Hydrogeologic Framework of Sedimentary Deposits in

Six Structural Basins, Yakima River Basin, Washington

Scientific Investigations Report 2006–5116

Prepared in cooperation with the 

Bureau of Reclamation, 

Washington State Department of Ecology, and the 

Yakama Nation

U.S. Department of the Interior

U.S. Geological Survey
Cover: Photograph of Clark Well No. 1, located on the north side of the Moxee Valley in North Yakima, 

Washington. The well is located in township 12 north, range 20 east, section 6. The well was drilled 

to a depth of 940 feet into an artesian zone of the Ellensburg Formation, and completed in 1897 at a 

cost of $2,000. The original flow from the well was estimated at about 600 gallons per minute, and 

was used to irrigate 250 acres in 1900 and supplied water to 8 small ranches with an additional 47 

acres of irrigation. (Photograph was taken by E.E. James in 1897, and was printed in 1901 in the U.S. 

Geological Survey Water-Supply and Irrigation Paper 55.)
Hydrogeologic Framework of Sedimentary 

Deposits in Six Structural Basins, 

Yakima River Basin, Washington

By M.A. Jones, J.J. Vaccaro, and A.M. Watkins

Prepared in cooperation with the

Bureau of Reclamation, 

Washington State Department of Ecology, and the

Yakama Nation

Scientific Investigations Report 2006–5116

U.S. Department of the Interior

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

Dirk A. Kempthorne, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

For sale by U.S. Geological Survey, Information Services

Box 25286, Denver Federal Center

Denver, CO 80225

For more information about the USGS and its products:

Telephone: 1-888-ASK-USGS

World Wide Web: http://www.usgs.gov/

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply 

endorsement by the U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Jones, M.A., Vaccaro, J.J., and Watkins, A.M., 2006, Hydrogeologic framework of sedimentary deposits in six 

structural basins, Yakima River Basin, Washington: U.S. Geological Survey Scientific Investigations Report 2006-5116, 

24 p. 
iii

Contents

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

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

Purpose and Scope ....................................................................................... 2

Description of Study Area .............................................................................. 2

Location and Setting .............................................................................. 3

Development of Water Resources ............................................................... 3

Overview of the Geology ........................................................................... 6

Well-Numbering System ................................................................................. 8

Methods of Investigation................................................................................. 9

Hydrogeologic Framework .............................................................................. 12

Roslyn Basin ....................................................................................... 12

Kittitas Basin ....................................................................................... 13

Selah Basin .......................................................................................... 13

Yakima Basin ....................................................................................... 14

Toppenish Basin .................................................................................... 14

Benton Basin ....................................................................................... 15

Summary and Conclusions .............................................................................. 22

Acknowledgments ....................................................................................... 22

Selected References .................................................................................... 22

Plates

Plate 1. Maps and hydrogeologic sections showing surficial geology, extent and

thickness of basin-fill deposits, hydrogeologic units, and locations of

selected wells in the Roslyn Basin, Yakima River Basin, Washington.

Plate 2. Maps and hydrogeologic sections showing surficial geology, extent and

thickness of basin-fill deposits, hydrogeologic units, and locations of

selected wells in the Kittitas Basin, Yakima River Basin, Washington.

Plate 3. Maps and hydrogeologic sections showing surficial geology, extent and

thickness of basin-fill deposits, hydrogeologic units, and locations of

selected wells in the Selah Basin, Yakima River Basin, Washington.

Plate 4. Maps and hydrogeologic sections showing surficial geology, extent and 

thickness of basin-fill deposits, hydrogeologic units, and locations of 

selected wells in the Yakima Basin, Yakima River Basin, Washington.

Plate 5. Maps and hydrogeologic sections showing surficial geology, extent and 

thickness of basin-fill deposits, hydrogeologic units, and locations of 

selected wells in the Toppenish Basin, Yakima River Basin, Washington.

Plate 6. Maps and hydrogeologic sections showing surficial geology (sheet 1), extent and 

thickness of basin-fill deposits, hydrogeologic units, and locations of 

selected wells (sheet 2) in the Benton Basin, Yakima River Basin, Washington.
iv

Figures

Figure 1. Map showing the Yakima River Basin, Washington .................................... 2

Figure 2. Map showing land use and land cover, Yakima River Basin, Washington, 1999 ... 4

Figure 3. Schematic diagram showing selected tributaries, diversion canals, return 

flows, and streamflow-gaging stations, Yakima River Basin, Washington ......... 5

Figure 4. Map showing simplified surficial geology, Yakima River Basin, Washington ...... 7

Figure 5. Diagram showing well-numbering systems used in the State of Washington ...... 8

Figure 6. Map showing location of six sedimentary basins, Yakima River Basin, 

Washington ................................................................................. 10

Figure 7. Map showing structure delineating six sedimentary basins, Yakima River 

Basin, Washington ........................................................................ 11

Figure 8. Maps showing thickness of subunits 1-6 in northeastern Benton Basin, 

Yakima River Basin, Washington ......................................................... 16

Conversion Factors, Datums, and Abbreviations

Inch/Pound to SI

Multiply By To obtain length

acre 4,047 square meter

acre-foot (acre-ft) 1,233 cubic meter

acre-foot (acre-ft) 0.001233 cubic hectometer

acre-foot per year (acre-ft/yr) 1,233 cubic meter per year

cubic foot (ft3) 0.02832 cubic meter

cubic foot per second (ft3/s) 0.02832 cubic meter per second 

foot (ft) 0.3048 meter

gallon (gal) 3.785 liter 

gallon (gal) 0.003785 cubic meter

gallon (gal) 3.785 cubic decimeter 

gallon per minute (gal/min) 0.06309 liter per second

gallon per day (gal/d) 0.003785 cubic meter per day

inch (in.) 2.54 centimeter

inch (in.) 25.4 millimeter

mile (mi) 1.609 kilometer

million gallons (Mgal) 3,785 cubic meter

million gallons per day (Mgal/d) 0.04381 cubic meter per second 

section (640 acres or 1 square mile) 259.0 square hectometer

square foot (ft2) 0.09290 square meter

square inch (in2) 6.452 square centimeter

square mile (mi2) 2.590 square kilometer 

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C=(°F-32)/1.8

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

Vertical coordinate information is referenced to the North American Vertical Datum of 1929 

(NAVD 29).

Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27).

Abbreviations

Abbreviation Definition

CRBG Columbia River Basalt Group

DEM digital elevation model

DGER Division of Geology and Earth Resources

DNR Washington State Department of Natural Resources

GIS Geographic Informaton System

GPS global positioning system

NWIS National Water Information System

SOAC System Operations Advisory Committee

TWSA current available storage in the reservoirs, estimates of 

unregulated flow, and other sources that are principally return 

flow

USGS U.S. Geological Survey

WaDOE Washington State Department of Ecology

WRIA Washington State Water Resources Inventory Area

YN Yakama Nation

Conversion Factors, Datums, and Abbreviatons—Continued
vi

This page intentionally left blank.
Abstract

The hydrogeologic framework was delineated for the 

ground-water flow system of the sedimentary deposits in six 

structural basins in the Yakima River Basin, Washington. The 

six basins delineated, from north to south are: Roslyn, Kittitas, 

Selah, Yakima, Toppenish, and Benton. Extent and thicknesses 

of the hydrogeologic units and total basin sediment thickness 

were mapped for each basin. Interpretations were based on 

information from about 4,700 well records using geochemical, 

geophysical, geologist’s or driller’s logs, and from the 

surficial geology and previously constructed maps and well 

interpretations. The sedimentary deposits were thickest in 

the Kittitas Basin reaching a depth of greater than 2,000 ft, 

followed by successively thinner sedimentary deposits in the 

Selah basin with about 1,900 ft, Yakima Basin with about 

1,800 ft, Toppenish Basin with about 1,200 ft, Benton basin 

with about 870 ft and Roslyn Basin with about 700 ft.

Introduction

Surface water in the Yakima River Basin, in south-central 

Washington (fig. 1) is under adjudication and the amount 

of surface water available for appropriation is unknown, 

but there are increasing demands for water for municipal, 

fisheries, agricultural, industrial, and recreational uses. These 

demands must be met by ground-water withdrawals and/or 

by changes in the way water resources are allocated and used. 

On-going activities in the basin for enhancement of fisheries 

and obtaining additional water for agriculture may be affected 

by ground-water withdrawals and by rules implemented under 

the Endangered Species Act for salmonids that have been 

either listed or are proposed for listing in the late 1990s. An 

integrated understanding of the ground-water flow system and 

its relation to the surface-water resources is needed in order 

to implement most water-resources management strategies in 

the basin. In order to obtain this understanding, a study of the 

Yakima River Basin aquifer system began in June 2000. The 

study is a cooperative effort of the U.S. Geological Survey 

(USGS), Bureau of Reclamation (Reclamation), the Yakama 

Nation (YN), and the Washington State Department of 

Ecology (WaDOE). 

The objectives of the study as a whole are to fully 

describe the ground-water flow system and its interaction 

with and relation to surface water, and to integrate this 

information into a management tool—a numerical model. 

The conceptual model of the flow system and the results of 

the study will be used to guide and support actions taken 

by management agencies with respect to ground-water 

availability and to provide information to other stakeholders 

and interested parties. The numerical model will be developed 

as an integrated tool for short-term to long-term management 

activities, including the testing of potential management 

strategies. 

The study includes three phases. The first phase includes 

(1) project planning and coordination, (2) compiling, 

documenting, and assessing available data, and (3) initial data 

collection. The second phase consists of data collection to 

support the following Phase 2 work elements: (1) mapping 

of hydrogeologic units, (2) estimating ground-water 

pumpage, (3) developing estimates of ground-water recharge, 

(4) assessing ground water-surface water interchanges, and 

(5) constructing maps of ground-water levels. Together, these 

five elements provide the information needed to describe the 

ground-water flow system, the conceptual model, and provide 

the building blocks for the hydrogeologic framework. In the 

third phase, six structural basin models and one regional 

model of the ground-water flow system will be constructed 

in order to integrate the available information. The numerical 

models will be used to gain a further understanding of the 

flow system and its relation to surface water, and to test 

management strategies. The models will be developed and 

maintained in such a fashion that it will be available and open 

to others.

The results from selected work elements will be 

described in a series of reports. The Introduction and 

Description of Study Area sections of this report are common 

to all reports.

Hydrogeologic Framework of Sedimentary Deposits in 

Six Structural Basins, Yakima River Basin, Washington

By M.A. Jones, J.J. Vaccaro, and A.M. Watkins
Purpose and Scope

This report describes the hydrogeologic framework of 

six structural sedimentary basins within the Yakima River 

Basin aquifer system. This framework will be used to develop 

a conceptual model describing local and regional groundwater flow systems. Maps presented in this report provide the 

hydraulic characteristics and boundaries of the hydrogeologic 

units located within the Yakima River Basin aquifer system.

Description of Study Area

The general location and setting of the study area, the 

development of water resources in the basin, and an overview 

of the geology are presented to provide a general background 

for understanding the study area.

82 

22

22

97 

97

97

12

12

82

82

240

24

410

240

90 

90 

90 

24

410

12

97

12 

241

82 

82 12 

KITTITAS COUNTY 

YAKIMA COUNTY 

COUNTY

BENTON COUNTY

KLICKITAT

COUNTY

YAKIMA

EXPLANATION

BOUNDARY OF YAKIMA

 RIVER BASIN

Canal

Roza

Sunnyside Canal

Main Canal

Extension

Kennewick

Main Canal

Marion Drain

North

Branch

Canal

Kittitas Main Canal

Bumping

Lake N Fk 

S Fk

S Fk 

N Fk 

S Fk 

N Fk 

N Fk 

Cle Elum River

Swauk Creek

Caribou Cr

Coleman Cr

Naneum

Cr

Cooke Cr

Crow Creek

Bumping River

American River

Rattlesnake Cr

Little Rattlesnake Cr

Nile Creek

Manastash

Badger Creek

Lmuma Cr

Ahtanum Creek

Oak Creek

Tieton River

Wide Hollow Cr

Wenas Creek

Selah Creek

North Fork

Dry Creek

Simcoe Creek

Agency Creek

Creek

Toppenish

Corral Cr

RIVER

Spring Cr

Logy Creek

Satus

Creek

Mule Dry

Creek

Cle

Elum

Lake

Rimrock

Lake

Kachess Lake

Keechelus Lake

Lake

Wallula

Priest

Rapids

Lake

Teanaway River Reecer Cr

Wilson Creek

Park Cr

Taneum Creek

Umtanum Creek

Little Naches River

Cr

Cowiche Creek

Cowiche Creek

River

Naches

Snipes Cr

Sulphur Cr Wasteway

Cherry Cr

S Fk

N Fk

YAKIMA

YAKIMA

RIVER

Cle Elum 

Parker

Wapato

Ellensburg

Umtanum

Kittitas

Thrall

Toppenish

Moxee City Union Gap

Yakima

Selah

Naches

Sunnyside Richland

Kiona

Kennewick Prosser

Grandview

Mabton

Satus

Zillah

Granger

Roza

Easton

Teanaway

Tieton Rimrock

Snoqualmie

Pass

Van Epps 

Pass

Esmeralda

Peaks

K I T T I T A S

V A L L E Y

M A N A S T A S H

KACHESS RIDGE

R I D G E

UNION GAP

CLEMAN 

MOUNTAIN 

TEANAWAY

NORTH RIDGE

U M T A N U M

R I D G E

Deception

Pass

Y A K I M A 

 V A L L E Y 

AHTANUM RIDGE

COWICHE MTN

AMERICAN RIDGE

CLE ELUM

RIDGE

RIDGE

TOPPENISH RIDGE

R A T T L E S N A K E H I L L S

Y A K I M A R I D G E

H O R S E

H E A V E N

H I L L S

C

A

S C A

D E R

A

N

G

E

W E N AT C H E E

M O U N TA I N S

Gilbert

Peak

121°

47°

47°

30'

46°

121°30' 120°30' 120° 119°30'

46°

30'

0 5 10 20 30 40 MILES 

0 5 10 20 30 40 50 60 KILOMETERS 

Yakima

River

Basin

WASHINGTON

waA4WT1_fig01

Figure 1. The Yakima River Basin, Washington.

 Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Location and Setting

 The Yakima River Basin aquifer system underlies about 

6,200 mi2 in south-central Washington (fig. 1). The Yakima 

River Basin produces a mean annual unregulated streamflow 

(adjusted for regulation and without diversions or returns) of 

about 5,600 ft3/s (about 4.1 million acre-ft) and a regulated 

streamflow of about 3,600 ft3/s (about 2.6 million acre-ft). 

The basin includes three Washington State Water Resource 

Inventory Areas (WRIA—numbers 37, 38, and 39), part of the 

Yakama Nation lands, and three ecoregions (Cascades, Eastern 

Cascades, and Columbia Basin—Omernik, 1987; Cuffney 

and others, 1997). The basin includes parts of four counties 

(Klickitat, Kittitas, Yakima, and Benton). Almost all of 

Yakima County and more than 80 percent of Kittitas County 

lie within the basin, and about 50 percent of Benton County is 

in the basin. Less than 1 percent of the basin lies in Klickitat 

County, principally in an unpopulated upland area. 

The headwaters of the basin are on the upper, humid 

east slope of the Cascade Range, where the mean annual 

precipitation is more than 100 in. The basin terminates at 

the confluence of the Yakima and Columbia Rivers in the 

low-lying, arid part of the basin, which receives about 6 in of 

precipitation per year. Altitudes in the basin range from 400 

to nearly 8,000 ft. There are eight major rivers and numerous 

smaller streams tributary to the Yakima River (fig. 1); the 

largest tributary is the Naches River. Most of the precipitation 

in the basin falls during the winter months as snow in the 

mountains. The mean annual precipitation over the entire 

basin is about 27 in (about 12,000 ft3/s or 8.7 million acre-ft). 

The spatial pattern of mean annual precipitation resembles 

the pattern of the basin’s highly variable topography. The 

difference between the mean annual precipitation and mean 

annual unregulated streamflow is 6,400 ft3/s (about 4.6 million 

acre-ft) or about 53 percent of the precipitation is lost to 

evapotranspiration under natural conditions.

The basin is separated into several broad valleys by large 

east-west trending anticlinal ridges. The valley floors are flat 

and slope gently towards the Yakima River. Few perennial 

tributary streams traverse these valleys. Most of the population 

and economic activity occurs in these valleys.

Agriculture is the principal economic activity in the 

basin. The average annual surface-water demand met by 

the Reclamation project is about 2.5 million acre-ft; there 

is about 336,000 acre-ft of additional demand in the lower 

river basin that is separate from the demand met by the 

project. Additional surface-water demand that is not met by 

Reclamation occurs in smaller tributaries and on the large 

rivers; this demand is based on State appropriated water. 

More than 95 percent of the demand is for irrigation of about 

500,000 acres in the low-lying semiarid to arid parts of the 

basin (fig. 2). The demand is partially met by storage of nearly 

1.1 million acre-ft of water in five Reclamation reservoirs. The 

major management point for Reclamation is at the Yakima 

River near Parker streamflow gaging station. Just upstream of 

this site, at Union Gap, is the location that is considered the 

dividing line between the upper (mean annual precipitation 

of 7 to 125 in) and lower (mean annual precipitation of 6 to 

45 in) parts of the Yakima River Basin. About 45 percent 

of the water diverted for irrigation is eventually returned to 

the river system as surface-water inflows and ground-water 

discharge, but at varying time-lags (Bureau of Reclamation, 

1999). During the low-flow period, these return flows, on 

average, account for about 75 percent of the streamflow below 

the Yakima River near Parker streamflow gaging station. Much 

of the surface-water demand in the basin below Parker is met 

by these return flows and not by the release of water from the 

reservoirs. As a result of water use in the basin, the difference 

between mean annual unregulated and regulated streamflow in 

the basin is about 2,000 ft3/s, suggesting that some 1.4 million 

acre-ft of water, or about 17 percent of the precipitation in the 

basin, is consumptively used—principally by irrigated crops 

through evapotranspiration.

Development of Water Resources

Missionaries arrived in the basin in 1848 and established 

a mission in 1852 on Atanum (now Ahtanum) Creek. They 

were some of the first non-Indian settlers to use irrigation on 

a small scale. Miners and cattlemen immigrated to the basin 

in the 1850s and 1860s, which resulted in a new demand for 

water. With increased settlement in the mid-1860s, irrigation 

of the fertile valley bottoms began and the outlying areas were 

extensively used for stock raising. One of the first known 

non-Indian irrigation ditches was constructed in 1867 and 

diverted water from the Naches River (Parker and Storey, 

1913; Flaherty, 1975). Private companies later delivered 

water through canal systems built between 1880 and 1904 

for the irrigation of large areas. The development of irrigated 

agriculture was made more attractive by the construction 

of the Northern Pacific Railway that reached Yakima in 

December 1884, which provided a means to transport 

agricultural goods to markets; two years later, the completion 

of the railway to the coast provided new and easily accessible 

markets for agricultural products. The State of Washington 

was created in 1889, spurring further growth in the basin, 

especially because the cities of Ellensburg and Yakima were 

in contention for being the state capital. By 1902 there were 

about 120,000 acres under mostly surface-water irrigation in 

the basin (Parker and Storey, 1913; Bureau of Reclamation, 

1999).

Description of Study Area 
The Federal Reclamation Act was enacted in 1902 

to enable the construction of Federal water projects in the 

western United States in order to expand the development 

of the West. In 1905, the Washington State Legislature 

passed the Reclamation Enabling Act and the Yakima 

Federal Reclamation Project was authorized to construct 

facilities to irrigate about 500,000 acres. As part of the 1905 

authorization and extensions, all forms of further appropriation 

of unappropriated water in the basin were withdrawn (Parker 

and Storey, 1913). Six dams were constructed as part of the 

Yakima Project: Bumping Dam in 1910, Kachess Dam in 

1912, Clear Creek Dam in 1914, Keechelus Dam in 1917, 

Tieton Dam (Rimrock Lake) in 1925, and Cle Elum Dam 

in 1933. The construction of the dams and other irrigation 

facilities resulted in an extremely complicated surface-water 

system (fig. 3). These Federal reservoirs provide water 

storage to meet irrigation requirements of the major irrigation 

districts at the time of year when the natural streamflow from 

unregulated streams can no longer meet demands; this time 

is referred to as the ‘storage control’ date. Several of the 

reservoirs also provide instream flows during the winter for 

the incubation of salmon eggs in the salmon redds (gravel 

spawning nests). waa4wt1_01_fig02

Richland

Yakima

EXPLANATION

SIMPLIFIED LAND COVER

BOUNDARY OF

 AGRICULTURAL AREA

FOREST (33%)

RANGE (36%)

CITIES AND TOWNS (2%)

AGRICULTURE (28%)

Hops

Irrigated hay

Mixed row crops

Orchards

Orchards and grapes

Undifferentated agriculture

LAKES AND RESERVOIRS (1%)

121°

47°

47°

30'

46°

121°30' 120°30' 120° 119°30'

46°

30'

KITTITAS COUNTY

YAKIMA COUNTY

COUNTY

BENTON COUNTY

KLICKITAT

COUNTY

YAKIMA

0 5 10 20 30 40 MILES

0 5 10 20 30 40 50 60 KILOMETERS

YAKIMA

RIVER

YAKIMA

RIVER

Figure 2. Land use and land cover, Yakima River Basin, Washington, 1999. 

(From Fuhrer and others, 2004.)

 Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Figure 3. Selected tributaries, diversion canals, return flows, and streamflow-gaging stations, Yakima River Basin, Washington. 

(From Fuhrer and others, 2004.)

Description of Study Area 

CITY OF YAKIMA 

RM 115.9 

RM 113.3 

RM 111.0 

RM 107.4 

RM 106.9 

RM 106.7 

RM 103.8 

RM 89.2 

RM 86.0 

RM 83.2 

RM 82.8 

RM 82.8 

RM 82.6 

RM 80.4 

RM 77.0 

RM 69.6 

RM 69.3 

RM 65.1 

RM 35.5 

RM 47.1 

RM 46.5 

RM 41.8 

RM 41.8 

RM 35.8 

RM 35.8 

RM 34.9 

RM 28.6 

RM 18.0 

Mouth of 

Yakima River 

RM 0.0 

RM 18.0 

RM 107.3 

12500450

RM 116.3 

RM 29.9 

12510500

RM 55.0 

12509050

RM 103.7 

12505000

RM 61.0 

COLUMBIA RIVER 

Kiona Canal

Benton City STP

Columbia Canal

Richland Canal

Corral Canyon Creek

Chandler Canal

Prosser STP

Spring Creek

Snipes Creek

Chandler Canal

Kennewick Canal

Satus Drain 303 

Mabton STP

Continued at top of next column 

RM 203.5 

RM 202.5 

RM 183.1 

RM 179.6 

RM 176.1 

RM 173.9 

RM 169.9 

RM 166.1 

RM 166.1 

RM 161.3 

RM 160.3 

RM 156.3 

RM 154.5 

RM 151.5 

RM 147.0 

RM 139.8 

RM 127.9 

RM 123.7 

RM 123.6 

RM 122.4 

RM 117.0 

RM 185.6 

RM 202.0 

12477000

RM 214.4 

12474500

RM 182.9 

12479500

RM 140.4 

12484500

RM 16.8 

12494000

RM 12.6 

RM 9.7 

RM 9.7 

RM 8.5 

RM 3.6 

RM 17.5 

RM 17.1 

YAKIMA RIVER

Moxee Canal

Roza Power Plant Return Flow 

Yakima STP 

Wide Hollow Creek 

Moxee Drain 

Moxee City STP 

North Fork 

Ahtanum Creek Ahtanum Creek 

South Fork 

Ahtanum Creek Wapato Canal

Sunnyside Canal

Zillah STP 

Toppenish STP 

East Toppenish Drain 

Sub-Drain No. 35 

Granger STP 

Toppenish Creek Coulee Drain

Satus Creek 

South Drain

DID No. 7

RM 60.2 

RM 59.5 

12506000

RM

23.1

RM 5.3 

12500500

Sunnyside STP

Sulphur Creek

RM 0.8 

12508850

YAKIMA 

RIVER

Kachess Kachess River 

Lake 

Kittitas Main Canal

Cle Elum WTP

Cle Elum STP

Teanaway River 

Kittitas Main Canal Return Flow 

Swauk Creek 

Taneum Creek 

West Side Ditch

Town Canal

Cascade Canal

Ellensburg Power Canal Outfall 

Manastash Creek 

Ellensburg STP 

Wilson Creek 

Naneum Creek 

Cherry

Creek 

RM

1.1

RM

20.0

RM 0.6 

12476000

RM

0.9

(Dam)

RM

8.2

(Dam)

RM 214.5 

(Dam)

Cle Elum 

Lake 

RM 7.9 Cle Elum River 12479000

RM 3.7 

12480500

RM 5.5 

12483800

Keechelus 

Lake 

Union and Fruitvale Canals

NACHES RIVER Cowiche Creek 

Granger Drain 

Wapato STP Harrah STP 

Marion Drain

Simcoe Creek 

Umtanum Creek 

Roza Canal

Selah Creek 

Selah-Moxee Canal

Wenas Creek 

Selah STP 

Little Naches River 

American River 

Bumping River 

Rattlesnake Creek 

Naches-Selah Canal

Tieton Canal 

Tieton River 

Wapatox Canal

Naches STP 

Wapatox Power Plant Return Flow 

Yakima WTP

Congdon Ditch

Naches-Cowiche Canal

Continued from bottom of previous column 

Rimrock 

Reservoir

RM 21.3 

(Dam)

RM 0.6 

12499000

RM 0.5 12488500

RM 16.6 

12488000

RM 19.4 

12489500

RM 20.9 

12491500

RM 14.2 

12492500

RM 44.6 

RM 27.8 

RM 18.4 

RM 13.9 

12506500

RM 4.0 

12501000

RM 2.7 

RM 2.7 

RM

3.5

DID No. 3

NACHES RIVER 

RM 44.2 

YAKIMA RIVER 

EXPLANATION

OUTFLOW FROM MAIN STEM

INFLOW TO MAIN STEM

GAGING STATION AND NO.

RIVER MILE

SEWAGE-TREATMENT PLANT

WATER-TREATMENT PLANT

DRAINAGE IRRIGATION DISTRICT

WTP

DID

STP

RM 140.4

12484500

waA4WT1_fig03
Legal challenges to water rights resulted in the 1945 

Consent Decree (U.S. District Court, 1945) that established 

the framework of how the Reclamation operates the Yakima 

Project to meet the water demands. The Decree determined 

two classes of rights—nonproratable and proratable. When 

the total water supply available (TWSA-defined as current 

available storage in the reservoirs, estimates of unregulated 

flow, and other sources that are principally return flows) is 

not sufficient to meet both classes of rights, the proratable 

(junior) rights are decreased according to the quantity of water 

available defined by the TWSA. This legally mandated method 

generally performs well in most years, but is dependent on the 

accuracy of the TWSA estimate. In some years, for example 

1977, problems have arisen because of errors in the TWSA 

estimate (Kratz, 1978; Glantz, 1982). System management 

also accounts for defined instream flows at selected target 

points on the river, and for suggested changes in storage 

releases recommended by the Systems Operations Advisory 

Committee (SOAC)—the advisory board of fishery biologists 

representing the different stakeholders (Systems Operations 

Advisory Committee, 1999).

The drilling of numerous wells for irrigation was spurred 

by new (post 1945) well-drilling technologies, legal rulings, 

and the onset of a multi-year dry period in 1977 (Vaccaro, 

1995). Population growth in the basin was, and still is, the 

driving force behind the increased drilling of shallow domestic 

wells and deeper public water supply wells. Currently, 

there are more than 20,000 wells in the basin. More than 

70 percent of these wells are shallow, 10-250 ft deep, domestic 

wells. Based on the digital water-rights database provided 

by WaDOE (R. Dixon, written commun., 2001) and other 

information there are at least 2,874 active ground-water rights 

associated with the wells in the basin that can withdraw an 

annual quantity of about 529,231 acre-ft during dry years. The 

irrigation rights are for the irrigation of about 129,570 acres. 

There are about 16,600 ground-water claims in the basin; these 

claims are for some 270,000 acre-ft of ground water (J. Kirk, 

written commun., Washington State Department of Ecology, 

1998). 

A water right claim is a statement of claim to water 

use that began before the state Water Codes were 

adopted, and is not covered by a water right permit 

or certificate. A water right claim does not establish 

a water right, but only provides documentation of 

one if it legally exists. Ultimately, the validity of 

claimed water rights would be determined through 

general water right adjudications. (Washington State 

Department of Ecology, 1998). 

A ground-water claim means a user claims that they were 

using ground water continuously, prior to 1945 when the State 

legislature enacted the Ground Water Code, for a particular 

use. Previous estimates of pumpage have varied widely and 

are presented in the report on pumpage (J.J. Vaccaro, U.S. 

Geological Survey, written commun., 2006).

Overview of the Geology

The Columbia Plateau has been informally divided 

into three physiographic subprovinces (Meyers and Price, 

1979). The western margin of the Columbia Plateau contains 

the Yakima Fold Belt subprovince and includes the Yakima 

River Basin. The Yakima Fold Belt is a highly folded and 

faulted region and within the study area part, it is underlain by 

various consolidated rocks, ranging in age from Precambrian 

to Tertiary, and unconsolidated materials and volcanic rocks 

of Quaternary age (fig. 4). In the Yakima River Basin, the 

headwater areas in the Cascade Range include metamorphic, 

sedimentary, and intrusive and extrusive igneous rocks. 

The central, eastern, and southwestern parts of the basin 

are composed of basalt lava flows of the Columbia River 

Basalt Group (CRBG) with some intercalated sediments that 

are discontinuous and weakly consolidated. The lowlands 

are underlain by unconsolidated and weakly consolidated 

valley-fill composed of glacial, glacio-fluvial, lacustrine, and 

alluvium deposits that in places exceed a 1,000 ft in thickness 

(Drost and others, 1990). Wind-blown deposits, called loess, 

occur locally along the lower valley.

Valley-fill deposits and basalt lava flows are important for 

ground-water occurrence in the study area. The basalt consists 

of a series of flows erupted during various stages of the 

Miocene Age, ranging from 17 to 6 million years ago. Basalt 

erupted from fissures from the eastern part of the Columbia 

Plateau and individual flows range in thickness from a few feet 

to more than 100 ft. The total thickness in the central part of 

the plateau is estimated to be greater than 10,000 ft (Drost and 

others, 1990) with a maximum thickness of more than 8,000 ft 

in the study area. Unlike most of the Columbia Plateau, the 

CRBG in the Yakima Fold Belt is underlain by sedimentary 

rocks. The valley-fill deposits were eroded from the Cascade 

Range and from the east-west-trending anticlinal ridges 

that were formed from the buckling of the basalt sequence 

during mid- to late-Miocene time. Much of these deposits are 

part of the Ellensburg Formation. This formation underlies, 

intercalates, and overlies the basalts along the western edge, 

and composes most of the thickness of the unconsolidated 

deposits (informally called the overburden; Drost and others, 

1990) in the basinal areas. The basins are narrow to large open 

synclinal valleys intervening between the numerous anticlinal 

ridges.

The deposition of a thick, upper sequence of sand, gravel, 

and some fine-grained material is the result of erosion by 

glacial ice and transport by meltwater streams. Damming of 

large lakes by glacial ice during the Pleistocene epoch resulted 

in the deposition of silt and clay beds in parts of the uplands. 

When the lakes drained, the fine sediments were exposed and 

subsequently eroded by wind and deposited over the lower, 

eastern parts of the study area. Thus, the unconsolidated 

materials in the basinal areas that are abutting and interbedded 

with the basalts range from Miocene to Holocene in age.

 Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Figure 4. Simplified surficial geology, Yakima River Basin, Washington. 

(From Fuhrer and others, 1994.)

waA4WT1_fig04

Kiona

Naches

Yakima

Wapato

Prosser

Cle Elum

Sunnyside Richland

Union Gap

Ellensburg

Toppenish

121°

47°

47°

30'

46°

121°30' 120°30' 120° 119°30'

46°

30'

0 5 10 20 30 40 MILES

0 5 10 20 30 40 50 60 KILOMETERS

EXPLANATION

SIMPLIFIED SURFICIAL GEOLOGY

Quaternary flood deposits

Quaternary deposits, loess

Quaternary and Pliocene volcanic rock

Columbia River Basalt Group rock

Miocene and older volcanic rock

Tertiary granitic and intermediate intrusive rock

Non-marine sedimentary rock

Marine sedimentary rock

Pre-Tertiary metamorphic and intrusive rock

Description of Study Area 
Well-Numbering System

The USGS assigns numbers to wells and springs 

in Washington that identify their location in a township, 

range, and section. Well number 20N/15E-26N01 indicates 

successively, the township (T. 20 N.) and the range (R. 15 E.) 

north and east of the Willamette baseline and meridian (fig. 5). 

The first number following the hyphen indicates the section 

(26) within the township, and the letter following the section 

number (N) gives the 40-acre subdivision of the section, as 

shown above. The number (01) following the letter is the 

sequence number of the well within the 40-acre subdivision. 

An “S” following the sequence number indicates that the 

site is a spring, a “D1” after the sequence number indicates 

that the original reported depth of the well has been changed 

once and successive numbers indicate the number of changes 

in the well depth. An “R” following the sequence number 

indicates the well has been reconditioned. A “P1” or “A” after 

the sequence number indicates a group of nested piezometers, 

with successive numbers or letters assigned to each piezometer 

in the group.

Willamette

Meridian

Willamette Base Line

SECTION 26 

20N/15E-26N01 

D C B A

E F G H

M L K J

N P Q R

R. 15 E. 

T. 

20 

 N. 

6 5 4 3 2 1

7 12 

18 13 

19 24 

30 26 25 

31 32 33 34 35 36 

W A S H I N G T O N 

Yakima River Basin

Figure 5. Well-numbering systems used in the State of Washington.

 Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Methods of Investigation

Three classes of well information were used to delineate 

the hydrogeologic framework for the sedimentary deposits in 

the six basins. The classes include the wells inventoried during 

this study, wells that were previously inventoried by USGS 

and WaDOE personnel, and wells that were not inventoried. 

The latter class of wells were selected to help refine the 

hydrogeologic framework in strategic areas where available 

inventoried well data were limited. 

The inventory of wells for this study began with the 

compilation of existing well, piezometer, geophysical, test 

hole, and geochemical records obtained from files of the 

USGS, WaDOE, consulting firms, and well owners. Beginning 

in the spring of 2000, more than 12,000 well records were 

reviewed; from these records, about 4,700 sites were selected 

for field inventory. Selections were based on the well owner’s 

or tenant’s permission to visit the well, the location and depth 

of the well, the availability of a driller’s log or equivalent, 

and the ease of access to the well. Priority also was given to 

wells that were previously inventoried and had water levels 

measured by the USGS, wells in the WaDOE observation 

network, and wells that were open to only one hydrogeologic 

unit. 

During the field inventory and water-level measurement 

period (autumn of 2000, 2001 and spring of 2001, 2002), 

2,017 sites were inventoried by USGS, Reclamation, WaDOE, 

and the YN. Information gathered at all inventoried sites 

included site location, land-surface altitude, primary use 

of water, owner’s or tenant’s comments on water quality, 

yield, surrounding land-use practices, and any changes in 

construction details from the original well log. In addition, the 

depth to water in the wells was measured when possible and, 

where available, the WaDOE identification tag numbers were 

recorded on field sheets.

Site locations for inventoried wells were plotted on USGS 

1:24,000 scale topographic maps. Latitude and longitude 

locations were determined using a satellite-based global 

positioning system (GPS) with a horizontal accuracy of ±10 ft, 

or from field maps compiled during the inventory. Altitudes 

of the land surface at each well were interpolated from the 

topographic maps based either on the GPS or the mapped 

location of the well. Altitude accuracy generally was between 

5 and 20 ft. Information collected during the inventory was 

entered into the USGS National Water Information System 

(NWIS) database. 

The goal of the inventory was to obtain an even areal 

distribution of the wells in the study area. However, this 

was not possible for the entire study area because of time 

constraints and a lack of wells in less populated areas. 

Therefore, wells selected in this study also include wells 

that had been previously inventoried and wells that were not 

inventoried.

Wells selected to help define the hydrogeologic 

framework that had been previously inventoried by USGS 

and WaDOE, but were not re-inventoried during this study, 

had been field inventoried in a similar manner as the field 

inventory described above. The major difference between 

the field inventory in this study and in the previous field 

inventories was that fewer wells were inventoried using a 

GPS and the well locations were plotted on topographic maps 

compiled in the field. The resulting latitude and longitude 

values for the wells were calculated from these topographic 

field maps. Locations of these field checked wells generally 

are accurate within a radius of several hundred feet of their 

actual location. 

Wells selected to help define the hydrogeologic 

framework that were not inventoried were plotted based on an 

available address that matched the driller’s reported township, 

range, section, and quarter-quarter section. If the address did 

not match, the well was plotted in the center of the 40-acre 

driller’s reported quarter-quarter section. Locations of these 

non-field-checked wells are generally accurate within a radius 

of 0.25 mi of their actual location.

The surficial geology for the Yakima River Basin was 

simplified from twelve 1:100,000 digital quadrangle maps 

available from Washington State Department of Natural 

Resources (DNR) Division of Geology and Earth Resources 

(DGER). These included the quadrangles for: Skykomish, 

Chelan, Snoqulamie, Banks Lake, Wenatchee, Mount Rainier, 

Yakima, Priest Rapids, Mount Adams, Toppenish, Richland, 

and Goldendale. In addition, published paper maps and 

detailed descriptions of the geologic units were acquired from 

DGER and the USGS to help in simplification and grouping of 

the geologic units.

The 12 maps were merged into 1 digital surficial 

geologic map; no attempt was made to reconcile matching 

of the surficial geologic units across mapped quadrangle 

boundaries. The surficial geologic units generally were then 

grouped by age (Quaternary, Tertiary, Mesozoic, Paleozoic, 

and preCambrian), and by type of deposit. Some deposits 

were grouped by formation, others were grouped by igneous 

phase. The CRBG was already mapped into the Grande 

Ronde, Wanapum, and Saddle Mountain Formations for 

most of the study area. Where it was mapped as a formation 

member, it was grouped into the associated CRBG formation. 

This process resulted in the original 512 surficial units being 

grouped into 64 units.

The resulting simplified surficial geology was used to 

assist in delineating the extent of six structural sedimentary 

basins and to delineate the hydrogeologic framework of 

each of these basins. The delineated basins are from north 

to south, the Roslyn, Kittitas, Selah (also referred to as the 

Selah-Wenas), Yakima (also referred to as the AhtanumMoxee), Toppenish, and Benton Basins (fig. 6). The geologic 

structure in the Yakima River Basin clearly defines most of the 

sedimentary basins (fig. 7). 

Methods of Investigation 
KITTITAS COUNTY

YAKIMA COUNTY

COUNTY

BENTON COUNTY

KLICKITAT

COUNTY

YAKIMA

Bumping

Lake

S Fk 

N Fk 

Cle Elum River

Bumping River

Ahtanum Creek

Tieton River Wenas Creek

North Fork

Dry Creek

Creek

Toppenish

RIVER

YAKIMA

Logy Creek

Satus

Creek

Cle

Elum

Lake

Rimrock

Lake

Kachess Lake

Keechelus Lake

Lake

Wallula

Teanaway River

Umtanum Creek

Little Naches River

Cowiche Creek

Cowiche Creek

River

Naches

RIVER

YAKIMA

RIVER

YAKIMA

Cle Elum

Parker

Wapato

Ellensburg

Umtanum

Kittitas

Thrall

Toppenish

Moxee City Union Gap

Yakima

Selah

Naches

Sunnyside Richland

Kiona

Kennewick Prosser

Grandview

Mabton

Satus

Zillah

Granger

Roza

Easton

Teanaway

Tieton Rimrock

Snoqualmie

Pass

Van Epps 

Pass

Esmeralda

Peaks

K I T T I T A S

V A L L E Y

M A N A S T A S H

KACHESS RIDGE

R I D G E

UNION GAP

CLEMAN 

MOUNTAIN 

TEANAWAY

NORTH RIDGE

U M T A N U M

R I D G E

Deception

Pass

Y A K I M A 

 V A L L E Y 

AHTANUM RIDGE

COWICHE MTN

AMERICAN RIDGE

CLE ELUM

RIDGE

RIDGE

TOPPENISH RIDGE

R A T T L E S N A K E H I L L S

Y A K I M A R I D G E

H O R S E

H E A V E N

H I L L S

C

A

S C A

D E R

A

N

G

E

W E N AT C H E E

M O U N TA I N S

Gilbert

Peak

121°

47°

47°

30'

46°

121°30' 120°30' 120° 119°30'

46°

30'

0 5 10 20 30 40 MILES

0 5 10 20 30 40 50 60 KILOMETERS

EXPLANATION

BASINS

Roslyn

Kittitas

Selah

Yakima

Toppenish

Benton

waA4WT1_fig06

Figure 6. Location of six sedimentary basins, Yakima River Basin, Washington.

Thickness and extent maps of the hydrogeologic units 

in the basin-fill deposits were constructed for the six basins 

based on: (1) the simplified surficial geology, (2) well 

interpretations from previous investigations and maps, (3) unit 

interpretations from sections constructed in each basin, and 

(4) unit interpretations made from well information collected 

from about 4,700 wells. Available data for the six basins were 

first integrated into a three-dimensional (3D) representation of 

the hydrogeologic framework for each basin. The deposits in 

the basins were then divided and mapped into hydrogeologic 

units and a total thickness of the basin-fill deposits. Except 

for the Roslyn Basin, the total thickness for each basin was 

based on the thickness of the deposits to the first encounter 

of the CBRG. The total thickness of the basin-fill deposits 

for the Roslyn Basin was based on the first encounter of 

the consolidated continental sedimentary bedrock deposits. 

The accuracy of the delineations of the hydrogeologic units 

are primarily dependent on the methods of identification. 

10 Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Ahtanum Moxee Syncline

Toppenish Ridge

Wapato Syncline

Ahtanum Ridge

Cleman Mtn. Anticline

Wilson Creek Monocline

Reeser Canyon

Monocline

Naneum Ridge Anticline

Naneum Creek

Monocline

Ainsley Canyon Anticline

Taneum Monocline

Manastash

Anticline

Umtanum Anticline

Yakima

Ridge

Kittitas

Valley Syncline

Wenas Anticline

Horse Heaven Hills Structure

Medicine Valley Syncline

Rattlesnake

Hills

Structure

Cold Creek Syncline

Hog

Ranch Structure

Yakima

Ridge

KITTITAS COUNTY 

YAKIMA COUNTY 

COUNTY

BENTON COUNTY

KLICKITAT

COUNTY

YAKIMA

Cle Elum

Parker

Wapato

Ellensburg

Umtanum

Thrall

Toppenish

Moxee City

Union Gap

Yakima

Selah

Naches

Sunnyside Richland

Kiona

Kennewick Prosser

Grandview

Mabton

Satus

Zillah

Granger

Roza

Easton

Teanaway

Tieton Rimrock

Kittitas

0 5 10 20 30 40 MILES

0 5 10 20 30 40 50 60 KILOMETERS

EXPLANATION

BASINS

Roslyn

Kittitas

Selah

Yakima

Toppenish

Benton

waA4WT1_fig07

121°

47°

47°

30'

46°

121°30' 120°30' 120° 119°30'

46°

30'

FOLD

FAULT

Figure 7. Structure delineating six sedimentary basins, Yakima River Basin, Washington.

The delineations made from a geologists’ lithologic log or 

geophysical log are relatively accurate, but vary according to 

the complexity of the geology. The delineations made from 

drillers’ logs are the least accurate, particularly in structurally 

complex areas. 

In addition, previously delineated and mapped 

hydrogeologic units were incorporated as part of this study, 

in particular for the Toppenish and Benton Basins. Mapping 

of hydrogeologic units in parts of the Yakima River Basin 

was previously completed by Drost and Whiteman (1986, and 

1990), Drost and others (1997), Newell Campbell, (unpub. 

maps produced for Yakama Nation, 2001), and Reidel and 

Thorn, Battelle Corp. (written commun., 2003 and 2005). 

How this previous work was incorporated is described in more 

detail in the discussions of the hydrogeologic framework for 

the applicable basins.

Methods of Investigation 11
All data types were entered into a Geographic 

Information System (GIS) software program in order to 

construct a gridded, digital hydrogeologic framework for 

each basin using a 10-meter (m) cell size. Data types for each 

basin included a digital elevation model (DEM), the simplified 

surficial geology, previously constructed hydrogeologic 

unit contour maps (where available), mapped extents of 

hydrogeologic units, well-log point values of the tops and 

thicknesses of a hydrogeologic unit, and the interpretations 

from sections that were constructed for each basin. 

In developing the 3D framework, the original data 

interpretations were honored as much as possible. Thus, 

the calculated top and thickness cell values and/or mapped 

contours for the hydrogeologic units were compared to the 

original well, section interpretations, and/or mapped contour 

data and adjusted to more accurately reflect the original 

interpretations. The areas where the calculated units are less 

accurate are in areas of (1) data gaps, (2) where the surficial 

geology changes abruptly, (3) structural complexity over short 

distances, and (4) where the well locations are less accurate 

and where unit contour intervals were more generalized. 

However, most discrepancies were reconciled through the use 

of a 10-m scale during the 3D framework construction. 

Hydrogeologic Framework

This section describes the hydrogeologic framework, 

which defines the physical, lithologic, and hydrologic 

characteristics of the hydrogeologic units that compose 

the ground-water system in the individual basins. An 

understanding of these characteristics is important in 

determining the occurrence and availability of ground 

water within each basin. The ground-water flow system in 

each sedimentary basin is part of the larger Yakima River 

Basin aquifer system. In turn, the part of the aquifer system 

contained by the CRBG is part of the Columbia Plateau 

regional aquifer system.

The hydrogeologic units vary by basin, and will be 

discussed separately for each basin. The hydrogeologic units 

identified in this report do not necessarily correspond to 

geologic time-stratigraphic deposits. The ground-water flow 

system within the basin-fill deposits in each basin is generally 

isolated from other basins but is interconnected with the larger 

Yakima River Basin aquifer system.

Knowledge of the geologic structure that exists within 

and surrounds each basin (fig. 7) also assisted in mapping 

of the hydrogeologic units. The structural setting helps to 

explain the depositional sequences, thickness variations, and 

segmentation of the ground-water movement or anomalous 

water-level distributions within the area. For example, a 

predominantly fine-grained unit could be vertically offset 

and juxtaposed with a coarse-grained unit, thereby truncating 

the lateral ground-water movement along a fault and also 

offsetting the water-level distribution on either side of the 

fault. Although these types of questions are not addressed in 

this report, the structural history has provided information 

for mapping the hydrogeologic units and should provide 

additional information related to the ground-water flow 

system.

Roslyn Basin

The Roslyn Basin is located southeast of the Kachess and 

Cle Elum Lakes (figs. 6 and 7) and encompasses an area of 

about 80 mi2. The south-central part of the basin is dissected 

by two northwest trending faults with their down-thrown sides 

toward the northeast, and the northeast part of the basin is 

divided by a series of synclines and anticlines (pl. 1). 

The basin-fill deposits consist predominantly of alluvial, 

lacustrine, and glacial deposits interspersed with Mesozoic 

metamorphics and Tertiary volcanic deposits. The deposits 

were divided and mapped into three hydrogeologic units—

Units 1 through 3 and a total basin thickness. Information 

from 307 well logs was used to define the units in the Roslyn 

Basin. This basin has been the least studied for ground-water 

availability, thus, only 31 percent of the well logs used to 

identify the hydrogeologic units and basin thickness were field 

located and most of these were inventoried during this study. 

The three hydrogeologic units consist of an upper coarsegrained unit, a clay unit, and a productive gravel unit (pl. 1). 

Unit 1 consists of the alluvial, lacustrine, and glacial deposits 

at and near the surface. The thickness of the unit ranges from 

0 to 360 ft, with a mean and median thickness of 80 ft. The 

altitude of this unit ranges from 1,760 to 3,420 ft, with a mean 

and median altitude of 2,120 and 2,130 ft, respectively. Unit 

2 consists predominantly of fine-grained, lacustrine deposits 

of clay and silt. The extent and thickness of the unit tends to 

follow the alluvium valley (pl. 1). The thickness of this unit 

ranges from 0 to 530 ft with a mean and median thickness of 

180 and 170 ft, respectively. The altitude of this unit ranges 

from 1,720 to 2,100 ft, with a mean and median altitude of 

1,910 and 1,890 ft, respectively. Unit 3 consists of coarser 

deposits, mostly sand and gravels. It is less extensive than the 

other units and occurs in the deeper parts of the alluvial valley 

(pl. 1). The thickness of Unit 3 ranges from 0 to 240 ft with a 

mean and median thickness of 60 and 50 ft, respectively. The 

altitude of this unit ranges from 1,330 to 2,000 ft with a mean 

and median altitude of 1,670 and 1,690 ft, respectively. 

The thickness of the basin-fill deposits in the Roslyn 

Basin is greatest in the central part of the basin in the Yakima 

alluvial valley (pl. 1). The total thickness of the basin-fill 

deposits in the Roslyn Basin ranges from 0 to 700 ft with a 

mean and median thickness of 150 and 110 ft, respectively. 

The altitude of the top of the bedrock units in this basin ranges 

from 1,190 to 3,330 ft, with a mean and median altitude of 

1,990 and 2,010 ft, respectively. 

12  Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Kittitas Basin

The Kittitas Basin lies within the northeastern part of 

the Yakima River Basin and encompasses an area of about 

270 mi2. The basin is bordered on the southwest by the 

Ainsley Canyon and Manastash Anticlines, on the northeast 

by the Wilson Creek Monocline, and is bisected by the Kittitas 

Valley Syncline (fig. 7). The northeastern part of the basin also 

contains several east-west and northwest trending high-angle 

faults with the downthrown side generally to the north and 

northeast. The southwestern part of the basin contains and is 

bordered by northwest trending strike-slip and thrust faults 

(pl. 2). 

The basin-fill deposits consist predominantly of alluvial, 

loess, glacial, continental sedimentary, and Ellensburg 

Formation deposits. The deposits were divided and mapped 

into three hydrogeologic units—Units 1 through 3 and a total 

basin thickness. Information from 419 well logs was used to 

define the units of the Kittitas Basin. Sixty percent of these 

wells were field located, and 40 percent were not field located 

but supplied additional information in areas with limited data. 

The three hydrogeologic units consist of alluvial, 

unconsolidated, and consolidated deposits. Unit 1 consists 

of the alluvial deposits and the delineation of this unit was 

confined to the Yakima River floodplain (pl. 2). The unit 

thickness ranges from 0 to 100 ft, with a mean and median 

thickness of 30 and 10 ft, respectively. The altitude of this 

unit ranges from 1,410 to 1,800 ft, with a mean and median 

altitude of 1,530 and 1,520 ft, respectively. Unit 2 consists 

of the unconsolidated deposits, and generally contains the 

loess, alluvial fan, glacial, terrace, and Thorp gravel deposits 

present at the surface and beneath Unit 1 (pl. 2). The thickness 

of this unit ranges from 0 to 790 ft, with a mean and median 

thickness of 180 and 150 ft, respectively. The altitude of this 

unit ranges from 1,370 to 3,890 ft, with a mean and median 

altitude of 1,930 and 1,870 ft, respectively. Unit 3 is present 

along the syncline that parallels the southwest boundary of the 

basin (pl. 2). The consolidated deposits of this unit consist of 

the Ellensburg Formation and similar undefined continental 

sedimentary deposits. The thickness of Unit 3 ranges from 

0 to 2,040 ft, with a mean and median thickness of 600 and 

350 ft, respectively. The altitude of this unit ranges from 770 

to 2,700 ft, with a mean and median altitude of 1,540 and 

1,520 ft, respectively. 

The thickness of the basin-fill deposits in the Kittitas 

Basin is greatest in the south-central part of the basin generally 

along the Kittitas Valley Syncline (fig. 7 and pl. 2). The 

total thickness of the basin-fill deposits in the Kittitas Basin 

ranges from 0 to 2,120 ft, with a mean and median thickness 

of 500 and 270 ft, respectively (pl. 2). The altitude of the top 

of the CRBG within the Kittitas Basin ranges from -540 to 

3,610 ft, with a mean and median altitude of 780 and 1,600 ft, 

respectively.

Selah Basin

The Selah Basin, also referred to as the Selah-Wenas 

Basin, is located in the central part of the Yakima River Basin 

and encompasses about 170 mi2. The basin is bounded on 

the northeast by the Manastash and Umtanum Anticlines and 

bounded on the southwest by the Yakima Ridge structure 

(figs. 6 and 7). The central part of this basin is dissected by a 

series of northwest-southeast trending folds (fig. 7). 

The basin-fill deposits consist predominantly of alluvial, 

alluvial fan, loess, terrace, continental sedimentary, and 

Ellensburg Formation deposits. The deposits were divided 

and mapped into three hydrogeologic units—Units 1 through 

3 and a total basin thickness (pl. 3). Information from 720 

well logs was used to define the units in the Selah Basin. 

Eighty-nine percent of these wells were field located and 

56 percent of the field located wells were located in previous 

investigations.

The three hydrogeologic units consist of the alluvial, 

unconsolidated, and consolidated deposits. Unit 1 consists 

of the alluvial deposits that are contained in the floodplains 

of Wenas and Cowiche Creeks and the Naches and Yakima 

Rivers (pl. 3). The thickness of Unit 1 ranges from 0 to 90 ft, 

with a mean and median thickness of 30 ft. The altitude of 

Unit 1 ranges from 1,080 to 2,450 ft, with a mean and median 

altitude of 1,470 and 1,420 ft, respectively. Unit 2 consists 

of the unconsolidated deposits, and generally contains the 

alluvial fan, loess, terrace, and Thorp gravel deposits present 

as a thin veneer over much of the surface and beneath Unit 1 

(pl. 3). The thickness of this unit ranges from 0 to 290 ft, with 

a mean and median thickness of 50 and 40 ft, respectively. 

The altitude of this unit ranges from 1,050 to 2,760 ft, with a 

mean and median altitude of 1,660 and 1,630 ft, respectively. 

Unit 3 is present throughout most of the basin (pl. 3) and 

consists of the consolidated deposits, which include the 

Ellensburg Formation and similar undefined continental 

sedimentary deposits. The thickness of Unit 3 ranges from 

0 to 1,920 ft, with a mean and median thickness of 320 and 

200 ft, respectively. The altitude of the unit ranges from 980 

to 3,160 ft, with a mean and median altitude of 1,740 and 

1,690 ft, respectively. 

The thickness of the basin-fill deposits in the Selah Basin 

is greatest in the north-central part of the basin (pl. 3). The 

thickness of the deposits ranges from 0 to 1,920 ft, with a 

mean and median thickness of 300 and 200 ft, respectively. 

The altitude of the top of the CRBG in the Selah Basin ranges 

from -300 to 3,100 ft, with a mean and median altitude of 

1,460 and 1,470 ft, respectively.

Hydrogeologic Framework 13
Yakima Basin

The Yakima Basin, also referred to as the AhtanumMoxee Basin, is a long narrow east-west trending basin in the 

central part of the Yakima River Basin and encompasses an 

area of about 230 mi2. The basin is bounded on the north by 

the Yakima Ridge, on the south by the Ahtanum Ridge, and is 

bisected by the Ahtanum-Moxee Syncline (figs. 6 and 7). 

The basin-fill deposits consist predominantly of alluvial, 

alluvial fan, loess, continental sedimentary, and Ellensburg 

Formation deposits. The deposits were divided and mapped 

into three hydrogeologic units—Units 1 through 3 and a total 

basin thickness. Information from 995 well logs was used to 

define the units in the Yakima Basin. Ninety-nine percent of 

the wells were field located and 51 percent of these wells were 

located in previous investigations. 

The three hydrogeologic units consist of the alluvial, 

unconsolidated, and consolidated deposits. Unit 1 consists of 

the alluvial deposits that are contained in the floodplains of 

Ahtanum Creek and the Yakima River (pl. 4). The thickness 

of Unit 1 ranges from 0 to 120 ft, with a mean and median 

thickness of 20 ft. The altitude of this unit ranges from 940 

to 2,780 ft, with a mean and median altitude of 1,270 and 

1,180 ft, respectively. Unit 2 consists of the unconsolidated 

deposits, which include the alluvial fan, loess, terrace, and 

Thorp gravel deposits. Unit 2 generally is present at the 

surface and beneath Unit 1 (pl. 4). The thickness of Unit 2 

ranges from 0 to 350 ft, with a mean and median thickness 

of 90 and 80 ft, respectively. The altitude of this unit ranges 

from 910 to 2,940 ft, with a mean and median altitude of 

1,480 and 1,460 ft, respectively. Unit 3 is present throughout 

most of the basin with the general exception of its western tip 

(pl. 4). Unit 3 consists of the consolidated deposits, principally 

the Ellensburg Formation and similar undefined continental 

sedimentary deposits. The thickness of Unit 3 ranges from 

0 to 1,840 ft with a mean and median thickness of 510 and 

450 ft, respectively. The altitude of this unit ranges from 760 

to 2,780 ft, with a mean and median altitude of 1,330 and 

1,320 ft, respectively. 

The thickness of the basin-fill deposits in the Yakima 

Basin is greatest in the northwestern part of the basin (pl. 4). 

Its thickness ranges from 0 to 1,840 ft, with a mean and 

median thickness of 530 and 410 ft, respectively. The altitude 

of the top of the CRBG in the Yakima Basin ranges from 

-510 to 2,900 ft, with a mean and median altitude of 980 and 

1,840 ft, respectively.

Toppenish Basin

The Toppenish Basin lies in the south-central part of 

the Yakima River Basin and encompasses an area of about 

440 mi2. The basin is bordered on the north by the Ahtanum 

Ridge, on the south by the Toppenish Ridge, and bisected by 

the Wapato Syncline (fig. 7). The eastern boundary of this 

basin abuts the Benton Basin (figs. 6 and 7). 

The basin-fill deposits consist predominantly of alluvial, 

alluvial fan, loess, terrace, continental sedimentary, Touchet, 

and Ellensburg Formation deposits. The deposits in this basin 

were divided and mapped into hydrogeologic units—Units 1 

through 5 and a total basin thickness. The hydrogeologic unit 

delineations were modified from contour maps constructed by 

Campbell (unpub. maps produced for Yakama Nation, 2001).

To derive the modified contour maps, a total basin thickness 

map was constructed first based on information from 1,104 

well logs of which 210 well logs fully penetrated the basin 

thickness (pl. 5). Ninety-seven percent of the well logs used 

were field located. The thickness map was then subtracted 

from the DEM to obtain a map of the top of the CRBG. This 

map was then compared to the top of the CRBG map compiled 

by Campbell (unpub. maps produced for Yakama Nation, 

2001). The maps were a close match in both the shape of 

the contours and the contour values. Small differences were 

predominantly due to newer maps of the surficial geology 

and the extent that was based on our criteria that the depth 

of the basin-fill deposits was defined as contact with the first 

basalt. The contour maps for the units were then digitized and 

modified based on the updated surficial geology and on the 

occurrence of the first basalt contact. 

The five hydrogeologic units consist of fine-grained and 

coarse-grained unconsolidated deposits, consolidated deposits, 

top of the Rattlesnake Ridge unit, and base of the Rattlesnake 

Ridge unit. Unit 1 consists of fine-grained unconsolidated 

surficial deposits that include Touchet, terrace, loess, and some 

alluvial deposits (pl. 5). The thickness of Unit 1 ranges from 

0 to 80 ft, with a mean and median thickness of 10 ft. The 

altitude of this unit ranges from 690 to 2,030 ft, with a mean 

and median altitude of 910 and 860 ft, respectively. Unit 2 

consists predominantly of coarse-grained unconsolidated 

deposits. The thickness of Unit 2 ranges from 0 to 270 ft, with 

a mean and median thickness of 90 and 80 ft, respectively. 

The altitude of this unit ranges from 660 to 2,310 ft, with a 

mean and median altitude of 930, and 850 ft, respectively. 

Unit 3 is present throughout most of the basin (pl. 5). It 

consists predominantly of the consolidated deposits of the 

upper Ellensburg Formation and similar undefined continental 

sedimentary deposits. The thickness of Unit 3 ranges from 

0 to 970 ft, with a mean and median thickness of 350 and 

320 ft, respectively. The altitude of this unit ranges from 

510 to 2,300 ft, with a mean and median altitude of 900 and 

820 ft, respectively. Unit 4 is present in the central part of the 

basin (pl. 5), and consists of fine-grained deposits. This unit 

is referred to as the top of the Rattlesnake Ridge unit of the 

Ellensburg Formation and the “Blue Clay” layer by Campbell 

(unpub. maps produced for Yakama Nation, 2001). The 

14  Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
thickness of Unit 4 ranges from 0 to 520 ft, with a mean and 

median thickness of 170 and 140 ft, respectively. The altitude 

of this unit ranges from -350 to 1,130 ft, with a mean and 

median altitude of 320 and 330 ft, respectively. Unit 5 which 

has an extent similar to Unit 4 (pl. 5) consists predominantly 

of coarse-grained gravels. This unit is referred to as the base 

of Rattlesnake Ridge unit of the Ellensburg Formation by 

Campbell (Tom Ring, Yakama Nation, written commun., 

2001). The thickness of Unit 5 ranges from 0 to 140 ft, with a 

mean and median thickness of 20 ft. The altitude of this unit 

ranges from -400 to 1,020 ft, with a mean and median altitude 

of 130 ft. 

The thickness of the basin-fill deposits in the Toppenish 

Basin is greatest in the central-southeastern part of the basin 

(pl. 5). The thickness of the basin-fill deposits ranges from 0 

to 1,210 ft, with a mean and median thickness of 550 ft. The 

altitude of the top of the CRBG in the Toppenish Basin ranges 

from -410 to 2,290 ft, with a mean and median altitude of 450 

and 380 ft, respectively.

Benton Basin

The Benton Basin lies in the southeastern part of 

the Yakima River Basin. It is the largest of the six basins 

encompassing an area of about 1,020 mi2. The western 

boundary of the Benton Basin abuts the eastern boundary 

of the Toppenish Basin and a small section of the Yakima 

Basin (figs. 6 and 7). The southern boundary is bordered 

by the Horse Heaven Hills structure and the northeastern 

boundary generally follows the northern flank of the Cold 

Creek Syncline (figs. 6 and 7). The basin is dissected with 

numerous faults and folds surrounding the Rattlesnake Hills 

structure in the eastern part of the basin (fig. 7 and pl. 6). The 

western part of the basin is dissected by the Wapato Syncline 

and several unnamed folds that lie within the broad flat plain 

that encompasses the Yakima River floodplain (fig. 7 and 

pl. 6). Sediment deposits are thickest on the northeastern 

side of the Rattlesnake Hills structure, which separates the 

sediment deposits on the northeastern side from those on the 

southwestern side.

The basin-fill deposits consist of loess, alluvial fan, dune 

sand, alluvial, terrace, continental sedimentary, and Ellensburg 

Formation deposits. The deposits for the entire Benton Basin 

were divided and mapped into two hydrogeologic units—

Units 1 and 2 and a total basin thickness. Information from 

1,141 well logs was used to define the units of the Benton 

Basin. All of these wells were field located. Sixty-five percent 

of the wells were field located during this study and 35 percent 

were located in previous investigations. 

The two hydrogeologic units consist of unconsolidated 

and consolidated deposits. Unit 1 consists of the 

unconsolidated deposits that generally consist of the alluvial, 

alluvial fan, loess, terrace, dune sand, Touchet, Missoula flood 

and Ringold Formation deposits (pl. 6, sheet 1 and sheet 2). 

The thickness of Unit 1 ranges from 0 to 870 ft, with a mean 

and median thickness of 120 and 70 ft, respectively. The 

altitude of this unit ranges from 300 to 3,620 ft, with a mean 

and median altitude of 990 and 830 ft, respectively. The 

unconsolidated basin-fill deposits generally are less than 400 ft 

throughout most of the basin except in the area northeast of 

the Rattlesnake Hills structure, where thicknesses exceed 

800 ft (pl. 6, sheet 2). 

Additional information incorporated from previous 

studies (Drost and others, 1997; Reidel and Thorn, Battelle, 

written commun., 2003 and 2005) enabled the unconsolidated 

unit in the east-northeast area of the basin to be divided into 

six subunits (figs. 8A through 8F). Subunit 1 consists of 

the fine-grained Touchet and similar deposits present at the 

surface. The thickness of subunit 1 ranges from 0 to about 

300 ft (fig. 8A). Subunit 2 consists of the coarse-grained 

Pasco gravels and similar deposits present at the surface and 

beneath subunit 1. The thickness of subunit 2 ranges from 0 

to about 100 ft (fig. 8B). Subunit 3 is of limited extent and 

consists of the fine-grained deposits of the upper Ringold 

Formation present beneath Subunit 2. The thickness of subunit 

3 ranges from 0 to about 50 ft (fig. 8C). Subunit 4, present 

throughout most of the northeastern area of the Benton Basin, 

consists of the coarse-grained deposits of the middle Ringold 

Formation. The thickness of subunit 4 ranges from 0 to about 

400 ft (fig. 8D). Subunit 5, also present throughout most of 

the northeastern area of the Benton Basin, consists of the 

fine-grained deposits of the lower Ringold Formation. The 

thickness of subunit 5 ranges from 0 to about 250 ft (fig. 8E). 

Subunit 6 generally is present beneath Subunit 5, and consists 

of the coarse-grained basal Ringold Formation. The thickness 

of Subunit 6 ranges from 0 to about 200 ft (fig. 8F). 

Unit 2 is mainly present in the southwestern part of the 

Benton Basin (pl. 6, sheet 2). The consolidated deposits of this 

unit include the Ellensburg Formation and similar undefined 

continental sedimentary deposits. The thickness of Unit 2 

ranges from 0 to 680 ft, with a mean and median thickness 

of 100 and 60 ft, respectively. The altitude of this unit ranges 

from 370 to 3,400 ft, with a mean and median altitude of 890 

and 790, respectively. 

The basin-fill deposits of the Benton Basin are thickest to 

the west where the basin abuts the Toppenish Basin and in the 

northeastern area of the basin (pl. 6, sheet 2). The thickness 

of the basin-fill deposits in the Benton Basin ranges from 

0 to 870 ft, with a mean and median thickness of 120 and 

60 ft, respectively. The altitude of the top of the CRBG in the 

Benton Basin ranges from -300 to 3,630 ft, with a mean and 

median altitude of 960 and 800 ft, respectively. 

Hydrogeologic Framework 15
waa4wti_01_fig08a
waa4wti_01_fig08b

0

100 50

50

0

100

100

0

0

0

0

0

0

0

50

50

50

0

0

50 100

0

100

50

50

50

50

150

0

50 100

46°30’

R23E R23E R23E R23E R23E R23E R23E

119°30’

T

12

N

T

11

N

T

10

N

T

09

N

T

08

N

T

07

N

T

13

N

EXPLANATION

0

Areas of basalt at the surface 

Subunit 2 (Pasco gravel deposits)

Not present

Line of equal thickness of Subunit 2.

 Interval is 50 feet

Subasin outline

0 5 10 15

5

MILES

0 10 15 20 KILOMETERS

B. Subunit 2 – Coarse-grained Pasco gravels and similar deposits

Richland

Yakima

River

Figure 8.—Continued.

Hydrogeologic Framework 17
waa4wti_01_fig08c

50

50

0

50

0

0

0

0

0

46°30’

R23E R23E R23E R23E R23E R23E R23E

119°30’

T

12

N

T

11

N

T

10

N

T

09

N

T

08

N

T

07

N

T

13

N

EXPLANATION

0

Areas of basalt at the surface 

Subunit 3 (upper Ringold Formation)

Not present

Line of equal thickness of Subunit 3.

 Interval is 50 feet

Subasin outline

0 5 10 15

5

MILES

0 10 15 20 KILOMETERS

C. Subunit 3 – Fine-grained deposits of the upper Ringold Formation

Richland

Yakima

River

Figure 8.—Continued.

18  Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
waa4wti_01_fig08d

0

250

350

150

300

200

100

0

300

300

150

50

0

0

250

50 50

200 400

200

150

100

100

50

200

250 300

300

50

300

250

0

0

46°30’

R23E R23E R23E R23E R23E R23E R23E

119°30’

T

12

N

T

11

N

T

10

N

T

09

N

T

08

N

T

07

N

T

13

N

EXPLANATION

0

Areas of basalt at the surface 

Subunit 4 (middle Ringold Formation)

Not present

Line of equal thickness of Subunit 4.

 Interval is 50 feet

Subasin outline

0 5 10 15

5

MILES

0 10 15 20 KILOMETERS

D. Subunit 4 – Coarse-grained deposits of the middle Ringold Formation

Yakima

River

Richland

Figure 8.—Continued.

Hydrogeologic Framework 19
waa4wti_01_fig08e

0

0

0

0

0

50

50

50

50

50

100

150

150 150

200

0

100 100

150

50

50

50

100 100

100 100

50

50

50

50

250 200 46°30’

R23E R23E R23E R23E R23E R23E R23E

119°30’

T

12

N

T

11

N

T

10

N

T

09

N

T

08

N

T

07

N

T

13

N

Yakima

River

EXPLANATION

0

Areas of basalt at the surface 

Subunit 5 (lower Ringold Formation)

Not present

Line of equal thickness of Subunit 5.

 Interval is 50 feet

Subasin outline

0 5 10 15

5

MILES

0 10 15 20 KILOMETERS

E. Subunit 5 – Fine-grained deposits of the lower Ringold Formation

Richland

Figure 8.—Continued.

20 Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
waa4wti_01_fig08f

0

0

0

0

0 0

50

50

50

100

100

100

200

150

100

50

150

150

100

100

50

50

0

46°30’

R23E R23E R23E R23E R23E R23E R23E

119°30’

T

12

N

T

11

N

T

10

N

T

09

N

T

08

N

T

07

N

T

13

N

0 5 10 15

5

MILES

0 10 15 20 KILOMETERS

EXPLANATION

0

Areas of basalt at the surface 

Subunit 6 (basal Ringold Formation)

Not present

Line of equal thickness of Subunit 6.

 Interval is 50 feet

Subasin outline

F. Subunit 6 – Coarse-grained basal Ringold Formation

Richland

Yakima

River

Figure 8.—Continued.

Hydrogeologic Framework  21
Summary and Conclusions

The Yakima River Basin aquifer system located in southcentral Washington encompasses about 6,200 square miles. 

The six structural sedimentary basins delineated, from north 

to south are: Roslyn, Kittitas, Selah, Yakima, Toppenish, and 

Benton. Information was collected, interpreted, and combined 

from simplified surficial geology maps, hydrogeologic contour 

maps from previous studies, and from about 4,700 well logs. 

This information was used to delineate the thicknesses of the 

hydrogeologic units in the basin-fill deposits in each of the six 

basins. 

All data types were entered into a Geographical 

Information System software program in order to construct 

a gridded, 3D digital hydrogeologic framework for each 

basin using a 10-m cell size. Data types for each basin 

included a digital elevation model, simplified surficial 

geology, previously constructed hydrogeologic unit contour 

maps (where available), mapped extents of hydrogeologic 

units, well-log point values of the tops and thicknesses of a 

hydrogeologic unit, and interpretations from sections that were 

constructed for each basin. The original data interpretations 

were honored as much as possible in developing the 3D 

framework. The calculated top and thickness cell values and/or 

mapped contours for the hydrogeologic units were compared 

to the original well and/or mapped contour data and adjusted 

to most accurately reflect the original interpretations. 

The hydrogeologic framework defines the physical, 

lithologic, and hydrogeologic characteristics of the 

hydrogeologic units that comprise the ground-water system in 

the individual basins. The hydrogeologic units vary by basin 

and the thickness, extent, and total basin thicknesses were 

described.

The Roslyn Basin basin-fill deposits, which total 

about 700 ft thick, were divided and mapped into three 

hydrogeologic units and a total basin thickness. The 

hydrogeologic units consist of an upper coarse-grained unit, a 

clay unit, and a productive gravel unit.

The basin-fill deposits in the Kittitas, Selah, and 

Yakima Basins, which total about 2,000, 1,900, and 

1,800 ft thick, respectively, were divided and mapped into 

three hydrogeologic units and total basin thickness. The 

hydrogeologic units consist of alluvial, unconsolidated, and 

consolidated deposits.

The Toppenish Basin basin-fill deposits, which total 

about 1,200 ft thick, were divided and mapped into five 

hydrogeologic units based on previous work compiled by 

Campbell (unpub. maps produced for Yakama Nation, 2001). 

The five hydrogeologic units consist of fine-grained and 

coarse-grained unconsolidated deposits, consolidated deposits 

of the upper Ellensburg Formation, a blue clay deposit of the 

top of the Rattlesnake Ridge unit, and a coarse-grained deposit 

of the basal Rattlesnake Ridge unit.

The Benton Basin basin-fill deposits, which total about 

870 ft thick, were divided and mapped into two hydrogeologic 

units and a total basin thickness. The hydrogeologic units 

consist of unconsolidated and consolidated deposits. The 

unconsolidated deposits in the northeastern area of the basin 

were further divided into six subunits based on information 

compiled from previous investigations.

Acknowledgments

The cooperation of many well owners, tenants, and 

well drillers who supplied information and allowed access 

to wells is gratefully acknowledged. The field assistance and 

information supplied by the Yakama Nation, the U.S. Bureau 

of Reclamation, Washington State Department of Ecology, 

and the U.S. Geological Survey offices in Idaho, Oregon, and 

Washington also are acknowledged. Appreciation is expressed 

to Steve Reidel, Staff Geologist, Pacific Northwest National 

Laboratory; Eric Cheney, Associate Professor, Department 

of Earth and Space Sciences, University of Washington; 

and Newell Campbell, retired Geology Professor, Central 

Washington University for their assistance.

Selected References

Bureau of Reclamation, 1999, Yakima River Basin Water 

Enhancement Project, Washington, Final Programmatic 

Environmental Impact Statement: U.S. Department of 

Interior, Bureau of Reclamation, Pacific Northwest Region, 

Upper Columbia Area Office, Yakima, Washington, 197 p.

Cuffney, T.F., Meador, M.R., Porter, S.D., and Gurtz, M.E., 

1997, Distribution of fish, benthic invertebrate, and 

algal communities in relation to physical and chemical 

conditions, Yakima River Basin, Washington, 1990: U.S. 

Geological Survey Water-Resources Investigations Report 

96-4280, 94 p.

Drost, B.W., Cox, S.E., and Schurr, K.M., 1997, Changes 

in ground-water levels and ground-water budgets, from 

predevelopment to 1986, in parts of the Pasco Basin, 

Washington: U.S. Geological Survey Water-Resources 

Investigations Report 96-4086, 172 p.

Drost, B.W., and Whiteman, K.J., 1986, Surficial geology, 

structure, and thickness of selected geohydrologic units in 

the Columbia Plateau, Washington: U.S. Geological Survey 

Water-Resources Investigations Report 84-4326, 11 sheets.

Drost, B.W., Whiteman, K.J., and Gonthier, J.B., 1990, 

Geologic framework of the Columbia Plateau Aquifer 

System, Washington, Oregon, and Idaho: U.S. Geological 

Survey Water-Resources Investigations Report 87-4238, 10 

p., 10 sheets. 

Flaherty, N.M., 1975, The Yakima Basin and its water: 

Washington State University, Water Research Center, 

Pullman, Wa, 29 p.

22  Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Frizzell, V.A., Jr., Tabor, R.W., Booth, D.B., Ort, K.M., and 

Waitt, R.B., Jr., 1984, Preliminary geologic map of the 

Snoqualmie Pass 1:100,000 quadrangle, Washington: U.S. 

Geological Survey Open-File Report 84-693, 36 p., 1 sheet, 

scale 1:100,000.

Fuhrer, G.J., McKenzie, S.W., Rinella, J.F., Sanzolone, R.F., 

and Skach, K.A., 1994, Surface-water-quality assessment of 

the Yakima River Basin in Washington: Analysis of major 

and minor elements in fine-grained streambed sediment 

1987 with sections on Geology by Marshall Gannett: U.S. 

Geological Survey Open-File Report 93-30, 226 p., 3 

sheets, scale 1:250,000. 

Fuhrer, G.J., Morace, J.L., Johnson, H.M., Rinella, J.F., 

Ebbert, J.C., Embrey, S.S., Waite, I.R., Carpenter, K.D., 

Wise, D.R., and Hughes, C.A., 2004, Water quality in 

the Yakima River Basin, Washington, 1999-2000: U.S. 

Geological Survey Circular 1237, 44 p.

Glantz, M.H., 1982, Consequences and responsibilities in 

drought forecasting: The case of Yakima, 1977: Water Resr. 

Res., v. 18, no. 1, p. 3-13.

Gulick, G.W., and Korosec, M.A., 1990, Geologic map of the 

Banks Lake 1:100,000 quadrangle, Washington: Washington 

Division of Geology and Earth Resources, Open File-Report 

90-6, 20 p., 1 sheet, scale 1:100,000.

Korosec, M.A., 1987, Geologic map of the Mount Adams 

quadrangle, Washington: Washington State Department of 

Natural Resources, Open-File Report 87-5, 41 p., 1 sheet, 

scale 1:100,000.

Kratz, M.R., 1978, Dilemmas, disruptions, but no disaster—

drought in the Yakima basin, Washington, 1977: State 

Climatologist for Arizona Climatological Publications, 

Scientific Paper No. 3, 16 p.

Lane, R.C., 1988, Selected ground-water information for the 

Columbia Plateau regional aquifer system, Washington 

and Oregon, 1982-1985; Volume I: Geohydrology: U.S. 

Geological Survey Open-File Report 88-182, 236 p.

Meyers, C.W., and Price, S.M., 1979, Geologic studies of the 

Columbia Plateau, a status report: Rockwell International, 

Rockwell Hanford Operations RHO-BWI-ST-4, 520 p.

Meyers, C.W., and Price, S.M., 1981, Subsurface geology 

of the Cold Creek syncline, a status report: Rockwell 

International, Rockwell Hanford Operations RHO-BWI-ST14, 396 p.

 Omernik, J.M., 1987, Ecoregions of the conterminous United 

States: Annals of the Association of American Geographers, 

v. 77, no. 1, p. 118-125.

Owens, R.R., 1995, The hydrogeology of the Kittitas Valley, 

Washington: Central Washington University, Master of 

Science Thesis, 205 p.

Parker, G.L., and Storey, F.B., 1913, Water powers of the 

Cascade Range, Part III, Yakima River Basin: U.S. 

Geological Survey Water-Supply Paper 369, 169 p., 18 pls.

Phillips, W.M., and Walsh, T.J., Geologic map of the 

northwest part of the Goldendale quadrangle, Washington: 

Washington Division of Geology and Earth Resources, 

Open-File Report 87-13, 9 p., 1 sheet, scale 1:100,000.

Reidel, S.P., and Fecht, K.R., 1994, Geologic map of the 

Richland 1:100,000 quadrangle, Washington: Washington 

Division of Geology and Earth Resources, Open-File Report 

94-8, 21 p., scale 1:100,000.

Reidel, S.P., and Fecht, K.R., 1994, Geologic map of the Priest 

Rapids 1:100,000 quadrangle, Washington: Washington 

Division of Geology and Earth Resources, Open-File Report 

94-13, 22 p., scale 1:100,000.

Russell, I.C., 1897, A reconnaissance of southeastern 

Washington: U.S. Geological Survey Water-Supply Paper 4, 

96 p.

Schasse, H.W., 1987, Geologic map of the Mount Rainier 

quadrangle, Washington: Washington State Department of 

Natural Resources, Open-File Report 87-16, 43 p., 1 sheet, 

scale 1:100,000.

Schuster, E.J., 1994, Geologic maps of the east half of 

the Washington portion of the Goldendale 1:100,000 

quadrangle and the Washington portion of the Hermiston 

1:100,000 quadrangle: Washington State Department of 

Natural Resources, Open-File Report 94-9, 17 p., 1 sheet, 

scale 1:100,000.

Schuster, E.J., 1994, Geologic map of the east half of the 

Toppenish 1:100,000 quadrangle, Washington: Washington 

State Department of Natural Resources, Open-File Report 

94-10, 15 p., 1 sheet, scale 1:100,000.

Schuster, E.J., 1994, Geologic map of the east half of the 

Yakima 1:100,000 quadrangle, Washington: Washington 

State Department of Natural Resources, Open-File Report 

94-12, 19 p., 1 sheet, scale 1:100,000.

Sinclair, Kelsey, 1998, Stratigraphic correlation of the N2 

Grande Ronde Basalt across Kittitas valley, Washington 

State: Central Washington University, Master of Science 

Thesis, 21 p.

Smith, G.O., 1901, Geology and water resources of a portion 

of Yakima County, Washington: U.S. Geological Survey 

Water-Supply and Irrigation Papers 55, 68 p.

Swanson, D.A., Anderson, J.L., Bentley, R.D., Byerly, 

G.R., Camp, V.E., Gardner, J.N., and Wright, T.L., 1979, 

Reconnaissance geologic map of the Columbia River Basalt 

group in eastern Washington and northern Idaho: U.S. 

Geological Survey Open-File Report 79-1363, 26 p., 12 

sheets, scale 1:250,000.

Swanson, D.A., Brown, J.C., Anderson, J.L., Bentley, R.D., 

Byerly, G.R., Gardner, J.N., and Wright, T.L., 1979, 

Preliminary structure contour maps on the top of the Grand 

Ronde and Wanapum Basalts, eastern Washington and 

northern Idaho: U.S. Geological Survey Open-File Report 

79-1364, 3 sheets.

Selected References  23
Systems Operations Advisory Committee, 1999, Report 

on biologically based flows for the Yakima River basin: 

Report to The Secretary of the Interior, May 1999, Yakima, 

Washington, Executive Summary, 6 chapters, Appendix A.

Tabor, R.W., Frizzell, V.A., Jr., Booth, D.B., Waitt, R.B., 

Whetten, J.T., and Zartman, F.E., 1993, Geologic map of the 

Skykomish River 30-by 60-minute quadrangle, Washington: 

U.S. Geological Survey Miscellaneous Investigations Series 

Map I-1963, 42 p., 1 sheet, scale 1:100,000.

Tabor, R.W., Frizzell, V.A., Jr., Whetten, J.T., Waitt, R.B., 

Swanson, D.A., Byerly, G.R., Booth, D.B., Hetherington, 

M.J., and Zartman, R.E., 1987, Geologic map of the Chelan 

30-minute by 60-minute quadrangle, Washington: U.S. 

Geological Survey Miscellaneous Investigations Series Map 

I-1661, 33 p., 1 sheet, scale 1:100,000.

Tabor, R.W., Waitt, R.B., Jr., Frizzell, V.A., Jr., Swanson, D.A., 

Byerly, G.R., and Bentley, R.D., 1982, Geologic Map of the 

Wenatchee 1:100,000 quadrangle, central Washington: U.S. 

Geological Survey Miscellaneous Investigations Series Map 

I-1311, 26 p., 1 sheet, scale 1:100,000.

U.S. Department of Energy, 1988, Site characterization plan, 

reference repository location, Hanford Site, Washington; 

volume 1: U.S. Department of Energy, DOE/RW-0164, 

unpaginated.

U.S. District Court, 1945, Consent decree in the District Court 

of the United States for the Eastern District of Washington, 

Southern Division: Civil action No. 21, Spokane, 

Washington.

Vaccaro, J.J., 1995, Changes in the hydrometeorological 

regime in the Pacific Northwest: Proceedings of the 12th 

Annual Pacific Climate (PACLIM) Workshop, Asilomar, 

Ca, Technical Report 46 of the Interagency Ecological 

Program for the Sacramento-San Joaquin Estuary, 

California Department of Water Resources, p. 143.

Walsh, T.J., 1986, Geologic map of the west half of the 

Toppenish quadrangle, Washington: Washington Division of 

Geology and Earth Resources, Open-File Report 86-3, 8 p., 

scale 1:100,000.

Walsh, T.J., 1986, Geologic map of the west half of the 

Yakima quadrangle, Washington: Washington Division of 

Geology and Earth Resources, Open-File Report 86-4, 12 

p., scale 1:100,000.

Washington State Department of Ecology, 1998, Washington 

State Water Law, A Primer: WR-98-152, on-line on the 

World Wide Web, accessed October 2000, at URL http://

www.ecy.wa.gov/pubs/98152.

Whiteman, K.J., Vaccaro, J.J., Gonthier, J.B., and Bauer, H.H., 

1994, The hydrogeologic framework and geochemistry of 

the Columbia Plateau aquifer system, Washington, Oregon, 

and Idaho: U.S. Geological Survey Professional Paper 

1413-B, 73 p.

24  Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington
Manuscript approved for publication, May 20, 2006

Prepared by the Publishing Network, 

Publishing Service Center, Tacoma, Washington

Bill Gibbs 

Robert Crist

Linda Rogers

Sharon Wahlstrom

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

Director, Washington Water Science Center 

U.S. Geological Survey, 1201 Pacific Avenue – Suite 600 

Tacoma, Washington 98402

http://wa.water.usgs.gov
SIR 2006–5116 Jones and others

Printed on recycled paper

Hydrogeologic Framework of Sedimentary Deposits in Six Structural Basins, Yakima River Basin, Washington