Base-Flow Yields of Watersheds in the 

Berkeley County Area, West Virginia

By Ronald D. Evaldi and Katherine S. Paybins

Prepared in cooperation with the Berkeley County Commission

Data Series 216

U.S. Department of the Interior

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

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

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

For product and ordering information:

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

Telephone: 1-888-ASK-USGS

For more information on the USGS--the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment:

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

Telephone: 1-888-ASK-USGS

Any use of trade, product, or firm names 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:

Evaldi, R.D., and Paybins, K.S., 2006, Base-flow yields of watersheds in the Berkeley County Area, West Virginia: U.S. 

Geological Survey Data Series 216, 4 p., 1 pl.
iii

Contents

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

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

Description of the Study Area ............................................................................................................1 

Hydrologic Conditions..........................................................................................................................2

Discharge Measurements............................................................................................................................2 

Base-Flow Yields............................................................................................................................................3 

References Cited............................................................................................................................................3

Figure

1. Map showing base-flow yields of watershed in the Berkeley County area, 

West Virginia ............................................................................................................separate file

Table

1. Discharge measurements of streams in the Berkeley County area, 

West Virginia, July 25–28, 2005, and May 4, 2006....................................................................4

Conversion Factors and Datums

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

Area

acre 0.4047 square hectometer (hm2) 

square mile (mi2) 259.0 square hectometer (hm2)

Rate

inch per year (in/yr) 2.54 centimeter per year (cm/yr)

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s)

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

gallon per day (gal/d) 0.003785 cubic meter per day (m3/d)

gallon per day per acre

 [(gal/d)/acre]

 0.000935 cubic meter per day per square

hectometer [(m3/d)/hm2]

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

°C = (°F-32)/1.8

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

Vertical control information is referenced to the National Geodetic Vertical Datum of 1929 

(NGVD 29). Altitude, as used in this report, refers to distance above the vertical datum.
iv
Base-Flow Yields of Watersheds in the Berkeley County 

Area, West Virginia

By Ronald D. Evaldi and Katherine S. Paybins

Abstract

Base-flow yields at approximately 50 percent of the 

annual mean ground-water recharge rate were estimated for 

watersheds in the Berkeley County area, W.Va. These baseflow yields were determined from two sets of discharge 

measurements made July 25–28, 2005, and May 4, 2006. Two 

sections of channel along Opequon Creek had net flow losses 

that are expressed as negative base-flow watershed yields; 

these and other base-flow watershed yields in the eastern half 

of the study area ranged from -940 to 2,280 gallons per day 

per acre ((gal/d)/acre) and averaged 395 (gal/d)/acre. The 

base-flow yields for watersheds in the western half of the 

study area ranged from 275 to 482 (gal/d)/acre and averaged 

376 (gal/d)/acre.

Introduction

Berkeley County, W.Va., is in the Eastern Panhandle of 

the State, about 65 mi northwest of Washington, D.C. The 

2004 population of Berkeley County was 89,400 and had 

increased about 50 percent since 1990 (U.S. Census Bureau, 

2006). The primary source of water for most domestic and 

community water-supply systems in Berkeley County is 

ground water (Shultz and others, 1995). State and local 

officials are concerned about the effects that the escalating 

demands for water are having on the ground-water resources 

of the county. Should long-term use of ground water exceed its 

rate of replenishment, water shortages could result. Estimates 

of ground-water-recharge rates throughout the county are 

needed for resource management planning. Ground-water 

recharge is a function of precipitation, temperature, runoff, 

infiltration rates, geology, topography, and vegetative cover. 

These factors are difficult to quantify by direct measurement 

and, as a surrogate, ground-water recharge can be estimated 

from stream-discharge data obtained during base-flow conditions. The base flow of streams is derived from ground-water 

outflow and, except for possible outflow differences caused by 

interbasin water transfers, the relative rates of base-flow yields 

from watersheds are assumed to be proportional to recharge.

 Discharges of streams and a wastewater-treatment-plant 

outfall in the Opequon Creek Watershed in Berkeley County 

were measured during base-flow conditions in July 25–28, 

2005 (Evaldi and Paybins, 2006). In order to extend the study 

area to describe the base flow of streams throughout the 

county, additional stream-discharge measurements were made 

during base-flow conditions on May 4, 2006. These included 

stream-discharge measurements in the Opequon Creek Watershed, in the Back Creek Watershed, and on small tributary 

streams that drain directly to the Potomac River (table 1, at 

back of report; fig. 1). Presentation of these measurements 

herein is the result of a cooperative effort by the U.S. Geological Survey (USGS) and the Berkeley County Commission.

Description of the Study Area

Berkeley County, which encompasses a land area of 

325 mi2, is bounded by Jefferson County, W.Va., to the east; 

Morgan County, W.Va., to the west; the State of Virginia to the 

south; and the Potomac River to the north (fig. 1). As reported 

by Shultz and others (1995), the eastern half of Berkeley 

County is characterized by gently rolling topography, with 

altitudes ranging from about 310 to 800 ft. The western half of 

the county is characterized by northeastward-trending parallel 

ridges and valleys, with altitudes ranging from about 310 to 

2,200 ft.

The Potomac River drains all of Berkeley County. The 

principal tributaries to the Potomac River are Meadow Branch, 

Cherry Run, Back Creek, Harlan Run, Opequon Creek, and 

Rockymarsh Run. Four tributaries of Opequon Creek are of 

significant size: Tuscarora Creek, Evans Run, Middle Creek, 

and Mill Creek. The base-flow discharges of all of these 

streams were measured, except for that of Meadow Branch 

(which flows through the Sleepy Creek Public Hunting and 

Fishing Area). Some tributaries to Opequon Creek that are 

entirely within Jefferson County are shown in this report 

because their flow contributions were used in the base-flow 

yield calculations for Berkeley County watersheds.

Introduction 1
Hydrologic Conditions

This study is based on stream discharge measurements 

obtained during similar base-flow conditions during July 

25–28, 2005, and on May 4, 2006. During these periods, the 

base-flow discharge provided by ground-water outflow to 

streams in the study area was approximately half of the longterm mean annual ground-water recharge rate estimated by 

Kozar and Mathes (2001).

Streamflow at USGS gaging station 01616500 Opequon Creek near Martinsburg, W.Va. (site 37, table 1, fig. 1), 

averaged 106 ft3/s (47,600 gal/min) during July 25–28, 2005 

a value that is approximately equivalent to the 40-percent 

duration (flow equaled or exceeded 40 percent of the time) of 

summer flows reported by Wiley (2006). The station recorded 

a hydrograph rise to 210 ft3/s (94,300 gal/min) on July 22; 

however, this rise in flow is believed to reflect runoff from that 

part of the 273-mi2 drainage area that is upstream from the 

study area because rainfall totaled only 0.02 in. during July 

16–24 at Martinsburg (National Climatic Data Center, 2005). 

Therefore, streamflows measured July 25–28, 2005, were 

assumed to be derived from base flow rather than from surface 

runoff. Although 0.12 in. of rain fell in Martinsburg on July 

25 and 0.13 in. fell on July 27, most of this precipitation was 

believed to have been evapotranspired as a result of high temperatures (62 to 97o

F) during July 25–28 in the Martinsburg 

area (National Climatic Data Center, 2005).

Streamflow at USGS gaging station 01616500 Opequon 

Creek near Martinsburg averaged 100 ft3/s (44,900 gal/min) 

on May 4, 2006, a value that is approximately equivalent to 

the 45-percent duration of summer flows reported by Wiley 

(2006). Streamflow at USGS gaging station 01614000 Back 

Creek near Jones Springs (site 5; table 1, fig. 1) averaged 71 

ft3/s (31,900 gal/min) on May 4, 2006, a value approximately 

equivalent to the 70-percent duration of summer flows.

Streams were considered at base flow on May 4, 2006, 

because no measurable rainfall was reported at Martinsburg 

during April 26 through May 4, 2006 (National Climatic Data 

Center, 2006).

It was not possible to define all of the hydrologic factors affecting the results of this study. Pumps were noted as 

running July 25–28, 2005, at Kilmer Spring and at Lefevre 

Spring, but outflow measurements were not adjusted because 

the amount of diversion was unknown (Evaldi and Paybins, 

2006). Other unknown diversions or interbasin transfers of 

water could have occurred during the study.

Discharge Measurements

Discharge information was obtained during July 25–28, 

2005, at 69 stream sites, 31 springs, and 1 wastewater-treatment-plant outfall in the Opequon Creek Watershed (Evaldi 

and Paybins, 2006). The wastewater-treatment-plant outfall 

measurement and 17 of the stream measurements were used in 

this study. Discharge measurements were made at 32 additional stream sites on May 4, 2006.

All sites during both time periods were measured by 

wading with current meters. Observations of width, depth, 

and velocity were made at intervals in a cross section of the 

stream or outflow. Measured discharge is the summation of 

the products of the subsection areas of the cross sections and 

their respective average velocities (Rantz and others, 1982). 

Equipment used for measuring flow was checked for accuracy 

before and after data collection and was within acceptable 

operational limits. The accuracy of individual discharge measurements was dependent on channel or outflow conditions, 

and error generally was estimated to be less than 10 percent.

A means of adjusting the measurements to similar conditions was employed because the stream-discharge measurements were obtained during slightly different flow conditions. 

The measurement adjustments were based on comparison 

of streamflow-gaging-station records for the dates of the 

Berkeley County discharge measurements to a flow statistic 

estimated from the long-term gaging-station records. The flow 

statistic chosen as the basis for the adjustments was the mean 

ground-water recharge rate estimates for USGS gaging stations 01616500 Opequon Creek near Martinsburg (9.8 in/yr) 

and 0161700 Back Creek near Jones Springs (8.5 in/yr) (Kozar 

and Mathes, 2001). These ground-water recharge rates can be 

expressed as mean watershed outflow rates, which for Opequon Creek near Martinsburg is 197 ft3

/s and for Back Creek 

near Jones Springs is 147 ft3/s.

The measurement adjustment factor used for Opequon 

Creek and other streams in the eastern half of the study area 

(sites 9–40, and 42–50) was the ratio of 50 percent of the longterm mean watershed outflow rate (98.5 ft3

/s) to the flow of 

Opequon Creek near Martinsburg at the time of data collection. The flow of Opequon Creek near Martinsburg averaged 

106 ft3/s July 25–28, 2005, and 100 ft3/s on May 4, 2006. 

Discharge measurements of streams in the eastern half of the 

study area during July 25–28, 2005, were adjusted by a factor 

of 0.929, and measurements on May 4, 2006, were adjusted by 

a factor of 0.985. The measurement adjustment factor used for 

Back Creek and other streams in the western half of study area 

(sites 1–8) was the ratio of 50 percent of the long-term mean 

watershed outflow rate (73.5 ft3/s) to the flow of Back Creek 

near Jones Springs at the time of data collection. The flow of 

Back Creek near Jones Springs averaged 71 ft3/s on May 4, 

2006. Stream discharge measurements of Back Creek and 

other streams in the western half of the study area for May 4, 

2006, were adjusted by a factor of 1.035.

 Base-Flow Yields of Watersheds in the Berkeley County Area, West Virginia
Base-Flow Yields

Base-flow yields equivalent to approximately 50 percent 

of the annual mean ground-water recharge rate were estimated 

for watersheds in Berkeley County (table 1, fig. 1). For headwater-channel sites, the base-flow yields were computed as 

the measured outflow divided by the watershed drainage area. 

Base-flow yields for other stream-channel sections were computed as the change in channel discharge between measurement sites divided by the amount of intervening drainage area 

between them. The base-flow yields were expressed in gallons 

per day per acre (gal/d)/acre) of intervening drainage area. 

For computation of change in discharge between measurement sites along a channel, all tributary inflows to the channel 

reach and known wastewater-treatment-plant discharges were 

subtracted. Flow losses of -332 and -940 (gal/d)/acre were 

thus determined for two subwatersheds along Opequon Creek 

(sites 15 and 37, respectively). These negative watershed 

yields might indicate flow losses to the ground-water system, 

channel underflow, or possible discharge-measurement errors. 

The base-flow yield of watersheds in the eastern half of the 

study area, based on measurement sites 9–50, ranged from 

-940 to 2,280 (gal/d)/acre and averaged 395 (gal/d)/acre. The 

base-flow yield of watersheds in the western half of the study 

area, based on measurement sites 1–8, ranged from 275 to 482 

(gal/d)/acre and averaged 376 (gal/d)/acre.

References Cited

Evaldi, R.D., and Paybins, K.S., 2006, Channel gains and 

losses in the Opequon Creek Watershed of West Virginia, 

July 25–28, 2005: U.S. Geological Survey Data Series 179, 

7 p.

Kozar, M.D., and Mathes, M.V., 2001, Aquifer-characteristics 

data for West Virginia: U.S. Geological Survey WaterResources Investigations Report 01–4036, 74 p.

National Climatic Data Center, 2005, Unedited local climatological data, accessed January 17, 2006, at http://cdo.ncdc.

noaa.gov/ulcd/ULCD

National Climatic Data Center, 2006, Unedited local climatological data, accessed July 20, 2006, at http://cdo.ncdc.

noaa.gov/ulcd/ULCD

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

of streamflow—Volume 1, Measurement of stage and discharge: U.S. Geological Survey Water-Supply Paper 2175, 

p. 79–183.

Shultz, R.A., Hobba, W.A., and Kozar, M.D., 1995, Geohydrology, ground-water availability, and ground-water 

quality of Berkeley County, West Virginia, with emphasis 

on the carbonate rock area: U.S. Geological Survey WaterResources Investigations Report 93–4073, 88 p.

U.S. Census Bureau, 2006, State & county QuickFacts, 

accessed January 13, 2006, at http://quickfacts.census.

gov/qfd/states

Wiley, J.B., 2006, Low-flow analysis and selected flow statistics representative of 1930–2002 for streamflow-gaging 

stations in or near West Virginia: U.S. Geological Survey 

Scientific Investigations Report 2006–5002, 190 p.

References Cited 
Table 1. Discharge measurements of streams in the Berkeley County area, West Virginia, July 25–28, 2005, and May 4, 2006.

[---; unknown; ft3/s, cubic feet per second; gal/d, gallon per day. Horizontal coordinates are referenced to North American Datum of 1983 (NAD 83)]

Site

numberDate Latitude Longitude

Drainage

area

(acres)

Discharge 1Adjusted

discharge 

(gal/d)

2

Baseflow

yield

[(gal/d)/

acre]

Site name (in West Virginia 

unless otherwise noted) ft3

/s gal/d

1 5/4/06 393714.0 780142.0 5,570 2.82 1,823,000 1,886,000 339 Cherry Run near Cherry Run

2 5/4/06 392124.0 781116.0 110,000 47.7 30,830,000 31,910,000 --- Back Creek near DeHaven, Va.

3 5/4/06 392608.0 780703.0 131,000 59.6 38,520,000 39,870,000 375 Back Creek near Shanghai

4 5/4/06 392711.0 780701.0 8,100 3.33 2,152,000 2,228,000 275 Elk Branch near Shanghai

5 5/4/06 393046.0 780212.0 150,000 71.0 45,890,000 47,490,000 482 Back Creek near Jones Springs

6 5/4/06 393522.0 780014.0 12,800 7.22 4,666,000 4,830,000 376 Tilhance Creek near Johnsontown

7 5/4/06 393536.0 780025.0 172,000 84.8 54,810,000 56,730,000 468 Back Creek near Johnsontown

8 5/4/06 393507.3 775713.1 10,500 4.61 2,980,000 2,935,000 280 Harlan Run at Little Georgetown

9 5/4/06 393542.2 775555.4 936 0 0 0 0 Unnamed tributary near Prospect Hill

10 5/4/06 393632.6 775216.1 --- 0 0 0 0 Unnamed tributary near Marlowe

11 5/4/06 393547.9 775207.9 703 0.103 66,570 65,570 93 Jordan Run near Marlowe

12 5/4/06 393358.0 775123.0 607 0.177 114,400 112,700 186 Magruder Run near Marlowe

13 5/4/06 391551.5 780159.8 90,900 52.4 33,870,000 33,360,000 --- Opequon Creek at Carters Ford

14 5/4/06 391707.8 780310.2 1,530 0.096 62,050 61,120 40 Dunean Run near Ridgeway

15 5/4/06 391718.3 780118.0 94,900 51.2 33,090,000 32,560,000 -332 Opequon Creek near Ridgeway

16 5/4/06 391725.7 780115.1 1,330 0.167 107,900 106,300 80 Silver Spring Run near Ridgeway

17 5/4/06 391808.7 780212.5 1,730 0.122 78,850 77,670 45 Specks Run near Ridgeway

18 7/25/05 391808.2 775924.7 3,960 2.71 1,752,000 1,627,000 411 Turkey Run at Middleway

19 7/25/05 391830.7 780010.0 10,200 3.82 2,469,000 2,294,000 107 Turkey Run near mouth near Middleway

20 7/26/05 392018.7 780326.4 10,200 3.49 2,256,000 2,095,000 205 Mill Creek at Bunker Hill

21 7/26/05 392000.3 780325.5 2,200 0.688 444,700 413,100 188 Torytown Run at Bunker Hill

22 7/26/05 391946.8 780225.9 14,100 7.90 5,106,000 4,743,000 1,360 Mill Creek below Bunker Hill

23 7/26/05 391854.3 780057.7 19,700 14.0 9,048,000 8,406,000 651 Mill Creek near mouth near Middleway

24 5/4/06 391840.8 775949.0 130,000 77.1 49,830,000 49,080,000 2,280 Opequon Creek near Middleway

25 5/4/06 392114.9 775759.2 136,000 93.1 60,170,000 59,270,000 1,660 Opequon Creek near Egypt

26 7/26/05 392234.0 780227.3 6,200 2.57 1,661,000 1,543,000 249 Middle Creek near Darkesville

27 7/26/05 392123.1 775813.8 9,440 4.92 3,180,000 2,954,000 435 Middle Creek near mouth near Egypt

28 7/26/05 392115.9 775808.8 1,200 0.080 51,700 48,030 40 Goose Creek near mouth near Egypt

29 7/26/05 392115.5 775601.3 1,760 2.06 1,331,000 1,237,000 701 East Branch Hopewell Run near Leetown

30 7/26/05 392115.4 775600.6 3,900 2.06 1,331,000 1,237,000 318 South Branch Hopewell Run near Leetown

31 7/26/05 392219.5 775625.0 7,090 5.56 3,594,000 3,338,000 604 Hopewell Run near mouth near Leetown

32 5/4/06 392312.4 775653.3 2,880 0.523 338,000 333,000 115 Buzzard Run near Vanville

33 5/4/06 392332.8 775706.6 891 0.254 164,200 161,700 181 Sulphur Spring Branch near Vanville

34 7/27/05 392416.4 775547.1 4,950 3.32 2,146,000 1,993,000 403 Shaw Run near mouth near Grubbs Corner

35 5/4/06 392434.7 775628.8 518 0.128 82,730 81,490 157 Unnamed tributary near Grubbs Corner

36 5/4/06 392445.5 775644.2 3,230 0.168 108,600 107,000 33 Cold Spring Run near Douglas Grove

37 5/4/06 392527.2 775616.1 172,000 100 64,630,000 63,660,000 -940 Opequon Creek near Martinsburg

38 7/27/05 392528.8 775629.3 4,560 2.94 1,900,000 1,765,000 378 Evans Run near mouth near Martinsburg

39 5/4/06 392639.0 775546.3 426 0.044 28,440 28,010 66 Unnamed tributary near Van Clevesville

40 7/27/05 392801.9 775808.2 7,590 4.84 3,128,000 2,906,000 383 Tuscarora Creek at Martinsburg

41 7/27/05 392706.1 775713.6 --- 3.94 2,546,000 2,546,000 --- Wastewater-treatment-plant outfall

42 7/27/05 392654.8 775607.7 16,900 17.0 10,990,000 10,210,000 509 Tuscarora Creek near mouth near Blairton

43 5/4/06 392655.3 775526.4 1,860 0.809 522,900 515,000 277 Unnamed tributary near Blairton

44 5/4/06 392735.8 775509.9 198,000 121 78,200,000 77,030,000 372 Opequon Creek near Files Crossroad

45 5/4/06 392748.4 775507.2 3,660 0.306 197,800 194,800 53 Unnamed tributary near Files Crossroad

46 5/4/06 392757.4 775506.1 901 0.414 267,600 263,600 293 Eagle Run near Files Crossroad

47 5/4/06 392925.6 775442.3 742 0.335 216,500 213,300 287 Unnamed tributary near Berkeley

48 5/4/06 393101.4 775325.4 207,000 126 81,440,000 80,210,000 572 Opequon Creek near Bedington

48 7/28/05 393115.1 775324.2 7,340 9.37 6,056,000 5,626,000 767 Hoke Run near mouth near Bedington

50 5/4/06 392913.9 774942.2 10,300 5.88 3,800,000 3,743,000 363 Rockymarsh Run near Scrabble

1

 Discharge measurements were adjusted to approximate outflow conditions at 50 percent of the long-term annual mean ground-water recharge rate. Discharge 

measurements of streams in the eastern half of the study area (sites 9–40, and 42–50) during July 25–28, 2005, were adjusted by a factor of 0.929, and measurements on May 4, 2006, were adjusted by a factor of 0.985. Discharge measurements of streams in the western half of the study area (sites 1–8) made on May 4, 

2006, were adjusted by a factor of 1.035. 

2

 Base-flow yields are computed as the change in channel discharge between measurement sites divided by the change in drainage area between the sites. 

Yields are negative for losing (influent) reaches and positive for gaining (effluent) reaches. See figure 1 for areas associated with the base-flow yield calculations 

for the indicated measurement sites. 

 Base-Flow Yields of Watersheds in the Berkeley County Area, West Virginia