

usefulness. Some of the basin parameters that will be tested are 

drainage area, length of stream, mean altitude of basin, percentage 

of basin covered by lakes, altitude of the site, altitude of the river 

source, and the slope of the main stem channel. Some of the channel 

parameters, using bankfull stage as a reference, may be wetted 

perimeter, average area, average width, average depth, and channel slope over the reach. The basin parameters can be evaluated 

from topographic maps, and the channel parameters can be evaluated easily at the site where the preferred discharge is to be 

determined.

REFERENCES

Burner, C. J., 1951, Characteristics of spawning nets of Columbia River 

salmon: U.S. Fish and Wildlife Service Fish. Bull. 61, v. 52, p. 97-110.

Burrows, R. E., 1963, Water temperature requirements for maximum productivity of salmon, in Water temperature influences, effects, and control: 

U.S. Pacific Northwest Water Laboratory, Pacific Northwest Symposium 

on Water Pollution Research, 12th, Corvallis [Oreg.] 1963, Proc., p. 29-35.

Chambers, J. S., Alien, G. H., and Pressey, R. T., 1955, Research relating to 

study of spawning grounds in natural areas annual report 1955: Rept. to 

U.S. Army Corps of Engineers by Washington State Dept. Fisheries, 

175 p.

Clay, C. H., 1961, Design of fishways and other fish facilities: Canadian Dept. 

Fisheries, 301 p.

Collings, M. R., 1969, Temperature analysis of a stream, in Geological Survey 

research, 1969: U.S. Geol. Survey Prof. Paper 650-B, p. B174-B179.

Deschamps, Gene, Wright, Sam, and Magee, J. K., 1966, Biological and engineering fisheries studies Wynoochee Reservoir, Washington: Washington 

State Dept. Fisheries, summ. rept., 40 p.

Huntting, M. T., Bennett, W. A. G., Livingston, V. E., Jr., and Moen, W. S., 

1961, Geologic map of Washington: Washington Div. Mines and Geology.

Kennedy, H. D., 1967, Seasonal abundance of aquatic invertebrates and their 

utilization by hatchery-reared rainbow trout: U.S. Fish and Wildlife 

Service Tech. Paper 12, 41 p.

Rantz, S. E., 1964, Stream hydrology related to optimum discharge for king 

salmon spawning in the northern California Coast Ranges: U.S. Geol. 

Survey Water-Supply Paper 1779-AA, 15 p.

Royce, W. F., 1959, Possibilities of improving salmon spawning areas: North

American Wildlife Conf., Trans. 24, p. 356-366. 

Ruggles, C. P., 1966, Depth and velocity as a factor in stream rearing and

production of juvenile coho salmon: Canadian Fish Culture, no. 38,

p. 37-53.
REFERENCES 109

U.S. Geological Survey, 1961, Surface-water records of Washington, 1961-64: 

Tacoma,- Wash., Water Resources Division.

 1965-67, Water resources data for Washington, part 1, Surface water 

records, 1965-67: Tacoma, Wash., Water Resources Division.

Westgate, John, 1958, The relationship between flow and usable salmon spawning gravel, Cosumnes River, region 2, Inland Fisheries: California Dept. 

Fish and Game, Rept. 58-2, 8 p.

 fr U. S. GOVERNMENT PRINTING OFFICE: 1971 O 437-932