Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals

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

By Glenn A. Hodgkins and Gary R. Martin

Water-Resources Investigations Report 03-4180

In cooperation with the Kentucky Transportation Cabinet, Department of Highways

Louisville, Kentucky 2003 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 contact: Copies of this report can be purchased from:

District Chief, Kentucky District U.S. Geological Survey U.S. Geological Survey Information Services 9818 Bluegrass Parkway Box 25286 Louisville, KY 40299–1906 Denver, CO 80225–0286 http://ky.water.usgs.gov CONTENTS

Abstract...... 1 Introduction...... 1 Description of study area...... 2 Climate...... 2 Physiography and geology...... 4 Seasonality of peak flows ...... 4 Data used for peak-flow estimates and estimating techniques ...... 8 Development of peak-flow estimates and estimating techniques...... 10 Peak flows at gaging stations...... 10 Detailed Bulletin 17B analyses ...... 10 Generalized skew for Kentucky...... 11 Peak flows at ungaged locations...... 12 Defining flood regions...... 13 Choosing explanatory variables...... 14 Determining final regression coefficients...... 17 Weighting gaging-station peak-flow estimates with regression-equation peak-flow estimates ...... 18 Estimating the magnitude of peak flows for selected recurrence intervals ...... 18 Choosing the appropriate peak-flow estimation technique ...... 18 Estimates of peak flows at U.S. Geological Survey streamflow-gaging stations...... 19 Presentation of the estimates ...... 19 Limitations and accuracy of the estimates...... 21 Estimating peak flows for ungaged sites on regulated streams or streams with diversions ...... 21 Estimating peak flows for ungaged, unregulated streams in urbanized drainage basins...... 21 Estimating peak flows for ungaged sites on gaged, unregulated streams in rural drainage basins ...... 22 Application of the technique ...... 22 Limitations of the technique...... 25 Estimating peak flows for ungaged, unregulated streams in rural drainage basins...... 25 Application of the technique ...... 25 Limitations and accuracy of the technique...... 26 Example applications of the estimating equations ...... 27 Summary...... 29 References cited...... 29

PLATE

1. Locations of Kentucky hydrologic region boundaries and streamflow-gaging stations used in the study...... (in pocket on inside back cover)

Contents iii FIGURES

1–4. 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. Flowchart for choosing the appropriate means of obtaining estimated peak flows in Kentucky .... 20 6. Graph of total drainage area and main-channel slope sampling spaces for the peak-flow regression equations for Regions 1 and 4 in Kentucky...... 23

TABLES

1. Estimated peak flows for 222 selected U.S. Geological Survey streamflow-gaging stations in Kentucky ...... 33 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky ...... 61 3. Regression equations and their accuracy for estimating peak flows for ungaged, unregulated streams in rural drainage basins in Kentucky...... 15 4. Range in values of the basin characteristics used as explanatory variables in the regional peak-flow regression equations for Kentucky...... 22 5. Coefficients (exponents) of the drainage-area-only regional peak-flow regression equations for Kentucky...... 24

CONVERSION FACTORS

Multiply By To obtain

inch (in.) 25.4 millimeter inch per hour (in/h) 0.0254 meter per hour foot (ft) 0.3048 meter foot per mile (ft/mi) 0.1894 meter per kilometer cubic foot (ft3) 0.02832 cubic meter cubic foot per second (ft3) 0.02832 cubic meter per second mile (mi) 1.606 kilometers square mile (mi2) 2.590 square kilometer

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

°C = (°F - 32) / 1.8

iv Contents Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals

By Glenn A. Hodgkins and Gary R. Martin

Abstract One section of this report describes techniques for estimating peak flows for This report gives estimates of, and ungaged sites on gaged, unregulated streams in presents techniques for estimating, the rural drainage basins. Another section magnitude of peak flows for streams in references two previous U.S. Geological Survey Kentucky for recurrence intervals of 2, 5, 10, 25, reports for peak-flow estimates on ungaged, 50, 100, 200, and 500 years. A flowchart in this unregulated, urban streams. Estimating peak report guides the user to the appropriate flows at ungaged sites on regulated streams is estimates and (or) estimating techniques for a beyond the scope of this report, because peak site on a specific stream. flows on regulated streams are dependent upon Estimates of peak flows are given for 222 variable human activities. U.S. Geological Survey streamflow-gaging stations in Kentucky. In the development of the peak-flow estimates at gaging stations, a new INTRODUCTION generalized skew coefficient was calculated for the State. This single statewide value of 0.011 Estimates of the magnitude of peak (with a standard error of prediction of 0.520) is streamflows (such as the 50-year-recurrence- more appropriate for Kentucky than the national interval peak flow) are necessary to safely and skew isoline map in Bulletin 17B of the economically design bridges, culverts, and other Interagency Advisory Committee on Water structures that are in or near streams. These Data. estimates also are needed by Federal, State, Regression equations are presented for regional, and local officials for effective flood-plain management. This report, prepared by the estimating the peak flows on ungaged, U.S. Geological Survey (USGS) in cooperation with unregulated streams in rural drainage basins. the Kentucky Transportation Cabinet (KTC), will The equations were developed by use of help KTC and many others make improved generalized-least-squares regression procedures estimates of the magnitude of peak flows for at 187 U.S. Geological Survey gaging stations in Kentucky streams. Kentucky and 51 stations in surrounding States. This report gives estimates of, and presents Kentucky was divided into seven flood regions. techniques for estimating, the magnitude of peak Total drainage area is used in the final regression flows for streams in Kentucky for recurrence equations as the sole explanatory variable, intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. except in Regions 1 and 4 where main-channel Peak flows are listed for USGS streamflow-gaging slope also was used. The smallest average stations with 10 years or more of recorded annual 1 standard errors of prediction were in Region 3 peak flows through water year 2000.

(from -13.1 to +15.0 percent) and the largest 1A water year is the 12-month period from October 1 average standard errors of prediction were in through September 30, and it is designated by the calendar year Region 5 (from -37.6 to +60.3 percent). in which it ends.

INTRODUCTION 1 A technique is presented for estimating the peak tributaries of the Ohio River (fig. 1). Variations in flows for ungaged, unregulated streams in rural climate, physiography, and geology cause localized drainage basins. Techniques also are described for variations in streamflow characteristics in Kentucky. estimating peak flows at ungaged sites on gaged streams (for unregulated sites in rural drainage basins). Two reports are referenced for estimating Climate peak flows on ungaged, unregulated streams in urbanized drainage basins. A technique for Kentucky has a moist-continental climate estimating peak flows for ungaged sites on regulated with distinct seasonal variations and changeable streams is beyond the scope of this report, although weather patterns. Winter temperatures are moderate, a possible approach is mentioned and cautions about rarely below 0oF; typical summer temperatures are inappropriate approaches are given. warm and rarely above 100oF. Average annual Various peak-flow studies have been snowfall is about 20 in., but the snow cover rarely published applicable to all or parts of Kentucky remains longer than 3 days at a time. Weather since 1958 (McCabe, 1958, 1962; Speer and patterns in Kentucky are affected variably by the Gamble, 1964, 1965; Hannum, 1976; Wetzel and meeting of cold, continental air masses arriving Bettandorff, 1986; Choquette, 1988). Each from the northwest and warm, moist air masses succeeding report generally used more years of moving up the Mississippi and Ohio River Valleys hydrologic data and more rigorous statistical from the southwest (Conner, 1982). techniques. This report supersedes Choquette Annual precipitation in Kentucky averages (1988) and the other reports in that the estimates and about 47 in. The distribution of precipitation varies estimating techniques described in this report areally, annually, and seasonally. The mean annual should provide improved estimates of rural peak precipitation in Kentucky ranges areally from about flows for Kentucky. Advances in techniques for this 41 to 53 in. Rainfall generally decreases to the report included the development of a generalized north, reflecting the increase in distance from the skew for Kentucky and the use of generalized-least- source of moisture, which primarily is the squares regression (explained later in the report). subtropical Atlantic Ocean and Gulf of Mexico. The U.S. Army Corps of Engineers (USCOE) Kentucky has considerable year-to-year variation in and the Tennessee Valley Authority generously precipitation. During the period 1951-80, annual provided peak-flow estimates for many regulated precipitation at reporting stations ranged from 14.5 rivers. William J. Byron, Jr., USCOE, Louisville to 78.6 in. Large amounts of precipitation in office, especially was helpful. This report would not Kentucky have been associated with tropical be possible without nearly 100 years of peak-flow cyclones moving north from the Gulf of Mexico data collection, often under hazardous conditions, (Conner, 1982). by USGS hydrologic technicians and hydrologists. Precipitation falls throughout the year but the This historical-data collection was done by the sources and amounts of precipitation vary USGS in cooperation with the Commonwealth of seasonally. Although March generally is the wettest Kentucky. month of the year, averaging from 4 to 6 in., the precipitation pattern is bimodal with a second peak, averaging from 3.3 to 5.5 in., occurring in July. DESCRIPTION OF STUDY AREA October generally is the driest month when precipitation averages from 2 to 3 in. Mean seasonal The Commonwealth of Kentucky precipitation in Kentucky is about 13.5 in. in spring encompasses an area of 40,395 mi2 in the east- (March through May), 12.4 in. in summer (June central United States. The major drainage basins in through August), 9.8 in. in fall (September through Kentucky—Big Sandy, Licking, Kentucky, Salt, November), and 11.5 in. in winter (December Cumberland, Green, and Tennessee Rivers—are through February) (Conner, 1982).

2 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Major drainagebasins in Kentucky.

Figure 1. 1. Figure

DESCRIPTION OF STUDY AREA 3 Winter precipitation is characterized by Jessamine Dome and adjacent areas; the location of frontal storm systems. Summer precipitation this area corresponds approximately to the Inner generally results from convective storm activity, Bluegrass region (fig. 3). These rocks consist of commonly in the form of afternoon thunderstorms. limestone, shale, and sandstone of Ordovician age. Precipitation intensity generally is higher in summer Narrow bands of shales and limestones of Silurian than during other seasons, but the number of days and Devonian age surround this area and correspond having precipitation is similar in winter and to The Knobs region. An expansive area of summer. The Bermuda high-pressure system has a limestone of Mississippian age (Mississippian strong effect on seasonal precipitation patterns in Plateaus Region) is exposed starting at the Ohio Kentucky. In the fall, this high-pressure system River in northeastern Kentucky, extending generally moves inland from the southeastern coast southwest to the State boundary, and extending of the United States and is centered over Kentucky northwest in a crescent-shaped area surrounding the and Tennessee, where it inhibits both convective Western Kentucky Coal Field. The eastern boundary activity and frontal storm movement and produces a of this area is the Cumberland Escarpment (fig. 3). dry season (Conner, 1982). Sandstones, shales, siltstones, and coals of Pennsylvanian age in eastern and northwestern Kentucky—the youngest rocks in Physiography and Geology Kentucky—compose the Eastern and Western Kentucky Coal Fields. Alluvial deposits of Topographic relief in Kentucky (fig. 2) Cretaceous and Tertiary age are in extreme western reflects the results of long-term stream-erosional Kentucky in the Mississippi Embayment. processes in relation to the character of the rock Much of the Mississippian Plateau is formations. The upland areas—hills, ridges, characterized by carbonate rock and karst features mountains, and plateaus—generally consist of such as sinkholes, caves, springs, and losing formations resistant to erosion. Western and central streams. Most well-developed karst features are parts of Kentucky have rolling terrain, whereas the located in a band originating in west-central eastern part of Kentucky has rugged terrain with Kentucky and extending to south-central Kentucky, high relief. Land-surface elevations in Kentucky southeast to the State boundary, east along the vary by more than 3,500 ft and range from 260 ft boundary, and then northeast and north (areas above sea level along the Mississippi River to shown in black on fig. 4). Less well-developed karst 4,145 ft at the peak of Black Mountain in Harlan features are in central and south-central Kentucky. County near the Kentucky–Virginia border (McGrain and Currens, 1978). The physiography of the State reflects the Seasonality of Peak Flows lithology of the surface rocks and largely is defined by the Cincinnati Arch (fig. 3). The axis of the Cincinnati Arch trends northward from south- Precipitation patterns strongly affect the central Kentucky to just south of the Outer magnitude and timing of peak flows. Seasonally Bluegrass boundary where it divides into two changing conditions, such as evapotranspiration branches—Kankakee and Findlay Arches. The rates, antecedent soil moisture, and the extent, branches approximately are parallel but are duration, and intensity of storm systems affect flood separated by approximately 25 mi at the Ohio River response in a given drainage basin. (McFarland, 1950). Lithologic units dip away from The timing of peak flows varies with the axis of the arch—a regional structural high—so drainage-basin size. In basins with drainage areas that geologic features generally are symmetrical on from 50 to 1,000 mi2, from 70 to 75 percent of the each side of the arch. annual maximum peaks occur between January and Progressively younger rocks are exposed at April. About 45 percent of the peaks in basins from the surface both east and west of the Cincinnati 0.1 to 10 mi2 and 58 percent of the peaks in basins Arch. The oldest exposed rocks are part of the from 10 to 50 mi2 occur between January and April.

4 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Shaded-reliefinlandforms image Kentucky. of

Figure 2.

DESCRIPTION OF STUDY AREA 5 rom Kentucky Geological Survey, 1980]. Geological Survey, rom Kentucky Physiographic regions in Kentucky [f Physiographic

(Base credit and projection information unavailable.) information projection and credit (Base Figure 3. 3. Figure

6 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals pment in Kentucky [from Crawford and Webster, 1986].pment in Kentucky [from Generalizedcarbonatedeveloand areas surficial karst (Base credit and projection information unavailable.) information and projection credit (Base

Figure 4. Figure

DESCRIPTION OF STUDY AREA 7 Basins less than 10 mi2 show a more uniform series titled “Water Resources Data—Kentucky.” distribution of peaks throughout the year, with a Urban drainage basins in Jefferson County were particularly high percentage of floods occurring documented in Martin and others (1997). USGS from June through September (about 28 percent) in field personnel identified which drainage basins in 2 comparison to the basins larger than 50 mi , where the rest of Kentucky were likely currently to be only about 10 percent of the annual floods occurred urbanized. during these months. A similar pattern of summer The peak flows from various gaging stations flooding also occurred in the 10- to 50-mi2 basins were not used for various reasons. The data at two where about 20 percent of the peaks occurred from June through September. The annual peaks in small stations were combined into one station if the drainages (generally less than 10 mi2) are more drainage area for a station was less than 10-percent frequently caused by convective summer storms, different from the drainage area of another station which generally are of more limited areal extent, and if doing so appeared reasonable based on the shorter duration, and higher intensity than the frontal data. A drainage-area correction was applied when storms in winter and spring that frequently cause the combining the stations if the drainage areas differed annual peaks in large basins (generally greater than from 3 to 10 percent. Drainage-area corrections 50 mi2) (Choquette, 1988). were not applied to stations for which the drainage areas differed by less than 3 percent. Data from the following stations were combined: Cumberland DATA USED FOR PEAK-FLOW River near Pineville, Ky. (USGS gaging-station number 03403000), was combined with ESTIMATES AND ESTIMATING Cumberland River at Pine Street Bridge at Pineville, TECHNIQUES Ky. (03402900). The peak flows for selected recurrence The USGS has been collecting and publishing intervals for Salt River at Glensboro (03295400, continuous-record streamflow data for gaging 172 mi2, 11 years of record) are not reported stations in Kentucky since 1907 (Beaber, 1970). The because the annual peak flows at this station appear data currently (2003) are published by the USGS in the annual report series titled “Water Resources to have been collected during an unrepresentative Data—Kentucky.” For the section of this report short period as compared to Salt River near Van 2 titled “Estimates of Peak Flows at USGS Buren (03295500, 196 mi , 44 years of record). Streamflow-Gaging Stations” (page 19), peak flows Regression equations are used to estimate a are reported for 222 Kentucky stations with 10 or response variable (in this case, a peak flow for a more years of annual peak-flow data that are given recurrence interval) for an ungaged drainage considered representative of current peak-flow basin by measuring explanatory variables (such as conditions (table 1, page 33). For the section of this drainage area). Explanatory variables should make report titled “Estimating Peak Flows for Ungaged, hydrologic sense, explain a large amount of the Unregulated Streams in Rural Drainage Basins” variability of the response variable, and be (page 25), the data for 238 streamflow-gaging reasonably easy to measure. A set of explanatory stations—187 in Kentucky, 7 in West Virginia, variables that were qualitatively judged to best meet 8 in Virginia, 6 in Ohio, 13 in Indiana, 6 in Illinois, these criteria was selected for testing. and 11 in Tennessee—with at least 10 years of rural, unregulated, annual peak flows were used (table 2, For the section of this report titled page 61). These data include the pre-regulation “Estimating Peak Flows for Ungaged, Unregulated period from various gaging stations where flows Streams in Rural Drainage Basins” (page 25), the currently (2003) are regulated. For both sections of values of 27 explanatory variables were determined this report, any sites with flow diversions or sites for gaged, unregulated streams in rural drainage likely to be urbanized were not used. Flow basins in Kentucky and surrounding States. These diversions are documented in the annual report 27 explanatory variables were:

8 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals total drainage area (TDA), in mi2, the area storage area, in percent, plus 1.00 percent, that measured in a horizontal plane that is enclosed part of the contributing drainage area occupied by a drainage divide, measured by planimeter, by lakes, ponds, and swamps, as shown on digitized, or measured by grid method from USGS 7.5-minute topographic quadrangle USGS 7.5-minute topographic quadrangle maps, not including temporary storage as a result maps; of detention basins or ponding at roadway contributing drainage area, in mi2, is the total embankments; drainage area excluding any parts characterized mean annual precipitation, in inches, minus by internal drainage, such as by way of sinkholes 30 in., estimated from Kentucky Department for in karstic terrain; Natural Resources and Environmental main-channel length, in mi, the length Protection (1979) and Conner (1982); measured along the main stream channel from maximum 24-hour precipitation frequencies, the gage to the basin divide (by extension of the in inches, with recurrence intervals of 25 and mapped main channel up to the divide), 50 years (Hershfield, 1961); following the longest tributary as determined maximum 24-hour precipitation, in inches, from USGS 7.5-minute topographic quadrangle occurring during the 30-year interval of 1951-80 maps; (Glenn Conner, Kentucky Climate Center, main-channel slope (S), in ft/mi, computed as written commun., 1986); the difference in elevation between points soils index, in inches ("S"; U.S. Department of located at 10 and 85 percent of the main-channel Agriculture, 1969), a measure of potential length from the gage, divided by the stream infiltration based on basin vegetative cover, soil length between these two points, as determined infiltration rate, and soil-water storage; from USGS 7.5-minute topographic quadrangle soil infiltration index, in in/h, based on maps; minimum infiltration rates for the U.S. Natural basin length, in mi, the straight-line distance Resources Conservation Service (formerly Soil from the gage to the basin divide (defined by the Conservation Service) hydrologic soil groups main-channel length); (Musgrave, 1955) for soil series in Kentucky (U.S. Department of Agriculture, 1975 and mean basin width, in mi, calculated by dividing 1984); the total drainage area by basin length; forested area, as a percentage of the contributing basin-shape factor, the ratio of basin length, in drainage area, plus 1.00 percent, measured from mi, squared to total drainage area, in mi2; USGS 7.5-minute topographic quadrangle maps main-channel sinuosity, the ratio of main- by use of the transparent-grid sampling method; channel length, in mi, to basin length, in mi; streamflow-recession index, defined as the mean basin elevation, in thousands of ft, number of days it takes base streamflow to computed in ARC/INFO as the average decrease one log cycle, or one order of elevation of the basin from a 1:250,000-scale magnitude, as determined graphically from digital elevation model (where elevations are hydrograph plots of daily mean streamflow referenced to the National Geodetic Vertical during representative periods of streamflow Datum of 1929, NGVD of 1929); recession (Riggs, 1964; Bingham, 1982, Ruhl average basin elevation index, in thousands of and Martin, 1991); ft, determined by averaging main-channel streamflow-variability index, (Lane and Lei, elevations at points 10 and 85 percent of the 1950) at a station ("station" value) is computed distance from a specified location on the main as the standard deviation of the logarithms of the channel to the topographic divide, as determined 19 discharges at 5-percent class intervals from 5 from USGS 7.5-minute topographic quadrangle to 95 percent on the flow-duration (cumulative- maps (where elevations are referenced to the frequency) curve (Searcy, 1959; Dempster, National Geodetic Vertical Datum of 1929, 1990) of daily mean streamflow for the entire NGVD of 1929); period of record;

DATA USED FOR PEAK-FLOW ESTIMATES AND ESTIMATING TECHNIQUES 9 azimuth, measured in degrees from north to the Peak Flows at Gaging Stations line defining basin length; gaging-station latitude, in decimal degrees, The 2-, 5-, 10-, 25-, 50-, 100-, 200-, and minus 36.0o, determined from USGS 7.5-minute 500-year peak flows for individual streamflow- topographic quadrangle maps; gaging stations discussed in this section were gaging-station longitude, in decimal degrees, calculated by use of the guidelines of the minus 81.0o, determined from USGS 7.5-minute Interagency Advisory Committee on Water Data topographic quadrangle maps. (1982) (Bulletin 17B). The calculations involved fitting the Pearson Type III probability distribution drainage-basin centroid latitude, in decimal to the logarithms (base 10) of the observed annual degrees minus 36.0o, determined in a geographic peak flows at a gaging station. This fitting required information system (GIS) by means of the computation of the mean, standard deviation, and “centroidlabels” command as applied to the skew of the logarithms of the annual peak-flow data. basin-boundary polygons in ARC/INFO. The peak flow for any selected recurrence interval drainage-basin centroid longitude, in decimal was determined from the fitted curve. degrees, minus 81.0o, determined in a GIS as described for centroid latitude. Detailed Bulletin 17B Analyses climate factor for the 2-, 25-, and 100-year recurrence intervals, an index integrating the Bulletin 17B analyses require that the peak- effects of climate on flood frequency as flow data used for statistical analysis at a gaging interpolated from climate factor isolines station be a reliable and representative sample of presented by Lichty and Karlinger (1990). random, homogeneous events. The annual peak regional indicator variables X1, X2, ... X7, flows at gaging stations described in this report are assumed to be random, reliable, and independent of which were set to a value of 1, if a site was in the each other. selected region, or 0 if the site was not in the The peak flows in a drainage basin will not be selected region. homogeneous if the hydrologic conditions in the region, a single regional indicator variable, basin change appreciably over time because of which was set to integer values 1, 2, ....7 urbanization or other human activities. A two-sided depending on the particular region in which the Mann-Kendall trend test (Helsel and Hirsch, 1992) gaging station was located. was done on the annual peak flows at gaging stations to test for trends over time. To produce accurate results for the significance of a trend, this test requires that the data have no serial correlation. DEVELOPMENT OF PEAK-FLOW Serial correlation, in this case, is the dependence or ESTIMATES AND ESTIMATING correlation in time sequence between annual peak TECHNIQUES flows. Annual peak-flow data can exhibit some serial correlation. This correlation can cause the Peak-flow estimates for selected recurrence Mann-Kendall trend test to indicate a significant intervals at gaging stations were developed based on trend when there is none, especially at gaging stations with less than 30 years of peak-flow data the guidelines of the Interagency Advisory (G.D. Tasker, U.S. Geological Survey, written Committee on Water Data (1982) (Bulletin 17B). commun., 1997). For this reason, some judgment is Peak-flow regression equations for ungaged necessary to determine whether the results of the locations were developed by use of ordinary-least- Mann-Kendall trend test are significant. The Mann- squares (OLS) and generalized-least-squares (GLS) Kendall test was not done at stations with less than regression techniques. The peak flows at the gaging 25 years of peak-flow data because trends cannot be stations then were weighted with regression- distinguished from serial correlation at stations with equation peak-flow estimates at the gaging stations. this data length. Ten (7 percent) of 142 gaging

10 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals stations tested had significant trends (at a adjustment for historical information, and for significance level of 5 percent) over time, with weighting the station skew coefficient with a 6 positive trends and 4 negative trends. These trends generalized skew coefficient. The station skew was all had significance levels ranging from 1 to not weighted with the generalized skew if the annual 5 percent. One-hundred two of these sites were peak flows at a gaging station were significantly located in Kentucky and 40 sites were located in affected by regulation. The annual peak flows from surrounding States. The number of stations with the gaging stations in this study did not show significant trends are close to the number expected obvious evidence of being caused by multiple simply by chance and are distributed rather generating mechanisms; therefore, the procedures uniformly between positive and negative trends. The used to handle this situation were not used. significant trends are believed to be chance Expected probability adjustments were not made; occurrences rather than true trends; no sites were these adjustments are explained in Bulletin 17B. removed from the analyses. The annual peak flows at all stations were plotted to look for large changes in the distribution Generalized Skew for Kentucky of peak flows over time, especially at gaging stations whose basins now are regulated. A station Four methods were analyzed to find the most was considered significantly regulated if its accurate generalized skew for Kentucky to use in drainage basin had more than 4.5 million ft3 of the Bulletin 17B analyses. The first method was to usable reservoir storage per mi2 (Benson, 1962) or if compute an arithmetic mean of the station skews. To pre-regulation peaks were significantly different compute this skew coefficient, the station skews from post-regulation peaks. The pre- and post- from 102 gaging stations in Kentucky were regulation annual peaks from all gaging stations computed by use of the procedures in Bulletin 17B. downstream of USCOE dams were tested for The stations used all had at least 25 years of significant differences. Significance was established unregulated annual peak-flow data. None of these with the Mann-Whitney test (also known as the stations were significantly affected by diversions or Wilcoxon rank-sum test) (Helsel and Hirsch, 1992) urbanization. The computed station skews for this at a one-sided significance level of 0.05. The results method, and the following methods, were adjusted of the regulation analyses are listed in for bias (Tasker and Stedinger, 1986). The table 1 (page 33). The Cumberland River at Pine 102 stations had an average of 40.4 years of annual Street Bridge at Pineville, Ky. (USGS gaging- peak-flow data. station number 03402900), had a p-value of 0.075. In the second method, mean skews were Given this p-value and the fact that the data at both calculated for stations that drain karst basins and upstream and downstream gaging stations indicated stations that drain other basins. For this method, the significant regulation, this gaging station also was karst stations were defined as stations with total considered regulated. The section of this report drainage areas that were different from their titled “Estimating Peak Flows for Ungaged, contributing drainage areas. By this criteria, there Unregulated Streams in Rural Drainage Basins” were 82 non-karst drainage basins and 20 karst (page 25), used annual peak flows from pre- drainage basins. The two samples were different regulation time periods only. When peak flows were from each other at a significance level of 0.094 computed by use of techniques described in Bulletin 17B, only post-regulation data from when the Mann-Whitney test was applied. The weak stations were used (see the section of this report p-value, combined with mean skews that are similar titled “Estimates of Peak Flows at USGS (0.16 for the karst sites and -0.02 for the non-karst Streamflow-Gaging Stations,” page 19), because the sites), lead to the decision not to separate these two pre-regulation data are no longer representative of populations of gaging stations in Kentucky. current (2003) flows. In the third method of computing a Bulletin 17B guidelines were followed for the generalized skew, an attempt was made to create a treatment of high and low outliers, for the State skew-isoline map by plotting the station skews conditional probability adjustment, for the on a map at the centroid of their drainage basins.

DEVELOPMENT OF PEAK-FLOW ESTIMATES AND ESTIMATING TECHNIQUES 11 The stations, however, showed no obvious an exploratory data analysis to develop linear geographic pattern. Positive and negative skew regression equations to relate peak flows, QT values both were scattered throughout the State. (“response” or “dependent” variable, where In the fourth method, an attempt was made to T = 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year develop a multiple-regression equation with station recurrence intervals), to selected basin skew as the response variable and drainage basin characteristics (“independent” or “explanatory” characteristics (such as drainage area and stream slope) as the explanatory variables. There were 95 variables). The most appropriate explanatory of the 102 gaging stations with the following basin variables for estimating peak flows were selected in characteristics available for testing as explanatory this OLS exploratory phase. The final regression variables: contributing drainage area, main-channel coefficients and regression errors then were slope, mean basin elevation, average basin elevation computed by use of GLS regression. GLS index, forested area, mean annual precipitation, regression compensates for differences in the maximum 24-hour precipitation frequencies with reliability of, and correlation among, the Q recurrence intervals of 25 and 50 years, basin T estimates at stations included in the analysis. The length, and azimuth. All-possible-subsets multiple regression analysis included the 238 streamflow- OLS regression and the Mallow’s Cp statistic were used to find the best combinations of variables gaging stations in Kentucky and nearby in (Helsel and Hirsch, 1992). Some combinations were neighboring States with at least 10 years of peak- eliminated from consideration if individual flow record that was not affected appreciably by explanatory variables were not significant. regulation (table 2–page 61, and plate 1 at back of Combinations also were eliminated if they report). contained both measures of precipitation intensity Inspection of scatter plots in the OLS and each measure had opposite signs. The best exploratory phase, which showed the relations remaining regression equation contained the single variable—percent forested area. This regression between response and explanatory variables, explained too little of the variation in skew values indicated that logarithmic (base 10) transformations (r2 = 0.076) to use, given the risk that the form of of the response variable and most of the explanatory the regression equation likely is to be imperfect variables were appropriate. This transformation (Helsel and Hirsch, 1992). generally helped make the relations more linear and It is obvious that the Bulletin 17B generalized the residuals (errors) more uniform in variance skew (the national skew-isoline map) is not about the regression line than before transformation. representative of station skews in Kentucky. The The relations between response and explanatory Bulletin 17B map isolines indicate negative skews variables after transformation were consistent with for all of Kentucky except the far eastern part. As the assumed linear form of the model. discussed earlier, both positive and negative computed station skews for 102 sites in Kentucky The general form of the regression equations were scattered throughout the State. developed in this study is The mean skew for Kentucky was used as the () generalized skew in the Bulletin 17B flood- log QT = bo +++b1logX1 b2logX2 . . . (1) ε frequency analyses. This new skew coefficient is ++bnlogXn , 0.011, with a standard error of prediction of 0.520. where

QT the response variable, is the peak flow of estimated long-term average Peak Flows at Ungaged Locations recurrence interval T, b is a constant, Regression equations are used to compute o peak flows at ungaged locations. OLS regression bi (i=1 to n) is the regression coefficient for the ith techniques (Helsel and Hirsch, 1992) were used in explanatory variable,

12 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Xi (i=1 to n) is the ith explanatory variable, attained significance level (p-value) of less than ε is the random-error component, and 0.001). Residuals from the statewide regression were compared to residuals from each region by use n is the total number of explanatory of the nonparametric Mann-Whitney U test. The variables. statewide residuals were significantly different The algebraically equivalent form when the (p<0.05) from the residuals of all regions except for equation is retransformed to the original units is Region 6, where the test-statistic p-value was 0.076.

bo b1 b2 bn Regional location-indicator variables were QT = 10 X1 X2 ... Xn . (2) used in the OLS regressions to test for statistically significant differences among the seven regions. In Defining Flood Regions these statistical tests, a 95-percent confidence level was defined as significant. The location-indicator During the exploratory data analysis, the variables were set either at 1, if the station was in a seven peak-flow hydrologic regions defined by particular region, or 0, if not. Methods described by Choquette (1988) were assessed based on the Montgomery and Peck (1982) were used to test for updated peak-flow values. The peak-flow significant variations of the slopes (coefficients) and characteristics of the seven regions were evaluated intercepts among regional regressions of the 50-year graphically and statistically. A statewide OLS peak flow with total drainage area. Intercepts for the regression of log-transformed 50-year peak-flow OLS-regression equations for Regions 2, 4, and 6 values with the log-transformed total drainage areas differ from those of Regions 1, 3, 5, and 7, and there (log Q50 = b0 + b1 log TDA) was completed using is variation among slopes of the seven regional all 238 gaging stations. Also, this same OLS regression equations. regression was completed for each of three Regional location-indicator variables also aggregated regions formed by combining Regions 1 were used to directly compare regressions for each and 2; Regions 3, 4, and 5; and Regions 6 and 7 region to regressions for the group of all the other (plate 1). The geographical distribution of the stations combined (Pope and others, 2001). This residuals (errors) from the statewide regression and comparison was done by adding the location- the residuals from the three regressions for the indicator variable and the product of the location- aggregated regions generally conformed to the indicator variable and the total-drainage-area term regional boundaries defined by Choquette (1988). to the regression. Thus, a three-variable OLS- Residuals from the statewide regression also were regression equation to estimate Q50, with all grouped by river basin for comparison; however, no available stations and utilizing (1) total drainage distinctive pattern in residuals relative to river area, (2) location-indicator variable, and (3) the basins was apparent. This lack of pattern may be product of the location-indicator variable and total related to the large geologic and physiographic drainage area as explanatory variables, was variability and climatic variability spanned by developed for each of the seven regions. In each Kentucky drainage basins. Plots of the residuals in regional model, a significant location variable downstream order by river basin showed a tendency indicates a difference in the regression intercept for the residual signs and magnitudes to vary locally between the stations in that region and the stations with changes in geologic and physiographic in the rest of the State; a difference in the product of characteristics. the location variable and total drainage area term Density plots and box plots of the residuals indicates a difference in the coefficients for total from the statewide regression (not shown) displayed drainage area between the stations in that region and patterns similar to those described by Choquette the stations in the rest of the State. Based on the (1988) where residuals for Regions 1, 3, 5, and 7 levels of significance of the indicator-variable terms appear similar in sign and magnitude and the in these regressions, only the Region 3 regression residuals for Regions 2, 4, and 6 appear similar in equation failed to indicate a significant difference sign and magnitude. A Kruskal-Wallis test indicated (0.05) from the regression for the group of all other that for at least one region, the central tendency of stations combined. However, further location- the residuals differ among the seven regions (at an indicator regression comparisons showed that

DEVELOPMENT OF PEAK-FLOW ESTIMATES AND ESTIMATING TECHNIQUES 13 Region 3 differs from Region 4, Region 3 differs Choosing Explanatory Variables from Region 2, and Region 3 also differs from the OLS-regression equations were developed by group of stations in the neighboring regions all-possible-subsets regression procedures combined (Regions 2, 4, and 5). (Statistical Analysis System Institute, Inc., 1985) Results of these statistical tests, which cannot with the 2-, 50-, and 500-year peak flows for the be used to statistically verify the seven regions, 238 unregulated stations as response variables, nonetheless are supportive of the regionalization initially utilizing all of the 27 prospective scheme. The tests, which compare the regional explanatory variables, or transformations thereof, regression characteristics, indicate that each region discussed in the section of this report titled “Data represents a grouping of stations that is Used for Peak-Flow Estimates and Estimating distinguishable from either all the other stations Techniques” (page 8). A subset of 54 of the stations combined as a group or all the stations in the had all of these explanatory variables available, neighboring regions combined. Indeed, the central because most of the explanatory variables at these tendencies (means and medians) of the residuals of stations were computed in a previous study the statewide regression in each region are not (Choquette, 1988). The variables out of the 27 statistically different from the central tendencies of prospective variables that least improved the each and every one of the other regions. As noted regression model, using data from the 54 stations, previously, the residuals in Regions 1, 3, 5, and 7 were dropped from the analyses. Also, variables appear similar in sign and magnitude, and the were removed if they were highly correlated with a residuals in Regions 2, 4, and 6 appear similar in better-performing variable. As the number of sign and magnitude. However, the odd-numbered explanatory variables was reduced, an increased regions are geographically separated as are the number of stations had all of the variables. even-numbered regions. Also, the regression Regression equations were rerun with additional equations for the individual regions (table 3) differ stations and fewer variables than before, and again in their coefficients and in their accuracy. Based on the variables that least improved the equations were the results of the graphical and statistical tests dropped. As more gaging stations were added, described in this section, the seven-region scheme regression analyses also were done for individual regions. This iterative process continued as the best developed by Choquette (1988) was accepted for the explanatory variables were retained, based on both updated peak-flow values presented in this report. the statewide and regional equations. Total drainage Some minor adjustments in the region area, instead of contributing drainage area, was boundaries were made to improve alignment with selected as the primary explanatory variable. the drainage-basin boundaries and the current 2 Contributing drainage area was eliminated as an residuals: An area of approximately 150 mi , which explanatory variable because of (1) the difficulty in included the basin for the Goose Creek at determining this basin characteristic accurately Manchester station (03281100), was shifted from from maps that generally are available, (2) the Region 4 into Region 3. An area of approximately minimal overall improvement in accuracy in most 2 220 mi , which included the basin for the Barren regions, and (3) a reduced accuracy in Region 5. River Tributary near Bowling Green station The top four explanatory variables were total (03314750), was shifted from Region 6 into Region drainage area, main-channel slope, main-channel 5. An area of approximately 50 mi2 in the lower sinuosity, and basin-shape factor. Based on the Green River Basin, just downstream from the results from these regressions, it was not considered confluence with Pond River, was shifted from useful to compute values of the other explanatory Region 7 into Region 6. variables that had not been determined previously.

14 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals

Table 3. Regression equations and their accuracy for estimating peak flows for ungaged, unregulated streams in rural drainage basins in Kentucky [Q is peak flow, in cubic feet per second; TDA is total drainage area, in square miles; S is main-channel slope, in feet per mile]

Peak-flow regression equation Average Average Estimated Average for given recurrence interval standard error equivalent model-error sampling-error (recurrence intervals from of prediction (PRESS/n)1/2 years of variance variance 2 to 500 years) (percent) (percent) record (base-10 logs) (base-10 logs)

Region 1 – 28 gaging stations 0.673 Q2 = 312 TDA 49.7 to -33.2 49.9 to -33.3 1.3 0.0277 0.0030 0.651 Q5 = 493 TDA 48.0 to -32.4 48.6 to -32.7 1.9 .0259 .0031 0.843 0.451 Q10 = 91.5 TDA S 46.2 to -31.6 47.2 to -32.1 2.8 .0230 .0042 0.872 0.535 Q25 = 81.2 TDA S 49.3 to -33.0 51.1 to -33.8 3.6 .0253 .0050 0.890 0.587 Q50 = 75.8 TDA S 52.9 to -34.6 55.5 to -35.7 3.9 .0283 .0057 0.907 0.632 Q100 = 71.4 TDA S 57.3 to -36.4 61.0 to -37.9 4.1 .0321 .0066 0.922 0.673 Q200 = 67.8 TDA S 62.4 to -38.4 67.3 to -40.2 4.2 .0367 .0076 0.941 0.722 Q500 = 63.6 TDA S 69.7 to -41.1 76.6 to -43.4 4.3 .0438 .0090 Region 2 – 68 gaging stations 0.728 Q2 = 152 TDA 44.0 to -30.6 45.1 to -31.1 1.9 .0238 .0013 0.721 Q5 = 239 TDA 39.5 to -28.3 40.8 to -29.0 3.0 .0197 .0012 0.715 Q10 = 304 TDA 38.6 to -27.9 40.5 to -28.8 4.2 .0188 .0013 0.709 Q25 = 393 TDA 38.7 to -27.9 41.5 to -29.3 5.8 .0187 .0015 0.704 Q50 = 464 TDA 39.3 to -28.2 43.0 to -30.1 6.9 .0191 .0016 0.699 Q100 = 538 TDA 40.4 to -28.8 44.8 to -30.9 7.9 .0199 .0018 0.695 Q200 = 615 TDA 41.7 to -29.4 47.0 to -32.0 8.7 .0209 .0020 0.690 Q500 = 721 TDA 43.6 to -30.4 50.2 to -33.4 9.6 .0225 .0022 Region 3 – 24 gaging stations 0.748 Q2 = 187 TDA 25.9 to -20.6 29.0 to -22.5 5.9 .0081 .0019 0.712 Q5 = 355 TDA 23.7 to -19.1 27.5 to -21.5 9.8 .0064 .0021 0.692 Q10 = 498 TDA 22.2 to -18.2 27.2 to -21.4 15.1 .0052 .0024 0.670 Q25 = 714 TDA 20.7 to -17.2 27.5 to -21.5 24.6 .0040 .0027 0.656 Q50 = 897 TDA 20.4 to -16.9 28.1 to -22.0 32.4 .0034 .0031 0.643 Q100 = 1100 TDA 20.4 to -16.9 29.1 to -22.5 39.4 .0031 .0034 0.632 Q200 = 1320 TDA 21.1 to -17.4 30.4 to -23.3 44.5 .0030 .0039 0.620 Q500 = 1640 TDA 22.6 to -18.4 32.7 to -24.6 47.9 .0033 .0045 Region 4 – 17 gaging stations 0.923 0.204 Q2 = 39.0 TDA S 31.4 to -23.9 32.3 to -24.4 3.5 .0112 .0029 0.894 0.186 Q5 = 69.8 TDA S 25.2 to -20.1 26.0 to -20.7 6.5 .0072 .0023 0.882 0.178 Q10 = 92.7 TDA S 24.3 to -19.5 25.6 to -20.4 9.2 .0065 .0024 0.873 0.173 Q25 = 121 TDA S 25.5 to -20.3 27.6 to -21.6 11.6 .0068 .0029

DEVELOPMENT OF PEAK-FLOW ESTIMATES AND ESTIMATING TECHNIQUES 15 Table 3. Regression equations and their accuracy for estimating peak flows for ungaged, unregulated streams in rural drainage basins in Kentucky—Continued [Q is peak flow, in cubic feet per second; TDA is total drainage area, in square miles; S is main-channel slope, in feet per mile]

Region 4 – 17 gaging stations—continued 0.870 0.173 Q50 = 140 TDA S 27.3 to -21.5 30.2 to -23.2 12.5 0.0077 0.0033 0.780 Q100 = 392 TDA 31.6 to -24.0 38.4 to -27.7 11.4 .0111 .0031 0.778 Q200 = 441 TDA 33.8 to -25.3 41.3 to -29.2 11.7 .0125 .0035 0.776 Q500 = 510 TDA 37.1 to -27.1 45.5 to -31.3 11.9 .0147 .0041 Region 5 – 40 gaging stations 0.704 Q2 = 260 TDA 34.5 to -25.7 36.3 to -26.6 3.3 .0151 .0015 0.692 Q5 = 437 TDA 38.9 to -28.0 41.8 to -29.5 3.8 .0186 .0018 0.686 Q10 = 571 TDA 43.9 to -30.5 48.0 to -32.4 4.2 .0228 .0022 0.682 Q25 = 754 TDA 51.1 to -33.8 57.0 to -36.3 4.6 .0293 .0028 0.679 Q50 = 901 TDA 56.7 to -36.2 64.0 to -39.0 4.7 .0347 .0033 0.677 Q100 = 1060 TDA 62.4 to -38.4 71.3 to -41.6 4.8 .0405 .0039 0.676 Q200 = 1220 TDA 68.4 to -40.6 78.7 to -44.0 4.9 .0467 .0045 0.674 Q500 = 1450 TDA 76.4 to -43.3 89.0 to -47.1 4.9 .0555 .0053 Region 6 – 27 gaging stations 0.600 Q2 = 256 TDA 49.9 to -33.3 49.9 to -33.3 1.3 .0280 .0029 0.586 Q5 = 397 TDA 45.1 to -31.1 46.4 to -31.7 2.0 .0234 .0027 0.578 Q10 = 499 TDA 43.9 to -30.5 46.5 to -31.7 2.8 .0222 .0028 0.569 Q25 = 636 TDA 44.1 to -30.6 48.4 to -32.6 3.8 .0221 .0031 0.564 Q50 = 740 TDA 45.4 to -31.2 50.9 to -33.7 4.4 .0229 .0035 0.559 Q100 = 846 TDA 47.1 to -32.0 53.9 to -35.0 4.9 .0243 .0038 0.555 Q200 = 953 TDA 49.6 to -33.2 57.6 to -36.5 5.2 .0263 .0043 0.551 Q500 = 1100 TDA 53.7 to -34.9 63.1 to -38.7 5.5 .0299 .0049 Region 7 – 34 gaging stations 0.623 Q2 = 293 TDA 56.6 to -36.1 58.2 to -36.8 1.4 .0350 .0029 0.616 Q5 = 476 TDA 55.0 to -35.5 57.5 to -36.5 2.1 .0332 .0030 0.613 Q10 = 614 TDA 54.5 to -35.3 58.1 to -36.8 3.0 .0325 .0032 0.610 Q25 = 804 TDA 54.7 to -35.4 59.9 to -37.4 4.1 .0323 .0036 0.610 Q50 = 956 TDA 55.3 to -35.6 61.6 to -38.1 5.0 .0326 .0039 0.609 Q100 = 1110 TDA 56.1 to -35.9 63.6 to -38.9 5.8 .0332 .0042 0.610 Q200 = 1280 TDA 57.3 to -36.4 66.0 to -39.7 6.6 .0342 .0045 0.610 Q500 = 1510 TDA 59.2 to -37.2 69.5 to -41.0 7.5 .0358 .0050

16 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Various factors were considered in evaluating normality, and the presence of outliers. Normal alternative regression equations with the top four probability plots of the residuals also were analyzed. explanatory variables, including (1) the coefficient Residuals were plotted against the explanatory of determination, a measure of the proportion of the variables to look for biases in the explanatory variation in the response variable explained by the variables over their range. All regression diagnostics regression equation; (2) the standard error of the estimate, a measure of model-fitting error; (3) the indicated that the final explanatory variables in each prediction sum of squares (PRESS) statistic, a region resulted in satisfactory regression equations. measure of model-prediction error; (4) the statistical significance of each individual explanatory variable; Determining Final Regression (5) potential multicollinearity as indicated by the Coefficients correlation of explanatory variables and the value of the variance inflation factor (Montgomery and Peck, The regression equations (table 3) were 1982); (6) the effort and modeling benefit of finalized by use of GLS-regression techniques determining the values of each additional (Stedinger and Tasker, 1985; Tasker and Stedinger, explanatory variable; and (7) the hydrologic validity of the signs and magnitudes of the explanatory 1989), utilizing the computer program GLSNET variables. (G.D. Tasker, K.M. Flynn, A.M. Lumb, and The best one-, two-, and three-variable W.O. Thomas, U.S. Geological Survey, written regression equations in the final OLS all-possible- commun., 1995). Two major assumptions of OLS subsets regression run were determined for all regression commonly are violated in regression of available gaging stations in each region with the top peak flows and explanatory variables: (1) the errors four explanatory variables. Total drainage area was in the computed peak flows of selected recurrence selected as an explanatory variable in all seven intervals are the same at all gaging stations and regions. The attained significance levels for the (2) the annual flows for overlapping years at T-statistics on total drainage area were less than 0.0001 in all regions. Main-channel slope was different gaging stations are independent of each chosen as a second explanatory variable in Regions other (not cross-correlated). Error in the peak flows 1 and 4. Addition of any of the three explanatory varies with the length of record, which differs variables other than drainage area did not among the gaging stations, and streamflows at appreciably (more than 3 percentage points) reduce gaging stations in a region usually are cross- the regression standard errors of estimate in the correlated because the same climatic conditions and other five regions. The values of drainage area and weather events can affect most of the streams within main-channel slope for all regions are listed in a hydrologic region. table 2 (page 61). Stedinger and Tasker (1985) and Tasker and Regression diagnostic tools were used to test the adequacy of the final OLS regressions. The Stedinger (1986) have shown that where streamflow OLS-regression coefficients all are statistically records are of widely varying length and concurrent different from zero (p-values less than 0.05). The flows at different sites are highly correlated, GLS influence of individual stations on the regressions regression provides more accurate estimates of the was measured by Cook’s D statistic (Helsel and regression coefficients, better estimates of the Hirsch, 1992). Multicollinearity in the explanatory accuracy of the regression equations, and better variables was tested with the variance inflation estimates of the model error when compared to OLS factor. There were no problems with high-influence points or multicollinearity between variables. regression. GLS regression gives more weight to Different types of residual plots were analyzed. The long-term than short-term gaging stations and less regression residuals were plotted against predicted weight to stations where flows are more highly values to look for linearity, homoscedasicity, correlated to flows at other gaging stations.

DEVELOPMENT OF PEAK-FLOW ESTIMATES AND ESTIMATING TECHNIQUES 17 Weighting Gaging-Station Peak- ω is either the systematic record length, in Flow Estimates with Regression- years, if no historical peak-discharge data are available for the site, or the Equation Peak-Flow Estimates effective record length, in years, if historical peak-discharge data are Recorded peak flows at individual gaging available for the site. stations, especially those with short periods of The effective record length is computed as record, may not be representative of peak flows P from long periods of record. Because of this, peak- ωω= + D0.55– 0.1ln------, (4) flow estimates determined by use of the methods in s 1 – P Bulletin 17B at each gaging station (see the section where of this report titled “Peak Flows at Gaging Stations,” D is minimum ()200, ()ω – ω ; page 10) were combined mathematically with the h s ()⁄ ()ω ω peak-flow estimates at that station, computed from P is 1 – Np h + s ; regression equations (table 3, page 15), to compute Np is the number of historic peaks; the best (weighted) estimate of peak flows for that ω h is the historic record length, in years, and station (table 1, page 33). If two independent ω is the systematic record length, in years. estimates are weighted inversely proportional to s their variances, the variance of the weighted average is less than the variance of either estimate (Interagency Advisory Committee on Water Data, ESTIMATING THE MAGNITUDE OF 1982). In other words, the weighted average will PEAK FLOWS FOR SELECTED produce the most accurate peak-flow estimates (number of years of record is inversely proportional RECURRENCE INTERVALS to variance, and thus the weighting in equation 3 below becomes direct with years of record). The This section describes techniques for estimating the magnitude of peak flows for streams weighted-average peak flow (Qtw) was calculated by use of the equation in Kentucky for recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. A flowchart is provided log()ωQ ()+ log()ωQ () ------to tr e- ωω as a guide to the appropriate estimates and (or) + e Qtw = 10 , (3) estimating techniques for a site on a specific stream. Example applications of the peak-flow estimating where equations also are provided.

Qto is the log-Pearson Type III estimate of the t-year peak discharge calculated by the methods described in the section of Choosing the Appropriate Peak- this report titled “Estimates of Peak Flow Estimation Technique Flows at USGS Streamflow-Gaging Stations” (page 19); Peak flows in this report refer to peak flows of Qtr is the regression estimate of the t-year a specified recurrence interval. The recurrence peak discharge calculated with the interval is the average period of time between peak methods described in the section of this flows that are equal to or greater than a specified report titled “Estimating Peak Flows for peak flow. For example, the 50-year peak flow is the Ungaged, Unregulated Streams in Rural flow that would be exceeded, on a long-term Drainage Basins” (page 25); average, once in 50 years. This does not imply, ω e is the equivalent years of record for the however, that flooding will happen at regular regression estimate as defined by intervals; two 50-year peak flows could occur in the Hardison (1971); and same year. In contrast, a 50-year peak flow might

18 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals not occur in 100 years. The recurrence interval does Site near a gaging station—the drainage not indicate when the estimated flood peak will area of the site ranges from 50 to 200 percent occur. of the drainage area of a USGS gaging The reciprocal of the recurrence interval is station (excluding the plus or minus 3 called the annual exceedance probability; that is, the percent considered “at a gaging station”) and probability that a given peak flow will be exceeded on the same stream; in any given year. For example, the annual Urbanized—more than 15 percent of the exceedance probability of the 50-year peak flow drainage-basin area above the site is covered would be 0.02. In other words, there is a 2-percent by some type of commercial, industrial, or chance that the 50-year peak flow will be exceeded residential development. in any given year. To obtain estimated peak flows for streams in Kentucky, information on the site (site refers to a location on a stream) of interest is needed, including Estimates of Peak Flows at USGS whether the site is at or near (and on the same Streamflow-Gaging Stations stream as) a USGS streamflow-gaging station and whether the site drains an urbanized or regulated The 2-, 5-, 10-, 25-, 50-, 100-, 200-, and drainage basin. The different peak-flow estimates 500-year peak flows for streamflow-gaging stations and estimating techniques in this report are discussed in this section were calculated by use of appropriate to various combinations of these site the guidelines of the Interagency Advisory characteristics. Committee on Water Data (1982) (Bulletin 17B). The flowchart in figure 5 should be used to The calculations involved fitting the Pearson Type choose the appropriate method of obtaining III probability distribution to the logarithms (base estimated peak flows. The boxes in the right column 10) of the observed annual peak flows at a gaging of the flowchart show the appropriate section of this station. This fitting required computation of the report for obtaining the peak flows. The mean, standard deviation, and skew of the “Limitations and Accuracy” statements in each logarithms of the annual peak-flow data. The peak section should be read before applying the equations flow for any selected recurrence interval was in that section. Although the discussions on determined from the fitted curve. limitations are intended to be comprehensive, it is possible that other specific limitations will arise in the application of the equations in these sections. The following definitions apply to figure 5: Presentation of the Estimates Site at a gaging station—the drainage area of the study site is within 3 percent of the The peak flows for recurrence intervals of 2, drainage area of a USGS streamflow-gaging 5, 10, 25, 50, 100, 200, and 500 years at USGS station and on the same stream (see plate 1 streamflow-gaging stations in Kentucky with for a map of the gaging stations); 10 years or more of record (with the exceptions Regulated—the drainage basin above the site noted in the section of this report titled “Data Used contains more than 4.5 million ft3 of usable for Peak-Flow Estimates and Estimating reservoir storage per mi2 (Benson, 1962) Techniques,” page 8) are listed in table 1 (page 33). (usable reservoir storage is the volume of Three different peak flows are given (where water normally available for release from a appropriate) for unregulated stations: the gaging- reservoir, between the minimum and station estimate (G), the regression-equation maximum controllable elevations) or peaks estimate (R), and a weighted average (W) of these have changed significantly following the two estimates. As discussed in the section of this addition of a reservoir(s) to a drainage basin; report titled “Development of Peak-flow Estimates Diversion—the peak flows from a drainage and Estimating Techniques” (page 10), the weighted basin are affected by diversion of flow into or average is the most accurate peak-flow estimate for out of the basin; each gaging station.

ESTIMATING THE MAGNITUDE OF PEAK FLOWS FOR SELECTED RECURRENCE INTERVALS 19

Appropriate section of the report

Site at a

gaging station? Yes Estimates of peak flows at U.S. Geological Survey streamflow-gaging stations (p. 19) No

Site has regulation Yes Estimating peak flows or diversion? for ungaged sites on regulated streams or streams with diversions (p. 21) No

Drainage basin Yes Estimating peak flows for urbanized? ungaged, unregulated streams in urbanized drainage basins (p. 21)

Site near a Yes Estimating peak flows for ungaged gaging station on sites on gaged, unregulated streams the same stream? in rural drainage basins (p. 22)

Estimating peak flows for ungaged, unregulated streams in rural drainage basins (p. 25)

Figure 5. Flowchart for choosing the appropriate means of obtaining estimated peak flows in Kentucky.

20 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals For regulated stations, the regression-equation Estimating Peak Flows for estimate cannot be weighted with the gaging-station Ungaged Sites on Regulated estimate because the regression equations do not apply to regulated stations. For sites with drainage- Streams or Streams With basin characteristics outside the bounds of the Diversions drainage-basin characteristics of stations used to create the regression equations, only the gaging- Techniques for estimating peak flows for station estimate is presented because the accuracy of ungaged, regulated streams or for streams with the regression-equation estimate is unknown. Also diversions that will affect peak flows are beyond the included in table 1 are the USGS gaging-station scope of this report, because peak flows on these number and name, the total drainage area, the period types of streams are dependent on variable human of recorded peak flows, the regulation status of the activities. A potential technique for estimating peak station, and the source of any regulation at a station. flows at ungaged sites on ungaged, regulated Station locations are shown on plate 1. streams would be to route peak inflows through the regulated reservoir(s), taking into account regulation practices. The applicable technique of this report Limitations and Accuracy of the could be used to estimate the magnitude of the peak Estimates inflows. Physical modeling could be used for sites affected by diversion. The recorded annual peak flows used to compute the peak flows for given recurrence intervals at gaging stations in this section are Estimating Peak Flows for assumed to be representative of recorded and Ungaged, Unregulated Streams in unrecorded peaks. Generally, collecting additional years of data at a station provides improved Urbanized Drainage Basins estimates of peak flows. The estimated peak flows at gaging stations will not be reliable if the drainage The regression equations presented in the basin of a station becomes significantly more section of this report titled “Estimating Peak Flows regulated or urbanized than it was during the period for Ungaged, Unregulated Streams in Rural used to calculate the peak flows. In addition, if the Drainage Basins” (page 25), are not appropriate for flow management at a regulated station changes, the urban basins. Peak-flow estimates for ungaged estimated peak flows presented in this section may urban basins in Jefferson County, Ky., should be not apply, depending on the magnitude of the made by use of the methods described in Martin and changes. The peak-flow data were analyzed in an others (1997). Peak-flow estimates for other urban attempt to identify significant changes in flow areas of Kentucky should use the USGS nationwide management; subtle or recent changes in flow regression equations contained in Sauer and others management may have gone undetected. (1983). If an extreme flood did not occur at a Martin and others (1997) found that the regulated station during the period of streamflow- USGS nationwide urban-regression equations data collection for that station, the estimated peak tended to overestimate peak flows for urban streams flows may underestimate appreciably the true peak in Jefferson County. Sherwood (1986) similarly flows. This underestimation could result because a indicated there was positive bias (overestimation) large inflow to a reservoir may cause outflows to be for the USGS nationwide urban-estimating regulated differently than at any previous time. equations when applied in Ohio. It has not been The estimated peak flows in this section do demonstrated that peak-flow estimates from the not consider the possibility of dam failures. If a dam nationwide urban-regression equations tend to failure occurs, the peak flows on streams with dams overestimate flows for other urban areas in that store large quantities of water could be much Kentucky, but such positive bias may well be greater than the given peak flows. present.

ESTIMATING THE MAGNITUDE OF PEAK FLOWS FOR SELECTED RECURRENCE INTERVALS 21 Sauer and others (1983) presented seven- and stream, a weighted peak flow is calculated. The three-variable nationwide urban-regression weights are determined as a function of the equations in their report. Although the three- difference in drainage area between the ungaged site variable equations are easier to apply, a later study and the gaging station. utilizing new data (Sauer, 1985) showed the three- variable equations to be biased in some areas of the country (mainly in some southeastern States). Only the seven-variable regression equations are Application of the Technique recommended for use in Kentucky, because of the potential for biases. Equation 5 (below) provides the means for Computed urban peak flows should be calculating a final weighted peak flow at an ungaged compared to the equivalent rural peak flows to make site on a gaged stream by weighting the peak flow sure that the urban peak-flow estimate is reasonable. from the gaging station with the peak flow from a The urbanization of a drainage basin generally regression equation. A different approach is given causes peak flows to increase for those basins that (equation 9) for sites where the explanatory do not have appreciable in-channel or detention variables, drainage area (Regions 2, 3, 5, 6, and 7), storage. The increase in peak flows is usually most or drainage area and slope (Regions 1 and 4), are dramatic for low recurrence-interval flows, which outside the range of the variables used in the occur frequently, and less pronounced for high development of the regression equations (see table 4 recurrence-interval flows, which occur infrequently and fig. 6). This range is two-dimensional for (Sauer and others, 1983). Regions 1 and 4. Another approach (equation 10) is The location of urbanization in a drainage basin may have an effect on peak flows that is not provided for ungaged sites located between two accounted for in the urban-regression equations. For gaging stations. example, if the lower part of a basin is urbanized and the upper part is not, rapid removal of floodwaters from the lower part may occur before Table 4. Range in values of the basin characteristics the upper part can contribute appreciable runoff. used as explanatory variables in the regional This pattern of urbanization potentially could peak-flow-regression equations for Kentucky decrease peak flows from a drainage basin (Sauer [--, not applicable] and others, 1983). Total drainage area Main-channel slope Region (square miles) (feet per mile)

1 0.16 - 1,197 3.49 - 206 Estimating Peak Flows for 2 .09 - 1,232 -- Ungaged Sites on Gaged, Unregulated Streams in Rural 3 .59 - 722 -- Drainage Basins 4 .26 - 960 3.60 - 343 5 .24 -1,299 --

If an ungaged site is near (see “Limitations of 6 .22 - 757 -- the Technique” later in this section for details) a USGS streamflow-gaging station and on the same 7 .10 - 706 --

22 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals

Figure 6. Total drainage area and main-channel slope sampling spaces for the peak-flow regression equations for Regions 1 and 4 in Kentucky.

Application of the equations in this section is where based on the assumption that the river is contained Quf is the final weighted peak flow for a completely in one of the seven regions of Kentucky. given recurrence interval (for example, If a basin spans more than one region, the the 50-year peak flow) for an ungaged appropriate equations in this section should be used site on a gaged stream, and by computing peak flows, assuming all of the basin Qr is the regression estimate of the peak is in one of the regions. The peak flows then should flow, at the ungaged site, for a given be recomputed assuming all of the basin is in the recurrence interval (for example, the other region (or regions, if there are more than two). 50-year peak flow) from table 3 in the Final peak flows should be computed as a weighted section of this report titled “Estimating Peak Flows for Ungaged, Unregulated average of the peak flows, with weights Streams in Rural Drainage Basins” corresponding to the fraction of the basin in each (page 25), for the appropriate region. region. Peak-flow estimates for ungaged sites in W is a weighting factor; for basins with drainage from adjacent States can be r made similarly by an area weighting of the > , ()⁄ Au Ag Wr = Au Ag – 1, and for (6) regression estimate for Kentucky with the < , ()⁄ regression estimate for the adjacent State. Peak-flow Au Ag Wr = Ag Au – 1, (7) estimating equations for West Virginia (Wiley and where others, 2000), Virginia (Bisese, 1995), and Tennessee (Law and Tasker, in press) have been Au is the total drainage area at the ungaged site, and published by the USGS and cooperating agencies. Ag is the total drainage area at the gaging () () Quf = Qr Wr + Qu 1 – Wr , (5) station.

ESTIMATING THE MAGNITUDE OF PEAK FLOWS FOR SELECTED RECURRENCE INTERVALS 23 ()⁄ b Qu = Qw Au Ag , (8) possible future reports). If the weighted-average peak flow is not where available, the gaging-station peak flow Qw is the weighted-average peak flow for a should be used. given recurrence interval (such as the A , A , and b were defined in equations 6, 7, and 8. 50-year peak flow) for the gaging u g station from table 1 (page 33) in the If the ungaged site is located between two section of this report titled “Estimates gaging stations, then the log base-10 interpolated of Peak Flows at USGS Streamflow- peak-flow estimate may be calculated using

Gaging Stations,” page 19 (or from equation 10, then detransformed from logs logQui possible future reports), and (Qui = 10 ). b is the coefficient (exponent) for the (() logQui = logQw1 + logQw2 – logQw1 (10) drainage-area-only regression equation ()logA – logA ⁄ ()logA – logA ) , for the region and for the appropriate u g1 g2 g1 recurrence interval (table 5). where If explanatory variables are outside the two- Qui is the interpolated peak flow for a dimensional range of the variables used for the given recurrence interval (for regression equations (Regions 1 and 4; fig. 6), or example, the 50-year peak flow) for outside the range of drainage areas (Regions 2, 3, 5, an ungaged site located between two 6, and 7; table 4) then gaging stations, Qw1 and Qw2 are the weighted-average peak flows ()⁄ b Quf = Qw Au Ag , (9) for a given recurrence interval (such as the 50-year peak flows) at the where upstream and downstream gaging Quf is the final weighted peak flow for a stations, respectively, from given recurrence interval (for example, table 1 (page 33) discussed in the the 50-year peak flow) for an ungaged section of this report titled, site on a gaged stream, and “Estimates of Peak Flows at USGS Streamflow-Gaging Stations” Qw is the weighted-average peak flow for a given recurrence interval (such as the (page 19), 50-year peak flow) for the gaging Au is the total drainage area at the station from table 1 (page 33) in the ungaged stream site, and section of this report titled “Estimates Ag1 and Ag2 are the total drainage areas at the of Peak Flows at USGS Streamflow- upstream and downstream gaging Gaging Stations,” page 19, (or from stations, respectively.

Table 5. Coefficients (exponents) of the drainage-area-only regional peak-flow regression equations for Kentucky

Recurrence interval Region (years) 1 2 3 4 5 6 7 2 0.673 0.728 0.748 0.824 0.704 0.600 0.623 5 .651 .721 .712 .803 .692 .586 .616 10 .642 .715 .692 .794 .686 .578 .613 25 .634 .709 .670 .786 .682 .569 .610 50 .629 .704 .656 .783 .679 .564 .610 100 .625 .699 .643 .780 .677 .559 .609 200 .622 .695 .632 .778 .676 .555 .610 500 .618 .690 .620 .776 .674 .551 .610

24 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Limitations of the Technique Regression equations are used in this section of the report to compute peak-flow estimates for This technique is applicable to ungaged sites ungaged, unregulated streams in rural drainage on gaged, unregulated streams in rural drainage basins in Kentucky. The response (dependent) variables used in developing the regression basins that range from 50 to 200 percent of the equations were the peak flows computed at USGS drainage area of the gaging station(s), except for gaging stations and the explanatory (independent) sites that are plus or minus 3 percent of the drainage variables were drainage-basin characteristics such area. For ungaged sites within 3 percent of the as drainage area and stream slope. gaging-station drainage area, the weighted-average peak-flow estimates (table 1, page 33) should be used. If the difference in drainage areas is less than 3 percent and the weighted-average peak-flow Application of the Technique estimate is not available for the station, the gaging- station peak-flow estimate from table 1 should be Peak-flow regression equations for recurrence used. intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years This method is not applicable to urbanized are presented in table 3 (page 15). The variables used in the equations are described in the text that drainage basins, to regulated streams, or to sites follows. The average standard error of prediction affected by diversion (see “Choosing the and other measures of error are discussed in the Appropriate Peak-Flow Estimation Technique,” section of this report titled “Limitations and page 18, for definitions of these terms); neither is it Accuracy of the Technique.” applicable if the area between the ungaged site and All of the regression equations in this report the gaging station(s) is urbanized nor contains are statistical models. These models are not based regulation (utilizing the same definitions of directly on rainfall-runoff processes. For this reason, urbanized and regulated recently referred to, but when applying these equations, the explanatory using drainage-area difference instead of drainage variables should be computed by the same area in these definitions). techniques that were used in the development of the equations. The use of “more accurate” techniques of computing the explanatory variables will result in Estimating Peak Flows for peak-flow estimates of unknown accuracy. Ungaged, Unregulated Streams in Definitions of equation variables in table 3: Rural Drainage Basins QT – Peak flow—The calculated peak flow, in ft3/s, for recurrence interval T (T = 2, 5, 10, 25, 50, 100, 200, or 500 years). Peak flows for ungaged drainage basins for TDA – Total drainage area—The total area, selected recurrence intervals generally are estimated measured in mi2 on a horizontal plane, of a drainage by rainfall-runoff procedures or by regression-based basin. Total drainage area includes all enclosed procedures. Newton and Herrin (1982) analyzed subbasins characterized by internal drainage, for various procedures of both types. The rainfall-runoff example, sinkholes in karst terrain. The drainage models that they analyzed, including the Natural area can be determined from a number of sources. Resources Conservation Service TR-20 and TR-55 Bower and Jackson (1981) lists drainage areas models, the USCOE HEC-1 model, and the rational measured from paper USGS topographic method, were not calibrated to at-site flow data. quadrangle maps (1:24,000 scale within Kentucky Newton and Herrin (1982) concluded that certain and 1:62,500 scale outside Kentucky) at selected regression-based methods (specifically, the USGS points for many streams in Kentucky. Drainage State-regression equations and index-flood areas can be computed by digitizing the area of a methods) are the most accurate and reproducible drainage basin, after delineating the drainage-basin procedures for estimating peak flows for given boundaries on 1:24,000-scale topographic recurrence intervals. quadrangle maps. Drainage areas also can be

ESTIMATING THE MAGNITUDE OF PEAK FLOWS FOR SELECTED RECURRENCE INTERVALS 25 computed from geographic information system also will be unknown if the total drainage area in (GIS) 1:24,000-scale map coverages. The drainage Regions 2, 3, 5, 6, and 7 is outside the respective areas for the 238 streamflow-gaging stations used in ranges in table 4 (page 22). The further the basin the development of the Kentucky regression characteristics are outside the sampling space (the equations (table 3) were determined by use of either gray areas on fig. 6 or the ranges in table 4), the paper or GIS maps of the resolutions cited greater the potential for large reductions in the previously. These values are listed in table 2 accuracy of the regression equations. (page 61). The average standard error of prediction S – Main-channel slope—The slope (ASEP) is a measure of how well the regression computed as the difference in elevation between equations estimate peak flows when they are applied points located at 10 and 85 percent of the to ungaged drainage basins. The ASEP is the square main-channel length from the gage, divided by the root of the average variance of prediction at a group stream length between these two points (in ft/mi), as of sites with the same basin characteristics as the determined from USGS 7.5-minute topographic gaging stations used in development of the quadrangle maps. The main-channel length is regression equations. The standard error of measured along the main-stream channel from the prediction varies from site to site, depending on the gage to the basin divide, following the longest values of the explanatory variables (drainage area tributary. and main-channel slope for Regions 1 and 4) for If the drainage basin at a site is located in two each site. The standard error of prediction will be (or more) hydrologic regions (plate 1), the peak smaller for sites that have explanatory variables near flow for a given recurrence interval is determined by the mean of their range; however, the error (1) applying the appropriate estimating equation associated with the different values of the from table 3 as though the basin is located entirely explanatory variables is a small part of the total in each region, and then (2) weighting the two (or standard error of prediction. For this reason, the more) estimates in proportion to the fraction of the ASEP can be used as an approximate standard error drainage basin in each region (see example 1, of prediction for individual sites. The probability page 27). that the true value of a peak flow at a study site is between the positive-percent ASEP and the negative-percent ASEP is approximately 68 percent. Limitations and Accuracy of the For example, there is a 68 percent probability that the true 50-year peak flow in Region 1 at an Technique ungaged site ranges from +52.9 to -34.6 percent (table 3, page 15) of the computed peak flow. The regression equations presented in this The average equivalent years of record is section of the report are not applicable to regulated another measure of the overall accuracy of the or urbanized drainage basins or drainage basins with regression equations. This measure represents the diversion. The terms “regulated,” “diversion,” and average number of years of gaging-station data “urbanized” are defined and the appropriate needed to determine estimates with accuracy equal methodologies for assessing these conditions are to the regression equations. The average equivalent described in the section of this report titled years of record is a function of the accuracy of the “Choosing the Appropriate Peak-Flow Estimation regression equations, the recurrence interval, and Technique” (page 18). the average variance and skew of the annual peak If the explanatory variables in Regions 1 and flows at gaging stations (Hardison, 1971). 4 (total drainage area and main-channel slope) used In GLS regression, the average variance of in the regression equations in this section are prediction is divided into two parts: the model-error outside the two-dimensional range of the values variance and the sampling-error variance. The used to develop the equations (the gray areas on average standard error of prediction is the square fig. 6, page 23), the accuracy of predictions of peak root of the average variance of prediction. The flows from the equations is unknown and could be estimated model-error variance and average reduced substantially. The accuracy of predictions sampling-error variance from the regression

26 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals equations in this section of the report are given in Example Applications of the table 3. The model-error variance is a measure of the error resulting from an incomplete model if the Estimating Equations true values of the estimated peak flows at gaging stations were known at all streams in Kentucky The regional peak-flow estimating equations (rather than the sample values that were used). In presented in this report (table 3) can be applied to other words, the explanatory variable (total drainage rural, unregulated streams by (1) determining the area and slope for Regions 1 and 4) in the regression basin characteristics required for the appropriate equation would not explain all the variation in peak equation, (2) checking to ensure that the basin flows from the complete population. The true characteristics are within the range of characteristics model-error variance cannot be reduced by used to develop the equations (table 4 and fig. 6), additional data collection, although the estimated and (3) use of the measured basin-characteristic model-error variance may change if additional data values with the appropriate equation(s) to compute are obtained. The average sampling-error variance for the regression equations is a measure of the error the estimate. associated with sampling only a subset of the total Example 1—Assume that an estimate of the population of streams in Kentucky (space-sampling 100-year peak flow, Q100, is needed for an ungaged error) and sampling only a subset of the total years stream site in Region 3 with a total drainage area of of data at the gaging stations (time-sampling error). 600 mi2, the upper 333 mi2 (55.5 percent of the The sampling error can by reduced by collecting basin) of which is located in Region 2. The peak- more data at existing gaging stations, collecting data flow estimate for drainage basins located in two at new gaging stations, or some combination of regions is determined by (1) applying the estimating both. equation as though the basin is located entirely in Another overall measure of how well each region, and then (2) weighting the two regression equations will estimate flood peaks when applied to ungaged basins is the PRESS statistic. estimates in proportion to the basin drainage area in The PRESS statistic is a validation-type statistic. To each region, as follows: compute the PRESS statistic, one gaging station is For the Region 2 estimate, removed from the stations used to develop the 0.699 regression equation, then the value of the one left Q100 = 538 TDA , out is predicted. The difference between the = 538 (600)0.699, predicted value from the regression equation and the = 47,100 ft3/s. observed peak flow at that station is computed. The gaging station removed then is changed and the For the Region 3 estimate, above process repeated until every station has been 0.643 Q100 = 1,100 TDA , removed once. The prediction errors then are = 1,100 (600)0.643, squared and summed. PRESS/n is analogous to the 3 average variance of prediction, and the square root = 67,300 ft /s. of PRESS/n is analogous to the average standard The area-weighted regression estimate for the error of prediction. Values of the square root of ungaged site is PRESS/n close to the values of the average standard error of prediction provide some measure of Q100 = 0.555 (47,100) + 0.445 (67,300) = validation of the regression equations. 56,100 ft3/s.

ESTIMATING THE MAGNITUDE OF PEAK FLOWS FOR SELECTED RECURRENCE INTERVALS 27 Example 2—Assume the 600 mi2 ungaged, For the Region 3 estimate, unregulated stream site in example 1 is located Q = 67,300 ft3/s, the regression estimate at downstream from a gaging station with a total r the ungaged site, as determined in drainage area of 466 mi2. In this case, a weighting example 1, and of the regression estimate of Q100 at the ungaged b site with the Q100 value at the adjacent gaging Qu = Qw(Au / Ag) , where Qw is the weighted station by use of equation 5 is appropriate. The 100-year peak-flow estimate at the drainage area of the ungaged site is less than gaging station (50,700 ft3/s), and b is 200 percent of the drainage area at the gaging the exponent of the drainage-area-only station ((600/466)100 = 129 percent), as required regression equation for Region 3, 0.643 for use of equation 5. Again, when the ungaged (table 5), drainage basin is located in two or more regions, the peak-flow estimate (using equation 5 in this case) is The gage peak-flow estimate “translated” determined by (1) applying the estimating equation downstream to the ungaged site is as though the basin is located entirely in each 0.643 3 Qu = 50,700(600/466) = 59,600 ft /s. region, and then (2) weighting the two estimates in proportion to the basin drainage area in each region Wr = 0.288, as determined previously. as The gage-weighted peak-flow estimate at the ungaged site in Region 3 is computed by use of Q = Q ()W + Q ()1 – W , uf r r u r equation 5 as For the Region 2 estimate, Quf = 67,300 (0.288) + 59,600 (1 - 0.288) = 3 61,800 ft3/s. Qr = 47,100 ft /s, the regression estimate at the ungaged site, as determined in The final estimate is an area-weighted average of example 1, and these Region 2 and Region 3 estimates, b Qu = Qw(Au / Ag) , where Qw is the weighted Quf = 0.555 (56,600) + 0.445 (61,800) = 100-year peak-flow estimate at the 3 gaging station, listed in table 1 58,900 ft /s. (page 33), and b is the exponent of the Example 3—Assume the 600 mi2 ungaged, drainage-area-only regression equation unregulated stream site in example 2 also is located for Region 2 (table 5), upstream from a gaging station that has a total 3 2 Assume Qw is 50,700 ft /s at the upstream gaging drainage area of 1,101 mi . In this case, a station (table 1) and b is 0.699 for the 100-year peak logarithmic interpolation is used between the peak flow in Region 2 (table 5). Therefore, the gaging flows at the gaging stations based on the drainage station peak-flow estimate “translated” downstream area at the ungaged site and at the two gages. The to the ungaged site is logarithmically interpolated peak-flow estimate may 0.699 3 be calculated by use of equation 10 as Qu = 50,700(600/466) = 60,500 ft /s. For A > A , W = (A / A ) - 1, or (() u g r u g logQui = logQw1 + logQw2 – logQw1 ()logA – logA ⁄ ()logA – logA ) , Wr = (600/466)-1 = 1.288 - 1 = 0.288. u g1 g2 g1 The gage-weighted peak-flow estimate at the log Qui = log 50,700 + ((log 70,000 - log 50,700) ungaged site in Region 2 is computed by use of (log 600 - log 466) / equation 5 as (log 1101 - log 466)), log Q = 4.7462 Quf = 47,100 (0.288) + 60,500 (1 - 0.288) = ui 3 4.7462 3 56,600 ft /s. Qui = 10 = 55,700 ft /s.

28 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals SUMMARY used for five of the regions while total drainage area and main-channel slope were used for the other two Estimates of the magnitude of peak regions. streamflows (such as the 50-year recurrence-interval A section of the report describes techniques peak flow) are necessary to safely and economically for estimating peak flows for ungaged sites on design bridges, culverts, and other structures that gaged, unregulated streams in rural drainage basins. are in or near streams. This report, prepared by the Another section references two previous USGS U.S. Geological Survey (USGS) in cooperation with reports for peak-flow estimates on ungaged, the Kentucky Transportation Cabinet (KTC), will unregulated, urban streams. Estimating peak flows help KTC and others better estimate the magnitude at ungaged sites on regulated streams is beyond the of peak flows for streams in Kentucky. scope of this report, because peak flows on regulated streams are dependent on variable human This report gives estimates of, and presents activities. techniques for estimating, the magnitude of peak flows for streams in Kentucky for recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years. The recurrence interval is the long-term average REFERENCES CITED period of time between peak flows that are equal to or greater than a specified peak flow. Beaber, H.C., 1970, A proposed streamflow data program Various peak-flow studies have been for Kentucky: U.S. Geological Survey Open-File published for all or parts of Kentucky since 1958 Report (unnumbered), 48 p. (McCabe, 1958, 1962; Speer and Gamble, 1964, Benson, M.A., 1962, Factors influencing the occurrence 1965; Hannum, 1976; Wetzel and Bettandorff, of floods in a humid region of diverse terrain: U.S. Geological Survey Water-Supply 1986; Choquette, 1988). The estimates and Paper 1580-B, 64 p. estimating techniques in this report should provide Bingham, R.H., 1982, Low-flow characteristics of more accurate estimates of rural peak flows for Alabama streams: U.S. Geological Survey Kentucky than previous reports; data through water Water-Supply Paper 2083, 27 p. year 2000 were used. Advances in techniques for Bisese, J.A., 1995, Methods for estimating the magnitude this report included the development of a and frequency of peak discharges of rural, generalized skew for Kentucky and the use of unregulated streams in Virginia: U.S. Geological generalized-least-squares (GLS) regression. Survey Water-Resources Investigations Estimates of peak flows are given for 222 Report 94-4148, 70 p. USGS streamflow-gaging stations in Kentucky. In Bower, D.E., and Jackson, W.H., 1981, Drainage areas of the development of the peak-flow estimates at streams at selected locations in Kentucky: U.S. Geological Survey Open-File Report 81-61, gaging stations, a new generalized skew coefficient 118 p. was calculated for Kentucky. This single statewide Choquette, A.F., 1988, Regionalization of peak discharges value of 0.011 (with a standard error of prediction of for streams in Kentucky: U.S. Geological Survey 0.520) is more appropriate for Kentucky than the Water-Resources Investigations Report 87-4209, national skew isoline map in Bulletin 17B of the 105 p. Interagency Advisory Committee on Water Data. Conner, Glen, 1982, Monthly, seasonal, and annual Regression equations are presented to precipitation in Kentucky 1951-1980: Bowling estimate the peak flows for ungaged, unregulated Green, Ky., Western Kentucky University, Kentucky streams in rural drainage basins. These equations Climate Center Publication Number 25, 30 p. were developed by use of GLS-regression Crawford, N., and Webster, J., 1986, Karst hazard assessment of Kentucky—Sinkhole flooding and procedures using data from 238 USGS gaging collapse: Bowling Green, Ky., Western Kentucky stations in and near Kentucky. The State was University, Center for Cave and Karst Studies, divided into seven hydrologic regions; separate prepared for the U.S. Environmental Protection regression equations were created for each region. Agency, Region IV, Atlanta, Ga., scale 1:1,000,000, Total drainage area was the final basin characteristic 1 sheet.

SUMMARY 29 Dempster, G.R., Jr., 1990, National water information McFarland, A.C., 1950, Geology of Kentucky: Lexington, user’s manual, v. 2, chap. 3, Automated data Ky., University of Kentucky, 531 p. processing system: U.S. Geological Survey McGrain, Preston, and Currens, J.C., 1978, Topography Open-File Report 90-116, 321 p. of Kentucky: Lexington, Ky., University of Hannum, C.H., 1976, Technique for estimating magnitude Kentucky, Kentucky Geological Survey, ser. X, and frequency of floods in Kentucky: Special Publication 25, 76 p. U.S. Geological Survey Water-Resources Montgomery, D.C., and Peck, E.A., 1982, Introduction to Investigations Report 76-62, 70 p. linear regression analysis: New York, Wiley, 504 p. Hardison, C.H., 1971, Prediction error of regression estimates of streamflow characteristics at ungaged Musgrave, G.W., 1955, How much of the rain enters the sites: U.S. Geological Survey Professional soil?: U.S. Department of Agriculture, Yearbook of Paper 750-C, p. 228-236. Agriculture—Water, p. 151-159. Helsel, D.R., and Hirsch, R.M., 1992, Statistical methods Newton, D.W., and Herrin, J.C., 1982, Assessment of in water resources: New York, Elsevier, 522 p. commonly used methods of estimating flood Hershfield, D.M., 1961, Rainfall frequency atlas of the frequency: Transportation Research Record 896, United States: U.S. Department of Commerce, p. 10-30. Technical Paper No. 40, 115 p. Pope, B.F., Tasker, G.D., and Robbins, J.C., 2001, Interagency Advisory Committee on Water Data, 1982, Estimating the magnitude and frequency of floods Guidelines for determining flood flow frequency– in rural basins of North Carolina—Revised: Bulletin 17B of the Hydrology Subcommittee: U.S. Geological Survey Water-Resources U.S. Geological Survey, Office of Water-Data Investigations Report 01-4207, 44 p. Coordination, 183 p. Riggs, H.C., 1964, The base-flow recession curve as an Kentucky Department for Natural Resources and indicator of groundwater: Berkeley, Calif., Environmental Protection, 1979, Rainfall frequency International Association of Scientific Hydrology values for Kentucky: Frankfort, Ky., Bureau of Publication 63, p. 352-363. Environmental Protection, Division of Water, Engineering Memorandum No. 2, 37 p. Ruhl, K.J., and Martin, G.R., 1991, Low-flow Kentucky Geological Survey, 1980, Physiographic characteristics of Kentucky streams: U.S. Geological diagram of Kentucky: Lexington, Ky., University Survey Water-Resources Investigations of Kentucky, 1 map, scale not specified. Report 91-4097, 50 p. Lane, E.W., and Lei, Kai, 1950, Streamflow variability, Sauer, V.B., 1985, New studies of urban flood frequency in Proceedings of the American Society of Civil in the southeastern United States, in International Engineers, Transactions, v. 115, p. 1,084-1,134. Symposium on Urban Hydrology, Hydraulic Law, G.S., and Tasker, G.D., in press, Flood-frequency Infrastructures, and Water-Quality Control, prediction methods for unregulated streams of July 23-25, 1985, Proceedings: Lexington, Ky., Tennessee, 2000: U.S. Geological Survey University of Kentucky, p. 195-201. Water-Resources Investigations Report 03-4176. Sauer, V.B., Thomas, W.O. Jr., Stricker, V.A., and Wilson, Lichty, R.W., and Karlinger, M.R., 1990, Climate factor K.V., 1983, Flood characteristics of urban for small-basin flood frequency: American Water watersheds in the United States: U.S. Geological Resources Association, Water Resource Bulletin, Survey Water-Supply Paper 2207, 63 p. v. 26, no. 4, p. 577-586. Searcy, J.K., 1959, Flow-duration curves: U.S. Geological Martin, G.R., Ruhl, K.J., Moore, B.L., and Rose, M.F., Survey Water-Supply Paper 1542-A, 33 p. 1997, Estimation of peak-discharge frequency of Sherwood, J.M., 1986, Estimating peak discharges, flood urban streams in Jefferson County, Kentucky: U.S. Geological Survey Water-Resources volumes, and hydrograph shapes of small ungaged Investigations Report 97-4219, 40 p. urban streams in Ohio: U.S. Geological Survey McCabe, J.A., 1958, Floods in Kentucky–magnitude and Water-Resources Investigations Report 86-4197, frequency: U.S. Geological Survey Open-File Report 52 p. (unnumbered), 13 p. Speer, P.R., and Gamble, C.R., 1964, Magnitude and ———1962, Floods in Kentucky–magnitude and frequency of floods in the United States–Part 3-B– frequency: Lexington, Ky., U.S. Geological Survey Cumberland and Tennessee River Basins: and Kentucky Geological Survey, (unnumbered), U.S. Geological Survey Water-Supply Paper 1676, 196 p. 340 p.

30 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals ———1965, Magnitude and frequency of floods in the U.S. Department of Agriculture, 1969, National United States–Part 3-A–Ohio River Basin except engineering handbook: Soil Conservation Service, Cumberland and Tennessee River Basins: sec. 4, Hydrology, chaps. 9, 10 [variously paged]. U.S. Geological Survey Water-Supply Paper 1675, ———1975, General soil map of Kentucky: Soil 630 p. Conservation Service Map No. 4-R-34874, Statistical Analysis System Institute, Inc., 1985, SAS scale 1:750,000. User’s Guide–Statistics: Cary, N.C., Statistical ———1984, Predicting soil loss in Kentucky: Lexington, Analysis System Institute, Inc., 956 p. Ky., Soil Conservation Service Technical Paper No. 4, 152 p. Stedinger, J.R., and Tasker, G.D., 1985, Regional Wetzel, K.L., and Bettandorff, J.M., 1986, Techniques for hydrologic analysis 1–Ordinary, weighted, and estimating streamflow characteristics in the eastern generalized least squares compared: Water and interior coal provinces of the United States: Resources Research, v. 21, no. 9, p. 1421-1432. U.S. Geological Survey Water-Supply Paper 2276, Tasker, G.D., and Stedinger, J.R., 1986, Regional skew 80 p. with weighted LS regression: Journal of Water Wiley, J.B., Atkins, J.T. Jr., and Tasker, G.D., 2000, Resources Planning and Management, v. 112, no. 2, Estimating magnitude and frequency of peak p. 225-237. discharges for rural, unregulated streams in West ———1989, An operational GLS model for hydrologic Virginia: U.S. Geological Survey Water-Resources regression: Journal of Hydrology, v. 111, p. 361-375. Investigations Report 00-4080, 93 p.

REFERENCES CITED 31 [This page intentionally blank.]

32 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC NC 2,740 2,540 2,650 1,390 1,600 1,500 9,610 9,970 500 96,800 88,000 11,600 25,800 17,700 23,400 years 115,000 NC NC 2,430 2,190 2,320 1,150 1,370 1,260 8,620 8,870 200 78,200 71,600 90,000 10,100 22,500 15,400 20,500 years NC 982 2,190 1,930 2,080 1,890 1,210 1,090 7,850 9,000 8,030 100 66,500 60,900 74,400 20,000 13,700 18,400 years 833 928

1,940 1,680 1,840 1,500 1,050 7,050 7,920 7,170 3,970 50 56,700 51,100 60,600 17,500 12,100 16,200 years

NC NC NC NC 698 891 776 1,700 1,430 1,610 6,220 6,850 6,290 3,820 25 14,900 10,500 14,000 years 538 694 589 1,360 1,120 1,290 1,500 5,050 5,430 5,090 3,580 8,360 10 37,600 32,700 37,000 11,500 11,100 years

891 426 549 458 5 1,090 1,050 1,500 4,100 4,370 4,120 3,350 8,920 6,760 8,680 29,100 27,400 31,200 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 696 574 678 282 352 295 2 1,500 2,630 2,860 2,640 2,900 5,200 4,440 5,150 19,800 21,600 24,600 years t computed; R5, ins R R R R G G G G G G G G G W W W W Code nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location or type of Source of Source regulation diversion and and start date North Fork Pound Lake, PoundNorth Fork Lake, 08/66 PoundNorth Fork Lake, 08/66; 10/68 Fishtrap Lake, PoundNorth Fork Lake, 08/66; 10/68 Fishtrap Lake, al Survey streamflow-gaging stations in Kentucky Survey al Fishtrap Lake, 10/68 Lake, Fishtrap Flannagan Lake, 12/63; Flannagan Lake, 12/63; Flannagan Lake, 12/63; 05/50 Lake, Dewey - U U U U R6 R6 R6 R6 R6 lation Regu ) a used (water record years 1989-91, 1995-2000 1942-93, 1995-2000 Period of Period 1974-82, COE COE COE 1976-86 COE 1938-39, 1951-92 1950-81 computed from analysis of the observed an computed from analysis of the observed 6.20 3.17 a weighted average a ofweighted the gage estimate (G average 56.3 392 554 206 103 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,232 1,702 Total miles) (square drainage name Station Phyllis Fishtrap Dam, near Millard City Prestonsburg Lear Staffordsville Grapevine Creek near near Creek Grapevine below Fork Levisa Russell at Fork Elkhorn at Pikeville Fork Levisa Bill D. Branch near Kite at Fork Levisa Johns Creek near Meta Johns Creek near Van at Creek Paint Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows

Station 03211500 number 03207965 03208000 03209300 03209500 03209575 03209800 03210000 b 03212000 Table 1. G, estimate known; none ---, unregulated; [U, estimate computed as equation (table 3); W, the U.S.computed by Army Corps of Engi

TABLE 1 33 NC 613 691 646 744 861 9,000 3,040 4,050 3,320 1,000 500 82,000 27,300 29,500 27,600 22,100 years 152,000 697,000 NC 546 589 563 674 856 754 7,000 2,670 3,500 2,890 200 69,800 22,800 25,900 23,200 19,100 years 133,000 632,000 NC 495 515 503 621 751 676 5,850 2,400 3,090 2,570 100 61,000 19,700 23,100 20,100 16,800 years 118,700 587,000 NC 445 444 445 567 649 600

4,800 2,140 2,700 2,270 50 53,600 16,800 20,500 17,200 14,500 years 104,900 545,000

NC NC NC NC 395 376 389 512 551 526 4,220 1,890 2,320 1,970 25 14,200 17,800 14,500 years 505,000 327 291 317 435 427 433 3,590 3,400 9,300 1,560 1,820 1,600 10 39,000 76,000 11,100 14,200 11,300 years 451,000 Continued 273 229 263 372 337 364 5 8,890 9,010 3,120 3,100 7,500 1,300 1,450 1,320 34,600 63,800 11,600 years 410,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 937 939 937 192 145 185 274 215 263 2 6,010 7,630 6,060 2,450 2,900 5,900 28,900 48,800 years 351,000 t computed; R5, ins R R R R G G G G G G G G G G W W W W

nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); Various location Code or type of Source of Source regulation diversion and and start date 10/68; Paintsville Lake, 09/83 Flannagan Lake, 12/63; PoundNorth Fork Lake, 08/66; Fishtrap Lake, Flannagan Lake, 12/63; PoundNorth Fork Lake, 08/66; 10/68 Fishtrap Lake, al Survey streamflow-gaging stations in Kentucky— Survey al Dewey Lake, 05/50; Lake, Dewey 05/50; Lake, Dewey Grayson 03/68 Lake, Grayson 03/68 Lake, Grayson 03/68 Lake, U U U U R6 R5 R6 R6 R6 NC lation Regu- ) a used (water record years 1938-84 Period of Period COE COE 1916-20, COE 1969-92 COE COE 1973-91 1976-87 1977-86 computed from analysis of the observed an computed from analysis of the observed .94 1.61 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 12.2 217 196 255 400 neers; R6, significant regulation (see report regulation neers; R6, significant area 2,144 3,897 Total miles) 60,750 (square drainage name Station Grayson Dam near Leon Leon Grayson near Fallsburg River Levisa Fork at Paintsville Fork Levisa Louisa at Big SandyRiver Blaine Creek at Yatesville at Ashland Ohio River below Little Sandy River at Little Sandy River at Little Sandy River LittleEast Sandy Fork Mile Branch near Rush Mile Branch at Coalton Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03212500 03215000 03215500 03216000 03216350 03216400 03216500 03216540 03216563 03216564 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

34 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC 632 775 700 1,730 2,050 1,820 500 15,600 12,100 14,600 42,400 31,800 40,700 10,000 14,600 10,800 18,200 21,800 18,700 years 756,000 775,000 NC 548 661 600 9,330 9,820 1,410 1,780 1,510 200 14,100 10,500 13,100 34,700 27,900 33,600 12,400 15,600 19,100 16,000 years 684,000 705,000 NC 488 579 528 9,370 8,750 9,080 1,190 1,570 1,290 100 12,900 12,000 29,400 24,900 28,800 10,800 13,700 17,000 14,100 years 633,000 654,000 NC 432 499 460 992

8,250 8,140 9,280 8,330 1,380 1,090 50 11,700 10,900 24,700 22,100 24,400 11,900 15,000 12,200 years 586,000 604,000

379 423 395 813 899 7,130 9,760 7,490 7,850 7,540 1,190 5,140 25 10,400 20,300 19,300 20,200 10,200 13,100 10,400 years 538,000 558,000 312 328 317 602 943 665 8,660 5,650 8,180 6,530 6,030 6,460 7,960 8,100 4,860 10 15,200 15,400 15,200 10,400 years 477,000 494,000 Continued 262 258 261 458 749 495 5 7,200 4,550 6,880 5,700 3,730 5,470 6,310 8,430 6,390 4,610 11,600 12,500 11,700 years 428,000 447,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 192 164 187 276 481 294 2 4,910 2,980 4,750 7,090 8,270 7,120 4,300 2,530 4,150 4,020 5,550 4,060 4,150 years 359,000 373,000 t computed; R5, ins R R R R R R G G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); Various Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Cave Run 12/73 Lake, Cave U U U U U U R6 NC NC lation Regu- ) a used (water record years 1995-97 Period of Period COE 1957-94 1976-85 1941-2000 1972-91 COE 1975-86 1939-92, 1975-94 computed from analysis of the observed an computed from analysis of the observed 1.11 1.90 a weighted average a ofweighted the gage estimate (G average 59.6 22.4 242 140 827 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) 62,000 70,130 (square drainage name Station Dam near Greenup Dam near Hill Hill near Olive Tributary Greenup Tollesboro Maysville Salyersville Ohio River at Greenup Ohio River Creek at Olive Tygarts Camp CreekTrough Creek near Tygarts Cabin Creek near at Maysville Ohio River near Creek Lawrence near Licking River at Farmers Licking River Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03216600 03216800 03216901 03217000 03237900 03238000 03238030 03248500 03249500 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 35 202 229 214 315 336 325 701 843 3,340 1,330 2,250 1,020 500 26,400 10,300 21,000 13,200 15,400 13,700 15,100 19,500 15,600 years 170 194 180 277 285 280 803 598 695 9,000 2,730 1,140 1,920 200 23,100 18,600 12,400 13,500 12,600 13,600 17,000 14,000 years 147 169 156 248 248 248 655 523 590 7,990 2,320 1,000 1,680 100 20,700 16,900 11,700 12,000 11,800 12,500 15,200 12,800 years 126 144 132 867 220 213 217 522 451 490

7,030 1,950 1,470 50 18,200 15,200 11,000 10,600 10,900 11,400 13,400 11,600 years

106 121 111 738 192 179 188 404 382 395 6,070 9,150 1,620 1,260 25 15,800 13,500 10,200 10,000 10,300 11,600 10,400 years 80.1 92.7 83.4 574 156 138 150 269 295 277 4,810 9,090 7,270 8,810 1,220 1,010 8,810 9,270 8,840 10 12,600 11,100 years Continued 61.7 72.2 63.8 943 453 819 128 107 123 181 232 193 5 3,870 9,190 8,080 5,870 7,820 7,590 7,500 7,580 10,000 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 37.0 45.4 38.1 87.0 67.8 83.6 82.7 91.7 595 290 541 148 2 6,390 2,530 6,040 6,320 3,850 6,110 5,700 4,930 5,680 years t computed; R5, ins R R R R R R R G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U lation Regu- ) a used (water record years 1989-92 1981-86 Period of Period 1941-80, 1976-85 1968-94 1975-86 1976-79, 1947-91 1977-86 computed from analysis of the observed an computed from analysis of the observed .19 .33 .96 2.43 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 47.5 84.7 119 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square drainage name Station Morehead Morehead Morehead near Owingsville Fairview near Lewisburg near Washington near Triplett CreekTriplett at Branch near Jacks North Fork Creek Triplett Indian Creek near Johnson Tributary Creek Licking River Fork North CreekTributary Wells Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03251000 number 03250000 03250080 03250100 03250150 03250620 b 03251008 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

36 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC 416 416 416 8,270 1,750 2,070 1,850 500 26,700 31,600 27,400 42,500 61,000 44,000 32,600 23,900 years 109,000 842,000 890,000 NC 344 353 348 7,130 1,470 1,710 1,550 200 23,500 27,700 24,100 39,400 53,700 40,500 23,900 18,200 years 100,000 772,000 816,000 NC 296 308 300 6,290 1,270 1,460 1,330 100 21,200 24,700 21,600 37,000 48,200 37,700 93,100 18,700 14,700 years 718,000 760,000 NC 252 264 256

5,500 1,070 1,230 1,120 50 18,900 21,900 19,200 34,300 42,900 34,900 85,800 14,400 11,700 years 663,000 705,000

212 223 215 888 921 4,720 9,230 1,000 25 56,200 16,600 19,100 16,900 31,500 37,600 31,800 78,200 10,900 years 608,000 645,000 164 172 166 657 731 675 7,180 3,730 6,460 10 44,400 13,700 15,300 13,800 27,300 30,200 27,400 67,500 years 532,000 565,000 Continued 130 134 131 491 384 466 5 4,980 2,700 4,650 36,200 11,400 12,400 11,500 23,600 24,700 23,700 59,100 years 488,000 510,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 87.1 85.0 86.8 273 241 268 2 8,100 8,190 8,100 2,620 1,810 2,550 25,600 17,500 16,400 17,500 48,500 years 437,000 449,000 t computed; R5, ins R R R R R G G G G G G G G G W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); Various Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Cave Run 12/73 Lake, Cave Run 12/73 Lake, Cave U U U U U R6 R6 NC NC lation Regu- ) a used (water record years Period of Period 1975-85 1975-94, 1997 1954-91 1918-94 COE 1968-83 COE 1976-86 COE computed from analysis of the observed an computed from analysis of the observed .45 .68 a weighted average a ofweighted the gage estimate (G average 13.6 239 621 neers; R6, significant regulation (see report regulation neers; R6, significant area 2,326 3,300 Total miles) 76,580 83,170 (square drainage name Station Mays Lick Mays McKinneysburg at Cynthiana Piner near Ohio Warsaw near Dam Lees Creek Tributary at at Tributary Creek Lees at Licking River Stoner Creek at Paris LickingSouth Fork River at Catawba Licking River Creek Grassy North Fork at Cincinnati, Ohio River Craigs Creek Tributary at Markland Ohio River Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03252500 number 03251015 03251500 03252000 b 03253500 03254400 03255000 03277185 03277200 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 37 NC 1,340 1,950 1,770 1,040 1,250 1,100 500 13,400 13,000 13,300 12,900 16,400 15,200 64,700 57,000 62,400 40,400 25,600 36,600 83,900 87,500 years 102,000 NC 900 946 1,100 1,570 1,430 1,070 200 11,000 11,400 11,100 11,300 13,800 12,900 58,000 49,800 55,700 35,700 22,500 32,500 74,700 89,700 77,500 years NC 938 799 937 834 9,270 9,450 1,310 1,200 100 10,100 10,000 12,000 11,200 52,800 44,600 50,700 32,000 20,100 29,300 67,700 80,700 70,000 years NC 792 983 700 811 726

7,720 8,900 7,950 8,770 9,620 1,080 50 10,200 47,500 39,600 45,700 28,300 17,700 26,200 60,600 72,100 62,300 years

NC 659 860 787 603 690 621 6,310 7,700 6,540 7,530 8,580 8,070 25 41,900 34,500 40,500 24,500 15,400 22,900 53,400 63,300 54,600 years 883 499 603 558 476 536 486 4,630 6,110 4,810 5,880 6,490 6,120 10 34,200 27,600 33,300 19,400 12,300 18,400 43,600 51,200 44,200 years Continued 802 388 433 410 380 423 385 5 3,470 4,920 3,600 4,590 4,990 4,710 9,980 27,800 22,400 27,300 15,300 14,700 35,700 42,000 36,100 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 664 245 230 239 243 271 246 2 2,020 3,220 2,080 2,770 3,000 2,810 9,280 6,580 9,120 18,000 14,800 17,800 23,800 28,200 23,900 years t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Carr Fork Lake, 01/76 Lake, Carr Fork 01/76 Lake, Carr Fork 01/76 Lake, Carr Fork U U U U U R6 R5 R5 lation Regu- ) a used (water record years 1999-2000 1992-98 1917-21, 1927-31, 1935-2000 Period of Period 1957-83, 1965-83, 1983-94 1940-92 1976-85 1955-82 1950-81 1905-07, computed from analysis of the observed an computed from analysis of the observed 1.32 2.21 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 66.4 40.9 60.6 466 177 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,101 Total miles) (square drainage name Station River at Whitesburg River Daisy at Hazard River Noble at Jackson River North Fork Kentucky Kentucky North Fork at Creek Leatherwood Sassafras near Fork Carr Kentucky North Fork Hazard near Fork Brier BranchBear near Noble Creek at Troublesome Kentucky North Fork Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03277500 03280000 number 03277300 03277400 03277450 c 03277630 03278000 03278500 c Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

38 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC NC 1,670 2,390 2,180 2,690 2,170 2,310 500 88,400 44,100 56,600 26,600 21,000 23,100 45,300 37,400 39,200 48,200 38,600 41,900 years NC NC 1,340 1,940 1,760 1,940 1,760 1,810 200 71,600 37,800 48,200 22,100 17,800 19,500 38,800 32,000 33,700 39,400 33,000 35,400 years NC 1,120 1,630 1,470 1,490 1,470 1,470 100 60,200 33,400 42,600 18,900 15,500 17,000 13,400 34,200 28,200 29,800 33,400 29,100 30,900 years NC 931

1,340 1,200 1,120 1,210 1,180 50 49,900 29,200 37,500 16,000 13,300 14,600 11,000 29,800 24,500 26,200 28,100 25,400 26,600 years

761 956 824 966 909 1,070 6,700 9,260 25 40,600 25,000 32,500 13,300 11,300 12,400 25,700 21,000 22,800 23,300 21,700 22,500 years 564 759 670 516 680 597 9,940 8,590 9,500 5,930 7,040 10 29,500 19,600 25,800 20,500 16,300 18,500 17,600 16,900 17,300 years Continued 432 548 485 336 489 397 5 7,580 6,650 7,360 5,320 5,900 21,900 15,500 20,200 16,700 12,900 15,300 13,600 13,300 13,500 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 270 295 279 154 262 184 2 9,910 4,500 4,060 4,440 4,370 4,660 8,130 8,600 8,440 8,570 12,600 12,100 11,500 10,600 years t computed; R5, ins R R R R R R G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Buckhorn 12/60 Lake, Buckhorn 12/60 Lake, U U U U U U R6 R6 lation Regu- ) a used (water record years Period of Period 1957-92 1958-2000 1976-86 1962-75 1975-86 COE 1973-2000 1965-2000 computed from analysis of the observed an computed from analysis of the observed 1.84 1.57 a weighted average a ofweighted the gage estimate (G average 61.3 202 420 537 155 163 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square drainage name Station River near Hyden near River at Buckhorn River at Tallega River Creek Manchester Middle Fork Kentucky Kentucky Middle Fork Cutshin Creek at Wooton Bull near Hyden Creek Kentucky Middle Fork Canoe at Fork Stamper Kentucky Middle Fork Big near River Bird Red at Creek Goose Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03281100 number 03280600 03280700 03280728 03280900 03280935 03281000 03281040 b Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 39 930 315 495 393 1,180 1,090 6,460 500 81,200 76,000 77,400 95,200 97,100 95,800 11,500 13,000 11,700 13,200 11,100 33,400 42,000 34,400 years 142,000 773 946 884 287 421 343 9,340 9,600 5,600 9,430 200 70,800 65,800 67,600 82,200 84,600 83,100 11,300 11,100 29,500 36,900 30,300 years 127,000 663 784 739 266 368 307 7,920 8,170 9,510 4,960 8,260 100 63,300 58,700 60,400 72,700 75,800 73,800 10,000 26,600 33,100 27,300 years 116,000 560 635 606 246 316 272

6,640 8,840 6,870 8,040 4,350 7,130 50 55,800 51,900 53,500 63,600 67,300 64,700 23,700 29,400 24,200 years 105,000

463 501 485 225 267 240 5,490 7,650 5,680 6,660 3,740 6,040 25 48,500 45,100 46,800 54,800 58,700 55,700 94,000 20,800 25,600 21,100 years 343 346 345 198 206 200 4,140 6,070 4,260 4,930 2,950 4,620 10 38,900 36,000 37,800 43,400 47,400 44,000 79,500 16,700 20,500 17,000 years Continued 258 244 252 176 161 173 5 3,220 4,890 3,290 3,700 2,360 3,540 31,500 29,000 30,800 34,800 38,500 35,200 69,200 13,600 16,700 13,700 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 148 126 140 144 102 136 2 2,060 3,200 2,090 2,090 1,540 2,050 8,850 8,900 20,800 19,100 20,500 22,800 25,700 22,900 53,400 11,100 years t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation Fork Lake, 01/76 Lake, Fork

diversion and and start date Carr al Survey streamflow-gaging stations in Kentucky— Survey al Buckhorn 12/60; Lake, U U U U U U U R6 lation Regu- ) a

used (water record years 1928-31, 1939-2000 1937-2000 Period of Period 1957-82 1926, COE 1975-85 1955-2000 1955-83 1975-85 1931-32, computed from analysis of the observed an computed from analysis of the observed .59 .58 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 65.8 24.0 486 722 362 neers; R6, significant regulation (see report regulation neers; R6, significant area 2,657 Total miles) (square drainage name Station River at at Oneida River at Booneville River Heidelberg 14 at Irvine West near Green Stillwater Zachariah South Fork Kentucky Kentucky South Fork Kentucky South Fork at Lock River Kentucky Tributary Creek Clear near Hazel River Red at Creek Stillwater at Red River Fork Middle City Clay at River Red Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03281200 03281500 03282000 03282198 03282500 03283000 03283305 03283500 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

40 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals 197 336 246 2,010 2,390 2,270 500 16,700 13,100 13,900 21,500 19,300 19,800 58,900 58,400 58,500 51,200 66,800 63,600 years 109,000 126,000 145,000 172 285 210 1,620 1,930 1,840 200 14,300 11,000 11,800 17,600 16,300 16,700 50,300 50,400 50,300 46,400 57,800 55,500 years 103,000 119,000 134,000 154 248 184 9,500 1,360 1,620 1,540 100 97,200 12,600 10,300 14,900 14,200 14,400 44,200 44,700 44,400 42,700 51,400 49,500 years 113,000 125,000 136 213 159

8,090 8,910 1,120 1,330 1,260 50 91,300 10,800 12,500 12,200 12,300 38,400 39,300 38,700 39,100 45,300 43,600 years 107,000 116,000

118 179 134 913 9,130 6,750 7,600 1,070 1,010 25 85,000 10,300 10,300 10,300 32,900 33,900 33,200 35,500 39,200 38,000 years 100,000 106,200 94.4 138 104 668 757 715 6,940 5,070 5,950 7,680 7,810 7,730 10 76,100 89,600 26,000 26,800 26,200 30,500 31,200 30,900 93,200 years Continued 75.9 81.2 107 502 546 522 5 5,290 3,870 4,690 5,860 6,030 5,910 69,000 79,900 21,000 21,500 21,000 26,500 25,100 25,800 83,100 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 49.1 67.8 51.2 297 294 296 2 3,040 2,300 2,820 3,550 3,660 3,580 58,100 62,300 14,000 13,900 14,000 20,300 16,400 18,900 68,800 years t computed; R5, ins R R R R R R G G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation Fork Lake, 01/76 Lake, Fork 01/76 Lake, Fork

diversion and and start date Carr Carr Lake, 11/25 Buckhorn 12/60; Lake, 01/76 Lake, Carr Fork al Survey streamflow-gaging stations in Kentucky— Survey al Buckhorn 12/60 Lake, Buckhorn 12/60; Lake, Herrington Inundated by Herrington 11/25; Lake, U U U U U U R6 R5 R5 lation Regu- ) a

used (water record years 1961-62, 1965-67, 1971-72, 1974-83 1915-22 Period of Period 1975-86 COE 1968-83 1959, 1976-85 1911-71 1943-2000 1912-13, COE computed from analysis of the observed an computed from analysis of the observed .33 1.83 a weighted average a ofweighted the gage estimate (G average 28.6 53.4 318 395 neers; R6, significant regulation (see report regulation neers; R6, significant area 3,955 4,414 5,102 Total miles) (square drainage name Station Tributary near Westbend near Tributary Winchester 10 near Kingston near Tributary Richmond Nelson Camp near near Salvisa Lulbegrud Creek Creek Lulbegrud at Lock River Kentucky near Creek Silver Berea near Creek Silver Branch Old Town at Lock 8 River Kentucky near Danville Dix River near Burgin River Dix at Lock 6 River Kentucky Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03283610 03284000 03284300 03284310 03284340 03284500 03285000 03285500 03287000 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 41 846 962 1,360 1,110 1,210 2,030 1,470 1,370 1,050 4,000 6,460 4,340 500 15,700 19,500 16,200 22,800 16,700 20,700 years 126,000 722 916 762 840 1,070 1,110 1,740 1,310 1,170 3,460 5,600 3,720 200 13,600 17,000 14,000 18,600 14,600 17,400 years 118,000 884 632 779 630 698 1,040 1,530 1,180 1,030 3,060 4,960 3,280 100 12,100 15,200 12,400 15,800 13,000 15,000 years 111,800 717 546 652 958 513 892 569

1,330 1,060 2,680 4,350 2,850 50 10,700 13,400 10,900 13,200 11,500 12,800 years 105,600

570 463 534 877 941 408 759 451 1,140 9,300 9,490 2,310 3,740 2,430 9,920 25 98,200 11,600 10,800 10,600 years 402 359 391 764 887 789 288 590 314 7,570 9,270 7,670 1,830 2,950 1,910 8,020 7,890 8,000 10 88,200 years Continued 292 282 290 670 704 676 208 467 224 5 6,280 7,500 6,330 1,480 2,360 1,520 6,070 6,370 6,100 80,000 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 161 180 164 520 452 512 113 299 120 974 991 2 4,470 4,930 4,480 1,540 3,590 4,180 3,630 68,800 years t computed; R5, ins R R R R R R G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date Buckhorn 12/60; Lake, 01/76 Lake, Carr Fork al Survey streamflow-gaging stations in Kentucky— Survey al Herrington 11/25; Lake, U U U U U U R5 lation Regu- ) a used (water record years 1989-98 1998-2000 Period of Period 1976-87 COE 1976-86 1951-83, 1953-79 1951-92, 1983-2000 computed from analysis of the observed an computed from analysis of the observed 1.26 4.47 2.53 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 24 95.0 119 neers; R6, significant regulation (see report regulation neers; R6, significant area 5,411 Total miles) (square drainage name Station Mortonsville at Frankfort Frankfort Georgetown Spring Fort Spring Midway Tanners Creek at Creek Tanners at Lock 4 River Kentucky South Benson Creek near North Elkhorn Creek near Creek near Fort Cave South Elkhorn Creek at South Elkhorn Creek near Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03287128 03287500 03287534 03288000 03288500 03289000 03289300 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

42 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals 788 851 807 4,620 2,710 4,390 3,150 500 42,800 50,500 43,500 11,600 10,400 13,100 10,700 12,900 69,800 47,900 68,800 years 132,000 675 743 695 9,510 3,980 8,550 2,190 3,800 2,600 9,520 200 36,900 44,500 37,600 11,500 11,300 61,100 42,800 60,300 years 124,000 596 661 616 8,080 3,510 7,320 1,840 3,360 2,210 8,660 100 32,800 39,900 33,400 10,400 10,200 54,900 39,100 54,200 years 118,000 522 583 540

6,780 3,070 6,190 1,530 2,940 1,850 9,250 7,810 9,140 50 28,900 35,500 29,400 48,900 35,300 48,300 years 111,000

453 505 467 5,600 2,630 5,180 1,250 2,530 1,510 8,180 6,980 8,100 25 25,200 31,000 25,600 43,000 31,800 42,600 years 103,600 914 366 402 375 4,200 2,070 3,950 2,000 1,090 6,810 5,860 6,760 10 20,600 24,900 20,800 92,700 35,400 27,000 35,200 years Continued 687 782 303 346 310 5 3,230 1,520 3,090 1,520 5,770 5,700 5,760 17,100 20,300 17,200 84,200 29,600 25,800 29,500 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 998 405 997 449 216 216 216 2 2,000 1,950 4,260 3,920 4,250 12,400 13,500 12,400 71,200 21,200 18,700 21,200 years t computed; R5, ins R R R R R R G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date Buckhorn 12/60; Lake, 01/76 Lake, Carr Fork al Survey streamflow-gaging stations in Kentucky— Survey al Herrington 11/25; Lake, U U U U U U R5 lation Regu- ) a used (water record years 1940-83, 1989-2000 1928-31, 1939-87, 1989-2000 Period of Period 1916-20, 1952-87 COE 1976-86 1941-83 1976-86 1915-20, computed from analysis of the observed an computed from analysis of the observed .58 5.63 5.62 a weighted average a ofweighted the gage estimate (G average 42.9 473 437 neers; R6, significant regulation (see report regulation neers; R6, significant area 6,180 Total miles) (square drainage name Station Frankfort at Lockport Castle Corinth Elkhorn Creek near Flat Creek near Frankfort at Lock 2 River Kentucky at New Creek Town Eagle Creek at Sadieville near South Rays Fork Glencoe at Creek Eagle Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03289500 number b 03290000 03290500 03290580 03291000 03291050 03291500 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 43 1,460 1,970 1,630 8,170 7,520 8,090 1,840 1,830 1,840 9,410 4,730 1,920 3,510 500 15,800 14,200 22,700 27,500 23,200 74,700 43,300 68,800 years 952,000 1,270 1,650 1,390 7,540 6,680 7,430 1,480 1,550 1,500 8,180 3,410 1,650 2,680 200 13,000 11,900 20,800 24,100 21,200 60,400 38,100 56,400 years 872,000 1240 1,130 1,420 1,230 7,050 6,070 6,930 1,350 1,270 7,260 2,610 1,450 2,150 100 11,100 10,300 19,400 21,500 19,600 50,900 34,300 48,000 years 812,000

1,000 1,210 1,070 6,550 5,460 6,420 1,010 1,160 1,050 9,410 6,380 8,860 1,960 1,260 1,700 50 17,900 19,100 18,000 42,400 30,500 40,500 years 750,000

876 916 813 973 853 1,010 6,020 4,860 5,890 7,880 5,510 7,510 1,430 1,070 1,310 25 16,300 16,600 16,300 34,700 27,000 33,600 years 686,000 718 753 728 578 740 611 886 832 872 5,280 4,060 5,170 6,050 4,360 5,860 10 14,000 13,200 14,000 25,800 22,200 25,400 years 605,000 Continued 601 450 565 420 483 430 573 602 578 5 4,660 3,910 4,610 4,790 3,500 4,680 12,100 10,700 12,000 19,700 18,400 19,600 years 553,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 437 284 409 227 306 235 257 384 270 2 3,640 2,660 3,600 3,180 2,290 3,130 8,930 7,090 8,880 12,100 13,100 12,100 years 494,000 t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U NC lation Regu- ) a used (water record years Period of Period 1976-85 1968-94 1975-87 COE 1953-83 1939-82 1976-86 1982-2000 computed from analysis of the observed an computed from analysis of the observed .87 .97 1.36 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 24.1 41.4 196 259 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) 91,170 (square drainage name Station LaGrange Crestwood near Creek Harrodsburg Shelbyville Taylorsville Jeff Branch near Sligo near Branch Jeff Harrods Creek near HarrodsSouth Fork at Louisville Ohio River near Salt River Buren near Van Salt River near Creek Bradshaw at Creek Brashears Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03295500 number 03292200 03292460 03292472 03294500 03295000 b 03295845 03295890 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

44 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals 9,550 7,130 9,190 9,340 5,160 8,540 9,380 9,820 2,320 1,490 1,980 500 19,500 11,600 18,100 11,400 51,400 22,500 49,200 57,700 58,100 57,700 years 102,000 8,520 6,300 8,190 7,480 4,390 6,910 8,440 8,810 1,660 1,260 1,500 200 17,400 10,200 16,100 10,200 41,200 20,100 39,600 83,800 50,100 49,400 50,100 years 7,740 5,680 7,450 6,260 3,840 5,830 9,110 7,750 9,250 8,070 1,270 1,090 1,200 100 15,900 14,600 34,500 18,300 33,400 71,700 44,700 43,200 44,500 years 955 939 949

6,960 5,080 6,700 5,180 3,320 4,870 8,070 7,080 8,340 7,340 50 14,300 13,200 28,700 16,500 28,000 61,000 39,400 37,100 39,200 years

701 786 727 6,160 4,490 5,950 4,220 2,810 4,000 7,060 6,430 7,440 6,620 25 12,600 11,700 23,600 14,800 23,200 51,500 34,200 31,600 34,000 years 442 595 479 5,080 3,700 4,940 3,100 2,170 2,990 5,730 9,780 5,560 6,250 5,670 10 10,400 17,800 12,600 17,600 40,500 27,400 24,400 27,200 years Continued 292 384 309 5 4,210 3,360 4,150 2,350 1,430 2,270 8,590 4,690 8,240 4,890 6,020 5,010 14,000 12,200 13,900 32,900 22,300 19,300 22,100 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 940 139 241 151 2 2,890 2,270 2,860 1,440 1,400 5,850 3,200 5,690 3,890 4,150 3,910 9,270 8,600 9,260 23,100 14,900 12,300 14,800 years t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); Various Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Taylorsville Lake, 01/83 Taylorsville U U U U U R5 R5 R6 lation Regu- ) a used (water record years 1980-83 Period of Period 1954-80 1954-78, 1954-77 1980-1991 1945-2000 COE 1976-85 1939-92 computed from analysis of the observed an computed from analysis of the observed .68 5.15 a weighted average a ofweighted the gage estimate (G average 19.1 31.8 46.7 138 239 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,197 Total miles) (square drainage name Station Wilsonville Waterford Crestwood Shepherdsville Clermont Lebanon Plum Creek near near Creek Plum Little Plum Creek at Waterford near Fork Floyds Fisherville at Fork Floyds at River Salt near Lick Creek Elm Rolling near Fork Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03296500 03297000 03297500 03297845 03298000 03298500 03298535 03299000 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 45 248 328 279 390 598 1,370 1,040 1,220 1,350 500 16,100 15,600 16,000 54,800 47,800 53,200 51,400 64,200 53,100 98,300 years 182,000 102,000 1,010,000 893 211 279 235 366 546 1,270 1,100 1,140 200 14,300 13,600 14,100 47,500 42,000 46,400 47,200 56,600 48,300 85,000 88,400 years 155,000 934,000 783 184 243 204 347 987 500 1,190 1,010 100 12,900 12,100 12,800 42,300 37,700 41,500 43,900 50,800 44,700 75,500 78,400 years 136,000 865,000 677 932 160 208 175 326 839 452

1,110 50 11,600 10,700 11,400 37,400 33,500 36,800 40,500 45,200 40,900 66,500 68,900 years 117,000 800,000

575 853 137 175 148 304 702 402 9,240 1,020 25 10,300 10,100 32,800 29,200 32,300 36,800 39,600 37,100 57,800 59,800 years 100,000 733,000 899 446 753 108 135 114 270 531 335 8,550 7,340 8,420 10 27,000 23,400 26,600 31,600 31,800 31,600 46,800 78,100 48,200 years 640,000 Continued 86.4 89.7 791 352 674 105 241 406 281 5 7,210 5,930 7,110 22,600 19,100 22,300 27,200 26,000 27,200 38,600 62,400 39,600 years 586,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 57.6 66.3 58.7 608 225 532 189 241 202 2 5,240 3,890 5,170 16,500 12,700 16,300 20,000 17,300 19,900 27,100 40,500 27,600 years 526,000 t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U NC lation Regu- ) a used (water record years 1998-99 1981-86 Period of Period 1953-83 1975-87 1973-2000 1975-86 1940-85, 1939-2000 1975-78, COE computed from analysis of the observed an computed from analysis of the observed .32 .90 1.71 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 85.9 436 669 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,299 Total miles) 97,000 (square drainage name Station Springfield Willisburg Bardstown Grove Vine near Dam Beech Fork near Fork Beech North near Prong at Maud Fork Beech at Creek Tributary Town Bardstown at Fork Beech Rolling near Fork Boston Otter CreekTributary at Cannelton Ohio River Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03300400 number 03300000 03300065 b 03300990 03301000 03301500 03302085 03303280 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

46 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC 836 926 909 3,240 2,420 3,090 1,210 1,330 1,250 1,150 5,300 2,890 500 41,100 11,800 34,600 32,100 16,300 29,100 60,300 49,400 59,400 years NC 724 968 794 764 2,640 2,040 2,540 9,980 1,080 1,120 1,090 3,930 2,230 200 32,800 27,900 26,800 13,800 24,400 48,100 42,000 47,600 years NC 982 972 977 644 841 700 663 2,220 1,770 2,150 8,700 3,050 1,810 100 27,100 23,200 23,000 12,100 21,000 40,100 36,700 39,800 years NC 885 826 865 569 714 610 563

1,840 1,510 1,780 7,440 2,300 1,430 50 22,000 19,000 19,400 10,300 17,800 33,000 31,500 32,900 years

787 691 754 497 597 525 470 1,470 1,270 1,440 6,280 8,730 9,200 1,670 1,100 25 17,300 15,200 16,100 14,800 26,700 26,800 26,700 years 962 654 523 610 405 451 418 355 726 1,040 1,030 4,820 6,710 8,210 1,000 10 11,800 10,700 11,900 11,100 19,500 20,700 19,600 years Continued 735 740 736 547 400 500 336 345 339 607 270 481 5 8,230 3,760 7,560 8,960 5,250 8,440 7,390 14,700 16,400 14,800 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 368 444 376 386 238 340 240 204 231 222 160 204 2 3,990 2,320 3,790 5,080 3,260 4,860 6,070 8,790 8,870 10,400 years t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Green River Lake, 02/69 River Green U U U U U U U R6 lation Regu- ) a used (water record years Period of Period 1952-79 1952-83 1954-83 1976-85 1976-86 1970-94 1976-85 1940-2000 computed from analysis of the observed an computed from analysis of the observed .88 .71 .50 2.14 a weighted average a ofweighted the gage estimate (G average 22.4 36.3 682 188 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square drainage name Station McKinney McKinney Salem near Tributary Hustonville Clementsville near Campbellsville near Tributary Montpelier Columbia McGills Creek near Creek McGills near River Green Mount near River Green Creek Carpenter Tributary Creek Gumlick near River Green Oak Creek White near Creek Russell Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03304500 03305000 03305500 03305559 03305835 03306000 03306640 03307000 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 47 799 9,180 9,290 5,830 4,480 5,600 1,160 1,010 500 62,300 10,300 92,900 17,900 16,400 17,700 41,100 67,500 43,400 12,300 12,800 12,300 years 145,000 123,000 981 691 867 7,430 8,710 7,560 4,760 3,790 4,590 200 53,000 92,300 77,000 15,700 13,900 15,500 33,800 57,700 35,800 10,100 11,200 10,200 years 106,000 854 612 763 6,280 7,590 6,410 4,020 3,290 3,900 8,560 8,750 100 82,800 46,300 73,700 66,500 14,100 12,100 13,800 28,800 50,600 30,500 10,200 years 732 534 662

5,270 6,490 5,390 3,350 2,810 3,260 7,140 9,090 7,340 50 63,600 39,800 58,000 57,100 12,400 10,300 12,200 24,200 43,600 25,700 years

613 457 564 4,380 5,470 4,480 2,740 2,360 2,680 8,750 5,820 7,990 6,000 25 47,900 33,900 44,800 48,800 10,800 10,500 20,100 37,300 21,400 years 462 357 436 3,340 4,190 3,420 2,000 1,800 1,970 8,530 6,720 8,340 4,210 6,520 4,340 10 31,600 26,200 30,500 37,500 15,200 29,100 16,100 years Continued 350 283 337 5 2,650 3,270 2,700 1,500 1,390 1,480 6,790 5,260 6,640 3,080 5,380 3,170 21,800 20,800 21,600 30,500 11,800 23,200 12,400 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 860 846 859 200 181 198 2 1,780 2,010 1,800 4,250 3,270 4,160 7,400 7,760 1,660 3,690 1,710 11,400 13,200 11,700 23,600 14,900 years t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Green River Lake, 02/69 River Green U U U U U U U R6 lation Regu- ) a used (water record years 1980-82 Period of Period 1965-83 1942-83 COE 1954-82 1942-78, 1960-2000 1975-85 1960-94 computed from analysis of the observed an computed from analysis of the observed .56 5.34 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 18.3 36.4 85.4 265 357 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,673 Total miles) (square drainage name Station Gresham at Edmonton River Munfordville Hodgenville Hodgenville Mills Upton near Priceville Russell Creek near near Creek Russell LittleSouth Fork Barren at River Green near Creek McDougal at NorthNolin Fork River White at River Nolin Tributary Creek Bacon near Creek Bacon Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03310300 number 03307100 03307500 03308500 03309500 03310000 c 03310385 03310400 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

48 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC NC 665 577 626 723 894 8,600 4,100 7,030 7,270 1,340 500 28,000 72,000 32,800 11,300 10,300 99,600 years 102,000 144,000 136,000 NC NC 540 498 522 612 752 7,110 3,590 5,940 6,390 9,390 1,130 200 25,200 62,100 29,200 84,600 10,400 84,800 years 115,000 109,000 NC NC 456 440 449 534 980 653 6,080 3,220 5,180 9,650 5,750 8,720 100 23,100 54,900 26,500 73,000 95,100 74,200 91,400 years 380 382 381 462 832 560

5,130 2,850 4,470 8,910 5,110 8,070 8,210 50 20,900 47,900 23,600 13,700 62,700 77,800 63,800 75,500 years

311 327 316 393 696 472 4,240 2,480 3,800 8,140 4,470 7,410 7,510 25 18,600 41,300 20,800 12,600 53,700 62,500 54,400 61,200 years 229 254 236 308 527 362 3,170 1,980 2,940 7,050 3,620 6,510 6,590 10 15,600 32,800 17,000 11,000 42,700 44,800 42,300 44,500 years Continued 174 200 179 246 403 283 5 9,610 2,420 1,610 2,300 6,140 2,960 5,760 5,860 13,000 26,500 14,000 35,900 33,100 33,600 33,200 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 104 127 107 162 240 180 2 9,130 9,620 7,380 1,440 1,070 1,410 4,670 2,000 4,460 4,790 17,600 28,700 19,000 21,500 19,300 years t computed; R5, ins R R R R R R G G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code River Lake, 02/69 Lake, River or type of Source of Source regulation

diversion and and start date Green al Survey streamflow-gaging stations in Kentucky— Survey al Nolin 03/63 Lake, Nolin 03/63; Lake, 03/64 Lake, Barren River U U U U U U R6 R6 R6 lation Regu- ) a used (water record years 1981-86 1983-94 Period of Period 1937-62 1976-85 1964-90, 1998 COE 1973-94 1950-83 1940-63 1976-79, 1965-80, computed from analysis of the observed an computed from analysis of the observed .31 .89 a weighted average a ofweighted the gage estimate (G average 10.9 30.8 600 703 531 942 neers; R6, significant regulation (see report regulation neers; R6, significant area 2,762 Total miles) (square drainage name Station near Ollie near Brownsville Rhoda Leitchfield Pageville Glasgow Nolin River at Wax Nolin River Brier CreekTributary Kyrock at River Nolin 6 at Lock at River Green at Creek Beaverdam near Creek Bear near River Barren near Creek Beaver Little Finney near River Barren Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03310500 number c 03310880 03311000 03311500 03311600 03312000 03312500 03312795 03313000 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 49 379 554 435 909 6,430 5,620 6,280 1,490 1,260 500 32,500 34,500 32,900 17,200 11,500 16,000 92,700 88,500 years 129,000 125,000 148,000 328 465 374 764 5,320 4,750 5,220 9,740 1,190 1,030 200 27,000 29,300 27,300 13,600 12,900 99,800 79,000 97,600 72,700 years 126,000 291 403 327 997 663 869 4,580 4,140 4,500 8,490 100 23,100 25,500 23,500 11,300 10,700 81,200 69,100 80,000 62,300 years 112,000 254 342 283 820 563 725

3,910 3,530 3,840 9,200 7,260 8,840 50 19,600 21,900 20,000 65,300 59,400 64,800 53,100 98,000 years

218 285 240 663 470 594 3,300 2,970 3,250 7,340 6,130 7,130 25 16,400 18,600 16,700 51,800 50,700 51,700 45,000 85,900 years 172 215 185 480 355 438 2,580 2,270 2,540 5,200 4,700 5,120 10 12,500 14,400 12,700 36,800 39,300 37,000 34,900 70,300 years Continued 136 163 144 357 270 331 5 2,090 1,760 2,040 9,730 9,920 3,780 3,660 3,770 11,300 27,200 31,200 27,500 28,100 60,200 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 86.5 95.2 88.8 207 160 194 2 1,450 1,070 1,400 6,170 7,110 6,270 2,080 2,260 2,100 16,100 20,000 16,400 19,200 50,000 years t computed; R5, ins R R R R R R G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code River Lake, 03/64; Lake, River

or type of Source of Source regulation diversion and and start date Barren Lake, 02/69 River Green al Survey streamflow-gaging stations in Kentucky— Survey al Barren River Lake, 03/64 Lake, Barren River Nolin 03/63; Lake, U U U U U U R6 R6 lation Regu- ) a used (water record years Period of Period 1976-84, 1986 1951-83 1969-2000 1959-83 1940-82 COE 1976-84, 1986 COE computed from analysis of the observed an computed from analysis of the observed .24 .50 7.47 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 21.6 110 478 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,849 5,404 Total miles) (square drainage name Station near Scottsville Scottsville Franklin near Alvaton Green Green Bowling near Woodbury Solomon Creek Tributary Tributary Creek Solomon Bays Fork at West Creek Drakes Fork West near Franklin Creek Lick near Creek Drakes at Bowling River Barren Tributary River Barren 4 at Lock at River Green Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03313020 03313500 03313700 03313800 03314000 03314500 03314750 03315500 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

50 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC NC 549 478 521 6,140 8,630 6,530 5,750 500 17,100 13,200 16,500 21,700 21,700 21,700 19,600 32,000 21,800 14,400 11,600 years NC NC 480 411 454 5,510 7,590 5,830 5,040 9,800 200 15,000 11,600 14,500 20,100 19,300 19,900 18,300 28,400 20,100 11,900 years NC 429 363 405 5,030 6,840 5,300 4,530 8,590 8,360 100 13,500 10,500 13,100 18,700 17,500 18,500 17,200 25,900 18,800 10,200 years NC 378 315 356

9,390 4,550 6,090 4,750 8,720 4,020 7,480 7,570 50 12,000 11,700 17,400 15,700 17,100 16,200 23,300 17,300 years

328 269 309 8,260 4,060 5,330 4,210 7,330 3,510 6,440 6,900 25 10,600 10,400 77,500 15,900 13,900 15,600 15,000 20,700 15,800 years 261 208 247 8,720 6,750 8,570 3,380 4,330 3,470 5,650 2,830 5,150 5,680 10 65,800 13,700 11,400 13,500 13,200 17,100 13,600 years Continued 209 163 200 5 7,290 5,560 7,200 9,490 2,840 3,550 2,880 4,480 2,300 4,190 4,810 56,900 11,900 11,700 11,600 14,300 11,800 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 134 103 130 2 5,210 3,820 5,160 8,790 6,600 8,670 2,000 2,410 2,020 8,920 8,990 2,940 1,550 2,830 4,120 44,100 10,100 years t computed; R5, ins R R R R R R G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code River Lake, 03/64; Lake, River

or type of Source of Source regulation diversion and and start date Barren Lake, 02/69 River Green al Survey streamflow-gaging stations in Kentucky— Survey al Nolin 03/63; Lake, 10/59 Lake, Rough River U U U U U U R6 R6 lation Regu- ) a used (water record years 1992-2000 1978-80, 1982-83 1983-85, 1987 Period of Period 1940-83 1970-81, 1937-59 1955-76, 1940-56 1957-78 COE 1975-81, computed from analysis of the observed an computed from analysis of the observed .22 a weighted average a ofweighted the gage estimate (G average 90.5 42.0 20.1 225 454 504 neers; R6, significant regulation (see report regulation neers; R6, significant area 6,183 Total miles) (square drainage name Station Lewisburg Westview near Rough Glen Dean Rough Rough of Falls near Mud River near Mud River Paradise at River Green near Madrid Rough River RoughNorth River Fork of Falls near RoughRiver near Creek Rock Lick of at Falls Rough River Run Tributary Pleasant Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03316000 03316500 03317000 03317500 03318000 03318200 03318500 03318505 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 51 339 524 392 557 556 556 3,650 4,760 3,900 2,620 1,430 1,940 500 18,200 15,700 17,900 34,400 52,000 37,500 50,200 years 110,000 1,080,000 303 451 345 459 479 466 3,500 4,170 3,660 2,130 1,210 1,640 28400 200 16,100 13,800 15,800 97,500 41,800 31,800 40,700 years 989,000 275 398 309 393 423 402 3,380 3,740 3,460 1,800 1,050 1,430 100 14,500 12,500 14,200 24,500 88,800 35,000 27,500 34,300 years 920,000 248 346 273 331 368 341 903

3,250 3,320 3,260 1,490 1,220 50 13,000 11,200 12,700 21,000 80,700 28,800 23,800 28,400 years 853,000

219 296 237 275 314 284 759 9,880 3,100 2,890 3,060 1,200 1,020 25 11,400 11,300 17,900 73,100 23,300 20,000 23,000 years 785,000 181 229 190 206 244 214 862 580 772 9,450 8,090 9,340 2,870 2,320 2,780 10 13,900 62,900 16,800 15,500 16,700 years 708,000 Continued 150 180 154 159 192 164 628 449 584 5 7,910 6,690 7,840 2,650 1,890 2,550 10,800 55,100 12,400 12,200 12,400 years 660,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 97.2 102 114 104 122 100 337 276 326 2 5,650 4,620 5,610 7,900 6,990 7,800 7,010 2,230 1,260 2,140 48,200 years 593,000 t computed; R5, ins R R R R R R G G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); Various location Code River Lake, 03/64; Lake, River

or type of Source of Source regulation diversion and and start date Nolin 03/63; Lake, Barren Lake, 02/69 River Green al Survey streamflow-gaging stations in Kentucky— Survey al Rough River Lake, 10/59 Lake, Rough River 10/59; Lake, Rough River U U U U U U R6 R6 NC lation Regu- ) a used (water record years 1982-86 1984-87, 1989-94 1981-86 Period of Period 1957-92 COE 1976-86 COE 1941-2000 1975-79, COE 1973-82, 1975-79, computed from analysis of the observed an computed from analysis of the observed .26 .29 .91 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 14.3 124 757 194 neers; R6, significant regulation (see report regulation neers; R6, significant area 7,566 Total miles) (square 107,000 drainage name Station Branch near Fordsville Tributary Calhoun Owensboro near Ind. Corydon Caney Creek near Horse Horse near Creek Caney near Dundee Rough River Adams Fork West 2 at Lock at River Green Apex near Pond River Rhodes CreekTributary at Evansville, Ohio River near Creek Beaverdam Lewiston at Creek Ward Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03318800 03319000 03319520 03320000 03320500 03321465 03322000 03322360 03382975 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

52 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals NC 1,790 2,370 1,900 8,100 500 23,100 44,400 25,100 16,800 15,100 16,500 34,700 25,300 27,600 27,700 65,800 13,200 11,900 17,900 12,300 16,800 years 1,345,000 NC NC NC 1,620 2,010 1,690 7,060 200 18,600 37,600 20,100 14,400 13,200 14,200 28,700 21,500 23,400 11,200 10,100 15,200 10,700 14,300 years 1,230,000 NC 1,480 1,740 1,530 9,820 6,320 8,900 9,630 100 15,600 32,400 16,800 12,600 11,700 12,500 24,500 18,800 20,500 19,800 53,200 13,300 12,600 years 1,143,000 NC

1,350 1,500 1,370 8,510 7,190 8,230 50 13,000 28,100 13,900 11,000 10,400 10,900 20,600 16,200 17,700 16,700 48,700 11,500 10,500 11,400 years 1,057,000

NC NC 1,210 1,260 1,210 9,330 8,960 9,290 1,570 7,280 6,280 7,070 9,870 9,180 9,760 25 10,600 23,600 11,300 17,000 13,700 15,100 years 974,000 968 7,900 8,270 1,010 1,010 7,240 7,120 7,230 1,220 5,750 5,090 5,640 7,780 7,450 7,740 10 18,300 12,700 10,500 11,700 10,400 34,700 years 855,000 Continued NC NC 847 752 840 983 5 6,080 6,290 5,680 5,750 5,680 9,650 8,210 9,160 4,650 4,160 4,590 6,260 6,100 6,240 14,500 years 762,000 Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression NC 593 465 586 675 2 3,810 9,250 3,900 3,520 3,770 3,530 5,720 5,070 5,570 4,750 3,150 2,810 3,120 4,180 4,150 4,180 years 622,000 t computed; R5, ins R R R R R R G G G G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al Martins Lake, Fork 11/78 Martins Lake, Fork 11/78 Martins Lake, Fork 11/78 Fern Lake U U U U U R6 R6 R6 R5 NC lation Regu- ) a used (water record years 1986-2000 1981-86 1967-83 Period of Period 1941-83, 1952-81 COE 1940-92, 2000 1960-78, 1980-2000 COE COE 1941-65, 1941-2000 computed from analysis of the observed an computed from analysis of the observed 2.10 a weighted average a ofweighted the gage estimate (G average 82.3 82.4 55.8 35.3 60.6 255 222 374 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square 143,900 drainage 51, at

name Station Golconda, Ill. Olney Harlan Middlesboro Middlesboro Tradewater River River atTradewater at Nebo Creek Rose at Dam Ohio River atPoor Fork Cumberland Evarts at Fork Clover Smith near Fork Martins Harlan at Fork Clover near River Cumberland at Bypass Creek Yellow Creek near Yellow Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03383000 number b 03384000 03384500 03400500 03400700 03400800 03400990 03401000 03401500 03402000 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 53 107 206 158 1,430 1,180 1,290 500 84,800 74,700 38,000 46,000 40,000 65,000 80,600 25,300 23,600 24,800 12,400 11,200 12,100 years 96.8 NC NC NC NC 177 137 1,310 1,030 1,140 9,790 200 33,600 40,300 35,400 21,300 20,600 21,100 10,100 10,000 years 88.7 914 157 123 1,210 1,040 8,540 8,780 8,610 100 76,000 66,200 30,400 36,200 31,900 57,400 71,100 18,400 18,500 18,400 years 80.3 97.3 988 112

1,110 1,040 7,160 6,720 7,040 50 71,100 61,800 27,200 35,000 29,400 54,300 66,700 15,800 12,900 14,900 years

71.6 96.3 84.4 NC NC NC NC 857 923 1,000 5,920 5,870 5,910 25 24,000 30,800 25,700 13,200 11,300 12,700 years 59.5 74.7 66.7 851 682 766 9,140 9,910 4,460 4,720 4,520 10 56,300 47,000 19,600 25,200 20,800 41,900 51,100 10,200 years Continued 49.5 57.5 52.8 NC NC NC NC 723 545 648 5 7,920 7,380 7,830 3,470 3,800 3,520 16,200 20,800 17,000 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 34.0 33.7 33.9 NC NC NC NC 517 349 468 2 4,950 4,870 4,940 2,220 2,480 2,250 11,100 14,400 11,400 years t computed; R5, ins R R R R R G G G G G G G G G W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date Fern Lake Fern Lake Fern Lake Fern Lake al Survey streamflow-gaging stations in Kentucky— Survey al Martins Lake, Fork 11/78; Martins Lake, Fork 11/78; Martins Lake, Fork 11/78; Martins Lake, Fork 11/78; U U U U U R6 R6 R5 R5 lation Regu- ) a used (water record years 1996-2000 Period of Period 1976-86 COE COE 1969-90, COE COE 1974-2000 1976-85 1957-2000 computed from analysis of the observed an computed from analysis of the observed .31 2.96 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 53.8 770 960 331 140 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,607 1,977 Total miles) (square drainage name Station Street Bridge at Pineville Barbourville Williamsburg Falls Cumberland CorbinDam near Corbin Corbin Shillalah Creek near Page at Pine River Cumberland at River Cumberland Saxton at Fork Clear at River Cumberland at River Cumberland Municipal at River Laurel near Hollow Gozey Camp at Creek Lynn Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03402020 03402900 03403500 03403910 03404000 03404500 03404820 03404867 03404900 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

54 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals 744 374 596 211 179 200 407 450 421 4,060 2,450 2,780 1,030 1,460 1,150 500 29,800 31,300 30,200 66,300 75,300 68,100 years 936 593 323 490 176 155 169 342 389 355 3,350 1,990 2,270 1,270 1,020 200 25,500 27,300 26,000 59,700 65,900 60,900 years 860 931 491 287 416 152 137 148 294 345 308 2,840 1,670 1,930 1,130 100 22,400 24,500 23,000 54,600 59,200 55,400 years 780 896 816 400 248 340 130 107 122 247 310 267

2,370 1,370 1,620 50 19,500 19,100 19,400 49,400 47,900 49,100 years

92.2 695 777 718 317 214 279 109 103 202 268 221 1,920 1,100 1,330 25 16,700 16,800 16,700 44,100 42,100 43,700 years 82.9 71.7 79.7 779 996 572 615 582 221 168 205 145 210 160 1,380 10 13,000 13,600 13,200 36,700 34,300 36,400 years Continued 64.2 55.4 62.2 563 757 468 485 472 157 131 151 104 165 115 5 1,000 10,300 11,100 10,500 30,700 28,100 30,500 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 80.7 79.9 80.6 39.5 32.7 38.6 51.3 55.9 523 303 426 304 303 304 101 2 6,620 7,460 6,690 21,500 19,200 21,300 years t computed; R5, ins R R R R R R R G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U lation Regu- ) a used (water record years 1943-73 Period of Period 1923-24, 1976-85 1954-86 1937-2000 1957-86 1957-86 1956-86 computed from analysis of the observed an computed from analysis of the observed .67 .26 .85 1.91 3.89 a weighted average a ofweighted the gage estimate (G average 201 604 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square drainage name Station Conway Billows Lake Lake Parkers near Greenwood Laurel River at Corbin River Laurel Big Hurricane Branch at Creek near London Wood at River Rockcastle Parkers near Branch Cane Branch Cave Fork West Helton Branch at Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station 03406500 number 03405000 03405854 03406000 c 03407100 03407200 03407300 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 55 993 315 485 4,860 7,380 5,500 2,070 1,630 1,210 500 34,900 26,800 33,000 16,200 18,400 16,600 years 128,000 148,000 130,000 170,000 179,000 171,000 834 293 434 4,500 6,430 5,000 1,500 1,250 1,010 200 30,900 23,400 29,100 13,200 15,600 13,600 years 115,000 126,000 116,000 150,000 153,000 150,000 724 999 276 880 396 4,210 5,750 4,610 1,150 100 27,800 21,000 26,200 11,200 13,600 11,600 years 106,000 110,000 106,000 135,000 134,000 135,000 875 615 787 258 748 359

3,910 4,750 4,170 9,390 9,730 50 24,800 17,700 22,900 95,600 95,000 95,600 11,700 years 121,000 115,000 120,000

649 514 606 240 625 320 3,590 4,150 3,750 7,730 9,870 8,030 25 21,700 15,600 20,100 85,600 81,200 85,300 98,700 years 106,000 106,000 416 388 408 215 473 268 3,120 3,330 3,170 5,760 7,580 6,000 10 17,500 12,600 16,500 72,000 63,200 71,500 87,200 76,900 86,200 years Continued 279 296 283 193 361 228 5 2,730 2,680 2,720 4,400 5,940 4,580 14,200 10,300 13,600 61,000 50,400 60,400 72,200 61,500 71,300 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 137 175 145 158 214 170 2 9,230 6,960 9,040 2,070 1,750 2,030 2,680 3,700 2,790 44,200 32,600 43,500 50,100 39,800 49,200 years t computed; R5, ins R R R R R R R G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U lation Regu- ) a used (water record years 1933-50 1990-2000 Period of Period 1953-91 1943-2000 1916-31, 1954-83 1969-83, 1976-86 1976-86 computed from analysis of the observed an computed from analysis of the observed .57 .76 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 31.3 43.4 165 954 neers; R6, significant regulation (see report regulation neers; R6, significant area 1,271 Total miles) (square drainage name Station Shopville Stearns near River at Nevelsville River Monticello Spann Cartwright near Buck Creek near near Creek Buck Cumberland South Fork Cumberland South Fork Pitman Creek at Somerset near Creek Beaver near Creek Elk Spring Creek Tributary Williams Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03407500 03410500 03411000 03412500 03413200 03413202 03413425 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

56 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals 4,340 3,390 4,010 9,620 1,430 2,720 1,910 9,570 500 90,000 15,100 13,300 14,500 15,700 14,800 42,700 43,200 42,800 12,100 10,300 years NC 3,480 2,860 3,260 8,150 1,200 2,300 1,580 8,480 8,960 200 12,700 11,300 12,100 13,300 12,300 33,800 36,600 34,100 10,300 years 2,900 2,480 2,760 7,050 9,910 1,040 2,000 1,340 7,700 8,900 8,000 100 50,000 11,000 10,400 11,500 10,500 28,100 31,600 28,400 years 886

2,380 2,120 2,290 9,450 6,090 8,610 1,720 1,120 8,800 9,940 8,950 6,940 7,690 7,100 50 42,500 23,100 27,300 23,400 years

NC 741 910 1,910 1,780 1,870 8,010 5,120 7,390 1,450 7,360 8,360 7,470 6,210 6,470 6,260 25 18,700 23,000 18,900 years 560 660 1,360 1,350 1,360 6,230 3,950 5,860 1,110 5,610 6,460 5,680 5,280 4,990 5,230 10 40,000 13,700 17,900 13,900 years Continued NC 986 430 862 489 5 1,040 1,000 4,950 3,090 4,720 4,380 5,070 4,420 4,560 3,910 4,480 10,500 14,100 10,600 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression NC 537 631 558 256 534 283 2 3,250 1,940 3,130 2,770 3,200 2,790 6,520 9,000 6,570 3,530 2,460 3,430 years t computed; R5, ins R R R R R R G G G G G G G W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date Laurel River Lake, 10/73; Lake, Laurel River Lake, 1/79;Martins Fork Fern Lake al Survey streamflow-gaging stations in Kentucky— Survey al Cumberland12/50; Lake, U U U U U U R6 lation Regu- ) a used (water record years Period of Period COE 1976-86 1973-91 1977-86 1950-83 1940-2000 1969-83 computed from analysis of the observed an computed from analysis of the observed 3.52 2.62 a weighted average a ofweighted the gage estimate (G average 20.8 46.5 30.5 244 neers; R6, significant regulation (see report regulation neers; R6, significant area 5,790 Total miles) (square drainage name Station Rowena Burksville Claymour near Tributary Hopkinsville Hopkinsville Cerulean near Cumberland River near near River Cumberland near Creek Bear Whippoorwill Creek near LittleSouth Fork River at Little River South Fork Cadiz near Little River Muddy Little Fork River Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03414000 03414102 03435140 03437490 03437500 03438000 03438070 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 57 82.0 371 147 1,670 1,470 1,600 2,590 1,340 1,980 500 55,300 23,500 47,400 40,200 30,000 36,900 59,500 41,300 56,800 18,500 19,900 18,900 years 325,000 70.6 NC 314 120 1,440 1,250 1,370 2,300 1,130 1,760 200 42,400 19,900 37,500 34,200 25,400 31,600 49,400 35,000 47,500 16,400 16,900 16,500 years 62.5 273 102 984 1,270 1,080 1,210 2,090 1,600 100 34,200 17,200 30,900 30,000 21,900 27,800 42,400 30,200 41,000 14,900 14,600 14,800 years 260,000 54.8 84.5 235 932 847

1,100 1,050 1,870 1,450 50 27,200 14,800 25,200 26,000 19,000 24,300 35,900 26,200 34,900 13,300 12,600 13,200 years 230,000

47.4 68.7 NC 197 939 784 900 712 1,650 1,310 25 21,300 12,500 20,100 22,300 16,000 21,000 29,700 22,000 29,100 11,700 10,600 11,500 years 38.2 50.4 150 731 599 705 544 9,670 1,340 1,100 9,480 8,210 9,320 10 14,700 14,200 17,600 12,400 16,700 22,200 17,100 21,900 years 165,000 Continued 31.3 38.4 NC 115 575 464 558 421 936 5 7,590 9,730 1,100 7,720 6,440 7,610 10,600 10,400 14,100 13,600 16,800 13,500 16,700 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 21.7 69.8 24.7 NC 358 286 350 729 259 644 2 5,830 4,820 5,780 9,380 6,200 9,100 9,850 8,600 9,810 5,100 4,090 5,030 years t computed; R5, ins R R R R R R R G G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------for definition); NC,for no definition); Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U NC lation Regu- ) a used (water record years 1981-86 1989-94 Period of Period 1975-85 COE 1952-83 1983-2000 1975-87 1939-83 1975-79, 1969-83, computed from analysis of the observed an computed from analysis of the observed .10 .96 .82 a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 89.7 68.7 134 227 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) 17,600 (square drainage name Station Tributary near Tributary Confederate Grand Rivers Benton Brewers near North Dryden Fork Creek near River Cumberland Murray at River Clarks Almo at River Clarks Creek near Benton York near Benton Clarks River Chestnut Creek near Clarks Fork River West Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03438120 03438220 03610000 03610200 03610470 03610500 03610503 03610545 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

58 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals 863 435 638 718 826 379 616 457 7,750 3,400 2,100 3,090 1,030 9,040 9,780 500 11,300 10,400 27,200 39,600 28,800 13,600 years 644 369 512 619 869 701 336 522 393 9,340 6,570 8,730 2,840 1,780 2,610 8,300 8,780 200 23,100 33,600 24,300 11,500 years 509 320 427 549 754 612 303 454 346 8,010 5,680 7,550 2,460 1,540 2,280 7,730 9,980 8,050 100 20,200 29,000 21,100 years 396 275 349 483 649 528 270 390 301

6,770 4,910 6,450 2,100 1,330 1,970 7,140 8,620 7,320 50 17,600 25,100 18,200 years

301 232 278 419 546 449 237 328 258 5,630 4,130 5,410 1,770 1,120 1,670 6,530 7,250 6,610 25 15,100 21,100 15,500 years 200 176 194 856 338 416 352 192 249 203 4,240 3,180 4,120 1,360 1,300 5,670 5,600 5,660 10 12,000 16,400 12,300 years Continued 138 135 138 665 277 322 284 157 193 162 5 3,260 2,480 3,190 1,060 1,030 9,810 9,930 4,950 4,390 4,910 12,900 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 71.4 82.2 72.8 676 411 661 193 197 193 104 117 105 2 1,980 1,560 1,960 6,820 8,240 6,870 3,780 2,770 3,730 years t computed; R5, ins R R R R R R R G G G G G G G W W W W W W W nual peak flows at the gaging stations; nual peak flows ------, upper row) and the regression estimate estimate the regression and row) , upper for definition); NC,for no definition); location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U U U U U U U lation Regu- ) a used (water record years 1981-86 1968-87 Period of Period 1975-79, 1972-2000 1953-65, 1937-77 1975-85, 1987 1952-83 1975-87 computed from analysis of the observed an computed from analysis of the observed .13 .53 .23 1.72 a weighted average a ofweighted the gage estimate (G average 14.6 36.8 212 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square drainage name Station near Reidland Paducah Mayfield Lovelaceville Kirbyton Pryorsburg at Water Chien Tributary Valley Clarks River Tributary Tributary Clarks River near Creek Massac near Creek Perry at Creek Mayfield near LickCreek Tributary Obion Creek at BayouSouth Fork De Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station number 03610820 03611260 07022500 07023000 07023040 07023500 07023935 Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

TABLE 1 59 NC 500 10,900 19,900 11,700 years NC 9,700 200 16,900 10,300 years tage of the total drainage 8,790 9,210 100 14,600 years 1,798,000

7,880 8,170 50 12,600 years tified. Information on historic peaks outside the period ons in proportion to the percen 1,719,000

6,950 7,150 25 10,600 years 1,587,000 5,700 8,210 5,800 10 years 1,415,000 Continued 5 4,690 6,440 4,750 years Peak flow (cubic feet per second) for given recurrence per interval (cubic second) feet for flow Peak 1,260,000 ignificant regulation (see reportregulation ignificant for details)] (R, middle row); COE, gaging-station flows COE,(R, gaging-stationmiddle flows row); R, estimate computed from regression 2 in which it ends. Periods of systematic record are iden 3,180 4,090 3,200 years 996,000 tained by weightingtained by the estimates from the regionalequati t computed; R5, ins R G G W nual peak flows at the gaging stations; nual peak flows --- year is designated by the calendar year for definition); NC,for no definition); Various location Code or type of Source of Source regulation diversion and and start date al Survey streamflow-gaging stations in Kentucky— Survey al U NC lation Regu- ogic regions. The regressionestimatesstations these for are ob ) a used (water record years 1985-2000 Period of Period 1940-82, COE October 1 through September 30. The water computed from analysis of the observed an computed from analysis of the observed a weighted average estimateof the gage estimate anda the regression (G, weighted upperaverage row) 68.7 neers; R6, significant regulation (see report regulation neers; R6, significant area Total miles) (square 922,500 drainage name Station Clinton Hickman Bayou De Chien near at Mississippi River Estimated peak flows for 222 selected U.S. Geologic 222 selected U.S. for Estimated peak flows Station record contains historic peak(s). Water year refers to the 12-month period from Stations havingdrainage area extending intomore two hydrol or a b c Station number of systematic record was used at selected stations (see note b). 07024000 07024070 area inarea each hydrologic region. Table 1. G, estimate known; none ---, unregulated; [U, equation (table 3); W, estimate computed as equation (table 3); W, computed by the U.S.computed by Army Corps of Engi

60 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03202400 Guyandotte River near Baileysville, West Virginia 2 306 35.2 03203000 Guyandotte River at Man, West Virginia 2 758 12.9 03203600 Guyandotte River at Logan, West Virginia 2 836 10.4 03204500 Mud River near Milton, West Virginia 2 256 4.10 03206600 East Fork Twelvepole Creek near Dunlow, West Virginia 2 38.5 21.7 03207020 Twelvepole Creek Below Wayne, West Virginia 2 300 5.70 03207400 Prater Creek at Vansant, Virginia 2 19.8 119 03207500 Levisa Fork near Grundy, Virginia 2 235 36.6 03207965 Grapevine Creek near Phyllis, Kentucky 2 6.20 129 03208000 Levisa Fork Below Fishtrap Dam, Kentucky 2 392 16.9 03208500 Russell Fork at Haysi, Virginia 2 286 19.3 03208950 Cranes Nest River near Clintwood, Virginia 2 66.5 42.5 03209500 Levisa Fork at Pikeville, Kentucky 2 1,232 11.5 03209575 Bill D Branch near Kite, Kentucky 2 3.17 181 03210000 Johns Creek near Meta, Kentucky 2 56.3 24.3 03211500 Johns Creek near Van Lear, Kentucky 2 206 6.40 03212000 Paint Creek at Staffordsville, Kentucky 2 103 8.25 03213700 Tug Fork at Williamson, West Virginia 2 936 10.2 03215500 Blaine Creek at Yatesville, Kentucky 2 217 3.50 03216500 Little Sandy River at Grayson, Kentucky 2 400 3.70 03216540 East Fork Little Sandy River near Fallsburg, Kentucky 2 12.2 18.3 03216563 Mile Branch near Rush, Kentucky 2 .94 85.0 03216564 Mile Branch at Coalton, Kentucky 2 1.61 74.0 03216800 Tygarts Creek at Olive Hill, Kentucky 2 59.6 17.8 03216901 Trough Camp Creek Tributary near Olive Hill, Kentucky 2 1.11 104 03217000 Tygarts Creek near Greenup, Kentucky 2 242 4.60 03237280 Upper Twin Creek at Mcgaw, Ohio 2 12.2 67.0 03237500 Ohio Brush Creek near West Union, Ohio 2 387 8.30 03237900 Cabin Creek near Tollesboro, Kentucky 1 22.4 32.4 03238030 Lawrence Creek near Maysville, Kentucky 1 1.90 53.1 03238500 White Oak Creek near Georgetown, Ohio 1 218 7.92 03246500 East Fork Little Miami River at Williamsburg, Ohio 1 237 5.27

TABLE 2 61 Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03247100 Paterson Run near Owensville, Ohio 1 3.34 31.9 03247500 East Fork Little Miami River at Perintown, Ohio 1 476 6.93 03248500 Licking River near Salyersville, Kentucky 2 140 4.70 03249500 Licking River at Farmers, Kentucky 2 827 3.29 03250000 Triplett Creek at Morehead, Kentucky 2 47.5 29.4 03250080 Jacks Branch near Morehead, Kentucky 2 .19 164 03250100 North Fork Triplett Creek near Morehead, Kentucky 2 84.7 15.8 03250150 Indian Creek near Owingsville, Kentucky 2 2.43 45.5 03250620 Johnson Creek Tributary near Fairview, Kentucky 2 .33 130 03251000 North Fork Licking River near Lewisburg, Kentucky 2 119 2.60 03251008 Wells Creek Tributary near Washington, Kentucky 2 .96 123 03251015 Lee Creek Tributary at Mays Lick, Kentucky 2 .45 81.2 03252000 Stoner Creek at Paris, Kentucky 2 239 2.40 03252500 South Fork Licking River at Cynthiana, Kentucky 2 621 2.41 03254400 North Fork Grassy Creek near Piner, Kentucky 1 13.6 28.2 03277185 Craigs Creek Tributary near Warsaw, Kentucky 1 .68 206 03277300 North Fork Kentucky River at Whitesburg, Kentucky 2 66.4 19.5 03277400 Leatherwood Creek at Daisy, Kentucky 3 40.9 51.2 03277450 Carr Fork near Sassafras, Kentucky 2 60.6 17.1 03277500 North Fork Kentucky River at Hazard, Kentucky 3 466 7.40 03277630 Brier Fork near Hazard, Kentucky 3 1.32 188 03278000 Bear Branch near Noble, Kentucky 2 2.21 125 03278500 Troublesome Creek at Noble, Kentucky 2 177 8.80 03280000 North Fork Kentucky River at Jackson, Kentucky 2 1,101 4.60 03280600 Middle Fork Kentucky River near Hyden, Kentucky 3 202 24.5 03280700 Cutshin Creek at Wooton, Kentucky 3 61.3 44.6 03280728 Bull Creek near Hyden, Kentucky 3 1.84 203 03280935 Stamper Fork at Canoe, Kentucky 3 1.57 129 03281000 Middle Fork Kentucky River at Tallega, Kentucky 3 537 4.70 03281040 Red Bird River near Big Creek, Kentucky 3 155 16.4 03281100 Goose Creek at Manchester, Kentucky 3 163 13.7 03281200 South Fork Kentucky River at Oneida, Kentucky 3 486 7.60 03281500 South Fork Kentucky River at Booneville, Kentucky 3 722 5.10

62 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03282198 Clear Creek Tributary near West Irvine, Kentucky 3 0.59 149 03282500 Red River near Hazel Green, Kentucky 2 65.8 9.90 03283000 Stillwater Creek at Stillwater, Kentucky 2 24.0 23.6 03283305 Middle Fork Red River at Zachariah, Kentucky 2 .58 160 03283500 Red River at Clay City, Kentucky 2 362 6.00 03283610 Lulbegrud Creek Tributary near Westbend, Kentucky 2 .33 105 03284300 Silver Creek near Kingston, Kentucky 3 28.6 22.2 03284310 Silver Creek near Berea, Kentucky 3 53.4 11.0 03284340 Old Town Branch Tributary near Richmond, Kentucky 3 1.83 61.9 03285000 Dix River near Danville, Kentucky 3 318 4.10 03285500 Dix River near Burgin, Kentucky 3 395 5.34 03287128 Tanners Creek at Mortonsville, Kentucky 2 1.26 58.0 03287534 South Benson Creek near Frankfort, Kentucky 2 4.47 12.1 03288000 North Elkhorn Creek near Georgetown, Kentucky 2 119 3.80 03288500 Cave Creek near Fort Spring, Kentucky 2 2.53 38.5 03289000 South Elkhorn Creek at Fort Spring, Kentucky 2 24.0 16.5 03289300 South Elkhorn Creek near Midway, Kentucky 2 95.0 5.17 03289500 Elkhorn Creek near Frankfort, Kentucky 2 473 3.60 03290000 Flat Creek near Frankfort, Kentucky 1 5.63 39.8 03290580 Town Creek at New Castle, Kentucky 1 5.62 37.2 03291000 Eagle Creek at Sadieville, Kentucky 1 42.9 9.00 03291050 South Rays Fork near Corinth, Kentucky 1 .58 73.9 03291500 Eagle Creek at Glencoe, Kentucky 1 437 3.49 03292200 Jeff Branch near Sligo, Kentucky 1 .87 139 03292460 Harrods Creek near Lagrange, Kentucky 1 24.1 11.7 03292472 South Fork Harrods Creek near Crestwood, Kentucky 1 .97 109 03294000 Silver Creek near Sellersburg, Indiana 1 189 5.50 03295000 Salt River near Harrodsburg, Kentucky 2 41.4 8.50 03295400 Salt River at Glensboro, Kentucky 2 172 3.83 03295500 Salt River near Van Buren, Kentucky 2 196 3.70 03295845 Bradshaw Creek near Shelbyville, Kentucky 1 1.36 75.1 03295890 Brashears Creek at Taylorsville, Kentucky 1 259 6.01 03296500 Plum Creek near Wilsonville, Kentucky 1 19.1 14.8

TABLE 2 63 Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03297000 Little Plum Creek near Waterford, Kentucky 1 5.15 52.1 03297500 Plum Creek at Waterford, Kentucky 1 31.8 15.0 03297845 Floyds Fork at Crestwood, Kentucky 1 46.7 8.85 03298000 Floyds Fork at Fisherville, Kentucky 1 138 5.50 03298500 Salt River at Shepherdsville, Kentucky 1 1,197 4.16 03298535 Elm Lick near Clermont, Kentucky 1 .68 130 03299000 Rolling Fork near Lebanon, Kentucky 5 239 9.05 03300000 Beech Fork near Springfield, Kentucky 2 85.9 5.80 03300065 North Prong near Willisburg, Kentucky 2 1.71 75.6 03300400 Beech Fork at Maud, Kentucky 2 436 3.76 03300990 Town Creek Tributary at Bardstown, Kentucky 2 .32 106 03301000 Beech Fork at Bardstown, Kentucky 2 669 3.70 03301500 Rolling Fork near Boston, Kentucky 5 1,299 3.50 03302085 Otter Creek Tributary near Vine Grove, Kentucky 5 .90 60.5 03302220 Buck Creek near New Middletown, Indiana 5 65.2 18.6 03302300 Little Indian Creek near Galena, Indiana 5 16.1 19.0 03302350 Georgetown Creek Tributary near Georgetown, Indiana 5 .56 140 03303000 Blue River near White Cloud, Indiana 6 476 3.80 03303300 Middle Fork Anderson River at Bristow, Indiana 6 39.8 15.4 03303400 Crooked Creek near Santa Claus, Indiana 6 7.86 23.7 03303440 Crooked Creek Tributary near Fulda, Indiana 6 .26 104 03303900 Little Red Creek Tributary near Heilman, Indiana 6 .25 82.0 03304500 Mcgills Creek near Mckinney, Kentucky 5 2.14 150 03305000 Green River near Mckinney, Kentucky 5 22.4 32.1 03305500 Green River near Mount Salem, Kentucky 5 36.3 28.4 03305559 Carpenter Creek Tributary near Hustonville, Kentucky 5 .88 105 03305835 Gumlick Creek Tributary near Clementsville, Kentucky 5 .71 154 03306500 Green River at Greensburg, Kentucky 5 736 3.50 03306640 White Oak Creek Tributary near Montpelier, Kentucky 5 .50 125 03307000 Russell Creek near Columbia, Kentucky 5 188 9.38 03307100 Russell Creek near Gresham, Kentucky 5 265 5.10 03307500 South Fork Little Barren River at Edmonton, Kentucky 5 18.3 16.4 03309500 Mcdougal Creek near Hodgenville, Kentucky 5 5.34 24.0

64 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03310000 North Fork Nolin River at Hodgenville, Kentucky 5 36.4 20.0 03310300 Nolin River at White Mills, Kentucky 6 357 4.20 03310385 Bacon Creek Tributary near Upton, Kentucky 6 .56 117 03310400 Bacon Creek near Priceville, Kentucky 6 85.4 7.99 03310500 Nolin River at Wax, Kentucky 6 600 2.60 03310880 Brier Creek Tributary near Ollie, Kentucky 6 .31 310 03311000 Nolin River at Kyrock, Kentucky 6 703 3.20 03311600 Beaverdam Creek at Rhoda, Kentucky 6 10.9 23.8 03312000 Bear Branch near Leitchfield, Kentucky 6 30.8 26.8 03312500 Barren River near Pageville, Kentucky 5 531 4.30 03312795 Little Beaver Creek near Glasgow, Kentucky 5 .89 186 03313000 Barren River near Finney, Kentucky 5 942 3.70 03313020 Solomon Creek Tributary near Scottsville, Kentucky 5 .24 122 03313500 West Bays Fork at Scottsville, Kentucky 5 7.47 47.2 03313700 West Fork Drakes Creek near Franklin, Kentucky 5 110 9.06 03313800 Lick Creek near Franklin, Kentucky 5 21.6 19.5 03314000 Drakes Creek near Alvaton, Kentucky 5 478 6.60 03314750 Barren River Tributary near Bowling Green, Kentucky 5 .50 227 03316000 Mud River near Lewisburg, Kentucky 6 90.5 7.10 03317000 Rough River near Madrid, Kentucky 6 225 4.90 03317500 North Fork Rough River near Westview, Kentucky 6 42.0 15.3 03318000 Rough River near Falls of Rough, Kentucky 6 454 3.40 03318200 Rock Lick Creek near Glen Dean, Kentucky 6 20.1 31.3 03318500 Rough River at Falls of Rough, Kentucky 6 504 2.43 03318505 Pleasant Run Tributary near Falls of Rough River, Kentucky 6 .22 246 03318800 Caney Creek near Horse Branch, Kentucky 6 124 3.00 03319000 Rough River near Dundee, Kentucky 6 757 2.90 03319520 West Fork Adams Tributary near Fordsville, Kentucky 6 .26 122 03320500 Pond River near Apex, Kentucky 7 194 4.63 03321465 Rhodes Creek Tributary near Owensboro, Kentucky 6 .29 62.1 03322360 Beaverdam Creek near Corydon, Kentucky 6 14.3 13.5 03366200 Herberts Creek near Madison, Indiana 1 9.31 18.3 03366400 Lewis Creek Tributary near Kent, Indiana 1 .16 71.0

TABLE 2 65 Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03378550 Big Creek near Wadesville, Indiana 6 104 3.80 03378590 Olive Creek Tributary near Solitude, Indiana 6 .32 79.5 03381600 Little Wabash River Tributary near New Haven, Illinois 7 .16 89.8 03382520 Black Branch Tributary near Junction, Illinois 7 1.10 28.2 03382975 Ward Creek at Lewiston, Kentucky 7 .91 10.7 03383000 Tradewater River at Olney, Kentucky 7 255 2.00 03384000 Rose Creek at Nebo, Kentucky 7 2.10 28.8 03385000 Hayes Creek at Glendale, Illinois 7 19.1 21.4 03385500 Lake Glendale Inlet near Dixon Springs, Illinois 7 1.05 145 03400500 Poor Fork at Cumberland, Kentucky 2 82.3 28.1 03400700 Clover Fork at Evarts, Kentucky 3 82.4 38.8 03400800 Martins Fork near Smith, Kentucky 3 55.8 33.0 03401000 Cumberland River near Harlan, Kentucky 3 374 13.0 03401500 Yellow Creek Bypass at Middlesboro, Kentucky 4 35.3 127 03402000 Yellow Creek near Middlesboro, Kentucky 4 60.6 74.4 03402020 Shillalah Creek near Page, Kentucky 4 2.96 343 03402900 Cumberland River Pine Street Bridge at Pineville, Kentucky 4 770 8.38 03403500 Cumberland River at Barbourville, Kentucky 4 960 7.40 03403910 Clear Fork at Saxton, Kentucky 4 331 15.4 03404820 Laurel River at Municipal Dam near. Corbin, Kentucky 4 140 3.70 03404867 Gozey Hollow near Corbin, Kentucky 4 .31 98.3 03404900 Lynn Camp Creek at Corbin Kentucky 4 53.8 10.3 03405000 Laurel River at Corbin, Kentucky 4 201 5.80 03405854 Big Hurricane Branch at Conway, Kentucky 3 1.91 103 03406000 Wood Creek near London, Kentucky 4 3.89 49.2 03406500 Rockcastle River at Billows, Kentucky 4 604 3.60 03407100 Cane Branch near Parkers Lake, Kentucky 4 .67 206 03407200 West Fork Cane Branch near Parkers Lake, Kentucky 4 .26 187 03407300 Helton Branch at Greenwood, Kentucky 4 .85 224 03407500 Buck Creek near Shopville, Kentucky 4 165 10.1 03408500 New River at New River, Tennessee 5 382 7.06 03409000 White Oak Creek at Sunbright, Tennessee 5 13.5 54.5 03410500 South Fork Cumberland River near Stearns, Kentucky 5 954 9.00

66 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03411000 South Fork Cumberland River at Nevelsville, Kentucky 5 1,271 8.00 03412500 Pitman Creek at Somerset, Kentucky 4 31.3 21.3 03413200 Beaver Creek near Monticello, Kentucky 5 43.4 20.2 03413202 Elk Spring Creek near Spann, Kentucky 5 .57 333 03413425 Williams Creek Tributary near Cartwright, Kentucky 5 .76 190 03414102 Bear Creek near Burksville, Kentucky 5 3.52 49.4 03414500 East Fork Obey River near Jamestown, Tennessee 5 202 37.0 03415000 West Fork Obey River near Alpine, Tennessee 5 115 33.6 03415700 Big Eagle Creek near Livingston, Tennessee 5 7.98 68.5 03416000 Wolf River near Byrdstown, Tennessee 5 106 12.3 03418000 Roaring River near Hilham, Tennessee 5 78.7 14.6 03435140 Whippoorwill Creek near Claymour, Kentucky 7 20.8 13.8 03435500 Red River near Adams, Tennessee 7 706 4.44 03436000 Sulphur Fork Red River near Adams, Tennessee 7 186 6.56 03436700 Yellow Creek near Shiloh, Tennessee 7 124 12.3 03437490 South Fork Little River Tributary near Hopkinsville, 7 2.62 27.1 Kentucky 03437500 South Fork Little River at Hopkinsville, Kentucky 7 46.5 7.10 03438000 Little River near Cadiz, Kentucky 7 244 3.60 03438070 Muddy Fork Little River near Cerulean, Kentucky 7 30.5 20.0 03438120 North Fork Draydon Creek Tributary near Confederate, 7 .10 157 Kentucky 03529500 Powell River at Big Stone Gap, Virginia 2 112 41.2 03530000 South Fork Powell River at Big Stone Gap, Virginia 2 40.0 156 03530500 North Fork Powell River at Pennington Gap, Virginia 3 70.0 59.4 03531500 Powell River near Jonesville, Virginia 3 319 16.8 03610000 Clarks River at Murray, Kentucky 7 89.7 8.59 03610200 Clarks River at Almo, Kentucky 7 134 7.45 03610470 York Creek near Benton, Kentucky 7 .96 57.7 03610500 Clarks River near Benton, Kentucky 7 227 6.20 03610503 Chestnut Creek near Benton, Kentucky 7 .82 52.9 03610545 West Fork Clarks River near Brewers, Kentucky 7 68.7 11.6 03610820 Clarks River Tributary near Reidland, Kentucky 7 .13 75.2 03611260 Massac Creek near Paducah, Kentucky 7 14.6 17.8

TABLE 2 67 Table 2. Total drainage areas and main-channel slopes for 238 streamflow-gaging stations used to develop the peak-flow regression equations for Kentucky—Continued

U.S. Geological Survey Total drainage Main-channel gaging-station U.S. Geological Survey area slope number gaging-station name Region (square miles) (feet per mile) 03612200 Q Ditch Tributary near Choat, Illinois 7 0.27 141 03614000 Hess Bayou Tributary near Mound City, Illinois 7 1.95 23.9 07022500 Perry Creek near Mayfield, Kentucky 7 1.72 28.1 07023000 Mayfield Creek at Lovelaceville, Kentucky 7 212 5.30 07023040 Lick Creek Tributary near Kirbyton, Kentucky 7 .53 58.6 07023500 Obion Creek at Pryorsburg, Kentucky 7 36.8 10.9 07023935 South Fork Bayou de Chien Tributary at Water Valley, 7 .23 59.3 Kentucky 07024000 Bayou de Chien near Clinton, Kentucky 7 68.7 8.00 07026500 Reelfoot Creek near Samburg, Tennessee 7 110 3.72

68 Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals Hodgkins and Martin—ESTIMATING THE MAGNITUDE OF PEAK FLOWS FOR STREAMS IN KENTUCKY FOR SELECTED RECURRENCE INTERVALS—U.S. Geological Survey Water-Resources Investigations Report 03-4180

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