U.S. Department of the Interior

U.S. Geological Survey

Estimating Mean Annual Streamflow of 

Rural Streams in Kentucky

In cooperation with the Kentucky Transportation Cabinet—Department 

of Highways

Water-Resources Investigations Report 02-4206
U.S. Department of the Interior

U.S. Geological Survey

Estimating Mean Annual Streamflow of 

Rural Streams in Kentucky

By Gary R. Martin

Water-Resources Investigations Report 02-4206

In cooperation with the Kentucky Transportation Cabinet— 

Department of Highways

Louisville, Kentucky

2002
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

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

endorsement by the U.S. Government. 

For additional information write to: Copies of this report can be purchased from:

District Chief, Kentucky District U.S. Geological Survey

U.S. Geological Survey Branch of Information Services

9818 Bluegrass Parkway Box 25286

Louisville, KY 40299–1906 Denver, CO 80225–0286

http://wwwdkylsv.er.usgs.gov 
Contents iii

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

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

Purpose and scope .................................................................................................................................. 1

Previous studies ...................................................................................................................................... 2

Acknowledgments .................................................................................................................................. 2

Description of study area................................................................................................................................. 2

Climate.................................................................................................................................................... 4

Physiography and geology...................................................................................................................... 4

Compilation and review of streamflow data.................................................................................................... 8

Mean annual streamflow estimates for gaged stream sites.............................................................................. 8

Development of the technique for estimating mean annual streamflow for ungaged, rural stream sites ........ 10

Basin characteristics .............................................................................................................................. 10

Regression analysis................................................................................................................................. 12

Limitations and accuracy ....................................................................................................................... 14

Procedures for estimating mean annual streamflow at stream sites in Kentucky............................................ 15

Stream sites with gage information ........................................................................................................ 15

Sites at gage locations ................................................................................................................... 16

Sites near gage locations ............................................................................................................... 16

Sites between gage locations......................................................................................................... 16

Stream sites with no gage information ................................................................................................... 16

Example applications of estimating equations ................................................................................................ 17

Summary.......................................................................................................................................................... 18

References cited............................................................................................................................................... 18

Glossary ........................................................................................................................................................... 20

FIGURES 

1–5. Maps showing:

1. Major drainage basins in Kentucky .......................................................................................... 3

2. Shaded-relief image of landforms in Kentucky........................................................................ 5

3. Physiographic regions in Kentucky .......................................................................................... 6

4. Generalized carbonate areas and surficial karst development in Kentucky.............................. 7

5. Locations of continuous-record streamflow-gaging stations in Kentucky and 

surrounding states for which data are presented in this report ................................................. 9

6. Graph showing comparison of measured mean annual streamflow and mean annual 

streamflow estimated by use of the three-variable regression equation for the 

170 continuous-record streamflow-gaging stations in Kentucky and surrounding States 

used in the regression ...................................................................................................................... 15

CONTENTS
iv Contents

TABLES

1. Continuous-record streamflow-gaging stations used in the study, selected basin 

characteristics, periods of record used in the analysis, corresponding mean annual flows, 

and selected reservoirs and diversions in the basin for Kentucky and surrounding States ................ 22

2. Equations (derived by generalized-least-squares regression) for estimating mean annual 

streamflow in Kentucky ..................................................................................................................... 13

CONVERSION FACTORS AND VERTICAL DATUM 

CONVERSION FACTORS 

Multiply By To obtain

inch (in.) 25.4 millimeter

foot (ft) 0.3048 meter

mile (mi) 1.609 kilometer

square mile (mi2) 2.590 square kilometer

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

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

°C = (°F - 32) / 1.8 

VERTICAL DATUM

Sea level: In this report “sea level” refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)—a geodetic datum derived 

from a general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929.
INTRODUCTION 1

Estimating Mean Annual Streamflow of Rural Streams 

in Kentucky

By Gary R. Martin

Abstract

Mean annual streamflow (Qa), defined as 

the mean of the series of annual mean 

streamflow values, was determined for selected 

rural stream sites in Kentucky. Streamflow data 

for the available period of record through the 

1999 water year (October 1, 1998–

September 30, 1999) at 235 continuous-record 

streamflow-gaging stations with at least 5 years 

of record located in and adjacent to Kentucky 

were used in the analysis. Record-extension 

procedures were applied for selected gaging 

stations to reduce time-sampling error and, thus, 

improve estimates of the long-term Qa.

Techniques to estimate the Qa at ungaged 

stream sites in Kentucky were developed. One-, 

two-, and three-variable regression equations 

that included total drainage area, station latitude 

minus 36 degrees, and mean basin elevation as 

explanatory variables were developed by use of 

ordinary- and generalized-least-squares 

regression. The three-variable regression 

equation has an approximate average standard 

error of prediction of 13.7 percent. The one- and 

two-variable equations exhibit geographical 

biases, and the indicated standard errors of 

prediction may poorly estimate the true 

prediction errors, depending upon the location 

in the State. Therefore, the three-variable 

equation should be used for estimating mean 

annual streamflow of rural streams in Kentucky 

whenever possible.

INTRODUCTION

The U.S. Geological Survey (USGS) has 

collected continuous-record streamflow-gaging data 

in Kentucky since 1907 (Beaber, 1970); other 

agencies collected such data in Kentucky as early as 

1890. Statistical characteristics of the streamflow 

data, such as the mean annual streamflow, are 

needed by water-resource managers and engineers 

for design of hydraulic structures constructed in the 

riverine environment. 

Resource limitations make it unfeasible for 

the collection of data on every stream and at every 

stream site where streamflow characteristics may be 

needed; therefore, techniques for estimating the 

needed streamflow characteristics at ungaged 

stream sites have been developed. The USGS, in 

cooperation with the Kentucky Transportation 

Cabinet—Department of Highways, compiled the 

available continuous-record streamflow-gaging 

station data, computed the Qa for these gaged 

stream sites, and developed regional equations for 

estimating Qa at ungaged rural stream sites on the 

basis of selected drainage-basin characteristics. 

Purpose and Scope

The purpose of this report is to provide 

(1) Qa values at continuous-record streamflowgaging stations having 5 or more years of record 

through the 1999 water year and (2) procedures for 

estimating the Qa at rural ungaged stream sites 

where flows are not appreciably affected by local 

diversions. This report presents Qa values for 

235 continuous-record streamflow-gaging stations 

in the study area. Procedures for estimating the Qa

at ungaged stream sites are described and illustrated 

with example computations.
2 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

Previous Studies

Mean annual streamflows in Kentucky have 

been investigated in various previous studies. 

Beaber (1970) analyzed streamflow-data needs and 

applications in Kentucky. Statistical multipleregression analyses were done to define relations 

between selected streamflow characteristics and 

drainage-basin characteristics. Various regression 

models to estimate mean annual streamflows at 

ungaged stream sites statewide were developed, 

including 

Qa = 1.19A1.02 (1)

Qa = 1.22A1.01E 0.10 (2)

Qa = 0.290A1.01E 0.25I

1.27 (3)

Qa = 0.270A1.01E 0.23I

1.36St-0.14 (4)

where, 

Qa is the mean annual streamflow, in ft3/s; 

A is the drainage area in mi2; 

E is the mean elevation of the basin, in 

thousands of feet above sea level; 

I is the maximum 24-hour, 2-year rainfall 

intensity, in inches; and 

St is the area of lakes and ponds in percent 

of drainage area (plus 1). 

The regression analyses provided estimates of 

the accuracy of the relations, which improved as the 

number of explanatory (regressor) variables and 

model complexity increased. The average standard 

error of estimate ranged from 14.8 percent for 

equation 1 to 12.1 percent for equation 4.

Melcher and Ruhl (1984) computed mean 

annual streamflows for the available period of 

record through the 1982 water year. Results 

presented were for combined regulated and 

unregulated periods of record at those sites with 

regulated flows. 

Wetzel and Bettandorff (1986) developed 

regression models for estimating streamflow 

characteristics, including Qa, based on data for 

629 streamflow-gaging stations in coal provinces 

covering parts of 11 States in the eastern United 

States, including the Eastern and Western Kentucky 

Coal Field physiographic regions. The basin 

characteristics used as explanatory variables in these 

regression models for estimation of Qa included 

drainage area, mean annual precipitation, and mean 

basin elevation. The average standard error of 

estimate ranged from 35.7 percent for the drainagearea-only model to 17.1 percent for the model that 

included all three of these basin characteristics as 

explanatory variables. The model coefficients of 

determination (R2) in log space ranged from 0.96 to 

0.99. 

Acknowledgments

The author would like to thank the Kentucky 

Transportation Cabinet for its support of this work. 

The author also wishes to thank the many local, 

State, and Federal agencies that have cooperated in 

the operation and maintenance of streamflowgaging stations in Kentucky and surrounding States 

that were used as part of this study. The author 

wishes to express appreciation to the many other 

USGS employees who assisted with collection and 

analysis of streamflow data, measurement of basin 

characteristics, and preparation of this report. 

DESCRIPTION OF STUDY AREA

The Commonwealth of Kentucky 

encompasses an area of 40,395 mi2 in the eastcentral United States. The major drainage basins in 

Kentucky—Big Sandy, Licking, Kentucky, Salt, 

Cumberland, Green, and Tennessee Rivers—are 

tributaries of the Ohio and Mississippi Rivers 

(fig. 1). In a generalized water balance for 

Kentucky, approximately 60 percent of precipitation 

leaves drainage basins as evapotranspiration, and 

approximately 40 percent of precipitation leaves as 

direct runoff or shallow ground-water flow into the 

streams and rivers. Variations in climate, 

physiography, and geology cause localized 

variations in streamflow characteristics in Kentucky.
 DESCRIPTION OF STUDY AREA 3 Figure 1. Major drainage basins in Kentucky.
4 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

Climate

Kentucky has a moist-continental climate 

with distinct seasonal variations and changeable 

weather patterns with generally short periods of 

extreme conditions. Winter temperatures are 

moderate, rarely below 0°F; typical summer 

temperatures are warm and rarely above 100°F. The 

weather patterns are affected variably by the 

meeting of cold-, arctic-, and continental-air masses 

arriving from the northwest and warm, moist-air 

masses moving up the Mississippi and Ohio River 

Valleys from the southwest.

Annual precipitation in Kentucky averages 

about 47 in. (Conner, 1982). The distribution of 

precipitation varies areally, year to year, and 

seasonally. The mean annual precipitation in 

Kentucky ranges areally from about 41 to 53 in. 

Rainfall generally decreases to the north, reflecting 

the increase in distance from the source of 

precipitation, which primarily is the subtropical 

Atlantic Ocean and Gulf of Mexico. Considerable 

year-to-year variation in precipitation results in 

Kentucky. During the period 1951-80, annual 

precipitation at reporting stations ranged from 14.5 

to 78.6 in. (Conner, 1982). Large amounts of 

precipitation in Kentucky have been associated with 

tropical cyclones moving north from the Gulf of 

Mexico. 

Physiography and Geology

Topographic relief in Kentucky (fig. 2) 

reflects the results of long-term stream-erosional 

processes in relation to the character of the rock 

formations. The upland areas—hills, ridges, 

mountains, and plateaus—generally consist of 

formations resistant to erosion. Western and central 

parts of Kentucky have rolling terrain, whereas the 

eastern part of Kentucky has rugged terrain with 

high relief. Land-surface elevations in Kentucky 

vary by more than 3,500 ft and range from 260 ft 

above sea level along the Mississippi River to 

4,145 ft at the peak of Black Mountain in Harlan 

County near the Kentucky–Virginia border 

(McGrain and Currens, 1978).

The physiography of the State reflects the 

lithology of the surface rocks and largely is defined 

by the Cincinnati Arch (fig. 3). The axis of the 

Cincinnati Arch trends northward from southcentral Kentucky to just south of the Outer 

Bluegrass boundary where it divides into two 

branches—Kankakee and Findlay Arches. The 

branches approximately are parallel but are 

separated by approximately 25 mi at the Ohio River 

(McFarland, 1950). Lithologic units dip away from 

the axis of the arch—a regional structural high—so 

that geologic features generally are symmetrical on 

each side of the arch.

Progressively younger rocks are exposed at 

the surface both east and west of the Cincinnati 

Arch. The oldest exposed rocks are part of the 

Jessamine Dome and adjacent areas; the location of 

this area corresponds approximately to the Inner 

Bluegrass region (fig. 3). These rocks consist of 

limestone, shale, and sandstone of Ordovician age. 

Narrow bands of shales and limestones of Silurian 

and Devonian age surround this area and correspond 

to The Knobs region. An expansive area of 

limestone of Mississippian age (Mississippian 

Plateaus Region) is exposed starting at the Ohio 

River in northeastern Kentucky, extending 

southwest to the State boundary, and extending 

northwest in a crescent-shaped area surrounding the 

Western Kentucky Coal Field. The eastern boundary 

of this area is the Cumberland Escarpment (fig. 3). 

Sandstones, shales, siltstones, and coals of 

Pennsylvanian age in eastern and northwestern 

Kentucky—the youngest rocks in 

Kentucky—compose the Eastern and Western 

Kentucky Coal Fields. Alluvial deposits of 

Cretaceous and Tertiary age are in extreme western 

Kentucky in the Mississippi Embayment.

Much of the Mississippian Plateau is 

characterized by karst features such as sinkholes, 

caves, springs, and losing streams. Most welldeveloped karst features are located in a band 

originating in west-central Kentucky and extending 

to south-central Kentucky, southeast to the State 

boundary, east along the boundary, and then 

northeast and north (areas shown in black in fig. 4). 

Less well-developed karst features are in central and 

south-central Kentucky. River main channels in 

karst areas commonly have sustained base flow 

during dry-weather periods.
 DESCRIPTION OF STUDY AREA 5 Figure 2. Shaded-relief image of landforms in Kentucky.
6 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

Figure 3. Physiographic regions in Kentucky [from Kentucky Geological Survey, 1980].
 DESCRIPTION OF STUDY AREA 7 Figure 4. Generalized carbonate areas and surficial karst development in Kentucky [from Crawford and Webster, 1986].
8 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

COMPILATION AND REVIEW OF 

STREAMFLOW DATA

Daily mean streamflow data for 

235 continuous-record streamflow-gaging stations 

located in Kentucky and adjacent states were 

retrieved by use of the USGS Automated Data 

Processing System (Bartholoma, 1997). The 

streamflow data in surrounding States were 

retrieved to provide additional information for use 

in the regionalization of Qa values. The data were 

checked and verified by comparing computed 

yearly and monthly summary statistics of the daily 

mean streamflows to published values 

(U.S. Geological Survey, 1958a, 1958b, 1964a, 

1964b, 1962-65, 1966-75, and 1976-2000).

Annual mean streamflows at 235 stations 

(198 in Kentucky and 37 in surrounding States) 

were tested for trends (p <= 0.10) by use of the 

Kendall’s Tau test, which indicated that 27 stations 

had an increasing trend in streamflow and 3 had a 

decreasing trend in streamflow. These trends 

appeared climate-related and consistent with 

reported trends for mid-range (median) flows in this 

region (Lins and Slack,1999). Precipitation-adjusted 

annual mean streamflows were approximated 

roughly as the residuals from regressions of annual 

mean streamflow with annual precipitation data (by 

water year; see Glossary for definition) at 

Louisville, Ky., which is centrally located in relation 

to the gaging stations in the data set. Kendall’s Tau 

tests of these residuals indicated that 28 had trend: 

19 with increasing trend and 9 with decreasing 

trend.

Daily mean streamflows at many gaging 

stations in Kentucky are affected by regulation and 

(or) local diversions. Regulation by multipurpose or 

flood-control reservoirs reduce peak flows and 

generally augment low flows on a seasonal time 

scale; however, when streamflows are averaged over 

an annual time step, as in the case of the annual 

mean streamflow statistic, regulation generally has 

no effect on this statistic when the volume of water 

stored is released during the same water year. Twosample statistical comparisons (Mathsoft, Inc., 

1999a and 1999b) of pre- and post-regulation, 

precipitation-adjusted annual mean streamflow 

values (the residuals of the regression of annual 

mean streamflow with annual precipitation) 

downstream from some of the major reservoirs in 

Kentucky failed to indicate a significant difference 

in the sample means (p = 0.05). 

Local diversions—localized transfers of water 

such as water-supply withdrawals or wastewater 

discharges—artificially decrease or increase 

streamflows within a reach. Local diversions are 

common near municipalities and in urban areas. The 

extent of alterations in natural streamflows caused 

by local diversions was reviewed based on available 

water-withdrawal and permitted-wastewaterdischarge data. (A.C. Downs, U.S. Geological 

Survey, written commun., 2002; and S. Bolssen, 

Kentucky Natural Resources and Environmental 

Protection Cabinet, Division of Water, written 

commun., 2002). Localized diversions were deemed 

minor in relation to Qa where available data 

indicated the flows diverted annually probably 

would not exceed 10 percent of Qa. 

MEAN ANNUAL STREAMFLOW 

ESTIMATES FOR GAGED STREAM 

SITES

Annual mean streamflows were computed 

from daily mean streamflows by use of the National 

Water Information System program DVMAS (Daily 

Values Monthly and Annual Statistics) (Bartholoma, 

1997). The mean annual streamflow (Qa) is defined 

as 

, (5)

where

Qai is annual mean streamflow for the ith 

year and 

Na is the number of annual mean 

streamflows in the gaging station 

period of record.

The computed values of Qa at streamflowgaging stations having at least 5 years of record are 

shown in table 1 (back of report). Locations of these 

gaging stations are shown in figure 5.

Qa Qai

i = 1

Na



      

/Na =
MEAN ANNUAL STREAMFLOW ESTIMATES FOR GAGED STREAM SITES 9

Figure 5. Locations of continuous-record streamflow-gaging stations in Kentucky and surrounding States for which data are presented in this report. (See table 1.)
10 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

Streamflow statistics are subject to error 

associated with the particular time period sampled 

(time-sampling error). Gaged record may occur 

during either an abnormally wet or dry period, thus 

making it unrepresentative of long-term average 

climatic conditions. Time-sampling error decreases 

as record length increases. An example of the 

effects of time-sampling error is reflected in the 

100 ft3

/s difference (reduction) of the computed Qa 

value at Barren River at Lock 1 at Greencastle 

(station 0331500) compared to the computed Qa 

value upstream at Barren River at Bowling Green 

(station 03314500) as shown in table 1.

Record-extension (augmentation) techniques 

may be used to reduce time-sampling error in 

streamflow values and statistics. Record extension is 

achieved by relating concurrent streamflows (and 

streamflow statistics) at a short-term and a nearby 

long-term (index) station that is hydrologically 

similar. The Qa at the index station and the relation 

between the concurrent daily mean streamflows at 

both stations may be used to provide an estimate of 

the long-term Qa at the short-term station. A 

mathematical record-extension technique, 

Maintenance of Variance Extension Type 1 

(MOVE.1) as described by Hirsch (1982), was used 

in this study. The estimate was computed by use of 

log-transformed values of the concurrent nonzero 

daily mean streamflows as 

, (6)

where

Qa(s) is the estimated long-term Qa for the 

short-term station;

Qa(l) is the Qa for the long-term station;

Ms, Ml are the mean of the log-transformed daily 

mean streamflows for the concurrent 

period at the short- and long-term 

stations, respectively; and

Ss, Sl are the standard deviations of the logtransformed daily mean streamflows 

for the concurrent period at the shortand long-term stations, respectively.

MOVE.1 was applied to improve Qa estimates 

for Ohio River main-stem stations only (table 1). 

The two long-term index stations on the Ohio River 

at Louisville, Ky. (03294500) and at Metropolis, Ill. 

(03611500) each had 71 full water years of record 

(1929-99). Stations designated “short-term” in 

equation 6 had fewer than 71 years of record. The 

adjustments reduced time-sampling errors and 

improved consistency in Qa and drainage-areastandardized values of Qa along the river. 

DEVELOPMENT OF THE 

TECHNIQUE FOR ESTIMATING 

MEAN ANNUAL STREAMFLOW 

FOR UNGAGED, RURAL STREAM 

SITES

A regression was used to develop regional 

equations for estimating Qa at ungaged, rural sites. 

Drainage-basin characteristics, including climate, 

affect streamflow patterns. Relations among 

selected basin characteristics and computed Qa were 

investigated by methods of linear correlation and 

multiple-linear regression. 

Basin Characteristics 

Various drainage-basin characteristics were 

tested for applicability in the regionalization of Qa. 

Selection of basin characteristics for inclusion in 

exploratory scatter plots, linear correlation analysis, 

and subsequent multiple-linear-regression analysis 

was based on (1) the possible hydrologic 

importance of the characteristic in relation to the Qa

statistic, (2) the availability of previously 

determined basin characteristics for the study 

basins, and (3) results of previous regionalization 

studies of other streamflow statistics (Beaber, 1970; 

Wetzel and Bettandorff, 1986; Choquette, 1988; 

Ruhl and Martin, 1991; and Martin and Ruhl, 1993).

Basin characteristics tested for significance in 

the regression analysis included the following:

total drainage area (A), in square miles, the 

area measured in a horizontal plane that is 

enclosed by a drainage divide, measured by 

planimeter, digitized, or grid method from 

USGS 7.5-minute topographic quadrangle 

maps;

Log Qa s Ms

Ss

Sl

----    x Log Qa l Ml = +   –
DEVELOPMENT OF THE TECHNIQUE FOR ESTIMATING MEAN ANNUAL STREAMFLOW FOR UNGAGED, RURAL STREAM SITES 11

contributing drainage area, in square miles, 

is the total drainage area excluding any parts 

characterized by internal drainage, such as 

by way of sinkholes in karst terrain;

main-channel length, in miles, the length 

measured along the main stream channel 

from the station to the basin divide, 

following the longest tributary as 

determined from USGS 7.5-minute 

topographic quadrangle maps;

main-channel slope, in feet per mile, 

computed as the difference in elevation 

between points located at 10 and 85 percent 

of the main-channel length from the gage, 

divided by the stream length between these 

two points, as determined from USGS 

7.5-minute topographic quadrangle maps;

basin length, in miles, the straight-line 

distance from the streamflow-gaging station 

to the basin divide (defined by the mainchannel length);

mean basin width, in miles, calculated by 

dividing the total drainage area by basin 

length;

basin shape, the ratio of basin length, in 

miles, squared to total drainage area, in 

square miles;

main-channel sinuosity, the ratio of mainchannel length, in miles, to basin length, in 

miles;

mean basin elevation (E), in thousands of 

feet above sea level, computed as the 

average elevation of the basin from a 

1:250,000-scale digital elevation model 

converted to a grid coverage in 

ARC/INFO;

average basin elevation index, in thousands 

of feet above sea level, determined by 

averaging main-channel elevations at points 

10 and 85 percent of the distance from a 

specified location on the main channel to the 

topographic divide, as determined from 

USGS 7.5-minute topographic quadrangle 

maps;

storage area, in percent, plus 1.00 percent, 

that part of the contributing drainage area 

occupied by lakes, ponds, and swamps, as 

shown on USGS 7.5-minute topographic 

quadrangle maps, not including temporary 

storage as a result of detention basins or 

ponding at roadway embankments;

mean annual precipitation, in inches, 

minus 30 in., estimated from Kentucky 

Department for Natural Resources and 

Environmental Protection (1979) and 

Conner (1982);

maximum 24-hour precipitation intensity, 

in inches, with recurrence intervals of 2 and 

10 years (Hershfield, 1961);

maximum 24-hour precipitation intensity, 

in inches, occurring during the 30-year 

interval of 1951-80 (Glenn Conner, 

Kentucky Climate Center, written commun., 

1986);

soils index, in inches ("S"; U.S. Department 

of Agriculture, 1969), is a measure of 

potential infiltration based on basin 

vegetative cover, soil infiltration rate, and 

soil water storage;

soil infiltration index, in inches per hour, is 

based on minimum infiltration rates for the 

U.S. Soil Conservation Service hydrologic 

soil groups (Musgrave, 1955) for soil series 

in Kentucky (U.S. Department of 

Agriculture, 1975 and 1984);

forested area, as a percentage of the 

contributing drainage area, plus 

1.00 percent, measured from USGS 

7.5-minute topographic quadrangle maps 

by use of the transparent-grid sampling 

method;

streamflow-recession index, defined as the 

number of days it takes base streamflow to 

decrease one log cycle, or one order of 

magnitude, as determined graphically from 

hydrograph plots of daily mean streamflow 

during representative periods of streamflow 

recession (Riggs, 1964; Bingham, 1982; and 

Ruhl and Martin, 1991);

streamflow-variability index, (Lane and 

Lei, 1950) at a station ("station" value) is 

computed as the standard deviation of the 

logarithms of the 19 discharges at 5-percent 

class intervals from 5 to 95 percent on the 
12 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

flow-duration (cumulative-frequency) curve 

(Searcy, 1959; and Dempster, 1990) of daily 

mean streamflow for the entire period of 

record; “mapped” values of variability index 

tested in the regression were computed as 

areally weighted average values from the 

regionalized variability index (Ruhl and 

Martin, 1991); 

azimuth, measured in degrees from north of 

line defining basin length;

gaging-station latitude (Latg), in decimal 

degrees, minus 36.0°, commonly 

determined from USGS 7.5-minute 

topographic quadrangle maps;

gaging-station longitude, in decimal 

degrees, minus 81.0°, commonly 

determined from USGS 7.5-minute 

topographic quadrangle maps;

drainage-basin centroid latitude, in 

decimal degrees minus 36.0°, determined in 

geographical information system (GIS) by 

means of the “centrallabels” command as 

applied to the basin-boundary polygons in 

ARC/INFO; and

drainage-basin centroid longitude, in 

decimal degrees, minus 81.0°, determined in 

a GIS as described for centroid latitude.

Regression Analysis

A multiple-linear-regression model was 

developed to relate Qa (dependent variable) to 

selected basin characteristics ("independent" or 

explanatory variables). Included in the regression 

analysis were 170 streamflow-gaging stations with 

at least 10 years of record where Qa was deemed not 

significantly affected by local diversions (identified 

as “minor” local diversions in table 1). The 

regression analysis included an exploratory phase 

using ordinary-least-squares (OLS) regression to 

select appropriate explanatory variables and a final 

phase using generalized-least-squares (GLS) 

regression. GLS regression compensates for 

differences in the variability and reliability of, and 

correlation among, the Qa estimates at stations 

included in the analysis.

Inspection of scatter plots showing relations 

among dependent and explanatory variables and 

plots of residuals from initial linear regressions 

indicated that logarithmic (base 10) transformation 

of the dependent and most of the explanatory 

variables would be appropriate. This transformation 

generally helped make the relations more linear and 

the residuals more uniform in variance about the 

regression line than before transformation. The 

relations between dependent and explanatory 

variables after transformation were consistent with 

the assumed linear form of the model.

The general form of the regression models 

developed in this study is 

(7)

where

Qa is mean annual streamflow,

bo is a constant,

bi (i=1 to n) is the regression coefficient for the ith 

explanatory variable,

Xi (i=1 to n) is the ith explanatory variable,

 is a random error component, and

n is the total number of explanatory 

variables.

The algebraically equivalent form when the 

log (base 10) transformation is used and when the 

equation is re-transformed to the original units is 

. (8)

The alternative OLS regression models were 

generated by all-possible-regression and stepwiseregression procedures (Statistical Analysis System 

Institute, Inc., 1985) using the prospective 

explanatory variables listed in “Basin 

Characteristics.” Various factors were considered in 

evaluating alternative regression models, including 

(1) the coefficient of determination, the proportion 

of the variation in the response variable explained 

by the regression equation; (2) the standard error of 

the estimate, a measure of model-fitting error; 

(3) the prediction sum of squares (PRESS) statistic, 

a measure of model-prediction error; (4) the 

statistical significance of each alternative 

Qa log  bo b1 X1 log b2 X2 log

... bn Xn log ,

+++

+ +

=

Qa 10boX1

b1

X2

b2

...Xn

bn =
DEVELOPMENT OF THE TECHNIQUE FOR ESTIMATING MEAN ANNUAL STREAMFLOW FOR UNGAGED, RURAL STREAM SITES 13

explanatory variable; (5) potential multicollinearity 

as indicated by the correlation of explanatory 

variables and the value of the variance inflation 

factor (Montgomery and Peck, 1982); (6) the effort 

and modeling benefit of determining the values of 

each additional explanatory variable; and (7) the 

hydrologic validity of the signs and magnitudes of 

the regression exponents.

The best one-, two-, and three-variable OLS 

regression models included total drainage area (A), 

latitude of the gaging station minus 36° (Latg-36), 

and mean basin elevation (E) in thousands of feet 

above sea level as explanatory variables. The 

drainage-area-only model accounts for a large part 

of the variability of Qa; however, the drainage-areaonly model exhibits geographical bias, which was 

reduced progressively by adding the second and 

third explanatory variables to the regression models. 

The locational variable, Latg, may serve to integrate 

and index statewide variations in precipitation and 

evapotranspiration. Mean basin elevation also may 

serve as an index to a combination of other factors 

that are difficult to evaluate, such as radiation, 

temperature, wind, vegetation, and basin relief, 

which can cause streamflow variations (Thomas and 

Benson, 1970).

The OLS regression coefficients all are 

statistically different from zero (p-value less than 

0.01). Regression residuals were analyzed to 

(1) identify outliers and high-leverage stations for 

examination, (2) confirm normality and 

homogeneity of variance, and (3) identify and 

remedy geographic bias.

The regression models (table 2) were 

finalized by use of GLS regression techniques

(Stedinger and Tasker, 1985; and Tasker and 

Stedinger, 1989), which were implemented in the 

computer program GLSNET (G.D. Tasker, 

K.M. Flynn, A.M. Lumb, and W.O. Thomas, 

U.S. Geological Survey, written commun., 1995). 

Two major assumptions of OLS regression 

commonly are violated in regression of streamflow 

statistics: (1) the errors of the streamflow statistic are 

homogeneous among the observations and (2) the 

observations statistically are independent. Error in 

streamflow statistics vary with the length of record, 

which differs among the gaging stations, and 

streamflows at the set of gaging stations are 

correlated because the same climatic conditions and 

weather events generally affect most of the streams 

within a hydrologic region. 

Stedinger and Tasker (1985, 1986) have 

shown that where streamflow records are of widely 

varying length and concurrent flows at different 

sites are highly correlated, GLS regression provides 

more accurate estimates of the regression 

coefficients, better estimates of the accuracy of the 

regression coefficients, and almost unbiased 

estimates of the model error when compared to OLS 

regression. GLS regression gives more weight to 

long-term gaging stations (with less time-sampling 

error) than short-term gaging stations and more 

weight to stations where flows are least correlated to 

flows at other gaging stations. GLS regression 

procedures use weighting matrices to 

proportionately account for the cross-correlation of 

streamflows and for the variations in time-sampling 

error of the streamflow statistic among the gaging 

stations.

Table 2. Equations (derived by generalized-least-squares regression) for estimating mean annual 

streamflow in Kentucky

[Qa, mean annual streamflow in cubic feet per second; A, total drainage area, in square miles; Latg, latitude of the gage, 

or basin outfall, in decimal degrees; E, mean basin elevation, in thousands of feet above sea level; --, not applicable]

Equations

Range of explanatory variable Approximate

average

standard

error of

prediction

(percent)

Average

equivalent

years of

A Latg E record

Qa = 1.38 A1.01 0.67–2,762 -- -- 15.8 10.9

Qa = 1.42 A1.01(Latg-36)-0.18 .67–2,762 36.341–39.140 -- 14.2 14.9

Qa = 1.39 A1.00(Latg-36)-0.15E 0.12 .67–2,762 36.341–39.140 0.391–2.414 13.7 15.4
14 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

The cross-correlations were estimated as an 

empirical, best-graphical-fit function of the distance 

between pairs of long-term gaging stations having at 

least 50 years of concurrent record. GLS regression 

required matrices of the mean, standard deviation, 

and skew of the annual mean streamflows associated 

with the matrix of the Qa. A regional estimate of the 

standard deviations of annual mean streamflows 

independent of the Qa estimating equation was 

developed within GLSNET by use of regression of 

the standard deviation against drainage area and 

mean basin elevation. A skew matrix was estimated 

by use of the observed skew of the series of annual 

mean streamflows at the gaging stations. The length 

of record at each gaging station was used as a 

measure of the reliability of the Qa estimates. 

GLSNET enables partitioning of total regressionmodel error into model error and sampling error, 

which consists of both time- and space-sampling 

error. Model error arises from limitations of the 

model formulation, and it cannot be reduced by 

additional data collection. Time- and space-sampling 

error, however, are reduced through additional data 

collection by extending the period of data collection 

and by expanding the variety of basin characteristics 

of the sites where data are collected, respectively.

Limitations and Accuracy

The one-, two-, and three-variable regional 

regression models for estimating Qa at ungaged 

stream sites have varying limitations and accuracies 

(table 2). As indicated previously, the one- and twovariable equations exhibit geographical biases, and 

the indicated standard errors of prediction may 

poorly estimate the true prediction errors, depending 

on the location in the State. The one- and twovariable models are suitable for initial approximate 

Qa estimates; however, the three-variable equation 

should be used whenever possible.

The regional regression models are applicable 

to rural streams in Kentucky that are not appreciably 

affected by local diversions, which commonly are 

associated with urban development. Caution is 

warranted when applying the regression models in 

areas where streamflows are affected by hydrologic 

discontinuities such as large springs and sinks 

common to karst terrain in areas underlain by 

limestone (see fig. 4). Streamflows in these areas 

may vary unpredictably in karst drainageways. It 

may be difficult (if not impossible) to determine an 

accurate basin drainage area in karst terrain solely 

on the basis of topographic divides. 

The regression model was developed by use 

of basin characteristics within a certain range of 

values. Drainage areas (A) of stations used in the 

regression analysis ranged from 0.67 to 2,762 mi2

, 

gage latitudes (Latg) ranged from 36.341 to 39.140°, 

and mean basin elevations (E) ranged from 0.391 to 

2.414 in thousands of feet above sea level. 

Application of the regression models for Qa

estimates in basins outside these ranges is an 

extrapolation; therefore, these models probably 

should not be applied for this situation. 

The standard error of prediction (of log Qa) 

of the three-variable model—a measure of the 

accuracy of the regression estimates compared to 

observed data for stations excluded from the 

regression—is 13.7 percent. Standard error of 

prediction was estimated as the square root of the 

PRESS divided by the error degrees of freedom 

(Statistical Analysis System Institute, Inc., 1985; 

Montgomery and Peck, 1982; and Choquette, 1988). 

The procedure used for computing PRESS is 

considered a form of data splitting and can be 

applied as a model-validation tool. The accuracy of 

the three-variable model predictions for ungaged 

sites similar to those used in the regression could be 

expected to compare favorably to the standard error 

of prediction. A scatter plot of the values of Qa

computed from the streamflow-gaging station data 

and values computed using the regression model are 

shown in figure 6. 
PROCEDURES FOR ESTIMATING MEAN ANNUAL STREAMFLOW AT STREAM SITES IN KENTUCKY 15

PROCEDURES FOR ESTIMATING 

MEAN ANNUAL STREAMFLOW AT 

STREAM SITES IN KENTUCKY

Procedures for obtaining Qa estimates differ 

depending on the location of the stream site in 

relation to streamflow-gaging (gage) locations 

where Qa has been determined. The appropriate 

procedures and examples are presented in the 

following sections.

Stream Sites With Gage 

Information

When streamflow-gaging information is 

available on the reach where an estimate of Qa is 

desired, the gage information is used where 

appropriate in making the estimate, as discussed 

below.

Figure 6. Comparison of measured mean annual streamflow and mean annual streamflow estimated 

by use of the three-variable regression equation for the 170 continuous-record streamflow-gaging 

stations in Kentucky and surrounding States used in the regression.
16 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

Sites at Gage Locations

Estimates of Qa values for 235 continuousrecord streamflow-gaging stations are presented in 

table 1. When an estimate of Qa is required at a 

stream site, refer to table 1 to determine whether 

values previously have been estimated for the site. 

At gage locations where the period of record is less 

than the equivalent years of record reported for the 

regression models (table 2), except on the Ohio 

River and where local diversions are significant, an 

improved estimate of Qa may be obtained from a 

weighted average of the gaging-station estimate and 

regression-model estimate. The equivalent years of 

record can be used to weight the regression-model 

estimate, and the years of gaged record can be used 

to weight the gaging-station estimate. 

Sites Near Gage Locations

If information is available for a stream reach 

where an estimate is desired, but not at the specific 

location, a weighting procedure can be used 

(Carpenter, 1983; and G.F. Koltun, U.S. Geological 

Survey, written commun., 2001). The drainage area 

of the ungaged site should differ by no more than 

50 percent from that of the gaged site (ranging from 

50 to 150 percent of the drainage area of the gaged 

site) to minimize the potential for hydrologic 

dissimilarity between the sites.

A weighted estimate of Qa can be computed 

as 

, (9)

where R = 

and is the weighted mean annual flow, Qa, 

for the ungaged site;

is the regression estimate of the Qa for 

the ungaged site;

is the Qa determined for the gaged site 

from measured streamflow data;

is the regression estimate of the Qa for 

the gaged site;

is the absolute value of the difference 

between the drainage areas of the 

gaged site and the ungaged site; and

is the drainage area of the gaged site.

As the difference in drainage area between the gaged 

and ungaged site approaches 50 percent, the value of 

the weighting factor in brackets in equation 9 

approaches 1 and no longer has an effect on the 

regression estimate at the ungaged site. 

Sites Between Gage Locations

If a Qa estimate is desired between two gage 

locations on the same stream, the value can be 

estimated by linear interpolation by use of the Qa

values and corresponding drainage areas at the two 

gaged sites.

Stream Sites With No Gage 

Information

If no streamflow information is available at a 

stream site, or at a nearby stream site on the same 

stream reach so that the estimating methods in the 

previous section cannot be used, then the regional 

regression models (table 2) can be used directly to 

estimate Qa. 

Total drainage area of the site of interest 

should be determined from USGS 7.5-minute 

topographic maps or from other maps or GIS 

coverages of equivalent or improved accuracy. The 

drainage areas for many locations along streams in 

Kentucky are listed in Bower and Jackson (1981).

Qauw Qaur R 2  	A   R – 1

Ag

------------------------------------    = –

Qagm/ Qagr

Qauw

Qaur

Qagm

Qagr

	A

Ag
EXAMPLE APPLICATIONS OF ESTIMATING EQUATIONS 17

EXAMPLE APPLICATIONS OF 

ESTIMATING EQUATIONS

The estimating equations presented in this 

report can be applied to rural, ungaged streams with 

flows not appreciably affected by local diversions 

by (1) determining the basin characteristics required 

for the appropriate equation, (2) checking to ensure 

that the basin characteristics fall within the range of 

characteristics values used to develop the equation, 

and (3) use of the measured basin characteristics 

values with the appropriate equation to compute the 

estimate. 

For example, assume that an estimate of Qa is 

needed for an ungaged rural stream site with a 

drainage area of 80 mi2, at a latitude of 37.525°, and 

a mean basin elevation of 900 ft above sea level. A 

comparison of basin characteristics with those listed 

in table 2 indicates that the characteristics for this 

basin are within the range of characteristics of 

gaging stations used to develop the estimating 

equations. Estimates of Qa are computed as 

Qa = 1.39 A1.00(Latg-36)-0.15E 0.12. 

Substituting the measured basin 

characteristics into the above equation yields 

Qa = 1.39(80)1.00(37.525-36)-0.15(0.900)0.12

= 103 ft3

/s.

If it is desired to quickly obtain an 

approximate estimate by use of the drainage-areaonly equation, then the first equation in table 2 is 

applied:

Qa = 1.38 A1.01. 

Substituting the measured basin 

characteristics into the above equation yields 

Qa = 1.38(80)1.01 = 115 ft3/s.

In situations where an estimate of Qa is 

needed at a stream site on a reach near a gage 

location and the drainage area at the point of interest 

is between 50 and 150 percent of the drainage area 

of the gaged site, then equation 9 can be applied to 

obtain a Qa estimate weighted by use of gagingstation information as shown in the following 

example.

Assume there is a streamflow-gaging station 

located downstream on the same stream reach used 

in the previous example with a drainage area of 

85.9 mi2, a latitude of 37.704°, and a mean basin 

elevation of 866 ft above sea level. The Qa at the 

gaged site as computed from the long-term 

streamflow data is 104 ft3

/s. The regression estimate 

of Qa at the gaged site is 

Qa = 1.39(85.9)1.00(37.704-36)-0.15(0.866)0.12

= 108 ft3

/s.

The coefficient R is determined as 

R = = = 0.963.

The gage-weighted Qa estimate for the 

ungaged site is computed as 

ft3/s. 

This adjusted Qa estimate for the ungaged 

upstream site, 99.7 ft3/s, is 96 percent of the 

measured long-term Qa (104) at the gaged site. This 

result is consistent with the ratio of the drainage 

areas of these two sites, 0.93, and is reasonable.

Qagm/ Qagr

104

108

--------

Qauw Qaur R 2  	A   R – 1

Ag

------------------------------------    = –

Qauw

103 0.963 2 85.9 80.01   –   0.963 1 –

85.9 --------------------------------------------------------------------    –

=

Qauw = 99.7
18 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

SUMMARY

Mean annual streamflow data are needed by 

water-resource managers and engineers for design 

of structures in streams and rivers. Techniques for 

estimating streamflow characteristics at ungaged 

sites are part of this need; therefore, the 

U.S. Geological Survey, in cooperation with the 

Kentucky Transportation Cabinet—Department of 

Highways, began a study in 1999 to compile 

available continuous-record streamflow-gaging 

data, compute mean annual flow at streamflowgaging stations, and develop equations for 

estimating mean annual streamflow at ungaged rural 

stream sites. 

The values of mean annual streamflow, Qa, 

were determined at selected streamflow-gaging 

stations in Kentucky and surrounding States. 

Streamflow data for the available period of record 

through the 1999 water year at 235 continuousrecord streamflow-gaging stations with at least 

5 years of record were used in the analysis. Record 

extension at selected stations was accomplished by 

use of the MOVE.1 technique to reduce timesampling error and, thus, improve estimates of longterm Qa values.

Techniques to estimate Qa at ungaged stream 

sites in Kentucky were developed. A multiplelinear-regression analysis was used to relate Qa

values to drainage-basin characteristics. One-, two-, 

and three-variable regression equations that 

included total drainage area, streamflow-gaging 

station latitude minus 36 degrees, and mean basin 

elevation as explanatory variables were developed 

by use of generalized-least-squares regression, 

which compensated for differences in the variability 

and reliability of, and correlation among, the Qa

estimates at the 170 gaging stations with 10 or more 

years of record included in the regression analysis. 

The three-variable regression equation has an 

approximate average standard error of prediction of 

13.7 percent. The one- and two-variable equations 

exhibit geographical biases, and the indicated 

standard errors of prediction may estimate poorly 

the true prediction errors, depending on the location 

in the State. The one- and two-variable models are 

suitable for initial approximate Qa estimates; 

however, the three-variable equation should be used 

whenever possible for estimating mean annual 

streamflow of rural streams in Kentucky. Estimating 

equations can be applied by (1) determining the 

basin characteristics required for the appropriate 

equation, (2) checking to ensure that the basin 

characteristics are within the range of values used to 

develop the equation, and (3) substituting the basincharacteristic values for the variables in the 

estimating equations as described in the example 

applications presented. 

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20 Estimating Mean Annual Streamflow of Rural Streams in Kentucky

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GLOSSARY

COEFFICIENT OF MULTIPLE 

DETERMINATION.—The proportion of the 

variation in the dependent variable explained by the 

variables in a fitted regression model. Reported 

values are adjusted for error degrees of freedom.

LEVEL OF SIGNIFICANCE.—The selected maximum 

probability of making a Type I error, or rejecting a 

true null hypothesis. Hypothesis tests were used to 

determine if statistically significant relations existed 

between dependent and explanatory variables of 

regression models.

LOCAL DIVERSION.—A localized transfer of water, 

such as a water-supply withdrawal or wastewater 

releases, that artificially increase or decrease 

streamflow in a reach.

MULTICOLLINEARITY.—The presence of a high 

correlation (near linear dependencies) between two 

or more explanatory variables of a regression. 

Multicollinearity causes instability in the estimates 

of the least-squares regression coefficients.

MULTIPLE-LINEAR REGRESSION.—A method of 

regression wherein a linear relation between a 

dependent variable and more than one explanatory 

variable is defined.

ORDINARY-LEAST-SQUARES REGRESSION.—A 

method of fitting a regression model in which the 

sum of squared residuals (see Residual) is 

minimized.

PREDICTION SUM OF SQUARES (PRESS) 

STATISTIC.—A measure of model-prediction error 

useful in regression-model selection. It is computed 

by summing the square of the prediction residuals 

resulting from the series of predictions of each 

observation by regressions defined using all other 

observations. Thus, each observation is in turn 

excluded from the regression data set and is not used 

in prediction of itself. This process simulates 

prediction using new data and is a form of data 

splitting useful for model validation (Allen 1971, 

1974; and Montgomery and Peck, 1982).

REGULATED STREAMFLOW.—Streamflow 

controlled by upstream hydraulic structures such as 

dams.

RESIDUAL.—The difference between values of mean 

annual streamflow computed by use of streamflowgaging data and values estimated by use of a 

regression model.

STANDARD ERROR OF ESTIMATE.—A measure of 

model-fitting error; it is the standard deviation of the 

residuals of a regression adjusted for error degrees of 

freedom. Percentage values in this report were 

estimated by use of model root-mean-square error, or 

the square root of the sum of the squares of the 

residuals divided by the error degrees of 

freedom—n-k-1, where n is the number of 

observations and k is the number of explanatory 

variables in the regression—(Statistical Analysis 

System Institute, Inc., 1985) and information from 

Hardison (1971).

STANDARD ERROR OF PREDICTION.—A measure 

of model-prediction error; it was estimated as the 

square root of the PRESS divided by the degrees of 

freedom for error (Statistical Analysis System 

Institute, Inc., 1985; Montgomery and Peck, 1982; 

and Choquette, 1988). (See Prediction Sum of 

Squares (PRESS) Statistic.)
GLOSSARY 21

STREAMFLOW.—Discharge, measured as the volume 

of water that passes a given point within a given 

period of time (cubic feet per second), that occurs in 

a natural channel whether or not it is affected by 

diversion or regulation.

STREAMFLOW-GAGING STATION.—An installation 

that provides systematic observations of stage from 

which streamflow is computed.

VARIANCE INFLATION FACTOR (VIF).—An 

indicator of multicollinearity; it is a measure of the 

combined effect of the dependencies among 

explanatory variables on the variance of each term in 

a regression model (Marquardt, 1970; and 

Montgomery and Peck, 1982).

WATER YEAR.—The 12-month period from October 1 

through September 30. The water year is designated 

by the calendar year in which it ends. 
22 Estimating Mean Annual Streamflow of Rural Streams in Kentucky Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States [mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted] Station number Station name Total drainage area (mi2) Gage latitude (decimal degrees) Gage longitude (decimal degrees) Mean basin elevation (feet above sea level) Period of record used in the analysis (water years1) Number of years Mean annual flow (ft3/s) Standardized mean annual flow (ft3/s/mi2) Selected reservoirs in basin and start date or type of local diversion and location 03202400 Guyandotte River near Baileysville, West Virginia 306 37.600 81.650 2,106 1969-98 30 424 1.39 -- 03203000 Guyandotte River at Man, West Virginia 758 37.740 81.880 1,878 1930-62 33 984 1.30 -- 03203600 Guyandotte River at Logan, West Virginia 833 37.840 82.000 1,827 1963-98 36 1,170 1.40 -- 03204500 Mud River near Milton, West Virginia 256 38.390 82.110 909 1939-80 42 290 1.13 -- 03206600 East Fork Twelvepole Creek near Dunlow, West Virginia 38.5 38.020 82.300 1,081 1965-98 34 53.5 1.39 -- 03207000 Twelvepole Creek at Wayne, West Virginia 291 38.220 82.450 986 1916-17, 1928-31,

1947-54,1956-66

25 320 1.10 --

03207020 Twelvepole Creek below Wayne, 

West Virginia

300 38.250 82.430 980 1916-17,

1928-31,1947-54,1956-82

40 349 1.16 --

03207500 Levisa Fork near Grundy, Virginia 235 37.300 82.130 2,036 1942-74,

1986-87 

34 290 1.23 --

03207962 Dicks Fork at Phyllis .82 37.449 82.338 1,500 1976-84 9 .94 1.15 --03207965 Grapevine Creek near Phyllis 6.20 37.432 82.354 1,429 1974-82,

1990-92,1995-99

17 8.46 1.36 --

03208000 Levisa Fork below Fishtrap Dam, 

near Millard

392 37.416 82.421 1,810 1939-92 54 475 1.21 Fishtrap Lake, 10/68

03208500 Russel Fork at Haysi, Virginia 286 37.210 82.300 1,996 1927-99 73 336 1.18 --03208950 Cranes Nest River near Clintwood, 

Virginia

66.5 37.120 82.440 2,074 1964-99 36 79.9 1.20 --

03209000 Pound River below Flannagan Dam 

near Haysi, Virginia

221 37.229 82.343 1,965 1927-99 72 277 1.26 Flannagan Lake, 12/63

03209300 Russell Fork at Elkhorn City 554 37.304 82.343 1,950 1961-92 32 708 1.28 Flannagan Lake, 12/63;

North Fork Pound 

Lake, 08/66
TABLE 1 23

03209500 Levisa Fork at Pikeville 1,232 37.476 82.518 1,789 1938-99 62 1,470 1.19 Flannagan Lake, 12/63;

North Fork Pound 

Lake, 08/66

Fishtrap Lake, 10/68

03209800 Levisa Fork at Prestonsburg 1,702 37.671 82.777 1,628 1964-81 18 2,130 1.25 Flannagan Lake, 12/63;

North Fork Pound 

Lake, 08/66

Fishtrap Lake, 10/68

03210000 Johns Creek near Meta 56.3 37.567 82.458 1,384 1942-93,

1995-99

57 68.9 1.22 --

03211500 Johns Creek near Van Lear 206 37.744 82.724 1,154 1940-92 53 232 1.12 Dewey Lake, 05/5003212000 Paint Creek at Staffordsville 103 37.835 82.871 965 1951-75 25 128 1.25 --03212500 Levisa Fork at Paintsville 2,144 37.815 82.792 1,485 1916,

1929-99

72 2,480 1.16 Dewey Lake, 05/50;

Flannagan Lake, 12/63;North Fork Pound 

Lake, 08/66

Fishtrap Lake, 10/68Paintsville Lake, 09/83

03213700 Tug Fork at Williamson, 

West Virginia

936 37.673 82.280 1,731 1968-98 31 1,140 1.22 --

03215000 Big Sandy River at Louisa 3,897 38.171 82.635 -- 1940-47,

1949-76

36 4,440 1.14 Dewey Lake, 05/50;

Flannagan Lake, 12/63;North Fork Pound 

Lake, 08/66

Fishtrap Lake, 10/68Paintsville Lake, 09/83

03215500 Blaine Creek at Yatesville 217 38.144 82.685 862 1916-18,

1939-75

40 247 1.14 --

03216000 Ohio River at Ashland 60,750 38.481 82.637 -- 1940-52 13 284,000 1.38 Various03216350 Little Sandy River below Grayson 

Dam near Leon

196 38.254 82.991 912 1967-92 26 241 1.23 Grayson Lake, 03/68

03216400 Little Sandy River at Leon 255 38.286 82.977 905 1962-80 19 314 1.23 Grayson Lake, 03/6803216500 Little Sandy River at Grayson 400 38.330 82.939 875 1939-99 61 479 1.20 Grayson Lake, 03/6803216540 East Fork Little Sandy River near 

Fallsburg

12.2 38.234 82.709 855 1973-91 19 15.6 1.28 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
24 Estimating Mean Annual Streamflow of Rural Streams in Kentucky 03216600 Ohio River at Greenup Dam 62,000 38.647 82.861 -- 1969-99 31 285,100 1.37 Various 03216800 Tygarts Creek at Olive Hill 59.6 38.299 83.174 1,010 1958-94 37 88.0 1.48 -- 03217000 Tygarts Creek near Greenup 242 38.564 82.952 920 1941-99 59 309 1.28 LD — gas- transmission-plant cooling 03237250 Kinniconick Creek at Tannery 294 38.543 82.225 972 1992-99 8 294 1.46 -- 03237280 Upper Twin Creek at McGaw, Ohio 12.2 38.644 83.216 1,050 1964-99 36 13.6 1.12 -- 03237500 Ohio Brush Creek near West Union, Ohio 387 38.800 83.420 877 1927-35, 1941-99 68 458 1.18 -- 03237900 Cabin Creek near Tollesboro 22.4 38.568 83.537 833 1973-91 19 31 1.39 -- 03238000 Ohio River at Maysville 70,130 38.649 83.764 -- 1941-63 23 293,700 1.34 Various

03246500 East Fork Little Miami River at 

Williamsburg, Ohio

237 39.050 84.050 1,002 1950-53,

1961-74

18 277 1.17 --

03247500 East Fork Little Miami River at 

Perrintown, Ohio

476 39.140 84.240 930 1916-17,

1926-99

76 563 1.18 --

03248500 Licking River near Salyersville 140 37.751 83.084 1,129 1939-92,

1995-97

57 173 1.24 --

03249500 Licking River at Farmers 827 38.115 83.543 1,021 1929-31,

1939-94

59 1,050 1.27 Cave Run Lake, 12/73

03250000 Triplett Creek at Morehead 47.5 38.184 83.430 1,036 1942-80,

1989-92

43 74.8 1.58 LD — water supply, 

Morehead

03250100 North Fork Triplett Creek near 

Morehead

84.7 38.199 83.481 1,018 1968-94 27 133 1.57 --

03250320 Rock Lick Creek near Sharkey 4.01 38.252 83.584 919 1974-83 10 7.66 1.91 LD — impervious 

surface drainage, Maxey Flats wastedisposal site

03250500 Licking River at Blue Lick Springs 1,785 38.422 83.999 950 1939-59 21 2,270 1.27 --03251000 North Fork Licking River near 

Lewisburg

119 38.549 83.794 875 1947-91 45 148 1.25 --

03251200 North Fork Licking River near 

Mount Olivet

226 38.649 83.764 857 1992-99 8 320 1.42 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
TABLE 1 25

03251500 Licking River at McKinneysburg 2,326 38.598 84.267 921 1925,

1939-94

57 3,030 1.30 Cave Run Lake, 12/73

03252000 Stoner Creek at Paris 239 38.229 84.256 929 1954-91 38 294 1.23 LD — waste disposal, 

Paris (minor)

03252300 Hinkston Creek at Carlisle 154 38.242 84.053 936 1992-99 8 208 1.35 --03252500 South Fork Licking River at 

Cynthiana

621 38.391 84.303 907 1939-94 56 766 1.23 LD — water supply, 

Cynthiana (minor)

03253500 Licking River at Catawba 3,300 38.710 84.311 -- 1916-17,

1929-99

73 4,140 1.26 Cave Run Lake, 12/73

03254400 North Fork Grassy Creek near Piner 13.6 38.792 84.514 816 1968-83 16 17.0 1.25 --03255000 Ohio River at Cincinnati, Ohio 76,580 39.094 84.511 -- 1940-62 23 299,700 1.30 Various03277200 Ohio River at Markland Dam 83,170 38.775 84.964 -- 1971-99 29 2108,000 1.30 Various03277400 Leatherwood Creek at Daisy 40.9 37.113 83.092 1,668 1965-74,

1992-98

17 60.4 1.48 --

03277450 Carr Fork near Sassafras 60.6 37.231 83.036 1,439 1964-94 31 77.6 1.28 Carr Fork Lake, 01/7603277500 North Fork Kentucky River at Hazard 466 37.247 83.182 1,544 1941-93 53 576 1.24 Carr Fork Lake, 01/7603278000 Bear Branch near Noble 2.21 37.451 83.195 1,167 1956-73 18 2.88 1.30 --03278500 Troublesome Creek at Noble 177 37.443 83.218 1,273 1951-81 31 251 1.42 --03280000 North Fork Kentucky River at 

Jackson

1,101 37.551 83.385 1,333 1929-31,

1938-99

65 1,460 1.32 Carr Fork Lake, 01/76

03280600 Middle Fork Kentucky River near 

Hyden

202 37.137 83.371 1,686 1958-92 35 296 1.47 LD — water supply, 

Hyden (minor)

03280700 Cutshin Creek at Wooton 61.3 37.165 83.308 1,530 1958-99 42 93.6 1.53 --03280900 Middle Fork Kentucky River at 

Buckhorn

420 37.346 83.469 1,498 1957-75 19 632 1.50 Buckhorn Lake, 12/60

03281000 Middle Fork Kentucky River at 

Tallega

537 37.555 83.594 1,382 1931,

1940-99

61 751 1.40 Buckhorn Lake, 12/60

03281040 Red Bird River near Big Creek 155 37.179 83.593 1,407 1973-99 27 280 1.81 --03281100 Goose Creek at Manchester 163 37.152 83.760 1,225 1965-99 35 266 1.63 --03281500 South Fork Kentucky River at 

Booneville

722 37.479 83.677 1,188 1926-31,

1940-99

66 1,060 1.47 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
26 Estimating Mean Annual Streamflow of Rural Streams in Kentucky 03282000 Kentucky River at Lock 14 at Heidelberg 2,657 37.555 83.768 1,264 1926-31, 1939-99 67 3,750 1.41 Buckhorn Lake, 12/60; Carr Fork Lake, 01/76 03282040 Sturgeon Creek at Cressmont 77.3 37.501 83.810 1,098 1993-99 7 125 1.62 -- 03282500 Red River near Hazel Green 65.8 37.812 83.464 1,106 1955-99 45 87.7 1.33 -- 03283000 Stillwater Creek at Stillwater 24.0 37.757 83.487 1,090 1955-73 19 34.9 1.45 -- 03283500 Red River at Clay City 362 37.864 83.933 1,040 1931, 1939-99 62 498 1.38 LD — waste disposal, Stanton (minor); water supply, Clay City (minor) 03284000 Kentucky River at Lock 10 near Winchester 3,955 37.895 84.262 -- 1908-99 92 5,350 1.35 Buckhorn Lake, 12/60 Carr Fork Lake, 01/76 LD — water supply, Lexington (minor)

03284300 Silver Creek near Kingston 28.6 37.631 84.280 1,064 1968-83 16 42.1 1.47 LD — water supply, 

waste disposal, Berea (minor)

03284500 Kentucky River at Lock 8 near 

Camp Nelson

4,414 37.745 84.587 -- 1940-71 32 5,530 1.25 Buckhorn Lake, 12/60

Carr Fork Lake, 01/76

03284550 West Hickman Creek at Jonestown 11.0 37.975 84.498 999 1975-84 10 16.8 1.52 LD — waste disposal, 

urban drainage, Lexington

03285000 Dix River near Danville 318 37.642 84.661 1,023 1943-99 57 475 1.49 --03285500 Dix River near Burgin 395 37.753 84.703 997 1912-13,

1915-22

10 733 1.86 --

03287000 Kentucky River at Lock 6 near 

Salvisa

5,102 37.926 84.821 -- 1926-99 74 6,790 1.33 Herrington Lake, 

11/25;

Buckhorn Lake, 12/60;Carr Fork Lake, 01/76

03287500 Kentucky River at Lock 4 at Frankfort 5,411 38.202 84.882 -- 1926-30,

1933-99

72 7,220 1.33 Herrington Lake, 

11/25;

Buckhorn Lake, 12/60;Carr Fork Lake, 01/76

03288000 North Elkhorn Creek near 

Georgetown

119 38.206 84.514 944 1951-83,

1989-98

43 175 1.47 --

03288100 North Elkhorn Creek at Georgetown 147 38.219 84.563 933 1993-99 7 252 1.71 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
TABLE 1 27

03288110 Royal Spring at Georgetown -- 38.209 84.562 890 1993-99 7 25.2 -- LD — water supply, 

Georgetown

03288500 Cave Creek near Fort Spring 2.53 38.021 84.594 968 1953-72 20 2.94 1.16 --03289000 South Elkhorn Creek at Fort Spring 24 38.043 84.626 965 1950-92 44 33.0 1.38 --03289300 South Elkhorn Creek near Midway 105 38.141 84.645 928 1983-99 17 174 1.65 LD — waste disposal, 

urban drainage, Lexington

03289500 Elkhorn Creek near Frankfort 473 38.269 84.815 889 1919-20,

1941-83,1988-99

58 644 1.36 LD — waste disposal, 

urban drainage, Lexington

03290000 Flat Creek near Frankfort 5.63 38.298 84.942 800 1952-71 20 6.48 1.15 --03290500 Kentucky River at Lock 2 at Lockport 6,180 38.439 84.963 -- 1927-30,

1933-37,1939-99

70 8,410 1.36 Herrington Lake, 

11/25;

Buckhorn Lake, 12/60;Carr Fork Lake, 01/76

03291000 Eagle Creek at Sadieville 42.9 38.389 84.543 915 1942-75 34 58.2 1.36 --03291500 Eagle Creek at Glencoe 437 38.705 84.824 830 1916-18,

1929-31,1939-77,1990-99

55 576 1.32 --

03292460 Harrods Creek near LaGrange 24.1 38.447 85.409 796 1969-94 26 36.9 1.53 --03292500 South Fork Beargrass Creek at 

Louisville

17.2 38.211 85.702 543 1945-53,

1955-62,1971-83,1989-99

41 22.9 1.33 LD — waste disposal, 

urban drainage, Louisville

03293000 Middle Fork Beargrass Creek at 

Louisville

18.9 38.237 85.665 621 1945-99 55 25.4 1.34 LD — waste disposal, 

urban drainage, Louisville

03294000 Silver Creek near Sellersburg, Indiana 189 38.371 85.726 597 1955-99 45 223 1.18 --03294500 Ohio River at Louisville 91,170 38.280 85.799 -- 1929-99 71 116,000 1.27 Various03295000 Salt River near Harrodsburg 41.4 37.757 84.873 944 1953-73 21 49.6 1.20 --03295400 Salt River at Glensboro 172 38.002 85.061 850 1990-99 10 273 1.59 --03295500 Salt River near Van Buren 196 37.968 85.134 839 1939-82 44 250 1.28 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
28 Estimating Mean Annual Streamflow of Rural Streams in Kentucky 03295890 Brashears Creek at Taylorsville 259 38.037 85.341 772 1982-99 18 342 1.32 -- 03296000 Plum Creek Subwatershed number 4 near Simpsonville 1.55 38.174 85.368 765 1956-64 9 1.68 1.08 -- 03296500 Plum Creek near Wilsonville 19.1 38.106 85.437 719 1955-61 7 23.6 1.23 -- 03297000 Little Plum Creek near Waterford 5.15 38.062 85.429 679 1955-61 7 6.97 1.35 -- 03297500 Plum Creek at Waterford 31.8 38.051 85.432 692 1955-74 20 41.4 1.30 -- 03297845 Floyds Fork near Crestwood 46.7 38.300 85.427 768 1980-91 12 56.7 1.21 -- 03297900 Floyds Fork near Pewee Valley 79.9 38.285 85.468 764 1992-99 8 113 1.41 -- 03298000 Floyds Fork at Fisherville 138 38.188 85.460 737 1945-99 55 182 1.32 LD — waste disposal, irrigation water supply

03298500 Salt River at Shepherdsville 1,197 37.985 85.717 722 1939-99 61 1,590 1.33 Taylorsville Lake, 

01/83

03298550 Long Lick near Clermont 7.91 37.928 85.654 683 1993-99 7 11.7 1.48 --03299000 Rolling Fork near Lebanon 239 37.497 85.324 932 1939-92 54 349 1.46 --03300000 Beech Fork near Springfield 85.9 37.704 85.146 866 1953-72 20 104 1.21 --03300400 Beech Fork at Maud 436 37.833 85.296 820 1973-99 27 638 1.46 --03301000 Beech Fork at Bardstown 669 37.797 85.481 786 1941-74,

1998-99

36 911 1.36 --

03301500 Rolling Fork near Boston 1,299 37.767 85.704 775 1938-99 61 1,820 1.40 --03301580 Wilson Creek near Deatsville 12.3 37.864 85.611 697 1992-96 5 18.9 1.54 --03302000 Pond Creek near Louisville 64.0 38.120 85.796 542 1945-99 55 90.7 1.42 LD — waste disposal, 

urban drainage, Louisville

03302220 Buck Creek near New Middletown, 

Indiana

65.2 38.119 86.086 750 1970-99 30 78.2 1.20 --

03302300 Little Indian Creek near Galena, 

Indiana

16.1 38.312 85.898 814 1969-99 31 22.7 1.41 --

03303000 Blue River near White Cloud, Indiana 476 38.237 86.228 754 1932-99 68 657 1.38 --03303280 Ohio River at Cannelton Dam 97,000 37.899 86.706 -- 1976-99 24 2123,000 1.27 Various

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
TABLE 1 29

03303400 Crooked Creek near Santa Claus, 

Indiana

7.86 38.118 86.890 495 1970-99 30 11.1 1.42 --

03303500 Ohio River at Owensboro 97,200 37.778 87.109 -- 1941-52 12 2125,000 1.29 Various03304500 McGills Creek near McKinney 2.14 37.444 84.698 1,194 1952-71 20 2.58 1.20 --03305000 Green River near McKinney 22.4 37.422 84.750 1,150 1952-73 22 31.5 1.41 --03305500 Green River near Mount Salem 36.3 37.411 84.753 1,151 1954-61 8 54.0 1.49 --03306000 Green River near Campbellsville 682 37.240 85.347 951 1931,

1964-94

32 1,120 1.64 Green River Lake, 

02/69

03306500 Green River at Greensburg 736 37.254 85.503 933 1940-75 36 1,120 1.53 Green River Lake, 

02/69

03307000 Russell Creek near Columbia 188 37.119 85.394 876 1940-99 60 292 1.55 --03307100 Russell Creek near Gresham 265 37.168 85.470 842 1965-75 11 451 1.70 --03307500 South Fork Little Barren River at 

Edmonton

18.3 36.974 85.603 899 1942-72 31 26.3 1.44 --

03308500 Green River at Munfordville 1,673 37.268 85.886 855 1916-22,

1928-31,1938-99

73 2,740 1.64 Green River Lake, 

02/69

03309000 Green River at Mammoth Cave 1,983 37.179 86.113 835 1939-50 12 2,880 1.45 --03309500 McDougal Creek near Hodgenville 5.34 37.544 85.672 883 1954-71 18 7.00 1.31 --03310000 North Fork Nolin River at 

Hodgenville

36.4 37.576 85.740 844 1942-73 32 46.9 1.29 --

03310300 Nolin River at White Mills 357 37.551 86.045 769 1960-99 40 492 1.38 --03310400 Bacon Creek near Priceville 85.4 37.359 85.998 775 1960-94 35 58.4 .68 --03310500 Nolin River at Wax 600 37.345 86.122 749 1937-62 26 793 1.32 --03311000 Nolin River at Kyrock 703 37.274 86.251 736 1931,

1940-50,1961-99

51 942 1.34 Nolin Lake, 03/63

03311500 Green River at Lock 6 at Brownsville 2,762 37.207 86.261 805 1925-31,

1939-92

61 4,370 1.58 Nolin Lake, 03/63;

Green River Lake, 

02/69

03311600 Beaverdam Creek at Rhoda 10.9 37.155 86.226 673 1973-94 22 18.2 1.66 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
30 Estimating Mean Annual Streamflow of Rural Streams in Kentucky 03312000 Bear Creek near Leitchfield 30.8 37.427 86.279 677 1950-71 22 42.7 1.39 -- 03312500 Barren River near Pageville 531 36.852 86.077 827 1940-63 24 844 1.59 -- 03312765 Beaver Creek at Highway 31 East near Glasgow 49.6 37.035 85.904 838 1992-99 8 97.5 1.96 -- 03313000 Barren River near Finney 942 36.895 86.134 804 1942-50, 1961-94 43 1,500 1.59 Barren River Lake, 03/64 03313500 West Bays Fork at Scottsville 7.47 36.748 86.196 785 1951-72 22 10.8 1.45 -- 03313700 West Fork Drakes Creek near Franklin 110 36.719 86.546 783 1969-99 31 194 1.77 -- 03314000 Drakes Creek near Alvaton 478 36.895 86.381 724 1941-71 31 697 1.46 -- 03314500 Barren River at Bowling Green 1,849 37.001 86.431 743 1939-94 56 2,600 1.41 Barren River Lake, 03/64

03315000 Barren River at Lock 1 at Greencastle 1,966 37.086 86.503 733 1925-31 7 2,500 1.27 --03315500 Green River at Lock 4 at Woodbury 5,404 37.182 86.630 -- 1938-92 55 8,460 1.57 Nolin Lake, 03/63;

Barren River Lake, 

03/64;

Green River Lake, 

02/69

03316000 Mud River near Lewisburg 90.5 37.004 86.907 599 1940-72 33 151 1.67 --03316500 Green River at Paradise 6,183 37.265 86.979 -- 1940-50,

1961-81,1992-99

40 9,360 1.51 Nolin Lake, 03/63;

Barren River Lake, 

03/64;

Green River Lake, 

02/69

03317000 Rough River near Madrid 225 37.592 86.329 711 1939-59 21 318 1.41 --03317500 North Fork Rough River near 

Westview

42.0 37.692 86.391 711 1955-73 19 36.7 .87 --

03318000 Rough River near Falls of Rough 454 37.609 86.496 685 1940-51 12 627 1.38 --03318200 Rock Lick Creek near Glen Dean 20.1 37.657 86.562 617 1957-71 15 24.9 1.24 --03318500 Rough River at Falls of Rough 504 37.589 86.551 676 1949-94 46 759 1.51 Rough River Lake, 

10/59

03318800 Caney Creek near Horse Branch 124 37.464 86.656 606 1957-92 36 188 1.52 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
TABLE 1 31

03319000 Rough River near Dundee 757 37.547 86.722 647 1941-92 52 1,080 1.43 Rough River Lake, 

10/59

03320000 Green River at Lock 2 at Calhoun 7,566 37.534 87.264 -- 1931-99 69 11,200 1.48 Rough River Lake, 

10/59;

Nolin Lake, 03/63;Barren River Lake, 

03/64;

Green River Lake, 

02/69

03320500 Pond River near Apex 194 37.122 87.319 599 1941-99 59 274 1.41 --03321000 Pond River near White Plains 343 37.227 87.349 562 1929-31,

1938-40

6 370 1.08 --

03321060 Pond River near Madisonville 469 37.317 87.369 535 1992-96 5 381 .81 --03321210 Cypress Creek near Madisonville 14.2 37.489 87.286 437 1980-81,

1991-94

6 160 1.13 --

03321350 South Fork Panther Creek near 

Whitesville

58.2 37.619 86.887 556 1969-83 15 96.9 1.66 --

03322000 Ohio River at Evansville, Indiana 107,000 37.972 87.576 -- 1941-74 34 133,000 1.24 Various03322100 Pigeon Creek at Evansville, Indiana 323 38.004 87.539 443 1961-84 24 369 1.14 --03322360 Beaverdam Creek near Corydon 14.3 37.704 87.698 446 1973-82,

1984-86,1989-94

19 14.8 1.04 --

03322420 Ohio River at Uniontown Dam 108,000 37.792 87.986 -- 1985-93 9 2138,000 1.28 Various03366200 Herberts Creek near Madison, Indiana 9.31 38.782 85.486 826 1969-99 31 13.5 1.45 --03378550 Big Creek near Wadesville, Indiana 104 38.082 87.769 456 1966-99 34 116 1.11 --03383000 Tradewater River at Olney 255 37.224 87.781 532 1941-83,

1986-99

57 334 1.31 --

03383500 Tradewater River near Dalton 283 37.274 87.797 526 1929-31,

1938-40

6 284 1.00 --

03384000 Rose Creek at Nebo 2.10 37.383 87.633 423 1953-70 18 1.99 .95 --03384500 Ohio River at Dam 51, at Golconda, 

Illinois

143,900 37.358 88.482 -- 1941-52 12 3173,000 1.20 Various

03400500 Poor Fork at Cumberland 82.3 36.974 82.993 2,399 1941-93 53 143 1.73 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
32 Estimating Mean Annual Streamflow of Rural Streams in Kentucky 03400785 Martins Fork above Smith 23.8 36.726 83.288 2,185 1986-90 5 47.0 1.98 -- 03400800 Martins Fork near Smith 55.8 36.749 83.248 2,077 1972-99 28 119 2.12 Martins Fork Lake, 11/78 03400990 Clover Fork at Harlan 222 36.848 83.326 2,181 1979-92 14 403 1.81 Martins Fork Lake, 11/78 03401000 Cumberland River near Harlan 374 36.847 83.356 2,219 1941-99 59 695 1.86 Martins Fork Lake, 11/78 03402000 Yellow Creek near Middlesboro 60.6 36.668 83.689 1,815 1941-99 59 120 1.98 LD — water supply, waste disposal, Middlesboro (minor) 03402900 Cumberland River at Pine Street Bridge at Pineville 770 36.763 83.692 1,971 1992-99 8 1,480 1.92 Martins Fork Lake, 11/78

03403000 Cumberland River near Pineville 809 36.813 83.766 1,943 1939-75,

1980-91

49 1,400 1.73 Martins Fork Lake, 

11/78;

LD — power plant 

(minor)

03403500 Cumberland River at Barbourville 960 36.862 83.887 1,850 1923-31,

1949-92,1996-99

57 1,770 1.84 Martins Fork Lake, 

11/78;

LD — water supply, 

Barbourville (minor)

03403910 Clear Fork at Saxton 331 36.634 84.112 1,633 1969-90,

1996-99

26 557 1.68 --

03404000 Cumberland River at Williamsburg 1,607 36.744 84.158 1,679 1951-99 49 2,730 1.70 Martins Fork Lake,

11/78

03404500 Cumberland River at 

Cumberland Falls

1,977 36.837 84.343 1,603 1908-11,

1916-31,1933-94

82 3,190 1.61 Martins Fork Lake, 

11/78

03404820 Laurel River at Municipal Dam near 

Corbin

140 36.970 87.120 1,204 1974-92 19 238 1.70 LD — water supply, 

Corbin (minor)

03404900 Lynn Camp Creek at Corbin 53.8 36.951 84.094 1,218 1974-99 26 88.9 1.65 --03405000 Laurel River at Corbin 201 36.969 84.127 1,206 1923-24,

1943-73

33 338 1.68 LD — water supply, 

Corbin (minor)

03406000 Wood Creek near London 3.89 37.161 84.112 1,238 1954-71 18 5.34 1.37 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
TABLE 1 33

03406500 Rockcastle River at Billows 604 37.171 84.296 1,178 1937-99 63 945 1.57 --03407000 Rockcastle River at 

Rockcastle Springs

745 37.010 84.315 1,163 1923-31 9 1,090 1.47 --

03407100 Cane Branch near Parkers Lake .67 36.868 84.449 1,216 1957-66,

1974

11 .92 1.37 --

03407300 Helton Branch near Greenwood .85 36.885 84.482 1,217 1957-74 18 1.22 1.43 --03407500 Buck Creek near Shopville 165 37.211 84.464 1,116 1953-91 39 277 1.68 --03410500 South Fork Cumberland River near 

Sterns

954 36.627 84.533 1,605 1943-99 57 1,790 1.88 --

03411000 South Fork Cumberland River at 

Nevelsville

1,271 36.840 84.583 1,501 1916-31,

1933-50

34 2,200 1.73 --

03411500 Cumberland River at Burnside 4,865 36.989 84.610 -- 1915-50 36 7,630 1.57 Laurel River Lake, 

10/73;

Martins Fork Lake, 

11/78

03412000 Pitman Creek near Somerset 26.3 37.135 84.588 1,082 1951-53 3 47.9 1.82 --03413200 Beaver Creek near Monticello 43.4 36.797 84.896 1,212 1969-83,

1990-99

25 64.1 1.48 --

03414000 Cumberland River near Rowena 5,790 36.884 85.139 -- 1940-92 53 9,010 1.56 Cumberland Lake, 

12/50;

Laurel River Lake, 

10/73;

Martins Fork Lake, 

11/78

03414500 East Fork Obey River near 

Jamestown, Tennessee

202 36.416 85.026 1,645 1943-91 49 418 2.07 --

03415000 West Fork Obey River near Alpine, 

Tennessee

115 36.397 85.174 1,391 1943-71,

1980-81

31 157 1.37 --

03416000 Wolf River near Byrdstown, 

Tennessee

106 36.560 85.073 1,319 1943-91 49 189 1.78 --

03418000 Roaring River near Hilham, 

Tennessee

78.7 36.341 85.426 1,112 1932-74 43 109 1.39 --

03435140 Whippoorwill Creek near Claymour 20.8 36.875 87.089 719 1974-91 18 34.7 1.67 --03435500 Red River near Adams, Tennessee 706 36.589 87.089 652 1921-69 49 937 1.33 --

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
34 Estimating Mean Annual Streamflow of Rural Streams in Kentucky 03436000 Sulfur Fork Red River near Adams, Tennessee 186 36.515 87.059 682 1940-91 52 252 1.35 -- 03436700 Yellow Creek near Shiloh, Tennessee 124 36.349 87.539 677 1958-80 23 191 1.54 -- 03437500 South Fork Little River at Hopkinsville 46.5 36.839 87.481 618 1950-73 24 65.8 1.42 -- 03438000 Little River near Cadiz 244 36.778 87.722 578 1941-99 59 356 1.46 -- 03438070 Muddy Fork Little River near Cerulean 30.5 36.978 87.710 569 1969-83 15 50.2 1.65 -- 03438220 Cumberland River near Grand Rivers 17,600 37.021 88.221 -- 1967-97 31 438,200 2.17 Dale Hollow Lake, 08/43; Lake Barkley, 08/44; Cumberland Lake, 12/50;

various others

03529500 Powell River at Big Stone Gap, 

Virginia

112 36.870 82.780 2,414 1945-59,

1979-81

18 202 1.80 --

03530500 North Fork Powell River at 

Pennington Gap, Virginia

70 36.770 83.030 2,109 1946-51,

1979-81,1994-95

11 137 1.95 --

03531000 Powell River near Pennington Gap, 

Virginia

290 36.734 82.999 2,161 1921-31 11 553 1.91 --

03531500 Powell River near Jonesville, Virginia 319 36.660 83.090 2,101 1932-99 68 543 1.70 --03609500 Tennessee River near Paducah 40,200 37.020 88.281 -- 1967-84 18 466,900 1.66 Kentucky Lake, 01/36;

various others

03610000 Clarks River at Murray 89.7 36.593 88.300 553 1952-71 20 88.6 .99 --03610200 Clarks River at Almo 134 36.692 88.274 540 1983-99 17 181 1.35 LD — waste-disposal, 

Murray

03610500 Clarks River near Benton 227 36.873 88.347 515 1939-73 35 278 1.22 LD — waste-disposal, 

Murray (minor)

03610545 West Fork Clarks River near Brewers 68.7 36.780 88.467 513 1969-83,

1990-94

20 91.5 1.33 --

03611260 Massac Creek near Paducah 14.6 37.041 88.711 436 1972-99 28 17.4 1.19 --03611500 Ohio River at Metropolis, Illinois 203,000 37.148 88.741 -- 1929-99 71 278,000 1.37 Various

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
TABLE 1 35

03611800 Bayou Creek at Heath 6.55 37.099 88.824 422 1991,

1994-99

7 6.42 .98 --

03611850 Bayou Creek near Grahamville 14.9 37.145 88.827 405 1991,

1994-99

7 20.8 1.40 --

03611900 Little Bayou Creek near Grahamville 5.78 37.139 88.791 365 1991,

1994-99

7 6.59 1.14 --

03612000 Cache River at Forman, Illinois 244 37.336 88.924 491 1925-99 75 297 1.22 --07022500 Perry Creek near Mayfield 1.72 36.679 88.632 517 1953-65,

1968-72

18 1.78 1.03 --

07023000 Mayfield Creek at Lovelaceville 212 36.952 88.825 481 1939-72 34 231 1.09 --07023500 Obion Creek at Pryorsburg 36.8 36.686 88.726 496 1952-73 22 40.1 1.09 --07024000 Bayou De Chien near Clinton 68.7 36.629 88.964 422 1940-78,

1985-99

54 103 1.50 --

07026500 Reelfoot Creek near Samburg, 

Tennessee

110 36.442 89.296 391 1952-73 22 120 1.09 --

1Water year refers to the 12-month period from October 1 through September 30. The water year is designated by the calendar year in which it ends.2Value adjusted based on correlation of concurrent record with Ohio River at Louisville (03294500).3Value adjusted based on correlation of concurrent record with Ohio River at Metropolis, Ill. (03611500).4Values in the table are for the period after 1966 only—after the Kentucky Lake-Lake Barkley Canal was opened in May 1966. 

Table 1. Continuous-record streamflow-gaging stations used in the study, selected basin characteristics, periods of record used in the analysis, 

corresponding mean annual flows, and selected reservoirs and diversions in the basin for Kentucky and surrounding States—Continued

[mi2, square miles; ft3/s, cubic feet per second; ft3/s/mi2, cubic feet per second per square mile; --, not applicable; LD, local diversion; all stations are in Kentucky unless otherwise noted]

Station

number Station name

Total

drainage

area

(mi2)

Gage

latitude

(decimal

degrees)

Gage

longitude

(decimal

degrees)

Mean

basin

elevation

(feet

above

sea level)

Period of

record used

in the

analysis

(water 

years1)

Number

of

years

 Mean

annual

flow

(ft3/s)

Standardized

mean annual

flow

(ft3/s/mi2)

Selected reservoirs

in basin and

start date or type of

local diversion and

location
LOUISVILLE, KY 40299–1906

9818 BLUEGRASS PARKWAYU.S. GEOLOGICAL SURVEYKENTUCKY—U.S. Geological Survey Water-Resources Investigations Report 02-4206Gary R. Martin—ESTIMATING MEAN ANNUAL STREAMFLOW OF RURAL STREAMS IN 

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