Seepage Investigation for Selected River Reaches in the 

Chehalis River Basin, Washington

Scientific Investigations Report 2008-5180

Prepared in cooperation with the Washington State Department of Ecology and the 

Chehalis Basin Partnership

U.S. Department of the Interior

U.S. Geological Survey
Cover: Photograph of Chehalis River near Independence, Washington. (Photograph 

taken by Matt Ely, U.S. Geological Survey, August 30, 2007.)
Seepage Investigation for Selected River 

Reaches in the Chehalis River Basin, 

Washington

By D. Matthew Ely, Kenneth E. Frasl, Cameron A. Marshall, and Fred Reed

Prepared in cooperation with the 

Washington State Department of Ecology and the 

Chehalis Basin Partnership

Scientific Investigations Report 2008–5180

U.S. Department of the Interior

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

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2008

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Suggested citation:

Ely, D.M., Frasl, K.E., Marshall, C.A., and Reed, Fred, 2008, Seepage investigation for selected river reaches in the 

Chehalis River basin, Washington: U.S. Geological Survey Scientific Investigations Report 2008-5180, 12 p.
iii

Contents

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

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

Purpose and Scope ..............................................................................................................................1

Study Area..............................................................................................................................................1

Methods..................................................................................................................................................2

Seepage Investigation ..................................................................................................................................4

Summary........................................................................................................................................................10

References Cited..........................................................................................................................................10

Appendix A. Details of Method to Estimate Discharge with Miscellaneous Measurements .....11

Figures

Figure 1. Map showing location of the Chehalis River basin, Washington ..................... 2

Figure 2. Graph showing mean monthly discharge for the period of record (1953–2006)

for U.S. Geological Survey streamflow-gaging station 12031000, Chehalis

River at Porter, Chehalis River Basin, Washington .................................... 3

Figure 3. Graph showing discharge for September 10-14, 2007, for two U.S. Geological

Survey streamflow-gaging stations, Chehalis River Basin, Washington ............ 3

Figure 4. Map showing discharge gains and losses in reaches along the Chehalis

River, Washington ........................................................................... 7

Figure 5. Graph showing cumulative discharge gains and losses by river mile, Chehalis

River, Washington ........................................................................... 8

Figure 6. Map showing approximate location of certificated surface-water diversion

rates and permitted surface-water discharges along the Chehalis River,

Washington ................................................................................. 9

Table

Table 1. Evaluation of gains and losses, with error analysis measurements for the

seepage investigation, Chehalis River basin, Washington, September 2007......... 5
iv

Conversion Factors and Datums

Conversion Factors

Multiply By To obtain

cubic foot per second (ft3

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

foot (ft) 0.3048 meter (m)

inch (in.) 2.54 centimeter (cm)

mile (mi) 1.609 kilometer (km)

square mile (mi2

) 2.590 square kilometer (km2)

Datums

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

(NAVD 88).

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

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

A study was completed in September 2007 in the 

Chehalis River basin to determine gain or loss of streamflow 

by measuring discharge at selected intervals within various 

reaches along the Chehalis River and its tributaries. Discharge 

was measured at 68 new and existing streamflow sites, 

where gains and losses were determined for 36 stream 

reaches. Streamflow gains were measured for 22 reaches and 

losses were measured for 13 reaches. No gain or loss was 

measured at the Chehalis River between the Newaukum and 

Skookumchuck Rivers. The Chehalis River exhibited a pattern 

of alternating gains and losses as it entered the area of wide, 

gentle relief known as the Grand Mound Prairie. The general 

pattern of tributary ground- and surface-water interaction was 

discharge to streams (gaining reaches) in the upper reaches 

and discharge to the ground-water system (losing reaches) as 

the tributaries entered the broad, flat Chehalis River valley. 

Introduction

In recent years, increasing demands for water for 

municipal, agricultural, industrial, and recreational uses in 

watersheds of Washington State has created concern that 

insufficient water resources remain for fish and other uses. 

The Chehalis River basin currently is one of many watersheds 

in Washington where local citizens and governments have 

elected to coordinate with Tribes and State agencies to 

develop a watershed management plan, according to the 

guidelines outlined in the Watershed Management Act of 1998 

(Washington State Engrossed Substitute House Bill 2514). 

The Chehalis Basin Partnership (CBP) currently is working 

to implement a long-range sustainable watershed plan to meet 

the needs of current and future water demands within the 

basin, while also working to protect and improve its natural 

resources. The ground-water flow system and its interaction 

with surface-water features is not understood well enough on a 

watershed scale to effectively plan and manage the use of the 

water resources.

Purpose and Scope

The purpose of the seepage investigation was to 

determine gain or loss of streamflow by measuring discharge 

at selected intervals within various reaches along the Chehalis 

River and its tributaries. This information on ground-water/

surface-water interaction is needed by managers to make 

informed water-resource decisions.

The U.S. Geological Survey (USGS) in cooperation 

with Washington State Department of Ecology and the 

CBP completed a study in September 2007 to measure the 

ground-water/surface-water interaction of the Chehalis River 

basin. This report documents the data collection effort that 

included synoptic discharge measurements needed to evaluate 

gaining and losing reaches of the Chehalis River and selected 

tributaries. 

Study Area

The Chehalis River flows about 125 mi from 

southwestern Washington east to the city of Chehalis and 

then north-northwesterly to Grays Harbor and the Pacific 

Ocean, draining an area of about 2,600 mi2 (fig. 1). The basin 

is bounded on the west by the Pacific Ocean, on the east 

by the Deschutes River basin, on the north by the Olympic 

Mountains, and on the south by the Cowlitz River basin. 

Land surface altitudes range from 0 ft at the Pacific Ocean 

to about 5,000 ft at Capitol Peak in the Olympic Mountains. 

The Chehalis River basin is predominately forests and shrubs 

(74 percent) with some developed areas (7 percent), wetlands 

(6 percent), and agriculture (5 percent; Homer and others, 

2004). The Chehalis River basin is divided into two Water 

Resource Inventory Areas (WRIAs). The upper Chehalis basin 

(WRIA 23) is upstream of the town of Porter and the lower 

Chehalis basin (WRIA 22) is downstream of the town of 

Porter.

The Chehalis River basin includes parts of Grays 

Harbor, Lewis, Mason, Pacific, and Thurston Counties and 

the cities of Aberdeen, Centralia, Chehalis, and Hoquiam, 

and the Confederated Tribes of the Chehalis Reservation. 

The Chehalis River basin is home to Coho and fall Chinook 

salmon and steelhead trout and the lakes, ponds, and reservoirs 

support various fish and wildlife species.

Seepage Investigation for Selected River Reaches in the 

Chehalis River Basin, Washington

By D. Matthew Ely, Kenneth E. Frasl, Cameron A. Marshall, and Fred Reed 
2 Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

tac08-0252_Figure 01

GRAYS HARBOR

GRAYS HARBOR

PACIFIC 

KITSAP

JEFFERSON

MASON

PIERCE

THURSTON

WAHKIAKUM

LEWIS

COWLITZ

Cowlitz River Basin

Deschutes River Basin

KING

Montesano

Pe Ell

Doty

Hoquiam

Aberdeen

Chehalis

Porter 

Centralia

Grand

Rochester

Mound

Bucoda

Tenino

Wynoochee River

Satsop

River Middle Fork

West Fork

East Fork

Wishkah River

Humptulips River

West Fork

East Fork

 Big

Cr

Hoquiam River, East Fork

West Fork

Skookumchuck

River Newaukum River, North Fork

Newaukum River, South Fork

Cloquallum

Cr

Chehalis River

South Fork

Chehalis

River

Chehalis River

 

PACIFIC OCEAN 

Grays

Harbor

Willapa

Bay

47° 

30' 

47° 

46° 

30' 

124° 123°30' 123° 122°30' 

WASHINGTON 

0 5 10 15 20 MILES 

0 10 20 KILOMETERS 5 15 

Scatter Creek

Black

River

Chehalis River

Base from U.S. Geological Survey Digital Data, 1:100,000, 1985

Universal Transverse Mercator projection,

Zone 10, North American Datum of 1983

Confederated

Tribes of the

Chehalis

Reservation

Olympic Mountains

Location of figures 4 and 6

Figure 1. Location of the Chehalis River basin, Washington.

Mean annual precipitation for the upper basin ranges 

from 40 in. near the city of Chehalis, to more than 120 in. near 

the headwaters of the Chehalis River (Garrigues and others, 

1998). Mean annual precipitation for the lower basin ranges 

from 55 in. near the town of Porter, to more than 220 in. near 

the headwaters of the Wynoochee and Humptulips River in the 

Olympic Mountains (Garrigues and others, 1998).

Methods

A reconnaissance of the Chehalis River basin was done in 

August 2007 to locate potential measurement sites and obtain 

landowner permissions. Seventy discharge measurements 

were made over a 3-day period in September 2007 at 68 

sites (59 new or existing miscellaneous streamflow sites and 
Introduction 3

9 active streamflow-gaging stations) along the Chehalis, 

Newaukum, Skookumchuck, and Black Rivers, Scatter 

Creek, and smaller selected tributaries. 

Discharge measurements made during the low-flow 

season, usually August–September (fig. 2), were used 

to capture baseflow conditions. The measurements were 

concentrated in the upper Chehalis basin (WRIA 23) 

partly because of the concentration of development in the 

upper basin, but also because the Chehalis River is tidally 

influenced downstream of the Satsop River.

Gains to or losses from the Chehalis River were 

determined by establishing a series of measurement 

(transect) sites along the river channel and measuring 

Discharge was not measured at Elk and Lincoln Creeks. 

Discharge at these creeks was estimated using a historical 

relation between the creek and a nearby USGS streamflowgaging station (appendix A). The estimates were considered 

“poor” due to the level of uncertainty.

No measurements were made at Chehalis River at Galvin 

(12026700) on the same day measurements were made at 

streamflow sites immediately upstream and downstream. 

The discharge at this site was adjusted upward by 9 ft3/s 

(192 to 201 ft3/s), the difference in the daily mean discharge 

from September 11, 2007 and September 13, 2007 at the 

streamflow-gaging station at Chehalis River near Grand 

Mound (12027500) (fig. 3). Error in the associated gain/loss 

was considered minimal.

Records of daily mean discharge and miscellaneous 

measurements for Washington are available by water year at 

http://wdr.water.usgs.gov/ (U.S. Geological Survey, 2008).

Figure 2. Mean monthly discharge for the period of 

record (1953–2006) for U.S. Geological Survey streamflowgaging station 12031000, Chehalis River at Porter, Chehalis 

River Basin, Washington.

tac08-0252_Figure 02

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

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

MEAN MONTHLY DISCHARGE,

IN CUBIC FEET PER SECOND 

Chehalis River at Porter (12031000)

Chehalis River near Grand Mound (12027500)

100

150

200

250

300

350

400

DISCHARGE, IN CUBIC FEET PER SECOND

12 13

SEPTEMBER 2007

10 11 14

Figure 3. Discharge for September 10-14, 2007, for 

two U.S. Geological Survey streamflow-gaging stations, 

Chehalis River Basin, Washington.

discharge at upstream and downstream locations during 1 day. 

The transect sites were located at river cross sections with a 

uniform shape and free flowing conditions. Stream depth and 

velocity measurements were made using two methods—a 

Price AA meter with top setting rod or an acoustic Doppler 

current profiler (ADCP). Discharge of the Chehalis River 

remained fairly constant during the 3-day period (fig. 3).

Discharge was measured with a Price AA meter according 

to standardized techniques of the USGS (Rantz, 1982). The 

USGS rates the accuracy of discharge measurements based 

on the equipment, character of the measurement section, 

number of observation verticals, stability of stage, wind 

and accuracy of depth, and velocity measurements (Rantz, 

1982, p. 179). Accuracy ratings of “good” indicate that the 

measurements are within 5 percent of true values and “fair” 

indicate the measurements are within 8 percent of true values. 

All discharge measurements were rated “good” or “fair,” 

except six measurements that were rated “poor” (greater than 

8 percent of true values), primarily due to aquatic growth in 

the streams.

An ADCP uses sonar to measure and record water current 

velocities over a range of depths. A complete description of 

the ADCP and the discharge measurement methods is provided 

by Oberg and others (2005). Two ADCPs were deployed using 

several methods, including mounted on a motor boat, towed 

behind a kayak, and pulled across the stream transect from 

riverbanks and bridges.

Numerous small unmeasured tributaries and surfacewater diversions and returns are in this system, and their 

omission would present some error in the calculation of gains 

and losses. Quantifying the rates of all tributary inflows and 

surface-water diversions and returns was beyond the scope 

of this study, but unmeasured diversions and inflows would 

influence the net seepage results. Diversions might mask or 

reduce measured streamflow gains along gaining reaches 

and artificially increase measured streamflow losses along 

naturally losing reaches. Similarly, unmeasured tributaries 

and return flows might mask or reduce streamflow losses 

along a losing reach and artificially increase streamflow gains 

along naturally gaining reaches. Gain or loss of streamflow, as 

described in this report, refers to a cumulative or “gross” gain 

or loss. 
4 Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

Seepage Investigation

The results of the 3-day seepage investigation are 

presented in table 1. An interactive Google MapsTM image 

shows the location of the discharge measurement sites and 

the gaining and losing reaches (http://wa.water.usgs.gov/

projects/chehalis/seepage_run.htm). The reach name is shown 

on the map when the cursor is over a reach. Clicking on any 

measurement point will display more detailed information of 

the site. Gains and losses, in cubic feet per second, and gains 

and losses, in cubic feet per second per mile, are shown when 

the cursor is placed over any section of the reach.

Measurements of gains and losses for 36 stream reaches 

were identified. Gaining reaches indicate a strong connection 

to a local or regional aquifer and losing reaches identify 

possible recharge zones to a local or regional aquifer. Of the 

36 reaches, 22 (61 percent) were gaining reaches (gain from 

the ground-water system) and 13 (36 percent) were losing 

reaches (loss to the ground-water system). No gain or loss in 

streamflow was measured at the Chehalis River between the 

Newaukum and Skookumchuck Rivers. This does not indicate 

a lack of ground- and surface-water interaction, but rather the 

cumulative gains and losses between measurement sites equal 

0 ft3

/s. Pitz and others (2005) measured the same reach in 

September 2003 and reported a net loss of 17 ft3/s (including a 

2 ft3/s discharge to the river). Their piezometer data indicated 

that the measured loss occurred over the lower 2 mi of the 

reach.

Headwaters of the tributary streams tended to be 

gaining reaches. Losses to the ground-water system were 

measured as the tributaries entered the broad, gentle relief of 

the main Chehalis River valley. Figure 4 shows gaining and 

losing reaches along the Chehalis River. Figure 5 shows the 

cumulative gain and loss, by river mile. 

Gain/loss per mile can be a more useful statistic than total 

gain/loss from or to the ground-water system. Measurements 

were not made at regular intervals due the lack of accessibility 

and suitability of a discharge measurement site. Dividing 

the gain/loss by the approximate length of the measured 

stream reach identifies locations of greater ground-water/

surface-water interaction. Gains greater than 10 ft3

/s-mi were 

measured in four reaches and losses greater than 10 ft3/s-mi 

were measured in three reaches. Similar to the large gains and 

losses shown in figure 5, all seven reaches are on the Chehalis 

River between river miles 20 and 60. The first reach occurs 

as the Chehalis River enters the topographic feature known 

as the Grand Mound Prairie, a wide area of gentle relief. The 

pattern of alternating gains and losses along the Chehalis 

River downstream of Centralia indicates that this is an area 

of greater interaction between the ground- and surface-water 

systems.

The reported gains and losses also include unmeasured 

surface-water diversions from the reaches and surface-water 

discharges to the reaches. The Department of Ecology’s Water 

Rights Tracking System (WRTS) provided the approximate 

location for certificated surface-water diversions along the 

measured stream reaches (M. Lynum, Washington State 

Department of Ecology, written commun., 2008). WRTS 

locates surface-water diversion rates by township, range, and 

section, resulting in more than one diversion at some locations 

(fig. 6). The total discharge rate of certificated surface-water 

diversions is 263 ft3/s, not including two diversions designated 

for power generation, and an average permitted rate of 0.6 ft3/s 

at each diversion. Actual rates of surface-water diversions 

during the seepage measurements are unknown, but likely 

were considerably less than the full surface-water right. 

Information on permitted surface-water discharges into 

the Chehalis and Black Rivers and Scatter Creek from the 

National Pollutant Discharge Elimination System (Section 

402 of the Clean Water Act) provided average daily discharge 

rates for the low-flow period for three fish hatcheries, three 

municipal sewage and wastewater treatment facilities, and 

one commercial operation (fig. 6). The total average daily 

discharge to the Chehalis River from the municipal sewage 

and wastewater treatment facilities, and dairy operation is 

9.5 ft3/s. 

Two fish hatcheries in the study area withdraw ground 

water and discharge surface water to Black River (fig. 6). One 

hatchery is permitted to discharge as much as 8 ft3/s to the 

Black River by percolation from a terminal pond; however, 

discharge was not measured for this study. Another hatchery 

discharges to a swamp bordering Black River. No permitted 

discharge limits could be found for this hatchery but Das 

(1993) reported that the average effluent rate over four weirs 

was 4 ft3/s during an inspection in September 1991. A third 

hatchery near Scatter Creek discharges from settling ponds 

into Scatter Creek (fig. 6). A discharge of 19 ft3

/s was reported 

to the Washington State Department of Ecology on September 

1, 2007. This discharge largely explains the measured 

20.7 ft3/s gain along the reach of Scatter Creek between Case 

Road (12028020) and Sargent Road (12028040) (table 1). 

Except for the gain at Scatter Creek, the surface-water 

diversions and return flows are thought to be small relative to 

ground-water/surface-water exchange.
Seepage Investigation 5

Measurement sites and No.

Measured 

streamflow 

(ft3/s)

Date

Assumed 

measurement 

error

(percent)

Gain 

or 

loss 

(ft3/s)

Erroradjusted 

minimum 

streamflow 

(ft3

/s)

Erroradjusted 

maximum 

streamflow 

(ft3/s)

Net gain 

or loss 

uncertainty 

range 

(cumulative 

measurement 

error; ft3

/s)

Chehalis River near Doty (12020000) 17.8 09-11-2007 5 16.9 18.7 

Chehalis River at Elk Creek Road near Doty (12020050) 18.7 09-11-2007 5 0.9 17.8 19.6 -0.9 to 2.7

Chehalis River at Dryad (12020565) 43.5 09-11-2007 5 1

18.0 41.3 45.7 14.1 to 21.8

Hope Creek near Dryad (12020595) <1e 09-11-2007 11 .9 1.1 

Chehalis River near Meskill (12020625) 35.7 09-11-2007 8 -7.8 32.8 38.6 -12.8 to -2.7

Chehalis River near Ceres (12020700) 35.6 09-11-2007 5 -.1 33.8 37.4 -4.7 to 4.5

South Fork Chehalis River near Wildwood (12020800) 3.18 09-11-2007 8 2.9 3.4 

South Fork Chehalis River near Klaber (12021600) 11.2 09-11-2007 8 8.0 10.3 12.1 6.8 to 9.1

South Fork Chehalis River near Curtis (12021750) 12.4 09-11-2007 5 1.2 11.8 13.0 -0.3 to 2.7

Chehalis River near Adna (12021800) 49.4 09-11-2007 8 1.4 45.4 53.4 -4.9 to 7.7

Chehalis River near Littell (12022300) 46.5 09-11-2007 5 -2.9 44.2 48.8 -9.1 to 3.3

South Fork Newaukum River near Onalaska (12024000) 19.9 09-11-2007 5 18.9 20.9 

South Fork Newaukum River at Forest (12024100) 20.8 09-11-2007 5 .9 19.8 21.8 -1.1 to 2.9

North Fork Newaukum River above Bear Creek near Forest (12024400) 9.86 09-11-2007 5 9.4 10.4 

North Fork Newaukum River at Forest (12024820) 10.5 09-11-2007 5 .6 10.0 11.0 -0.3 to 1.6

Newaukum River at Jackson Hwy near Forest (12024830) 30 09-11-2007 8 -1.3 27.6 32.4 -5.2 to 2.6

Newaukum River near Chehalis (12025000) 31.7 09-11-2007 5 1.7 30.1 33.3 -2.2 to 5.6

Newaukum River at Chehalis (12025020) 32.8 09-11-2007 5 1.1 31.2 34.4 -2.1 to 4.3

Chehalis River below Newaukum River near Chehalis (12025025) 93 09-11-2007 5 13.7 88.4 97.7 5 to 22.3

Salzer Creek at Airport Road near Centralia (12025400) .96 09-11-2007 11 .9 1.1 

Skookumchuck River near Bucoda (12026400) 99.9 09-11-2007 5 94.9 104.9 

Skookumchuck River at mouth near Centralia (12026620) 103 09-11-2007 8 3.1 94.8 111.2 -10.1 to 16.3

Chehalis River at Fort Borst Park near Centralia (12026625) 197 09-11-2007 8 .0 181.2 212.8 

Chehalis River at Galvin (12026700) 192 09-13-2007 8 176.6 207.4 

Chehalis River at Galvin (12026700) 2

201 09-11-2007 11 24.0 178.9 223.1 -33.8 to 41.8

Chehalis River near Grand Mound (12027500) 201 09-11-2007 5 1

2.2 191.0 211.1 -34.6 to 30.2

Prairie Creek near Grand Mound (12027540) 0 09-11-2007 .0 .0 

Scatter Creek at Case Road near Grand Mound (12028020) 0 09-11-2007 .0 .0 

Scatter Creek at Sargent Road near Rochester (12028040) 20.7 09-11-2007 8 20.7 19.0 22.4 19 to 22.3

Scatter Creek at James Road near Rochester (12028055) 18.1 09-11-2007 8 -2.6 16.7 19.5 -5.7 to 0.5

Chehalis River near Rochester (12028060) 296 09-11-2007 11 76.9 263.4 328.6 32.8 to 120.9

289 09-12-2007 8 265.9 312.1 

Chehalis River near Independence (12028080) 242 09-12-2007 5 -47.0 229.9 254.1 -82.2 to -11.7

Chehalis River above Black River near Oakville (12028300) 237 09-12-2007 8 -5.0 218.0 256.0 -36 to 26

Black River below Salmon Creek near Littlerock (12028330) 10.5 09-12-2007 11 9.3 11.7 

Blooms Ditch below Littlerock Road near Littlerock (12028360) .45 09-12-2007 8 .4 .5 

Black River near Littlerock (12028440) 13.2 09-12-2007 8 2.3 12.1 14.3 0 to 4.4

Wadell Creek near Littlerock (12028500) 3.68 09-12-2007 5 3.5 3.9 

Black River at Littlerock (12029000) 12.8 09-12-2007 5 -4.1 12.2 13.4 -5.9 to -2.2

Beaver Creek near Maytown (12029025) .59 09-12-2007 8 .5 .6 

Beaver Creek at Littlerock (12029060) 3.02 09-12-2007 8 2.4 2.8 3.3 2.1 to 2.7

Unnamed tributary to Black River near Mima (12029090) 0 09-12-2007 0 .0 .0 

Mima Creek near Mima (12029160) 2.39 09-12-2007 8 2.2 2.6 

Unnamed tributary to Black River near Gate (12029175) .61 09-12-2007 11 .5 .7 

Black River at Gate (12029180) 70.2 09-12-2007 11 51.4 62.5 77.9 42.5 to 60.2

Table 1. Evaluation of gains and losses, with error analysis measurements for the seepage investigation, Chehalis River basin, 

Washington, September 2007.

[Measurement sites are shown at http://wa.water.usgs.gov/projects/chehalis/seepage_run.htm. Abbreviations: ft3/s, cubic foot per second; <, less than; 

e, estimated; –, no data]
6 Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

Measurement sites and No.

Measured 

streamflow 

(ft3/s)

Date

Assumed 

measurement 

error

(percent)

Gain 

or 

loss 

(ft3/s)

Erroradjusted 

minimum 

streamflow 

(ft3

/s)

Erroradjusted 

maximum 

streamflow 

(ft3/s)

Net gain 

or loss 

uncertainty 

range 

(cumulative 

measurement 

error; ft3

/s)

Black River near Oakville (12029200) 50.8 09-12-2007 8 -19.4 46.7 54.9 -31.1 to -7.6

Willamette Creek near Howanut Road near Oakville (12029201) <.1e 09-12-2007 11 .1 .1 

Black River near mouth near Oakville (12029210) 72.1 09-12-2007 8 21.2 66.3 77.9 11.3 to 31

Garrard (Garrod) Creek near Oakville (12029500) <1e 09-12-2007 11 .9 1.1 

Chehalis River near Oakville (12029700) 363 09-12-2007 8 52.9 334.0 392.0 36.9 to 68.8

Davis Creek near Oakville (12029780) 0 09-12-2007 0 .0 .0 

Chehalis River near Cedarville (12029800) 297 09-12-2007 5 -66.0 282.2 311.9 -109.8 to -22.1

292 09-13-2007 5 277.4 306.6 

Rock Creek near Cedarville (12030020) .92 09-13-2007 8 .8 1.0 

Cedar Creek near Cedarville (12030505) 8.28 09-13-2007 8 7.6 8.9 

Gibson Creek near Porter (12030550) 1.63 09-13-2007 5 1.5 1.7 

Chehalis River near Porter (12030600) 331 09-13-2007 5 28.2 314.5 347.6 -3.7 to 60.1

Gaddis Creek near Porter (12030650) 0 09-13-2007 .0 .0 

Porter Creek at U.S. Highway 12 at Porter (12030950) 8.63 09-13-2007 8 7.9 9.3 

Chehalis River at Porter (12031000) 330 09-13-2007 8 -9.6 303.6 356.4 -53.2 to 34

Chehalis River near Malone (12031020) 352 09-13-2007 5 22.0 334.4 369.6 -22 to 66

Eaton Creek at Rony (12031050) .41 09-13-2007 11 .4 .5 

Delezene Creek near Saginaw (12031860) 2.4 09-13-2007 8 2.2 2.6 

Cloquallum Creek at Elma (12032500) 25.2 09-13-2007 5 23.9 26.5 

Chehalis River near South Elma (12033100) 379 09-13-2007 8 -1.0 348.7 409.3 -50.4 to 48.4

Chehalis River above Satsop River at Fuller (12033305) 423 09-13-2007 8 44.0 389.2 456.8 -20.1 to 108.1

Satsop River near Satsop (12035000) 277 09-13-2007 5 263.2 290.9 

1

 Tributary streamflow (not shown) calculated by MOVE methods (Hirsch, 1982).

2

 Streamflow adjusted to date of downstream measurement site.

Table 1. Evaluation of gains and losses, with error analysis measurements for the seepage investigation, Chehalis River basin, 

Washington, September 2007.—Continued

[Measurement sites are shown at http://wa.water.usgs.gov/projects/chehalis/seepage_run.htm. Abbreviations: ft3/s, cubic foot per second; <, less than; 

e, estimated; –, no data]
Seepage Investigation 7

tac08_0252_Fig04

123°30' 123°15' 123°

47°

46°

45'

0 2 4 6 8 10 MILES

0 2 4 6 8 10 KILOMETERS

Chehalis 

River 

Chehalis 

River

 Satsop

River

Black

River Scatter Creek

Elk Creek

Newaukum River

Skookumchuck River

P

O

N

M

L

K

I J

H

G

F

E

D

C

B

A

S R

Elk Creek

(12020500)

Lincoln Creek

(12027000)

Q

T

Pe Ell

Chehalis

Centralia

Grand

Mound

Porter 

Doty

Rochester

Elma

GRAYS HARBOR CO.

PACIFIC CO.

THURSTON CO.

LEWIS CO. Lincoln Creek

EXPLANATION

Seepage reach index letter

 (refer to figure 5)

Seepage reach end point

Measurement

 site

Gaining reach

Losing reach

No gain or loss

J

Base from U.S. Geological Survey Digital Data, 1:100,000, 1985

Universal Transverse Mercator projection,

Zone 10, North American Datum of 1983

Figure 4. Discharge gains and losses in reaches along the Chehalis River, Washington.
8 Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

Figure 5. Cumulative discharge gains and losses by river mile, Chehalis River, Washington.

tac08-0252_Figure 05

MLKJIHGFEDCBA PON SRQ T

-80

-60

-40

-20

0

20

40

60

80

100

0 20 40 60 80 100

RIVER MILE

CUMULATIVE GAIN OR LOSS, IN CUBIC FEET PER SECOND

SEEPAGE REACH

44

-1 -5

22 18

-66

-47

-2.2

0

-2.9

1.4

-0.1

0.9 4

-9.6 -7.8

28.2

53.4

76.9

13.7
Seepage Investigation 9

Figure 6. Approximate location of certificated surface-water diversion rates and permitted surface-water 

discharges along the Chehalis River, Washington.

tac08-0252_Fig06

123°30' 123°15' 123°

47°

46°

45'

0 2 4 6 8 10 MILES

0 2 4 6 8 10 KILOMETERS

Chehalis 

River 

Chehalis River

 Satsop

River

Newaukum River

Skookumchuck River

Black

River Scatter Creek

Elk Creek

Lincoln Creek

Pe Ell

Chehalis

Centralia

Grand

Mound

Porter 

Doty

Rochester

Elma

GRAYS HARBOR CO.

PACIFIC CO.

THURSTON CO.

LEWIS CO.

EXPLANATION

Municipal and commercial

 surface-water discharge

Fish hatchery surface-

 water discharge

0.02 - 1.00

1.01 - 2.00

2.01 - 3.00

3.01 - 4.00

4.01 - 5.00

5.01 - 10.00

Certificated surface-water

 diversions, in cubic feet

 per second

Base from U.S. Geological Survey Digital Data, 1:100,000, 1985

Universal Transverse Mercator projection,

Zone 10, North American Datum of 1983
10 Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

Summary

A seepage investigation was completed in September 

2007 on the Chehalis River and selected tributaries to 

determine the amount and spatial extent of exchange between 

the ground and surface-water systems. Discharge was 

measured at 68 new and existing streamflow sites, resulting 

in measured gains and losses for 36 stream reaches. Gains 

were measured for 22 reaches and losses were measured for 

13 reaches. No gain or loss was measured at Chehalis River 

between the Newaukum and Skookumchuck Rivers. The 

Chehalis River exhibited a pattern of alternating gains and 

losses as it entered the area of wide, gentle relief known as the 

Grand Mound Prairie. The general pattern of tributary groundand surface-water interaction was discharge to streams 

(gaining reaches) in the upper reaches and discharge to the 

ground-water system (losing reaches) as the tributaries entered 

the broad, flat Chehalis River valley. All gains and losses 

greater than 10 cubic feet per second occurred as the Chehalis 

River entered the Grand Mound Prairie and continued to flow 

downstream to the Satsop River.

References Cited

Das, Tapas, 1993, Chehalis River basin Class II inspections at 

eight NPDES permitted dischargers August 1991–August 

1992: Washington State Department of Ecology, Publication 

no. 93-e11, 54 p.

Garrigues, R.S., Sinclair, K., and Tooley, J., 1998, Chehalis 

River watershed surficial aquifer characterization: 

Washington State Department of Ecology, Publication no. 

98-335, 33 p., accessed August 1, 2008, at http://www.ecy.

wa.gov/biblio/98335.html

Hirsch, R.M., 1982, A comparison of four record extension 

techniques: Water Resources Research, v. 18, no. 4, 

p. 1081–1088.

Homer, C.C., Huang, C., Yang, L., Wylie, B., and Coan, M., 

2004, Development of a 2001 national landcover database 

for the United States: Photogrammetric Engineering and 

Remote Sensing, no. 70, p. 829–840.

Oberg, K.A., Morlock, S.E., and Caldwell, W.S., 2005, Quality 

assurance plan for discharge measurements using acoustic 

Doppler current profilers: U.S. Geological Survey Scientific 

Investigations Report 2005-5183, 35 p.

Pitz, C.F., Sinclair, K.A., and Oestreich, A.J., 2005, 

Washington State groundwater assessment program—

Hydrology and quality of groundwater in the Centralia–

Chehalis area surficial aquifer: Washington State 

Department of Ecology, Publication no. 05-03-040, 104 p., 

4 pls.

Rantz, S.E., 1982, Measurement and computation of 

streamflow, volume 1—Measurement of stage and 

discharge: U.S. Geological Survey Water-Supply Paper 

2175, 284 p.

U.S. Geological Survey, 2008, Annual water-data reports: U.S. 

Geological Survey, available on-line at http://wdr.water.

usgs.gov/
Appendix A. Details of Method to Estimate Discharge with Miscellaneous Measurements 11

Appendix A. Details of Method to 

Estimate Discharge with 

Miscellaneous Measurements

Discharge was not measured at Elk and Lincoln Creeks. 

Discharge at these creeks was estimated using the maintenance 

of variance extension (MOVE; Hirsch, 1982) method. 

( ) ˆ

where

ˆ is the estimated discharge at the 

miscellaneous site;

is the mean of the measured discharge 

at the miscellaneous site;

is the standard deviation of measured 

discharge at the mis

=+ − y

i i

x

i

y

s

YY X X

s

Y

Y

s

cellaneous site;

is the standard deviation of measured 

discharge at the index gaging station;

is the measured discharge at the index 

gaging station for the concurrent 

period; and

is the mean of the 

x

i

s

X

X measured discharge 

at the index gage for the concurrent 

period.

(1)

The conditions for this method are not strictly met, but 

they did provide an adequate estimate of discharge. Using the 

MOVE method, a relation was calculated using the means 

and standard deviations of a series of miscellaneous discharge 

measurements collected at each creek during late summer to 

early autumn and daily mean discharge at established USGS 

streamflow-gaging stations on concurrent days. That relation 

was applied for the day of the seepage measurement and 

discharge for Elk and Lincoln Creeks (fig. 4) was estimated. 

Station 12020500 (Elk Creek) is 2.6 mi west of Doty and 

2.5 mi from the confluence with the Chehalis River. Station 

12027000 (Lincoln Creek) is 7 mi southwest of Rochester and 

8.2 mi from the confluence with the Chehalis River.

Results of the discharge estimation are shown in tables 

A1 and A2 for Elk and Lincoln Creeks, respectively. The two 

locations for which discharge were estimated are not located at 

the confluences with the Chehalis River. It is not known what 

gains or losses normally occur on Elk and Lincoln Creeks 

between the miscellaneous site and the Chehalis River. Pitz 

and others (2005) measured discharges of 0.75 ft3

/s at Lincoln 

Creek near the mouth and 211 ft3/s at Chehalis River near 

Grand Mound. This indicated that the estimated discharge 

presented here for the Lincoln Creek measurement site 

(12027000) may be an overestimation of discharge for Lincoln 

Creek at the confluence with the Chehalis River.

Table A1. Miscellaneous discharge measurements for Elk Creek 

and daily mean discharge for Chehalis River at Doty, Washington.

[Abbreviation: ft3/s, cubic foot per second]

Date

Elk Creek 

(12020500) discharge 

(ft3

/s)

Chehalis River at Doty 

(12020500) discharge 

(ft3/s)

08-16-1951 11 25

08-12-1959 16 38

08-25-1966 11 28

10-06-1966 13 31

08-03-1967 10 27

08-28-1973 13 35

09-11-2007 18

Mean 12.3 30.7

Standard deviation 2.2 5.0

Estimated streamflow 6.8

Table A2. Miscellaneous discharge measurements for Lincoln 

Creek and daily mean discharge for Chehalis River near Grand 

Mound, Washington.

[Abbreviation: ft3/s, cubic foot per second]

Date

Lincoln Creek 

(12027000) discharge 

(ft3

/s)

Chehalis River near 

Grand Mound 

(12031000) discharge 

(ft3

/s)

08-16-1951 0.42 124

07-10-1958 4.0 240

07-23-1958 2.0 181

08-04-1958 2.5 150

07-13-1959 5.9 435

07-27-1959 2.9 245

08-10-1959 1.8 192

10-02-1973 2.5 370

09-22-1944 5.9 298

10-26-1944 3.9 235

09-12-2007 192

Mean 3.2 247.0

Standard Deviation 1.8 97.3

Estimated streamflow 2.2
12 Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington

This page intentionally left blank.
Manuscript approved for publication, September 25, 2008

Prepared by the USGS Publishing Network, 

Publishing Service Center, Tacoma, Washington

Bob Crist

Bill Gibbs

Debra Grillo

Virginia Renslow

Bobbie Jo Richey

For more information concerning the research in this report, contact the 

Director, Washington Water Science Center

U.S. Geological Survey, 934 Broadway — Suite 300

Tacoma, Washington 98402

http://wa.water.usgs.gov
Ely and others—Seepage Investigation for Selected River Reaches in the Chehalis River Basin, Washington—Scientific Investigations Report 2008-5180