Prepared in cooperation with the West Virginia Department of Transportation, Division of Highways

Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Scientific Investigations Report 2010–5033

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

Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

By Jeffrey B. Wiley and John T. Atkins, Jr.

Prepared in cooperation with the West Virginia Department of Transportation, Division of Highways

Scientific Investigations Report 2010–5033

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2010

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Suggested citation: Wiley, J.B., and Atkins, J.T., Jr., 2010, Estimation of flood-frequency discharges for rural, unregulated streams in West Virginia: U.S. Geological Survey Scientific Investigations Report 2010–5033, 78 p.

ISBN 978-1-4113-2769-6 iii

Contents

Abstract...... 1 Introduction...... 1 Regional Historical Floods...... 1 Description of Study Area...... 4 Previous Studies...... 4 This Study...... 6 Development of Flood-Frequency Discharge Equations...... 7 Peak Discharges...... 7 Basin Characteristics...... 7 Correlation of Basin Characteristics...... 9 West Virginia Skew Coefficients...... 9 Flood-Frequency Discharges...... 10 Regional Regression of Flood-Frequency Discharges...... 11 Accuracy of Flood-Frequency Discharge Equations...... 14 Procedures For Estimating Flood-Frequency Discharges...... 15 At a Streamgage Station...... 15 At an Ungaged Location...... 15 Upstream From a Streamgage Station...... 18 Downstream From a Streamgage Station...... 18 Between Streamgage Stations...... 18 Hydrologic Conditions Change Linearly between Streamgage Stations...... 19 Hydrologic Conditions Change Linearly to the Regional Hydrologic Conditions between Streamgage Stations...... 19 Not on the Same Stream as a Streamgage Station...... 20 Example Applications...... 20 Limitations of Procedures for Estimating Flood-Frequency Discharges...... 21 Summary...... 21 References Cited...... 22 Appendix 1. Matrices Used to Compute Individual Standard Errors of Prediction...... 78 iv

Figures

1–4. Map showing— 1. Selected streams used for identifying regional extent of historic floods in West Virginia...... 2 2. Appalachian Plateaus, Valley and Ridge, and Blue Ridge Physiographic Provinces, and Climatic Divide in West Virginia...... 5 3. The 290 U.S. Geological Survey streamgage stations in West Virginia and adjacent states considered in the estimation of flood-frequency discharges in West Virginia...... 8 4. The Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia for which equations for estimation of flood frequency discharges were developed in this study...... 12 5–7. Graph showing— 5. Range of differences of the individual standard errors of the prediction from the average prediction errors for the indicated drainage areas...... 14 6. LOESS curves of the absolute difference between the 100-year flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method and (2) regional equations, in relation to the ratios of the drainage areas...... 17 7. LOESS curves of the absolute difference between the 1.1- through 500-year flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method and (2) regional equations, in relation to the ratios of the drainage areas...... 17

Tables

1. Identification numbers, station numbers, streamgage-station names, and skew coefficients and statistics for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states...... 25 2. Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states...... 36 3. Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states...... 46 4. Equations used to estimate selected flood-frequency discharges for streams in the Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia...... 13 5. Description of the 88 pairs of U.S. Geological Survey streamgage stations in West Virginia and adjacent states that were evaluated to quantify “near” for application of the drainage-area ratio method in this study...... 73 6. Values of the exponent, and upstream and downstream limits of the drainage- area ratios used to quantify the definition of “near” for estimating selected flood-frequency discharges for ungaged locations in West Virginia...... 16 v

Conversion Factors, Datums, Acronyms, and Abbreviations

Multiply By To obtain Length inch (in.) 2.54 centimeter (cm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) Area square mile (mi2) 2.590 square kilometer (km2) Flow rate cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) cubic foot per second per square 0.01093 cubic meter per second per square mile [(ft3/s)/mi2] kilometer [(m3/s)/km2]

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83). Altitude, as used in this report, refers to distance above the vertical datum.

Acronyms

GLSNet USGS software for computing generalized least-square regression LOESS Locally weighted regression PeakFQ USGS software for computing flood-frequency discharges S-PLUS Commercially available software for computing statistics USGS U. S. Geological Survey SWSTAT USGS software for computing surface-water statistics

Abbreviations

AOP Annual-occurrence probability

AU Drainage area at the location of the unknown flood-frequency discharge

AK Drainage area at the location of the known flood-frequency discharge

AUS Drainage area at the upstream location

ADS Drainage area at the downstream location AOP Annual-occurrence probability DRNAREA Drainage area EX Exponent for drainage-area ratios vi

EY Equivalent years of record K Frequency factor MSE Mean-square error N Number of years of peak-discharge record Q Discharge

QDS Flood-frequency discharge at the downstream location

QK Known flood-frequency discharge

QKE Regional equation evaluated at the location of the known flood-frequency discharge

Qr Flood-frequency discharge determined from the appropriate regional equation

Qs Flood-frequency discharge determined from systematic and historical record

QU Unknown flood-frequency discharge

QUE Regional equation evaluated at the location of the unknown flood-frequency discharge

QUS Flood-frequency discharge at the upstream location

Qw Discharge weighted by number of years of peak-discharge record at the gaging station and equivalent years of record for the appropriate regional equation Q(n) Discharge for the n-year recurrence interval

RDS Downstream limit of the ratio of drainage areas

RU/K Ratio of the drainage area at the location of the unknown flood-frequency discharge to the drainage area at the location of the known flood-frequency discharge

RUS Upstream limit of the ratio of drainage areas S P Standard deviation of the log10-transformed annual peak discharges X Log10-transformed annual peak discharges X mean Mean of the log10-transformed annual peak discharges Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

By Jeffrey B. Wiley And John T. Atkins, Jr.

Abstract Introduction

Flood-frequency discharges were determined for 290 Many engineering projects are built within or adjacent to streamgage stations having a minimum of 9 years of record in flood-prone areas. Information on past flooding and estimates West Virginia and surrounding states through the 2006 or 2007 of the magnitude and frequency of potential future floods are water year. No trend was determined in the annual peaks used critical to the safe and economical design of hydraulic struc- to calculate the flood-frequency discharges. tures such as bridges, culverts, dams, flood dikes, and levees. Multiple and simple least-squares regression equations for the 100-year (1-percent annual-occurrence probability) flood discharge with independent variables that describe the Regional Historical Floods basin characteristics were developed for 290 streamgage Before 1930, neither floods nor streamflow in West stations in West Virginia and adjacent states. The regression Virginia were systematically documented. Since 1930, data on residuals for the models were evaluated and used to define regional flooding has been collected as part of the operation three regions of the State, designated as Eastern Panhandle, of a statewide streamgaging network supported by State and Central Mountains, and Western Plateaus. Exploratory data Federal funding. Local floods in small, ungaged watersheds analysis procedures identified 44 streamgage stations that remain only sparsely quantified. Major regional floods affect- were excluded from the development of regression equations ing parts of West Virginia occurred in 1844, 1877, 1878, 1888, representative of rural, unregulated streams in West Virginia. 1889, 1912, 1918, 1932, 1936, 1949, 1963, 1967, 1977, 1984, Regional equations for the 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 1985, and 1996. For floods prior to 1930, the regional extent 100-, 200-, and 500-year flood discharges were determined is not defined, but rivers other than those identified in West by generalized least-squares regression using data from the Virginia may have been affected. Locations of selected West remaining 246 streamgage stations. Drainage area was the Virginia streams are shown in figure 1. A list of flood dates only significant independent variable determined for all equa- with a brief description of the flood and the report that docu- tions in all regions. ments the flood follows. Procedures developed to estimate flood-frequency dis- charges on ungaged streams were based on (1) regional equa- tions and (2) drainage-area ratios between gaged and ungaged • July 1844: Flooding on the Cheat River was docu- locations on the same stream. The procedures are applicable mented by Speer and Gamble (1965, p. 148). This only to rural, unregulated streams within the boundaries of flood was about equal in magnitude to those in July West Virginia that have drainage areas within the limits of 1888 and May 1996. the stations used to develop the regional equations (from 0.21 • November 1877: Flooding on the South Branch to 1,461 square miles in the Eastern Panhandle, from 0.10 to Potomac River was documented by Tice (1968, p. 488, 1,619 square miles in the Central Mountains, and from 0.13 to 490). This flood was about equal in magnitude to those 1,516 square miles in the Western Plateaus). The accuracy of in March 1936 and September 1996. the equations is quantified by measuring the average predic- tion error (from 21.7 to 56.3 percent) and equivalent years of • September 1878: Flooding on the New River was record (from 2.0 to 70.9 years). documented by Speer and Gamble (1965, p. 284–288). 2 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

81°W 78°W

EXPLANATION State boundary Major stream

PENNSYLVANIA

40°N OHIO

la e River h a g MARYLAND n r o C Potomac e n h v o e

i a

M River t

R R io Ty h g i O a v r e t r

V

a North Branch

L l

l it e t l y e

R South Branch K i a v na e w iv r h a R er

er i v R lk K E a

y n

d aw r VIRGINIA r n h e a iv e a y R v S e i R i G aul R g ve i G r r River e B N i u e r y w b n a R e n e d i r 38°N o v G t e

t r T e u g R i F v e o r KENTUCKY r k R iv e r 0 20 40 60 MILES

0 20 40 60 KILOMETERS

Base from U.S. Geological Survey 1:100,000 digital line graphics. Universal Transverse Mercator projection, zone 17, NAD 83.

Figure 1. Selected streams used for identifying regional extent of historic floods in West Virginia. Introduction 3

• July 1888: Flooding on the Monongahela River was • April 1977: Flooding was documented on the Tug Fork documented by Speer and Gamble (1965, p. 121, 138, and Guyandotte Rivers. This flood was documented by 146–149). This flood was about equal in magnitude to Runner (1979) and Runner and Chin (1980) as having those in July 1844 on the Cheat River and May 1996 affected northeastern Tennessee, southwestern Vir- on the Cheat and upper Monongahela Rivers. ginia, eastern Kentucky, and southern West Virginia. This flood resulted from a frontal storm that moved • May–June 1889: Flooding on the North Branch southeastward through the region, became stationary, Potomac River was documented by Tice (1968, p. 480, then moved slowly northwestward drawing a warm 490, 494, 497). This flood was about equal in magni- moist maritime airmass from the Gulf of Mexico and tude to those in March 1936 and September 1996. combining to produce heavy rainfall. The highest peak • July 1912: Flooding on the Tygart Valley River was discharges ever recorded on the Tug Fork and Guyan- documented by Speer and Gamble (1965, p. 118, 121, dotte Rivers resulted from this storm. 127–128). • May 1984: Flooding was documented on the Tug • March 1918: Flooding on the Greenbrier and Gauley Fork and Guyandotte Rivers (U.S. Geological Survey, Rivers was documented by Speer and Gamble (1965, 1991). p. 298, 310). • November 1985: Flooding was documented on the • February 1932: Flooding on the Tygart Valley, Green- Monongahela, Potomac, upper Little Kanawha, upper brier, and Gauley Rivers was documented by Speer and Elk, and upper Greenbrier Rivers. This flood was Gamble (1965, p. 119, 121, 129, 295, 298, 304, 307, documented by Lescinsky (1987) and Carpenter (1990) 310). as having affected eastern West Virginia, western and northern Virginia, southwestern Pennsylvania, and • March 1936: Flooding was documented on the western Maryland. This flood resulted from a complex Potomac and Cheat Rivers. This flood, which was sequence of meteorological events. Hurricane Juan documented by Grover (1937) as having a regional moved from the Gulf of Mexico through southern extent including the upper Ohio, Potomac, and James Mississippi, ultimately causing precipitation as far Rivers (the James River in Virginia), was caused north as Michigan and generating less than 2 in. of by four separate cyclonic storms passing over the rainfall in West Virginia. This rainfall was caused by northeastern United States, resulting in multiple peak a second low pressure system that developed from discharges and superposition of later peak discharges the hurricane remnants. The low pressure developed on earlier peak discharges. This flood was about equal near the Tennessee-North Carolina border and trav- in magnitude to those in November 1877 on the South eled rapidly eastward to the Atlantic Ocean. A third Branch Potomac River, May through June 1889 on the low pressure system moved from the Gulf of Mexico North Branch Potomac River, and September 1996 into the Florida panhandle then moved slowly up the on the upper Potomac River (both North and South east coast of the United States, resulting in additional Branch). rainfall in West Virginia of up to 9 in. The highest peak discharges ever recorded on the upper Monongahela • June 1949: Flooding on the South Branch Potomac and Potomac Rivers resulted from this flood. River was documented by Tice (1968, p. 483–488). • January 1996: About 2 in. of rain fell on a 3 to 4 ft • March 1963: Flooding was documented on the Big snowpack, resulting in flooding in the upper Potomac, Sandy (including the Tug Fork in West Virginia), Guy- upper Cheat, upper Elk, and Greenbrier Rivers. andotte, Little Kanawha, Cheat, and Greenbrier Rivers. This flood, which was documented by Barnes (1964) • May 1996: A frontal storm caused flooding on the as having affected the western slopes of the Appala- Cheat and upper Monongahela Rivers that was about chian Mountains from Alabama to West Virginia, was equal in magnitude to flooding on the Cheat River in caused by three separate frontal storms in which rain July 1844 and July 1888. fell on a snowpack and was followed by two additional storms. • September 1996: Tropical storm Fran caused regional flooding on the upper Potomac River. This flood was • March 1967: Flooding was documented on the about equal in magnitude to that in November 1877 Kanawha and Monongahela Rivers. This flood was on the South Branch Potomac River, to that in May caused by 4 to 5 in. of rainfall over 3 days, augmented through June 1889 on the North Branch Potomac by runoff from melting snow (U.S. Geological Survey, River, and to that in March 1936 on the upper Potomac 1991). River. 4 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Description of Study Area Annual precipitation averages about 42 to 45 in. state- wide with about 60 percent received from March through West Virginia can be differentiated into three phys- August. July is the wettest month, and September through iographic provinces, the Appalachian Plateaus, Valley and November are the driest. Annual average precipitation in Ridge, and Blue Ridge (Fenneman, 1938) (fig. 2). The move- the State generally decreases northwestward from about 50 ment of air masses across the State allows identification of two to 60 in. along the Climatic Divide to about 40 in. along the climatic regions, separated by a line defined as the Climatic Ohio River, and increases from about 30 to 35 in. east of the Divide (Wiley, 2008) (fig. 1). Climatic Divide to about 40 in. in the extreme eastern tip of Generally, the part of the State west of the Climatic the State. Greater precipitation along and west of the Cli- Divide is in the Appalachian Plateaus Physiographic Province, matic Divide is a consequence of the higher elevations along where altitudes range from about 2,500 to 4,861 ft (NAVD88) the Divide and the general movement of weather systems at Spruce Knob along the Climatic Divide to about 550 to approaching from the west and southwest. Annual average 650 ft along the Ohio River. The part of West Virginia east of snowfall follows the general pattern of annual average pre- the Climatic Divide is in the Valley and Ridge Physiographic cipitation, decreasing northwestward from about 36 to 100 in. Province, except for the extreme eastern tip of the State, along the Climatic Divide to about 20 to 30 in. along the Ohio which is in the Blue Ridge Physiographic Province. Altitudes River. Annual average snowfall ranges from 24 to 36 in. east decrease eastward from the Climatic Divide to 274 ft at Harp- of the Climatic Divide (U.S. Geological Survey, 1991; Natural ers Ferry in the Eastern Panhandle (U.S. Geological Survey, Resources Conservation Service, 2006; National Oceanic and 1990, 2006; National Oceanic and Atmospheric Administra- Atmospheric Administration, 2006a, 2006b). tion, 2006a). Flooding across large drainage areas results from regional The Appalachian Plateaus Physiographic Province con- climatic events like frontal systems in winter and early spring, sists of consolidated, mostly noncarbonate sedimentary rocks rainfall on snowpack in early spring, and tropical cyclones that have a gentle slope from southeast to northwest near the (hurricanes and tropical storms) in late summer or early fall. Climatic Divide and are nearly flat-lying along the Ohio River. Generally, the most severe flooding across small drainage One exception is in the northeastern area of the province (west areas results from local intense thunderstorms in late spring of the Climatic Divide), where the rocks are gently folded and through summer (Doll and others, 1963). some carbonate rock crops out (Fenneman, 1938). The rocks in the Appalachian Plateaus Physiographic Province have been Previous Studies eroded to form steep hills and deeply incised valleys; drainage patterns are dendritic. Flood-frequency studies completed by Wiley and oth- The Valley and Ridge Physiographic Province in West ers (2000, 2002) used data for peak discharges from 267 Virginia consists of consolidated carbonate and noncarbon- rural, unregulated streamgage stations in West Virginia and ate sedimentary rocks that are folded sharply and extensively adjacent states. Simple and multiple least-squares regression faulted (Fenneman, 1938). Northeast-trending valleys and models were used to determine three regions in the State and ridges parallel the Climatic Divide; drainage patterns are to develop initial estimating equations with drainage area as trellis. the only significant independent variable. The final estimat- The Blue Ridge Physiographic Province within West Vir- ing equations were determined for the 1.1-, 1.2-, 1.3-, 1.4-, ginia consists predominantly of metamorphosed sandstone and 1.5-, 1.6-, 1.7-, 1.8-, 1.9-, 2-, 2.5-, 3-, 5-, 10-, 25-, 50-, 100-, shale (Fenneman, 1938). The province has high relief between 200-, and 500-year flood discharges using a generalized least- mountains and wide valleys that parallel the Climatic Divide. squares regression model (Stedinger and Tasker, 1985; Tasker The climate of West Virginia is primarily continental, and Stedinger, 1989). with mild summers and cold winters. Major weather systems New procedures for transferring the flood-frequency generally approach from the west and southwest, although discharges determined by Wiley and others (2000, 2002) polar continental air masses of cold, dry air that approach from to ungaged locations were presented by Wiley (2008, the north and northwest are not unusual. Air masses from the Appendix 1). These methods incorporated a comparison of Atlantic Ocean sometimes affect the area east of the Climatic discharge estimates determined using drainage-area ratios to Divide and less frequently affect the area west of the Climatic discharge estimates determined by application of the flood-fre- Divide. Generally, tropical continental masses of hot, dry air quency equations. This current study repeats that analysis and from the southwest affect the climate west of the Climatic supersedes the results presented in Wiley (2008, Appendix 1). Divide. Tropical maritime masses of warm, moist air from the Atkins and others (2009) determined generalized skew Gulf of Mexico affect the climate east of the Climatic Divide coefficients applicable to West Virginia (WV skew) for use more than west of the Climatic Divide. Evaporation from local in determining flood-frequency discharges at streamgage sta- and upwind land surfaces, lakes, and reservoirs also provides tions. The WV skew coefficients supersede the United States a source of moisture that affects the climate of the State (U.S. skew coefficients (U.S. skew) determined by the Interagency Geological Survey, 1991; National Oceanic and Atmospheric Advisory Committee on Water Data (1982). Analysis of Administration, 2006a). Introduction 5

81°W 78°W

EXPLANATION State boundary Geographic location

PENNSYLVANIA

40°N Wheeling

OHIO MARYLAND

Morgantown Harpers Ferry

BLUE RIDGE Elkins VALLEY AND RIDGE

Spruce Knob APPALACHIAN PLATEAUS VIRGINIA Huntington Charleston

38°N

Climatic Divide

KENTUCKY Beckley

0 20 40 60 MILES

0 20 40 60 KILOMETERS

Base from U.S. Geological Survey 1:100,000 digital line graphics. Physiographic provinces from Fenneman, 1938 Universal Transverse Mercator projection, zone 17, NAD 83.

Figure 2. Appalachian Plateaus, Valley and Ridge, and Blue Ridge Physiographic Provinces, and Climatic Divide in West Virginia. 6 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia discharges at 147 rural, unregulated streams in West Virginia Runner (1980a) presented equations for estimating the 2-, and adjacent states with streamgage stations followed guide- 5-, 10-, 25-, 50-, 100-, and 500-year flood discharges for rural, lines established by the Interagency Advisory Committee on unregulated streams in West Virginia. The estimating equa- Water Data (1982), except that streamgage stations having 50 tions were used only for drainage areas of 0.3 to 2,000 mi2. or more years of record were used instead of those with the The flood-frequency discharges in this study were made using recommended 25 years of record. The increased record length methods recommended by the Interagency Advisory Commit- of 50 years was determined to be statistically significant when tee on Water Data (1976), including adjustments to station- compared to the recommended 25 years. The generalized- frequency determinations by applying weighted regional and skew analysis considered contouring, averaging, and regres- station skews. The peak-discharge data from 170 streamgage sion of station skews; the best method was determined to be stations included data from Maryland and Virginia. Records that with the smallest mean-square error (MSE). The con- of peak discharges for 15 stations with small drainage areas touring of station skews was found to be the best method for (ranging from 1.8 to 12.2 mi2) were synthesized to greater than determining generalized skew for West Virginia, with a MSE 40 years of record (Runner, 1980b) by use of a rainfall-runoff of 0.2174 (Atkins and others, 2009). The MSE of 0.2174 is a model developed by Dawdy and others (1972). On the basis of significant improvement (28 percent reduction) over the MSE regression analyses using 12 basin characteristics as indepen- of 0.3025 for the U.S. skew, presented by the Interagency dent variables, regional flood-frequency discharge equations Advisory Committee on Water Data (1982). were developed separately for stations with more than 40 Flood-frequency studies completed by Frye and Run- years of record (including 15 small drainage-area streamgage ner (1969, 1970, 1971) and Runner (1980a and b) for West stations for which at least 40-year records were estimated) Virginia lacked data on peak discharges at streamgage stations and for all 170 stations. Three regions were delineated using having drainage areas less than 50 mi2. These studies found an analysis of the regression residuals, and drainage area was that the lack of data for small drainage areas could be over- determined to be the only statistically significant independent come by (1) not using the flood-frequency estimating methods variable. A composite of the equations for stations with greater for small drainage areas, (2) limiting the flood-frequency than 40 years of record and all 170 streamgage stations was discharge estimates to small recurrence intervals, (3) increas- determined. ing the record lengths for small drainages by using a rainfall- runoff model, or (4) using a composite analysis of long-term data (primarily stations with a minimum of 40 years of record) This Study with an analysis of long-term data combined with short-term To provide flood-related information and estimates data for small drainage areas. needed for the design of structures that will meet existing Frye and Runner (1969) estimated flood-frequency or proposed safety standards, yet not incur excessive costs discharges for rural, unregulated streams in West Virginia because of overdesign, the U.S. Geological Survey (USGS), in by using equations presented in U.S. Geological Survey cooperation with the West Virginia Department of Transpor- Water Supply Papers 1672 (Tice, 1968) and 1675 (Speer and tation, Division of Highways, revised previously developed Gamble, 1965). The nationwide flood-frequency discharge equations for estimating the magnitude and frequency of flood equations in these publications were developed for regional or discharges on rural, unregulated streams in West Virginia. The major river basins. The authors suggested that the equations results of this study supersede those published by Wiley and only be used for drainage areas greater than 50 mi2 in the Ohio others (2000, 2002). River Basin and greater than 30 mi2 in the Potomac River This report presents newly revised equations for estimat- Basin. ing the discharges of the 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, Frye and Runner (1970) presented a method for estimat- 200-, and 500-year recurrence interval floods (flood-frequency ing flood-frequency discharges using an analytical technique discharges) on rural, unregulated streams in West Virginia. similar to that proposed by Benson (1962). Peak-discharge A flood frequency is the reciprocal of the annual-occurrence data from streamgage stations on rural, unregulated streams probability (AOP), in percent, where the 100-year flood fre- in West Virginia with a minimum of 10 years of record were quency is equal to the 1-percent AOP. This report documents analyzed. The authors suggested that the analytical techniques the information used to estimate flood-frequency discharges be used only for drainage areas greater than 50 mi2 because and includes a list of regional floods in West Virginia; a adequate data were not available. discussion of climatic conditions affecting flooding; a presen- Frye and Runner (1971) presented a method for esti- tation of results from previous studies; and an inventory of mating the 2-, 5-, and 10-year flood discharges for rural, data sources containing peak discharges, basin characteristics, unregulated streams in the Ohio River Basin of West Virginia. and skew coefficients. The statistical methods are described, Data from a network of small streams with an average record including an accounting of error, which provides project length of 6 years were correlated with long-term data from designers with the associated uncertainty of flood discharge streamgage stations to estimate additional years of peak dis- estimates determined from applying flood-frequency discharge charges. The equations were applicable only to streams with equations to West Virginia streams. drainage areas between 1 and 50 mi2. Development of Flood-Frequency Discharge Equations 7

Development of Flood-Frequency data collected at Rowlesburg prior to the flood of November 5, 1985, include flow from Saltlick Creek for a drainage area Discharge Equations of 974 mi2. Peak-discharge data collected at Rowlesburg from Novem­ber 6, 1985, through September 30, 1996, exclude Annual peak discharge data, basin characteristics data, flow from Saltlick Creek for a drainage area of 939 mi2. and generalized West Virginia skew coefficients for 290 Streamgage station ratings (relations between stream stage and streamgages on rural, unregulated streams in West Virginia discharge) were difficult­ to define accurately after Novem- and adjacent states were analyzed to determine regional equa- ber 5, 1985, because they were affected by scour throughout tions to be used to estimate the magnitude of flood discharges the range of stage. Peak discharges were not adjusted for the for selected recurrence intervals. Basin characteristics, gener- 4-percent differ­ence in drainage area (typically necessary alized West Virginia skew coefficients, and flood-frequency when records are combined) because the rating definition­ dif- discharges for streamgage stations in adjacent states developed ficulties resulted in peak discharges with much greater than 4 for this study do not supersede values used by adjacent states. percent uncertainties. The equations for the 100-year recurrence interval (1-percent Peak discharges at the streamgage station Right Fork AOP) flood discharges were regionalized by plotting the areal Holly River at Guardian (ID 229 and streamgage 03195100) distribution of residuals determined by use of multiple and for the 1979 to 1982 water years, and peak discharges at simple least-squares regression models. Independent variables the station Left Fork Holly River near Replete (ID 230 and describe basin characteristics (such as drainage area, mean streamgage 03195250) for the 1979 to 1982 and 1987 to 2007 annual precipitation, and percent forest cover) for each station water years were provided­ by the U.S. Army Corps of Engi- location. Areal distributions of residual plots from regres- neers, Huntington District (Phillip E. Anderson, oral and writ- sions of the 100-year discharges were used to select stations ten commun., 1997 and 1998; Charlotte L. Hazelett, written in adjacent states to represent flood discharges expected in commun., 2007). West Virginia and to determine regional boundaries. The Peak discharges at the streamgage station Fernow Water- initial regional equations for the selected recurrence intervals shed Number Four near Hendricks (ID 113 and streamgage were derived with the use of multiple and simple least-square 03067100) for the 1952 to 2006 water years were provided by regression models and by determining the significance of inde- the U.S. Forest Service, Fernow Experimental Forest (Fred- pendent variables. The final regional equations were derived erica Wood, written commun., 2006 and 2007). No data were with the use of a generalized least-square regression model available for the 2007 water year at the time of this study. and independent variables from the initial regional equations. Peak discharge records for the streamgage station Elk River below Webster Springs (ID 227 and streamgage 03194700) were lengthened using records for the station Elk Peak Discharges River at Centralia (ID 228 and streamgage 03195000). Peak discharges at the station Twelvepole Creek below Wayne Annual peak discharges at 290 streamgage stations on (ID 266 and streamgage 03207020) were lengthened using rural, unregulated streams with a minimum of 9 years of records for the station Twelvepole Creek at Wayne (ID 265 record through the 2007 water year (the period beginning and streamgage 03207000). Peak discharges at the station October 1 of the previous year through September 30 of the Tug Fork at Kermit (ID 285 and streamgage 03214500) were indicated year) in West Virginia and through the 2006 (2007 lengthened using records for Tug Fork near Kermit (ID 284 for some stations in Maryland) water year for stations in and streamgage 03214000). Peak discharges at the station adjacent states were available for this study (fig. 3; table 1, New River at Fayette (ID 207 and streamgage 03186000) were at end of this report). Guidelines established by the Inter- lengthened using records for New River at Caperton (ID 206 agency Advisory Committee on Water Data (1982) required and streamgage 03185500); and peak discharges at the station that streamgage used in the analysis have a minimum of Cheat River near Pisgah (ID 123 and streamgage 03071000) 10 years of record, but stations with 9 years of record were were lengthened using records for Cheat River near Mor­ accepted because the addition of six stations with drainage gantown (ID 124 and streamgage 03071500). Records were areas less than 30 mi2 was considered more beneficial to this lengthened by estimating discharges using drainage-area study than adhering to the 10-year guideline. Annual-peak- ratios; the stations used to lengthen records were not consid- discharge data are maintained in the U.S. Geological Sur- ered in the regression analysis. vey’s “Peak File” database available on the World Wide Web from the USGS United States NWIS-W Data Retrieval site (http://waterdata.usgs.gov/). Basin Characteristics Peak discharges at the streamgage station Cheat River at Rowlesburg, identification number (ID) 121 in fig. 3 and Characteristics of the basins draining to the 290 streamgage station number (streamgage) 03070000 in table 1, streamgage stations on rural, unregulated streams in West are from a combination of records that include and exclude Virginia and adjacent states (Paybins, 2008) were available flow from the tributary stream Saltlick Creek. Peak-discharge for use as independent variables in the regression analysis. 8 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

81°W 78°W

EXPLANATION 134 State boundary 135 County boundary 133 Major stream 136 212 Streamgage station and identification number 137 132 141 PENNSYLVANIA 142 139, 140 138 143 145 40°N 144 146 147 149, 150, 151, 152 33 148 125 126 34 OHIO 158 29 35,36 124 11 30 MARYLAND 153 131 4, 7 159 108 122 130 12 24, 25 154 5 43 155 107 123 10 32 45 106 129 6 8 28 38 67 13 23 42 156 127 27 68 160 41 44 46 157 97 3 9 105 121 128 2 96 95 1 66 70 104 102 120 26 69 175 37 103 119 31 92 94 118 112 111 39, 40 174 164 65 73 176 172 101 93 117 110 22 72 171 91 88 86 71 173 100 89 113 21 64 170 165 99 85 17 90 115 16 63 167 87 84 252 163 98 116 62 251 168 166 109 18 59 169 162 83 60 161 61 250 177 232 230 15 19, 20 56 58 231 114 14 234 228 229 57 249 189 246 227 191 48 247 245 190 49 261 50 233 208 192 290 260 248 235 209 51 VIRGINIA 288 262 226 47 214 211 53 52 244 222 221 220 210 193 289 266 213 194 74 265 219 55 259 243 238 223 215 212 195 76 54 287 264 218 77 242 217 237 224 216 78 263 241 240 207 38°N 286 206 75 239 236 225 79 278 285 196 258 81 277 284 204 199 82 257 205 203 202 198 283 256 253 80 KENTUCKY 254 188 200 197 276 187 201 255 186 270 281 183 0 20 40 60 MILES 282 185 271 279 181 275 269 280 182 268 180 178 0 20 40 60 KILOMETERS 274 267 272 184 179 273 Base from U.S. Geological Survey 1:100,000 digital line graphics for state boundaries and streams and from the West Virginia Department of Environmental Protection 1:24,000 digital data for county boundaries. Universal Transverse Mercator projection, zone 17, NAD 83.

Figure 3. The 290 U.S. Geological Survey streamgage stations in West Virginia and adjacent states considered in the estimation of flood-frequency discharges in West Virginia. (Identification numbers are cross-references with streamgage-station names and numbers in table 1.) Development of Flood-Frequency Discharge Equations 9

The 36 basin characteristics evaluated for use in this study are were removed from consideration for regression because of the following: drainage area (DRNAREA), in mi2 (Mathes, singularity. 1977; Wilson, 1979; Mathes and others, 1982; Preston and The number of basin characteristics considered for Mathes, 1984; Stew­art and Mathes, 1995; Wiley, 1997; Wiley regression was reduced from 36 to 32 with the removal of the and others, 2007); latitude of the basin centroid, in decimal characteristics because of singularity. Additional characteris- degrees; longitude of the basin centroid, in decimal degrees; tics having singularity were removed if they became signifi- basin perimeter, in mi; basin slope, in ft/mi; basin relief, in cant in the regression analysis. ft; basin orientation, in degrees; channel length, in mi; valley length, in mi; channel slope, in ft/mi; stream length, in mi; mean basin elevation, in ft; 24-hour 2-year rainfall, in inches; West Virginia Skew Coefficients annual precipitation, in inches; January minimum temperature, Atkins and others (2009) determined generalized skew in degrees Fahrenheit; annual snow depth, in inches; forest coefficients applicable to West Virginia, the WV skew, to cover, in percent; grassland cover, in percent; barren land supersede the U.S. skew presented by the Interagency Advi- cover, in percent; urban land cover, in percent; wetland cover, sory Committee on Water Data (1982) (table 1, at the end of in percent; open-water cover, in percent; agriculture cover, this report). The generalized skew coefficient is a regional in percent; impervious cover, in percent; basin width, in mi; measure (of individual streamgage-station skews) of the fit- shape factor, dimensionless; elongation ratio, dimensionless; ness of annual-peak discharges to a Pearson Type III prob- rotundity of basin, dimensionless; compactness ratio, dimen- ability curve. The WV skew coefficients used in this current sionless; relative relief, in ft/mi; sinuosity ratio, dimensionless; study do not supersede values used for studies in adjacent stream density, in mi/mi2; channel maintenance, in mi2/mi; states but are applicable only to analyses in West Virginia. The slope proportion, dimensionless; ruggedness number, in ft/mi; difference between the WV- and U.S.-skew coefficients (WV and slope ratio, dimensionless. skew minus U.S. skew) ranged from -0.493, unitless, for Brier Creek at Fanrock (ID 255 and streamgage 03202480) to 0.491, Correlation of Basin Characteristics unitless, for Dry Fork at Hendricks (ID 110 and streamgage 03065000).

The basin characteristics were log10 transformed and A direct relation was not observed between the differ- evaluated for linear correlation by using a Pearson coefficient, ence between the WV- and U.S.-skew coefficients and the or Pearson’s r (Helsel and Hirsch, 2002). The numeral one was difference between the flood-frequency discharge calculations added to values of grassland cover, barren land cover, urban made using the WV- and U.S.-skew coefficients. (Skew coef- land cover, wetland cover, open-water cover, agriculture cover, ficients are weighted and adjusted using systematic years of and impervious cover to ensure that values were greater than record, systematic skews, low- and high-outlier criterion, and zero for log10 transformation. To decrease values for regres- historic years to determine flood frequencies.) The 100-year sion analysis, 77 was subtracted from longitude of the basin flood discharges determined in this study using the WV skew centroid, and 37 was subtracted from latitude of the basin were compared to the 100-year flood discharges calculated centroid. using the U.S. skew. The differences in the 100-year flood Basin characteristics were considered highly correlated discharges (discharge using WV skew minus discharge using where the absolute value of the Pearson coefficient was U.S. skew, divided by discharge using WV skew, times 100) greater than or equal to 0.80. The following characteristics ranged from -23.8 percent for Marsh Fork at Maben (ID 253 were highly correlated within each group: drainage area, basin and streamgage 03202245) to 13.3 percent for Job Run near perimeter, channel length, valley length, basin width, stream Wymer (ID 109 and streamgage 03063950). An area of large length, compactness ratio, and slope proportion; channel slope, negative differences was observed for the headwaters of the relative relief, and slope ratio; shape factor, elongation ratio, Coal, Guyandotte, and Tug Fork Rivers near the southern and rotundity of basin; basin relief and ruggedness number; border of the State, and an area of large positive differences valley length and basin relief; and urban land cover and imper- was observed for the headwaters of the South Branch Potomac vious cover. River near the eastern border of the State. The difference for The Pearson coefficient was equal to the numeral one Brier Creek at Fanrock (ID 255 and streamgage 03202480) is (singularity) for some combinations of basin characteristics -14.3 percent (-0.493, unitless, difference in skews discussed including stream density and channel maintenance; shape above), and the difference for Dry Fork at Hendricks (ID 110 factor, elongation ratio, and rotundity of basin; drainage area, and streamgage 03065000) is 3.8 percent (the 0.491, unitless, basin width, shape factor, and rotundity of basin; and stream difference in skews discussed above); these streamgage sta- length, compactness ratio, relative relief, stream density, and tions are located near the southern and north-central areas of ruggedness number. The characteristics elongation ratio, the State, respectively. rotundity of basin, channel maintenance, and basin width 10 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Flood-Frequency Discharges Geological Survey, 2001). The frequency factors are used to determine discharge by computing the antilog of discharge The flood-frequency discharges at the 290 streamgage from the following modified equation (Interagency Advisory stations on rural, unregulated streams were determined fol- Committee on Water Data, 1982, equation 1, p. 9): lowing the guidelines established by the Interagency Advisory

Committee on Water Data (1982). The U.S. Geological Survey Log10 Q = Xmean + KSP , (1) computer program PeakFQ (Flynn and others, 2006) was used to compute the flood-frequency discharges. In the analysis of where flood-frequency discharges for adjacent states, information from previous studies was used (Bisese, 1995; Dillow, 1996; Xmean = ∑ X / N, (2) Stuckey and Reed, 2000; Hodgkins and Martin, 2003; and Koltun, 2003) as a reference for determining flood-frequency where discharges calculated with the WV skew for use in this current X is the log10-transformed annual peak study. discharges (Bulletin-17B adjusted), in ft3/s; and The log10-transformed systematic (continuous record or broken record that can be statistically treated as a continu- N is the number of years of peak-discharge ous record) annual-peak series for each streamgage station record, unitless; was fitted to the Pearson Type III probability curve. Regional K is the frequency factor, unitless; and general skew (WV skew) was obtained from the map devel- SP is the standard deviation of the log10- oped by Atkins and others (2009). Regional general skew is transformed annual peak discharges weighted with station skew to determine a final adjustment to (Bulletin-17B adjusted), in ft3/s: the Pearson Type III probability curve. Additionally, high- 2 0.5 outlier, low-outlier, and historical peak assessments were [∑ (X – Xmean) / (N – 1)] . (3) made to adjust the annual-peak series. Mixed populations, such as floods from snowmelt and those from tropical storms Typically, the magnitude of a flood-frequency discharge or hurricanes, were not analyzed separately. Selected statis- increases with increasing drainage area. For floods with recur- tics from the flood-frequency discharge analyses for the 290 rence intervals greater than 10 years, however, the flood-fre- streamgage stations in West Virginia and adjacent states are quency discharges calculated for the streamgage station Tygart listed in table 2 (at the end of this report). Flood-frequency Valley River near Dailey (ID 83 and streamgage 03050000) discharges determined following the guidelines established by are greater than those for the station Tygart Valley River the Interagency Advisory Committee on Water Data (1982) for near Elkins (ID 84 and streamgage 03050500), although the 10 recurrence intervals for the 290 streamgage stations in West drainage area for Tygart Valley River near Dailey (185 mi2) is smaller than the drainage area for Tygart Valley River near Virginia and adjacent states are identified as sQ in table 3 (also at the end of this report); the 10 recurrence intervals are the Elkins (271 mi2) (tables 2 and 3, at the end of this report). This 1.1- (90-percent AOP), 1.5- (67-percent AOP), 2- (50-percent inconsistency may be due to the wide floodplain along the AOP), 5- (20-percent AOP), 10- (10-percent AOP), 25- (4-per- river between Daily and Elkins, which contrasts with the more cent AOP), 50- (2-percent AOP), 100- (1-percent AOP), 200- mountainous and narrower floodplains upstream from Daily (0.5-percent AOP), and 500-year (0.2-percent AOP). and, therefore, increases the stream storage and attenuates The PeakFQ computer program does not output flood-fre- the flood peak. The inconsistency also may occur because the quency discharges for all the recurrence intervals needed for frequency analysis for each station is based on different time this study. However, subroutines within PeakFQ (the HARTIV periods, thus creating a time-sampling error. subroutine with related subroutines and functions, originally Wiley and others (2000) investigated data for the developed by Kirby, 1980) were used to calculate the needed streamgage station Poplar Fork at Teays (ID 248 and flood-frequency discharges. The 1.1-year and sometimes the streamgage 03201410) for nonhomogeneity. The study 1.5-year flood discharges were computed for 15 streamgage concluded that the data for the period 1967 to 1978 indicate stations using the PeakFQ subroutines; these discharges are annual peaks were higher than those for 1992 to 1997, but footnoted in table 3 (at the end of this report). The identified collection of additional years of record would be necessary to subroutines within PeakFQ do not calculate discharge directly, resolve the question of nonhomogeneity. This current study but determine a frequency factor (K or “the K value”) that is determined that nonhomogeneity exists between the periods used to calculate the discharge. A short Fortran computer pro- 1967 to 1978 and 1992 to 2007. It is hypothesized that exces- gram (Wiley and others, 2002, Appendix 1) was used to calcu- sive runoff from nearby impervious areas resulted in higher late all the frequency factors using the Bulletin-17B weight- annual peaks for the period 1967 to 1978. The excessive run- ing procedures and the WV skew (Atkins and others, 2009) off no longer affects annual peaks since the streamgage station (table 1, at the end of this report). The short computer program was moved to a location upstream from the nearby impervious uses the current versions of computer subroutines contained in areas for the period 1992 to 2007. The flood-frequency dis- a library of USGS water-resources application programs (U.S. charges for Popular Fork at Teays were determined using only Development of Flood-Frequency Discharge Equations 11 annual peaks for the period 1992 to 2007 because they better 2-year floods agreed with the regional divisions determined by represent a rural, unregulated stream. analysis of the 100-year floods.) The final regional equations The randomness of the systematic annual-peak series were then developed from application of a generalized least- was statistically tested to detect a trend using Kendall’s test square (GLS) regression model (Stedinger and Tasker, 1985; for correlation (Kendall, 1975; Hirsch and others, 1982). The Tasker and Stedinger, 1989) (U.S. Geological Survey com- computer program SWSTAT (Surface Water STATistics), ver- puter program GLSNet, version 4.0) for the three regions with sion 4.1, dated February 25, 2002, (Lumb and others, 1990; DRNAREA as the only independent variable (table 4). A.M. Lumb, W.O. Thomas, Jr., and K.M. Flynn, USGS, writ- The three regions—Eastern Panhandle, Central Moun- ten commun., titled “Users manual for SWSTAT, a computer tains, and Western Plateaus (fig. 4)—are separated by topo- program for interactive computation of surface-water statis- graphic features. The boundary between the Eastern Panhandle tics,” June 15, 1995) was used to calculate Kendall’s tau and and Central Mountains Regions follows the Potomac River the level of significance (the probability or p-value). For the Basin boundary. The Central Mountains Region (from north- Kendall’s test for correlation, the hypothesis that there is no east to southwest) contains the drainage areas of the Cheat trend is tested. If the hypothesis fails to attain a particular level River, Tygart Valley River (including the Buckhannon River), of significance, the hypothesis of no trend is rejected. For this Elk River upstream from the confluence of Birch River, and study, the particular level of significance selected was 0.05, the New and Gauley Rivers upstream of the Kanawha River. so a trend is determined for an annual-peak series if the level The Western Plateaus Region encompasses the remainder of of significance is less than 0.05. Kendall’s tau and the level the State. of significance were determined for the annual-peak series of Forty-four streamgage stations were removed from 246 streamgage stations (44 stations were eliminated from the regression analysis (table 1, at the end of this report), consideration as part of the regression analysis discussed later including 12 stations in West Virginia. Thirty-two stations in this report) in West Virginia (table 2). Streamgage stations in adjacent states were removed primarily because residual were further limited to the 125, those with a minimum of plots indicated that the stations were not representative of 30 years of record, to eliminate affects that might be due to flows expected in West Virginia, except for Potomac River natural climatic variations (U.S. Geological Survey, 2005). at Hancock (ID 34 and streamgage 01613000), Shepherd- The annual-peak series for 12 streamgage stations (about 10 stown (ID 44 and streamgage 01618000), and Point Of percent of the 125 stations) indicated a trend, 7 positive and Rocks (ID 70 and streamgage 01638500) in Maryland where 5 negative. If chance were the only factor, 6 streamgage sta- the flood-frequency discharges at these streamgage stations tions would be expected to indicate a trend (about 5 percent with large drainage areas (4,075 to 9,651 mi2) leveraged the of the 125 stations). Statistics indicate trends at twice as many regional regression equations, resulting in greater estimation streamgage stations as would be expected by chance, but the errors for small drainage areas. The 12 streamgage stations trends were nearly equally divided between stations with posi- removed from the regression analysis in West Virginia are tive and negative values. Therefore, no significance could be Tuscarora Creek above Martinsburg (ID 42 and streamgage determined for the trends indicated at the 12 stations. 01617000) because the station was located in a karst area of the State (equations developed in this current study are not Regional Regression of Flood-Frequency applicable to karst areas of the state); Elk River at Centralia (ID 228 and streamgage 03195000) because the peak record Discharges for this station was used to lengthen the record for Elk River below Webster Springs (ID 227 and streamgage 03194700); Regression models with the 10 log10-transformed flood- frequency discharges as dependent variables and the 36 Twelvepole Creek at Wayne (ID 265 and streamgage 03207000) because the peak record for this station was used log10-transformed basin characteristics as potential indepen- dent variables were evaluated. The flood-frequency equations to lengthen the record for Twelvepole Creek below Wayne for the 100-year recurrence interval (1-percent AOP) were (ID 266 and streamgage 03207020); Tug Fork near Kermit regionalized by plotting the areal distribution of residuals from (ID 284 and streamgage 03214000) because the peak record the application of multiple and simple least-squares regres- for this station was used to lengthen the record for Tug Fork sion models. Regional regression procedures were performed at Kermit (ID 285 and streamgage 03214500); New River using the computer program S-PLUS 7.0 (Insightful Corpora- at Caperton (ID 206 and streamgage 03185500) because the tion, 2005), a commercially available statistical computing peak record for this station was used to lengthen the record package. Areal distributions of residual plots indicated three for New River at Fayette (ID 207 and streamgage 03186000); regions—Eastern Panhandle, Central Mountains, and West- Cheat River near Morgantown (ID 124 and streamgage ern Plateaus—with drainage area (DRNAREA) as the only 03071500) because the peak record for this station was used to significant independent variable (fig. 4). Initial equations for lengthen the record for Cheat River near Pisgah (ID 123 and all flood-frequency discharges were determined using the streamgage 03071000); and Potomac River at Paw Paw (ID 28 regions determined by analysis of the 100-year flood, and the and streamgage 01610000), Shenandoah River at Millville outcomes of all equations identified DRNAREA as the only (ID 66 and streamgage 01636500), New River at Bluestone significant independent variable. (A regional analysis of the Dam (ID 188 and streamgage 03180000), New River at 12 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

81°W 78°W

EXPLANATION Eastern-Panhandle Region Central-Mountains Region Western-Plateaus Region Hancock State boundary County boundary Brooke PENNSYLVANIA Major stream Ohio 40°N

Marshall OHIO MARYLAND Monongalia Wetzel Morgan Marion Preston Berkeley Tyler Mineral Pleasants Hampshire Taylor Jefferson Harrison Doddridge Wood Ritchie Barbour Tucker Grant Wirt Hardy Lewis Gilmer Calhoun Upshur Jackson Randolph Mason Roane Braxton Pendleton

Putnam Clay Webster Cabell VIRGINIA Kanawha Nicholas Pocahontas Lincoln Wayne 38°N Boone Fayette Greenbrier

Logan Raleigh Mingo KENTUCKY Wyoming Summers Monroe 0 20 40 60 MILES McDowell Mercer 0 20 40 60 KILOMETERS

Base from U.S. Geological Survey 1:100,000 digital line graphics for state boundaries and streams and from the West Virginia Department of Environmental Protection 1:24,000 digital data for county boundaries. Universal Transverse Mercator projection, zone 17, NAD 83.

Figure 4. The Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia for which equations for estimation of flood frequency discharges were developed in this study. Development of Flood-Frequency Discharge Equations 13

Table 4. Equations used to estimate selected flood-frequency discharges for streams in the Eastern Panhandle, Central Mountains, and Western Plateaus Regions of West Virginia.

[PK(n_n), peak discharge in cubic feet per second for the (n.n)-year recurrence interval; PK(n), peak discharge in cubic feet per second for the (n)-year recur- rence interval; %, percent; AOP, annual-occurrence probability; DRNAREA, drainage area in square miles]

Standard error Average standard Average Equivalent years Equation of the model, error of sampling, prediction error, of record, in percent in percent in percent unitless Eastern Panhandle Region (Range in DRNAREA from 0.21 to 1,461 for 57 streamgage stations) PK1_1(90%AOP) = 29.6 DRNAREA 0.818 43.4 10.3 44.8 3.4 PK1_5(67%AOP) = 46.4 DRNAREA 0.828 35.7 8.9 36.9 3.3 PK2(50%AOP) = 59.8 DRNAREA 0.832 32.1 8.6 33.4 4.1 PK5(20%AOP) = 105 DRNAREA 0.838 25.6 8.9 27.2 10.6 PK10(10%AOP) = 145 DRNAREA 0.842 22.5 9.5 24.5 19.1 PK25(4%AOP) = 204 DRNAREA 0.848 19.7 10.3 22.4 34.1 PK50(2%AOP) = 254 DRNAREA 0.852 18.6 11.1 21.7 46.1 PK100(1%AOP) = 307 DRNAREA 0.855 18.3 11.6 21.7 56.7 PK200(0.5%AOP) = 365 DRNAREA 0.859 18.4 12.4 22.4 64.7 PK500(0.2%AOP) = 447 DRNAREA 0.864 19.4 13.5 23.8 70.9 Central Mountains Region (Range in DRNAREA from 0.10 to 1,619 for 83 streamgage stations) PK1_1(90%AOP) = 33.4 DRNAREA 0.914 40.0 8.3 41.0 2.4 PK1_5(67%AOP) = 53.8 DRNAREA 0.887 34.6 7.3 35.4 2.0 PK2(50%AOP) = 69.4 DRNAREA 0.873 33.4 7.3 34.2 2.1 PK5(20%AOP) = 116 DRNAREA 0.845 34.1 8.0 35.1 3.2 PK10(10%AOP) = 153 DRNAREA 0.831 36.3 8.6 37.4 4.0 PK25(4%AOP) = 206 DRNAREA 0.816 39.9 9.8 41.2 4.8 PK50(2%AOP) = 250 DRNAREA 0.807 42.9 10.6 44.4 5.3 PK100(1%AOP) = 297 DRNAREA 0.800 46.2 11.3 47.9 5.6 PK200(0.5%AOP) = 347 DRNAREA 0.793 49.7 12.0 51.5 5.9 PK500(0.2%AOP) = 420 DRNAREA 0.785 54.3 13.1 56.3 6.1 Western Plateaus Region (Range in DRNAREA from 0.13 to 1,516 for 106 streamgage stations) PK1_1(90%AOP) = 56.9 DRNAREA 0.763 38.2 7.6 39.1 3.8 PK1_5(67%AOP) = 97.8 DRNAREA 0.741 33.4 6.5 34.1 2.8 PK2(50%AOP) = 129 DRNAREA 0.730 31.6 6.1 32.2 2.8 PK5(20%AOP) = 221 DRNAREA 0.710 29.3 6.5 30.0 4.4 PK10(10%AOP) = 292 DRNAREA 0.699 28.9 6.5 29.7 5.9 PK25(4%AOP) = 391 DRNAREA 0.688 29.4 7.3 30.3 7.9 PK50(2%AOP) = 472 DRNAREA 0.681 30.2 7.6 31.3 9.1 PK100(1%AOP) = 557 DRNAREA 0.674 31.4 8.0 32.5 10.1 PK200(0.5%AOP) = 647 DRNAREA 0.668 32.7 8.3 33.9 10.8 PK500(0.2%AOP) = 775 DRNAREA 0.661 34.8 8.9 36.1 11.4 14 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Hinton (ID 203 and streamgage 03184500), New River at Fay- 6 ette (ID 207 and streamgage 03186000), and Kanawha River at Kanawha Falls (ID 224 and streamgage 03193000) because 4 the flood-frequency discharges at these stations with large drainage areas (4,602 to 8,371 mi2) leveraged the regional 2 regression equations, resulting in greater estimation errors for small drainage areas. 0

-2 Accuracy of Flood-Frequency Discharge

Equations DIFFERENCES, IN PERCENT -4

NOT TO SCALE The accuracy of equations used to estimate discharge is -6 Regional 10 100 Regional quantified by calculating the average prediction error (Tasker minimum maximum and Stedinger, 1989; Hodge and Tasker, 1995) and equivalent DRAINAGE AREA, IN SQUARE MILES years of record (Hardison, 1969, 1971). Average prediction error is the square root of the sum of the squared standard Figure 5. Range of differences (shaded) of the individual error of the model (the portion of the total error due to an standard errors of the prediction from the average prediction imperfect model) and the average squared standard error errors for the indicated drainage areas. The graph represents all of sampling (the portion of the total error due to estimating regional equations. model parameters from a sample), in log units. The average prediction errors range from 21.7 to 56.3 percent (table 4). The average prediction error is within 3.4 percentage points of the standard error of the model for all regression equa- errors of prediction increase to a maximum of 5.8 percentage tions, indicating that addition of the average standard error of points greater than the average standard error of prediction for sampling to the standard error of the model accounts for very the minimum drainage areas. little additional unexplained variance of the flood-frequency It is not necessary to compute the individual standard discharge estimate. errors of prediction when using the regression equations Also, the average prediction error is the square root of developed in this study for drainage areas greater than or equal the average of individual squared standard errors of predic- to about 10 mi2 because the differences between the individual tion. Individual standard errors of prediction for the regres- standard errors of prediction and average prediction error are sion equations shown in table 4 were computed over the insignificant (within 1.0 percentage point). Also, it is not nec- entire range of applicable drainage areas and compared to the essary to compute the individual standard errors of prediction average prediction errors (fig. 5). The x-axis of figure 5 is not for drainage areas less than about 10 mi2 if an additional error to scale because the minimum and maximum drainage areas of up to 5.8 percentage points (the maximum of individual are unequal among regions. The individual standard errors standard errors of prediction for the minimum drainage areas) of prediction were computed using the matrices presented is acceptable for the particular application. in Appendix 1 and methods described by Hodge and Tasker Equivalent years of record (table 4) is an estimate of the (1995, p. 37–42), Wiley and others (2000, Appendix 1), number of systematic years of record that must be collected at Wiley and others (2002, Appendix 2), and Koltun (2003, a streamgage station to calculate flood-frequency discharges Appendix A). The individual standard errors of prediction with an accuracy equal to that of the regional equation. The increase for drainage areas less than and greater than about equivalent years of record ranged from 2.0 to 70.9 years. The 100 mi2 (where the individual standard errors are 1.0 percent- equivalent years of record is not a direct measurement of age point less than average prediction error) for all regression accuracy between equations of flood-frequency discharges. A equations. The maximum individual standard errors of predic- comparison of the equation for PK1_1 (90% AOP) to that for tion for the maximum drainage areas are within 0.5 percent- PK25 (4% AOP) in the Eastern Panhandle Region shows that age point of the average standard error of prediction for all the equivalent years of record increased 10 times (3.4 to 34.1), regression equations. The maximum individual standard errors but the average prediction error decreased only by half (44.8 of prediction for the minimum drainage areas are less than to 22.4). Equivalent years of record is a weighting factor that 5.8 percentage points greater than the average prediction error is applied when determining flood-frequency discharges at for all regression equations. The individual standard errors of streamgage stations. prediction are about equal (within 0.3 percentage point) to the The high values for the equivalent years of record in the average prediction error at 10 mi2 for all regression equations. Eastern Panhandle Region are atypical compared to values In summary, the individual standard errors of prediction are for flood-frequency equations in surrounding states and the within 1.0 percentage point of the average prediction error for previous study in West Virginia. The atypical high values drainage areas greater than 10 mi2, and the individual standard are probably due to (1) a good correlation with the distance Procedures For Estimating Flood-Frequency Discharges 15

between stations for weighting in the GLS regression com- Qr is the flood-frequency discharge determined pared to the correlations for other regions in this study; (2) from the appropriate regional equation, in unusually low residuals for short-term streamgage stations ft3/s; (less than 15 years) that have small drainage areas (less than N is the number of years of peak-discharge 5 mi2) compared to residuals for other regions in this study, record, unitless; and the previous study in West Virginia, and regression studies for EY is the equivalent years of record, unitless. other hydrologic statistics conducted by the authors; and (3) the longer average record length for stations in the Eastern No weighted value was calculated for one of the two Panhandle Region (41) compared to average record lengths in streamgage stations on the same stream that were combined the Central Mountains (39) and Western Plateaus (33). into a single time-series record; the flood-frequency discharge near (at) the streamgage station without a weighted value is to be determined using procedures for an ungaged location. No weighted value was calculated for Tuscarora Creek above Procedures For Estimating Flood- Martinsburg (ID 42 and streamgage 01617000) because the Frequency Discharges streamgage station is located in a karst area of the State; the frequency discharge of the systematic record (Qs) is to be used Estimating procedures for the 1.1- (90-percent AOP), 1.5- at this station. (67-percent AOP), 2- (50-percent AOP), 5- (20-percent AOP), 10- (10-percent AOP), 25- (4-percent AOP), 50- (2-percent At an Ungaged Location AOP), 100- (1-percent AOP), 200- (0.5-percent AOP), and 500-year (0.2-percent AOP) flood discharges were devel- Four different procedures are used to determine a oped for streamgage stations and ungaged locations in West flood-frequency discharge at an ungaged location (1) when Virginia. the ungaged location is upstream from a streamgage sta- tion, (2) when the ungaged location is downstream from a At a Streamgage Station streamgage station, (3) when the ungaged location is between two streamgage stations on the same stream, and (4) when the A flood-frequency discharge at a streamgage station ungaged location is not on the same stream as a streamgage station. Two locations were considered to be on the same is determined by reading the weighted (Qw) value directly from table 3 (at the end of this report). This discharge was stream when the stream path from the downstream location to calculated by weighting (1) the discharge determined from the basin divide followed the stream segment with the largest drainage area at each stream confluence and passed through the systematic and historical record (Qs in table 3), using the guidelines established by the Interagency Advisory Committee the upstream location. on Water Data (1982) with the WV skew, and (2) the discharge It is necessary to determine if the ungaged location is near a streamgage station, and arithmetic methods are used determined by the appropriate regional regression equation (Qr in table 3). The weighting technique considers (1) the number to quantify the definition of “near.” A drainage-area-ratio of years of peak-discharge record which equals the number method for estimating statistics at ungaged locations has been of years of systematic record, plus the number of histori- used by several researchers, including Hayes (1991), Ries and cal peaks, minus the number of high-outlier peaks (values Friesz (2000), Flynn (2003), and Wiley (2008). The ratio of from table 2, at the end of this report), and (2) the number of the drainage areas (RU/K) is defined as the ratio of the drain- equivalent years of record (an estimate given in table 4 of the age area where the flood-frequency discharge is unknown number of systematic years of record for a streamgage station (AU) to the drainage area where the flood-frequency discharge necessary to calculate flood-frequency discharges with an is known (AK). These researchers use arithmetic methods for accuracy equal to that of the regional regression equation). determining the upstream and downstream limits of the range The following equation was used. of drainage-area ratios over which flood-frequency discharges can be accurately estimated from those at a streamgage station using an equation similar to the following: Qw = (Qs N + Qr EY) / (N + EY) , (4)

EX where QU = QK (RU/K) , (5) 3 Qw is the weighted discharge, in ft /s; where Qs is the flood-frequency discharge determined from the systematic and historical record QU is the unknown flood-frequency discharge, in using the guidelines established by the ft3/s;

Interagency Advisory Committee on Water QK is the known flood-frequency discharge, in Data (1982), in ft3/s; ft3/s; 16 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

RU/K is the ratio of the drainage area at the location The downstream limit of 26.4 for application of drainage- of the unknown flood-frequency discharge area ratios determined in this study is much greater than

(AU) to the drainage area at the location of values determined by Hayes (1991), Ries and Friesz (2000),

the known flood-frequency discharge (AK), and Flynn (2003), probably because the streamgage stations unitless; and used to compute ratios in this study were limited to those on EX is the exponent for the particular flood- the same stream (the stream path from the downstream loca- frequency discharge, unitless. tion to the basin divide followed the stream segment with the largest drainage area at each stream confluence and passed The 1.1-, 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500- through the upstream location). The downstream limit of 26.4 year flood discharges at 88 pairs of streamgage stations located determined in this study is much greater than the value of 4.76 on the same stream in West Virginia and adjacent states determined by Wiley (2008), but both studies used LOESS (table 5, at the end of this report) were evaluated to quantify plots to set the downstream limit to the maximum ratio “near” for application of the drainage-area-ratio method in this studied. study. Two computations, one upstream and one downstream, The upstream limit of 0.40 for application of drainage- were made for each pair of stations. Ratios of the drainage area ratios determined in this study was equal to that deter- areas for the 176 computations ranged from 0.038 to 26.4. mined by Wiley (2008) for flood frequencies at and below the Equation 5 was solved for the exponent (EX) as the dependent 10-year recurrence interval. The upstream limit of 0.21 for variable: flood frequencies at and above the 25-year recurrence interval determined by Wiley (2008) is superseded by the value 0.40

Log10 (QU / QK) = EX (Log10 (RU/K)) . (6) determined in this study because more than three times as many pairs of stations were used to determine the value in this The exponent was evaluated for the 88 pairs of study (26 pairs compared to 88 pairs). streamgage stations for each flood-frequency discharge using simple linear regression with no intercept (regression line goes through the graph origin). The values of the exponent (EX) for the flood-frequency discharges ranged from 0.68 to 0.79 (table 6). The upstream and downstream limits for application of drainage-area ratios used to quantify the definition of “near” were determined by plotting the x-axis as the drainage-area Table 6. Values of the exponent, and upstream and downstream ratios and the y-axis as the absolute percent differences limits of the drainage-area ratios used to quantify the definition between the flood-frequency discharges at the streamgage of “near” for estimating selected flood-frequency discharges for ungaged locations in West Virginia. station (Qw) and the flood-frequency discharges estimated by applying (1) the drainage-area-ratio method and (2) the [EX, exponent; RUS, upstream limit of the drainage-area ratio; RDS, down- stream limit of the drainage-area ratio; PK(n_n), peak discharge in cubic feet regional equations (Qr). S-PLUS 7.0 was used to construct locally weighted regression (LOESS) curves (a data-smooth- per second for the (n.n)-year recurrence interval; PK(n), peak discharge in ing technique) through differences between flood-frequency cubic feet per second for the (n)-year recurrence interval; %, percent; AOP, annual-occurrence probability] discharges computed from streamgage-station records and the estimated values (selected LOESS parameters were “span = Statistic EX R R 0.5; degree = one, locally linear fitted; family = Symmetric, US DS no feature for handling outlier distortions, strictly applying PK1_1(90%AOP) 0.79 0.40 26.4 locally linear fitting”). The absolute percent differences for PK1_5(67%AOP) .76 .40 26.4 estimates of the 100-year flood made by applying the drain- PK2(50%AOP) .75 .40 26.4 age-area-ratio method are lower than the estimates made by applying the regional equation at drainage-area ratios greater PK5(20%AOP) .73 .40 26.4 than about 0.40 (fig. 6). Similar results were determined for all PK10(10%AOP) .72 .40 26.4 flood frequencies estimated in this study, and absolute percent differences for all equations were combined to determine PK25(4%AOP) .71 .40 26.4 ratio limits applicable for all flood frequencies (fig. 7). The PK50(2%AOP) .70 .40 26.4 upstream limit used to quantify the definition of “near” for all flood frequencies was determined to be 0.40, and the down- PK100(1%AOP) .70 .40 26.4 stream limit was set to the maximum ratios studied, 26.4, PK200(0.5%AOP) .69 .40 26.4 because no assessment could be made for ratios greater than 26.4 (table 6). PK500(0.2%AOP) .68 .40 26.4 Procedures For Estimating Flood-Frequency Discharges 17

200

Drainage-area ratios Regional equations

Upstream limit of the drainage-area 150 ratios used to quantify the definition of "near" for estimating statistics is 0.40

100 Figure 6. LOESS curves of the absolute difference between the 100-year (1-percent annual- occurrence probability) 50

ABSOLUTE DIFFERENCE, IN PERCENT flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method 0 and (2) regional equations, 0.0 0.1 1.0 10.0 100.0 in relation to the ratios of RATIO OF DRAINAGE AREAS, UNITLESS the drainage areas.

200

Upstream limit of the drainage-area Drainage-area ratios ratios used to quantify the definition of Regional equations "near" for estimating statistics is 0.40

150

Figure 7. LOESS curves 100 of the absolute difference between the 1.1- through 500-year (90- through 0.2-percent annual- occurrence probabilities) 50 ABSOLUTE DIFFERENCE, IN PERCENT flood discharges determined at streamgage stations and values estimated from the (1) drainage-area ratio method 0 and (2) regional equations, 0.01 0.10 1.00 10.00 100.00 in relation to the ratios of RATIO OF DRAINAGE AREAS, UNITLESS the drainage areas. 18 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Upstream From a Streamgage Station circumstance is that the conditions affecting flood-frequency discharges at the streamgage station change, in the down- This procedure is used when there is a streamgage station stream direction, toward those of the regional tendency. The downstream from the ungaged location but none upstream conditions affecting flood-frequency discharges in the vicinity on the same stream. The hydrologic assumption for this of the streamgage station could be atypical impervious land circumstance is that the conditions affecting flood-frequency cover, unusual basin slope, uncommon basin orientation, or discharges, such as land cover, basin topography, and climatic diversion of storm runoff that likely would not significantly conditions, are unchanged upstream from the streamgage sta- affect flood-frequency discharges if the drainage area were tion. Mathematically, the values of flood-frequency discharges larger and, therefore, conditions were more similar to the are proportioned by drainage area. It is suggested that a regional tendency. Mathematically, the value of a flood-fre- streamgage be established when RU/K is less than or equal to quency discharge is changed to that estimated by applying the the upstream limit of the ratio of drainage areas (RUS) (table 6). regional equation as RU/K approaches the downstream limit of

The following equation is used to estimate flood-frequency the ratio of drainage areas (RDS) (table 6). It is suggested that discharges: a streamgage be established when RU/K is greater than or equal

to RDS . The flood-frequency discharge is estimated by apply- EX QU = QK (RU/K) , (7) ing the regional equation when RU/K is greater than or equal to

RDS , and the following equation is used to estimate the flood- where frequency discharge when RU/K is less than RDS : QU is the unknown flood-frequency discharge, 3 in ft /s; QU = QUE + (QK – QKE) (RDS – RU/K) / (RDS – 1) , (8) QK is the known flood-frequency discharge (table 3), in ft3/s; when

RU/K is the ratio of the drainage area at the location

of the unknown flood-frequency discharge RU/K < RDS ; and (AU) to the drainage area at the location of

the known flood-frequency discharge (AK), where

unitless; and QU is the unknown flood-frequency discharge, EX is the exponent for the particular flood- in ft3/s;

frequency discharge (table 6), unitless. QUE is the regional equation (table 4) evaluated at the location of the unknown flood- In this method, it is not assumed that the conditions frequency discharge, in ft3/s; affecting flood-frequency discharges change in the upstream QK is the known flood-frequency discharge direction toward the regional tendency. The critical situation (table 3), in ft3/s; for this assumption is where the unknown location approaches QKE is the regional equation (table 4) evaluated at the headwaters of a stream. This assumption might be accept- the location of the known flood-frequency able if the flood-frequency discharge at the known location discharge, in ft3/s; is less than that estimated by applying the regional equation RDS is the downstream limit of the ratio of at the known location because the upstream estimate of the drainage areas (table 6), unitless; and flood-frequency discharge would be greater, and therefore, RU/K is the ratio of the drainage area at the location more conservative from a flood inundation perspective than of the unknown flood-frequency discharge that determined using the method presented. However, this (AU) to the drainage area at the location of assumption would be unacceptable if the flood-frequency the known flood-frequency discharge (AK), discharge at the known location is greater than that estimated unitless. by applying the regional equation because the upstream estimate of flood-frequency discharge would be less than that determined using the method presented, thus requiring an Between Streamgage Stations assumption of reducing unit inflow. The method presented This procedure is used when there are streamgage sta- would require establishing a streamgage station in order to tions both upstream and downstream from the ungaged loca- reduce unit inflow when the known flood-frequency discharge tion on the same stream. The hydrologic assumption for this is greater than that estimated using the regional equation. circumstance is that the conditions affecting flood-frequency discharges are changing on the basis of the relation between Downstream From a Streamgage Station the flood-frequency discharges at the streamgage stations, the ratios of the drainage areas, and differences between regional This procedure is used when there is a streamgage station hydrologic conditions and those that affect flood-frequency upstream from the ungaged location but none downstream discharges at the stations. It is suggested that a streamgage be on the same stream. The hydrologic assumption for this established when RU/K is greater than RDS and less than RUS , Procedures For Estimating Flood-Frequency Discharges 19 and when one of the values of the flood-frequency discharge where at the upstream and downstream locations is greater than, and QU is the unknown flood-frequency discharge, in one of the values is less than, that estimated by applying the ft3/s; regional equation. Two alternative hydrologic assumptions are QUS is the flood-frequency discharge at the described in detail below. upstream location (table 3), in ft3/s;

QDS is the flood-frequency discharge at the Hydrologic Conditions Change Linearly between downstream location (table 3), in ft3/s;

Streamgage Stations QKE is the regional equation evaluated at the location of the known flood-frequency This hydrologic assumption is that the conditions affect- discharge, in ft3/s; ing flood-frequency discharges at the upstream streamgage sta- AU is the drainage area at the location of the tion change linearly with drainage area to those at the down- unknown flood-frequency discharge, in stream location when (1) both streamgage stations are near the mi2; ungaged location, or (2) both streamgage stations are not near AUS is the drainage area at the upstream location the ungaged location, but the hydrologic conditions affecting (table 2), in mi2; flood-frequency discharges at the stations and ungaged loca- ADS is the drainage area at the downstream tion are consistent. The conditions affecting flood-frequency location (table 2), in mi2; discharges between the upstream and downstream locations RUS is the upstream limit of the ratio of drainage are well defined by streamgage stations when both are near areas (table 5), unitless; and the ungaged location; the conditions affecting flood-frequency RDS is the downstream limit of the ratio of discharges are consistent from the upstream to the downstream drainage areas (table 5), unitless. location when neither is near the ungaged location and the conditions at both stations are more similar to each other than Hydrologic Conditions Change Linearly to the Regional to the regional hydrologic conditions. Mathematically, the Hydrologic Conditions between Streamgage Stations value of flood-frequency discharges changes linearly with respect to drainage area from the upstream to the downstream This hydrologic assumption is that the conditions affect- value when (1) RU/K is less than RDS at the upstream location ing flood-frequency discharges at the streamgage station and RU/K is greater than RUS at the downstream location; or (2) change linearly with drainage area to those represented by

RU/K is greater than or equal to RDS at the upstream location, the regional equation when neither streamgage station is near

RU/K is less than or equal to RUS at the downstream location, the ungaged location and the hydrologic conditions affecting and the discharges of the flood frequencies at the upstream and flood-frequency discharges at the two stations are inconsistent. downstream locations are both greater than or both less than The conditions affecting flood discharges can vary greatly those estimated by applying the regional equation. The follow- as a result of factors such as (1) significant changes in land ing equation is used to estimate the flood-frequency discharge cover, basin topography, or climatic conditions; (2) input under the limitations described above: from a tributary stream that is hydrologically different from the stream on which the streamgage station is located or from

QU = [QUS (ADS – AU) + QDS (AU – AUS)] / (ADS – AUS) , (9) regional hydrologic conditions; or (3) transfer of storm runoff into or out of the basin. Mathematically, the hydrologic condi- when tions are inconsistent if one of the flood-frequency discharges at the upstream and downstream locations is greater than and

RU/K < RDS at upstream location and one of the flood-frequency discharges is less than those esti-

RU/K > RUS at downstream location, mated by applying the regional equation—that is, the flood- frequency discharge changes from a value greater than the or when flood-frequency discharge estimated by applying the regional equation at the upstream location to a value equal to the flood-

RU/K ≥ RDS at upstream location and frequency discharge estimated from the regional equation,

RU/K ≤ RUS at downstream location; and and then to a value less than the flood-frequency discharge estimated from the regional equation at the downstream loca- tion, or the reverse. The regional equation (table 4) is applied

QKE at the upstream location > QUS and to estimate the flood-frequency discharge ifR U/K is greater than

QKE at the downstream location > QDS or or equal to RDS at the upstream location and RU/K is less than or

equal to RUS at the downstream location. Equation 8 presented in the section “Downstream from a Streamgage Station” is

QKE at the upstream location < QUS and used to estimate the flood-frequency discharge ifR U/K is less

QKE at the downstream location < QDS ; and than RDS at the upstream location and RU/K is less than or equal 20 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

to RUS at the downstream location. The following equation stream, and (4) when the ungaged location is not on the same is used to estimate the flood-frequency discharge ifR U/K is stream as a streamgage station. greater than or equal to R at the upstream location and R is DS U/K • At a streamgage station: A flood-frequency discharge greater than R at the downstream location: US for a streamgage station is determined by reading the weighted (Q ) value from table 3. For example, the Q = Q + (Q – Q ) (R – R ) / (1 – R ) , (10) w U UE K KE U/K US US 500-year flood discharge (PK500, 0.2-percent AOP) at the streamgage station Big Coal River at Ash- when ford (ID 238 and streamgage 03198500) is given as 50,300 ft3/s. RU/K ≥ RDS at upstream location and

RU/K > RUS at downstream location, and • Upstream from a streamgage station: The 50-year flood discharge (PK50, 2-percent AOP) for the South where Fork South Branch Potomac River just downstream

QU is the unknown flood-frequency discharge, in from the confluence of George Run in Pendleton ft3/s; County (Sugar Grove 7½-minute U.S. Geological

QUE is the regional equation (table 4) evaluated Survey topographic map) and upstream from the at the location of the unknown flood- streamgage station at Brandywine (ID 19 and frequency discharge, in ft3/s; streamgage 01607500) can be calculated using equa-

QK is the known flood-frequency discharge tion 7. The known 50-year flood discharge Q( K) at the (table 3), in ft3/s; Brandywine streamgage station is 18,600 ft3/s (the

QKE is the regional equation (table 4) evaluated at value for Qw from table 3). The drainage area at the 2 the location of the known flood-frequency unknown location (AU) is 84.56 mi (Wiley and oth- discharge, in ft3/s; ers, 2007, p. 29), and the drainage area at the known 2 RDS is the downstream limit of the ratio of location (AK) is 103 mi (table 2). The exponent (EX)

drainage areas (table 5), unitless; for the 50-year flood discharge is 0.70 (table 6).R U/K

RUS is the upstream limit of the ratio of drainage (which equals AU / AK) is calculated to be 0.82, which areas (table 5), unitless; and is greater than the upstream limit of the ratio of drain-

RU/K is the ratio of the drainage area at the location age areas, 0.40 (RUS from table 6), indicating that the of the unknown flood-frequency discharge installation of a streamgage station is not suggested.

(AU) to the drainage area at the location of The 50-year flood discharge of the South Fork South

the known flood-frequency discharge (AK), Branch Potomac River just downstream from the con- unitless. fluence of George Run is calculated from equation 7 to be 16,200 ft3/s. Not on the Same Stream as a Streamgage • Downstream from a streamgage station: The 2-year Station flood discharge (PK2, 50-percent AOP) for Sand Run just downstream from the confluence of Laurel Fork This procedure is used when there is no streamgage sta- in Upshur County (Century 7½-minute U.S. Geologi- tion on the same stream as the ungaged location. The hydro- cal Survey topographic map) and downstream from logic assumption for this circumstance is that the conditions the streamgage station near Buckhannon (ID 90 and affecting flood-frequency discharges are those represented by streamgage 03052500) can be calculated using equa- the regional equation. A streamgage station could be estab- tion 8. (No other streamgage station is present down- lished when there is no streamgage station on the same stream stream from Sand Run near Buckhannon on the same as the ungaged location. Mathematically, the flood-frequency stream.) The known 2-year flood discharge (QK) at the discharge is estimated by applying the regional equation Buckhannon streamgage station is 794 ft3/s (the value (table 4). for Qw from table 3). The drainage area at the unknown 2 location (AU) is 27.56 mi (Stewart and Mathes, 1995, p. 19), and the drainage area at the known location Example Applications 2 (AK) is 14.3 mi (table 2). The result of the regional equation calculation at the unknown location (Q ) Estimates of flood-frequency discharges are made by UE is 1,260 ft3/s (Central Mountains Region determined directly reading from table 3 when the location of interest is at from fig. 4, equation from table 4) and for the known a streamgage station, or using one of the four procedures at an location (Q ) is 708 ft3/s. R (which equals A / A ) ungaged location: (1) when the ungaged location is upstream KE U/K U K was calculated to be 1.93, which is less than the from a streamgage station, (2) when the ungaged location is downstream limit of the ratio of drainage areas, 26.4 downstream from a streamgage station, (3) when the ungaged (R from table 6). The drainage areas are within the location is between two streamgage stations on the same DS Summary 21

limits of the regional equation from 0.10 to 1,619 mi2 Limitations of Procedures for Estimating Flood- (table 4), indicating that the procedure is valid and that Frequency Discharges the installation of a streamgage station is not sug- gested. The 2-year flood discharge of Sand Run just Procedures developed in this study are applicable only downstream from the confluence of Laurel Fork was to rural, unregulated streams located within the boundaries 3 calculated from equation 8 to be 1,340 ft /s. of West Virginia. Procedures also are limited to the range • Between two streamgage stations on the same of drainage areas used to develop the equations—from 0.21 2 stream: The 100-year flood discharge (PK100, to 1,461 mi in the Eastern Panhandle Region, from 0.10 to 2 1-percent AOP) for the Greenbrier River just down- 1,619 mi in the Central Mountains Region, and from 0.13 to 2 stream from the confluence of Wolf Creek in Mon- 1,516 mi in the Western Plateaus Region. The procedures are roe County (Alderson 7½-minute U.S. Geological not meant to be applied to urban areas with paved surfaces, Survey topographic map), downstream from the concrete channels, or culverts that substantially increase streamgage station at Alderson (ID 198 and streamgage runoff or decrease infiltration. The procedures are not meant 03183500), and upstream from the streamgage station to be applied to streams regulated by dams or with large lakes at Hilldale (ID 201 and streamgage 03184000) can and ponds that substantially retain runoff. Procedures are be calculated using equation 9. The upstream 100- not applicable to heavily mined areas if excessive runoff is diverted into or outside the basin, retained along strip benches, year flood discharge (QUS) at the Alderson streamgage station is 80,400 ft3/s, and the downstream 100-year or retained underground. Procedures are not applicable to karst areas if excessive runoff is diverted into, outside, or flood discharge Q( DS) at the Hilldale streamgage sta- tion is 85,400 ft3/s (the values for Q from table 3). deep within the basin through solution channels or other w cavities in carbonate (limestone and dolomite) rocks. Jones The drainage area at the unknown location (AU) is 1,535.79 mi2 (Mathes and others, 1982, p. 55), the (1997) describes the locations of karst areas in eastern coun- upstream drainage area at the Alderson streamgage ties of West Virginia, including parts of Monongalia, Preston, station (A ) is 1,364 mi2 (table 2), and the downstream Barbour, Tucker, Grant, Mineral, Hardy, Hampshire, Morgan, US Berkeley, Jefferson, Randolph, Pendleton, Pocahontas, Green- drainage area at the Hilldale gaging station (ADS) is 2 brier, Summers, Monroe, and Mercer (counties are shown in 1,619 mi . RU/K (which equals AU / AK) at the upstream location was calculated to be 1.13, which is less than fig. 4). the downstream limit of the ratio of drainage areas,

26.4 (RDS from table 6). RU/K at the downstream loca- tion was calculated to be 0.95, which is greater than Summary the upstream limit of the ratio of drainage areas, 0.40

(RUS table 6), indicating that the procedure is valid and Flood-frequency discharges were determined for 290 that installation of a streamgage is not suggested. The streamgage stations on rural, unregulated streams in West 100-year flood discharge of the Greenbrier River just Virginia and adjacent states that have a minimum of 9 years downstream from the confluence of Wolf Creek was of record through the 2006 or 2007 water year. This study was 3 calculated from equation 9 to be 83,800 ft /s. conducted by the USGS, in cooperation with the West Virginia • Not on the same stream as a streamgage station: Department of Transportation, Division of Highways. West The 10-year flood discharge (PK10, 10-percent AOP) Virginia skew coefficients were used instead of the United for Fishing Creek just downstream from the confluence States skew coefficients used in previous studies in West of North and South Forks of Fishing Creek in Wetzel Virginia. Flood-frequency discharges and skew coefficients for County (Pine Grove 7½-minute U.S. Geological stations in adjacent states are applicable only for determining Survey topographic map) can be calculated from the estimates in West Virginia and do not supersede values used in regional equation. (There are no streamgage stations on the adjacent states. The results of a correlation analysis of 36 log -trans- Fishing Creek or South Fork Fishing Creek that could 10 have been on the same stream.) The streams are in formed basin characteristics available for the 290 streamgage the Western Plateaus Region (fig. 4), and the drainage stations reduced the number of characteristics to 32 for con- area is 113.92 mi2 (Wiley, 1997, page 30). The drain- sideration as independent variables in the regression analy- age area is within the limits of the regional equation sis. Elongation ratio (ER), rotundity of basin (RB), channel from 0.13 to 1,516 mi2 (table 4), indicating that the maintenance (CM), and basin width (BW) were removed from procedure is valid, but that installation of a streamgage consideration as independent variables because the Pearson’s station could improve the estimate. The 10-year flood coefficient was equal to 1 (singularity) for this group of basin discharge was calculated from the regression equa- characteristics. Regression analysis was conducted using log -trans- tion for the Western Plateaus Region (table 4) to be 10 8,000 ft3/s. formed flood-frequency discharges as dependent variables and log10-transformed basin characteristics as independent 22 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia variables for 246 streamflow stations. Forty-four stream- References Cited flow stations were excluded from the analysis because the (1) peak data were used to lengthen records for other nearby streamgage stations, (2) station is located in a karst area, (3) Atkins, J.T., Jr., Wiley, J.B., and Paybins, K.S., 2009, Gen- plot of the regression residual indicated the station was not eralized skew coefficients of annual peak flows for rural, representative of West Virginia, and (4) station has a large unregulated streams in West Virginia: U.S. Geological drainage area and leveraged the regression equation, affecting Survey Open-File Report 2008–1304, 13 p. estimates for small drainage areas. Residuals from multiple Barnes, H.H., Jr., 1964, Floods of March 1963, Alabama to and simple least-squares regression models of the 100-year West Virginia: U.S. Geological Survey Open-File Report (1-percent AOP) flood discharge with independent variables 63-8, 44 p. describing the basin characteristics were used to determine drainage area as the only significant independent variable and Benson, M.A., 1962, Factors influencing the occurrence of to delineate boundaries of three regions in West Virginia— floods in a humid region of diverse terrain: U.S. Geological Eastern Panhandle, Central Mountains, and Western Plateaus. Survey Water-Supply Paper 1580-B, 64 p. Regional equations for the 1.1- (90-percent AOP), 1.5- (67-percent AOP), 2- (50-percent AOP), 5- (20-percent AOP), Bisese, J.A., 1995, Methods for estimating magnitude and 10- (10-percent AOP), 25- (4-percent AOP), 50- (2-percent frequency of peak discharges of rural, unregulated streams AOP), 100- (1-percent AOP), 200- (0.5-percent AOP), and in Virginia: U.S. Geological Survey Water-Resources Inves- 500-year (0.2-percent AOP) flood discharges were determined tigations Report 94-4148, 70 p. by executing a generalized least-squares regression model. Carpenter, D.H., 1990, Floods in West Virginia, Virginia, Drainage area was the only significant independent variable Pennsylvania, and Maryland, November 1985: U.S. determined for all equations in all regions. Geological Survey Water-Resources Investigations Report The 246 streamgage stations were reduced to 125 for 88-4213, 86 p. consideration in the trend analysis. For the trend analysis, streamgage stations with a minimum of 30 years of record Dawdy, D.R., Lichty, R.W., and Bergmann, J.M., 1972, A were considered in order to eliminate effects that might be due rainfall-runoff simulation model for estimation of flood to climate variability. Twelve streamgage stations indicated a peaks for small drainage basins: U.S. Geological Survey trend, twice as many as would be expected by chance, but the Professional Paper 506-B, 28 p. stations were about equally divided between those having a positive trend and those having a negative trend. No signifi- Dillow, J.A., 1996, Technique for estimating magnitude and cance was determined for the streamgage stations having a frequency of peak flows in Maryland: U.S. Geological Sur- trend. vey Water-Resources Investigations Report 95-4154, 55 p. The accuracy of estimating equations was quantified by Doll, W.C., Meyer, Gerald, and Archer, R.J., 1963, Water measuring the average prediction error and equivalent years of Resources of West Virginia: Charleston, WV, West Vir- record. The average prediction error ranged from 21.7 to 56.3 ginia Department of Natural Resources, Division of Water percent, and the equivalent years of record ranged from 2.0 to Resources, 134 p. 70.9 years. Procedures for estimating flood-frequency discharges at a Fenneman, N.M., 1938, Physiography of Eastern United streamgage station and at an ungaged location are presented in States: New York, McGraw-Hill, 714 p. the text of this report. The procedures for an ungaged location include a combination of (1) estimates based on drainage-area Flynn, K.M., Kirby, W.H., and Hummel, P.R., 2006, User’s ratios between stations and ungaged locations on the same manual for program PeakFQ annual flood-frequency analy- stream and (2) estimates from regional equations. Examples of sis using Bulletin 17B guidelines: U.S. Geological Survey the procedures are presented in the text. Techniques and Methods bk 4, chap. B4, 42 p. Equations developed in this study are applicable only Flynn, R.H., 2003, Development of regression equations to to rural, unregulated streams located within the boundaries estimate flow durations and low-flow-frequency statistics in of West Virginia. Equation application is limited to the range New Hampshire streams: U.S. Geological Survey Water- of drainage areas used in equation development—from 0.21 Resources Investigations Report 02-4298, 66 p. to 1,461 mi2 in the Eastern Panhandle Region, from 0.10 to 1,619 mi2 in the Central Mountains Region, and from 0.13 to Frye, P.M., and Runner, G.S., 1969, Procedure for estimating 1,516 mi2 in the Western Plateaus Region. The authors suggest magnitude and frequency of floods in West Virginia: West using caution in evaluating the results if the equations are Virginia State Road Commission design directive, 10 p. applied to heavily mined or karst areas. Frye, P.M., and Runner, G.S., 1970, A proposed streamflow data program for West Virginia: U.S. Geological Survey Open-File Report, 38 p. References Cited 23

Frye, P.M., and Runner, G.S., 1971, A preliminary report on Koltun, G.F., 2003, Techniques for estimating flood-peak dis- small streams flood frequency in West Virginia: West Vir- charges of rural, unregulated streams in Ohio: U.S. Geologi- ginia Department of Highways design directive, 9 p. cal Survey Water-Resources Investigations Report 03-4164, 75 p. Grover, N.C., 1937, The floods of March 1936, Part 3, Potomac, James, and upper Ohio Rivers: U.S. Geological Lescinsky, J.B., 1987, Flood of November 1985 in West Vir- Survey Water-Supply Paper 800, 351 p. ginia, Pennsylvania, Maryland, and Virginia: U.S. Geologi- cal Survey Open-File Report 86-486, 33 p. Hardison, C.H., 1969, Accuracy of streamflow characteris- tics: U.S. Geological Survey Professional Paper 650-D, Lumb, A.M., Kittle, J.L., Jr., and Flynn, K.M., 1990, Users p. D210–D214. manual for ANNIE, computer program for interactive hydrologic analysis and data management: U.S. Geological Hardison, C.H., 1971, Predictive error of streamflow charac- Survey Water-Resources Investigations Report 89-4080, teristics at ungaged sites: U.S. Geological Survey Profes- 236 p. sional Paper 750-C, p. 228–236. Mathes, M.V, Jr., 1977, Drainage areas of the Guyandotte Hayes, D.C., 1991, Low-flow characteristics of streams in River Basin, West Virginia: U.S. Geological Survey Open- Virginia: U.S. Geological Survey Water-Supply Paper 2374, File Report 77-801, 56 p. 69 p. Mathes, M.V., Kirby, J.R., Payne, D.D., and Shultz, R.A., Helsel, D.R., and Hirsch, R.M., 2002, Statistical methods in 1982, Drainage areas of the Kanawha River Basin, West water resources: U.S. Geological Survey Techniques of Virginia: U.S. Geological Survey Open-File Report 82-351, Water-Resources Investigations Report, bk 4, chap. A3, 222 p. 510 p. National Oceanic and Atmospheric Administration, 2006a, Hirsch, R.M., Slack, J.R., and Smith, R.A., 1982, Techniques Climate of West Virginia, accessed September 30, 2006, of trend analysis for monthly water quality data: Water at http://cdo.ncdc.noaa.gov/climatenormals/clim60/states/ Resources Research, v. 18, no. 1, p. 107–121. Clim_WV_01.pdf. Hodge, S.A., and Tasker, G.D., 1995, Magnitude and fre- National Oceanic and Atmospheric Administration, 2006b, quency of floods in Arkansas: U.S. Geological Survey Total precipitation in inches by month for climate divisions, Water-Resources Investigations Report 95-4224, 52 p. accessed September 30, 2006, at http://www.cdc.noaa.gov/ Hodgkins, G.A., and Martin, G.R., 2003, Estimating the mag- USclimate/pcp.state.19712000.climo.html. nitude and frequency of peak flows for streams in Kentucky Natural Resources Conservation Service, 2006, West Virginia for selected recurrence intervals: U.S. Geological Survey Precipitation data/maps, accessed September 30, 2006, at Water-Resources Investigations Report 03-4180, 68 p. http://www.ncgc.nrcs.usda.gov/products/datasets/climate/ Insightful Corporation, 2005, S-PLUS 7.0 Professional edi- data/precipitation-state/wv.html. tion software for Windows: Seattle, Washington, Insightful Paybins, K.S., 2008, Basin characteristics for selected Corporation. streamflow-gaging stations in and near West Virginia: U.S. Interagency Advisory Committee on Water Data, 1976, Guide- Geological Survey Open-File Report 2008–1087, 9 p. lines for determining flood flow frequency: Water Resources (Also available at http://pubs.er.usgs.gov/usgspubs/ofr/ Council Bulletin 17, 26 p. ofr20081087.) Interagency Advisory Committee on Water Data, 1982, Guide- Preston, J.S., and Mathes, M.V., 1984, Stream drainage areas lines for determining flood flow frequency: Water Resources for the Little Kanawha River Basin, West Virginia: U.S. Council Bulletin 17B, 28 p. Geological Survey Open-File Report 84-861, 171 p. Jones, W.K., 1997, Karst hydrology of West Virginia: Charles Ries, K.G., III, and Friesz, P.J., 2000, Methods for estimating Town, WV, Karst Waters Institute, Inc., Special Publication low-flow statistics for Massachusetts streams: U.S. Geologi- 4, 111 p. cal Survey Water-Resources Investigations Report 00-4135, 81 p. Kendall, M.G., 1975, Rank correlation methods (4th ed.): London, Charles Griffin, 202 p. Runner, G.S., 1979, Flood of April 1977 on the Tug Fork, Matewan to Williamson, West Virginia and Kentucky: U.S. Kirby, W., 1980, Computer routines for probability distribu- Geological Survey Hydrologic Investigations Atlas HA-588, tions, random numbers, and related functions: U.S. Geologi- scale 1:12,000. cal Survey Open-File Report 80-448, 61 p. 24 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Runner, G.S., 1980a, Technique for estimating magnitude U.S. Geological Survey, 1991, National water summary and frequency of floods in West Virginia: U.S. Geological 1988-89—Hydrologic events and floods and droughts: U.S. Survey Open-File Report 80-1218, 44 p. Geological Survey Water-Supply Paper 2375, 591 p. Runner, G.S., 1980b, Hydrologic data for Runoff studies on U.S. Geological Survey, 2001, Water Resources Applications small drainage areas, West Virginia Department of High- Software: LIB3.2, revised June 29, 1998, accessed Novem- ways Research Project 16: U.S. Geological Survey Open- ber 2001, at http://water.usgs.gov/software/lib.html/. File Report 80-560, 169 p. U.S. Geological Survey, 2005, Streamflow trends in the United Runner, G.S., and Chin, E.H., 1980, Flood of April 1977 in the States: U.S. Geological Survey Fact Sheet FS2005–3017, Appalachian region of Kentucky, Tennessee, Virginia, and 4 p. West Virginia: U.S. Geological Survey Professional Paper 1098, 43 p. U.S. Geological Survey, 2006, The National Map, accessed September 30, 2006, at http://nationalmap.gov. Speer, P.R., and Gamble, C.R., 1965, Magnitude and fre- quency of floods in the United States, Part 3-A, Ohio River Wiley, J.B., 1997, Drainage areas of West Virginia streams basin except Cumberland and Tennessee River basins: U.S. tributary to the Ohio River: U.S. Geological Survey Open- Geological Survey Water-Supply Paper 1675, 630 p. File Report 97-231, 70 p. Stedinger, J.R., and Tasker, G.D., 1985, Regional hydro- Wiley, J.B., 2008, Estimating selected annual streamflow logic analysis 1: ordinary, weighted, and generalized least statistics representative of 1930–2002 in West Virginia: squares compared: Water Resources Research, v. 21, no. 9, U.S. Geological Survey Scientific Investigations Report p. 1421–1432. 2008–5105, 24 p. Stewart, D.K., and Mathes, M.V., 1995, Drainage areas of the Wiley, J.B., Atkins, J.T., Jr., and Newell, D.A., 2002, Estimat- Monongahela River Basin, West Virginia: U.S. Geological ing the magnitude of annual peak discharges with recur- Survey Open-File Report 95-170, 79 p. rence intervals between 1.1 and 3.0 years for rural, unregu- lated streams in West Virginia: U.S. Geological Survey Stuckey, M.H., and Reed, L.A., 2000, Techniques for estimat- Water-Resources Investigations Report 02-4164, 73 p. ing magnitude and frequency of peak flows for Pennsyl- vania streams: U.S. Geological Survey Water-Resources Wiley, J.B., Atkins, J.T., Jr., and Tasker, G.D., 2000, Estimat- Investigations Report 00-4189, 43 p. ing magnitude and frequency of peak discharges for rural, unregulated streams in West Virginia: U.S. Geological Sur- Tasker, G.D., and Stedinger, J.R., 1989, An operational GLS vey Water-Resources Investigations Report 00-4080, 93 p. model for hydrologic regression: Journal of Hydrology, v. 111, p. 361–375. Wiley, J.B., Hunt, M.L., and Stewart, D.K., 2007, Drainage areas of the Potomac River Basin, West Virginia: U.S. Geo- Tice, R.H., 1968, Magnitude and frequency of floods in the logical Survey Open-File Report 95-292 (3d ed.), 60 p. United States, Part 1-B, North Atlantic Slope Basins, New York to York River: U.S. Geological Survey Water-Supply Wilson, M.W., 1979, Drainage areas of the Twelvepole Creek Paper 1672, 585 p. Basin, West Virginia; Big Sandy River Basin, West Virginia; Tug Fork Basin, Virginia, Kentucky, West Virginia: U.S. U.S. Geological Survey, 1990, National water summary Geological Survey Open-File Report 79-746, 49 p. 1987—Hydrologic events and water supply and use: U.S. Geological Survey Water-Supply Paper 2350, 553 p. Table 1 25 - 10

.193 .232 .259 .223 .267 .259 .234 .302 .259 .255 .211 .300 .341 .229 .251 .276 .377 .329 .307 .311 .142 .295 .255 .193 .360 .223 0.245 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 3.531 3.127 3.914 3.924 3.194 2.714 3.561 3.289 3.013 4.215 3.817 4.270 3.565 3.681 1.322 3.942 4.149 1.622 3.560 1.512 3.805 1.669 4.385 3.591 2.445 3.034 3.593 second discharges, transformed Mean of log flood-frequency in cubic feet per

.900 .466 .639 .722 .628 .502 .060 .500 .792 .697 .017 .450 .644 .874 .719 .551 .816 .500 .621 .125 .598 .146 .580 .198 .324 0.376 1.093 skews, unitless and station Weighted WV Weighted

.175 .224 .198 .230 .209 .203 .181 .104 .150 .237 .164 .047 .281 .399 .435 .406 .274 .226 .280 .248 .293 .117 .031 -.028 -.111 -.084 0.257 skews, unitless between Difference WV and US .348 .344 .351 .335 .334 .350 .354 .371 .366 .358 .365 .383 .419 .401 .389 .396 .415 .433 .435 .423 .419 .398 .393 .394 .414 .406 0.337 unitless U.S. skew, U.S. skew, .523 .568 .549 .565 .543 .553 .535 .475 .516 .595 .529 .430 .700 .800 .824 .802 .689 .659 .715 .671 .391 .691 .510 .425 .303 .322 0.594 unitless WV skew, WV skew, MD MD MD MD MD MD MD MD MD MD MD MD WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name North Branch Potomac River at Steyer Abram Creek at Oakmont Potomac River at Kitzmiller North Br. Potomac River at Bloomington North Br. Savage River near Barton Crabtree Creek near Swanton Savage River at Bloomington Creek at Franklin Georges New Creek near Keyser North Branch Potomac River at Pinto Creek near Cumberland Wills Potomac River near Cumberland N. Br. Patterson Creek near Headsville South Branch Potomac River at Franklin near Franklin Tributary Reeds Creek Potomac River at Cabins N. Fk. S. Br. Potomac River near Petersburg S. Br. Brushy Run near Petersburg Potomac R. at Brandywine S. Fk. Br. Heavener Run near Brandywine Potomac R. near Moorefield S. Fk. Br. Hollow near Moorefield Williams Potomac River near Springfield S. Br. Creek near Oldtown Town Sawpit Run near Oldtown Little Cacapon River at Frenchburg Little Cacapon River near Levels

01595000 01595300 01595500 01596000 01596500 01597000 01598000 01599000 01599500 01600000 01601500 01603000 01604500 01605500 01605700 01606000 01606500 01606800 01607500 01607510 01608000 01608100 01608500 01609000 01609500 01609650 01609800 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

1 2 3 4 5 6 7 8 9 11 10 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water 26 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia - 10

.214 .288 .333 .362 .318 .271 .240 .231 .166 .348 .250 .315 .281 .307 .253 .339 .224 .360 .273 .398 .270 .273 .186 .253 .291 .278 .165 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 4.637 2.585 3.569 3.875 4.115 2.730 4.745 2.387 2.036 2.925 3.761 3.388 2.734 3.659 2.235 2.012 4.837 1.354 3.428 2.894 3.393 2.759 2.691 1.644 3.861 1.778 1.733 second discharges, transformed Mean of log flood-frequency in cubic feet per

.465 .213 .169 .085 .025 .225 .494 .322 .519 .310 .081 .157 .294 .023 .322 .417 .288 .492 .911 .464 .585 .728 .587 .243 .320 -.130 -.020 skews, unitless and station Weighted WV Weighted

.053 .059 .082 .028 .006 .089 .134 .047 .036 -.204 -.105 -.154 -.021 -.051 -.235 -.236 -.276 -.252 -.216 -.175 -.172 -.185 -.135 -.053 -.045 -.068 -.149 skews, unitless between Difference WV and US .404 .395 .399 .446 .411 .400 .407 .412 .412 .462 .445 .488 .487 .470 .459 .481 .490 .507 .498 .471 .477 .490 .506 .507 .514 .513 .489 unitless U.S. skew, U.S. skew, .457 .454 .481 .242 .306 .246 .435 .391 .418 .411 .210 .252 .211 .218 .243 .306 .318 .322 .363 .560 .611 .537 .453 .462 .550 .445 .340 unitless WV skew, WV skew, VA VA VA VA VA VA VA VA VA VA VA MD MD MD MD MD MD MD MD MD MD WV WV WV WV WV WV State Streamgage-station name Potomac River at Paw Bear Creek at Forest Park Sideling Hill Creek at Bellegrove Spring Yellow Cacapon River at Cacapon River near Great Creek near Hancock Tonoloway Little Potomac River at Hancock Ditch Run near Hancock near Hancock Tributary Potomac River Hogue Creek near Hayfield Back Creek near Jones Springs Opequon Creek near Berryville Winchester Abrams Creek near Opequon Creek near Martinsburg Creek above Martinsburg Tuscarora Marsh Run at Grimes Potomac River at Shepherdstown near Locust Grove Tributary Dog Creek Antietam Creek near Sharpsburg North River near Stokesville Dry River at Rawley Springs Branch near Hinton War Blacks Run at Harrisonburg near Harrisonburg Tributary Blacks Run North River near Burketown at Mount Crawford Tributary North River Agusta Springs near Trib. Branch Buffalo

01611500 01610000 01610150 01610155 01610500 01612500 01613000 01613150 01613160 01613900 01614000 01615000 01616000 01616500 01617000 01617800 01618000 01619475 01619500 01620500 01621000 01621200 01621400 01621450 01622000 01622100 01622300 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water Table 1 27 - 10

.260 .293 .407 .373 .198 .363 .292 .286 .372 .314 .340 .298 .405 .311 .364 .228 .369 .335 .282 .101 .245 .226 .177 .200 .236 .602 .254 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 1.760 3.909 2.137 3.328 1.363 2.421 4.037 3.327 2.059 4.077 3.524 4.524 2.766 3.402 3.584 5.018 3.596 3.880 2.599 1.512 3.584 3.469 3.643 3.770 4.003 1.562 3.725 second discharges, transformed Mean of log flood-frequency in cubic feet per

.511 .010 .395 .151 .244 .040 .300 .224 .416 .205 .154 .344 .141 .236 .101 .341 .228 .385 .537 .489 .096 .068 -.010 -.070 -.120 -.260 -.140 skews, unitless and station Weighted WV Weighted

.033 .014 -.114 -.086 -.114 -.127 -.139 -.050 -.139 -.232 -.111 -.277 -.156 -.190 -.193 -.267 -.328 -.311 -.325 -.293 -.078 -.175 -.060 -.149 -.281 -.410 -.402 skews, unitless between Difference WV and US .492 .482 .499 .496 .474 .482 .489 .475 .475 .489 .476 .515 .522 .529 .554 .556 .558 .593 .579 .416 .413 .405 .404 .407 .417 .413 .417 unitless U.S. skew, U.S. skew, .378 .515 .413 .382 .347 .343 .439 .336 .243 .378 .199 .359 .332 .336 .287 .228 .247 .268 .286 .338 .238 .419 .344 .258 .136 .003 .015 unitless WV skew, WV skew, VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA MD MD MD WV State Streamgage-station name Buffalo Branch Tributary near Christian Tributary Branch Buffalo N. Fk. Shenandoah R. at Cootes Store Long Meadow near Broadway Smith Creek near New Market near Conicville Tributary Crooked Run Crooked Run near Mount Jackson N. Fk. Shenandoah R. at Mount Jackson Stony Creek at Columbia Furnace Woodstock Pughs Run near N. Fk. Shenandoah River near Strasburg Winchester Cedar Creek near Shenandoah River at Millville Little Catoctin Creek at Harmony Catoctin Creek near Middletown Taylorstown Catoctin Creek at Potomac River at Point Of Rocks Goose Creek near Middleburg Goose Creek near Leesburg South Fork Sycolin Creek near Leesburg Cattail Run near Bolar Jackson River near Bacova Back Creek near Sunrise at Rt. 600 near Mountain Grove Back Cr. Back Creek near Mountain Grove Jackson River at Falling Spring at Sweet Chaylbeate Trib. Sweet Spgs. Cr. Dunlap Creek near Covington

02011400 02011460 02011480 02011500 01622400 01632000 01632300 01632900 01632950 01632970 01633000 01633500 01633650 01634000 01634500 01636500 01637000 01637500 01638480 01638500 01643700 01644000 01644100 02009500 02012500 02012950 02013000 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water 28 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia - 10

.241 .170 .137 .284 .139 .199 .177 .191 .243 .141 .152 .263 .271 .176 .155 .230 .205 .130 .172 .183 .147 .262 .301 .179 .148 .272 .256 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 3.595 3.841 3.874 1.700 4.016 3.695 3.789 2.197 2.916 3.870 4.355 1.828 2.333 3.683 4.498 2.310 3.197 3.107 3.507 3.781 3.993 3.423 2.908 4.243 3.714 2.700 3.195 second discharges, transformed Mean of log flood-frequency in cubic feet per

.334 .471 .758 .291 .278 .231 .221 .356 .234 .070 .352 .284 .328 .104 .072 .126 .029 .575 .363 -.130 -.210 -.160 -.060 -.310 -.190 -.130 -.060 skews, unitless and station Weighted WV Weighted

.226 .281 .302 .295 .148 .147 .009 .181 .101 .104 .148 .202 .094 .124 .178 -.424 -.122 -.008 -.152 -.184 -.184 -.195 -.215 -.071 -.248 -.179 -.148 skews, unitless between Difference WV and US .425 .320 .306 .306 .284 .276 .265 .246 .265 .257 .251 .260 .259 .227 .219 .225 .238 .226 .218 .205 .191 .206 .165 .178 .178 .190 .187 unitless U.S. skew, U.S. skew, .001 .546 .587 .608 .579 .424 .412 .124 .274 .249 .432 .361 .363 .375 .421 .319 .086 .042 .034 .010 .135 .030 .314 .365 -.024 -.083 -.001 unitless WV skew, WV skew, VA WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name Potts Creek near Covington River near Dailey Valley Tygart River near Elkins Valley Tygart Unnamed Run at Gilman River at Belington Valley Tygart Middle Fork River at Midvale Audra Middle Fork River at Mud Lick Run near Buckhannon Sand Run near Buckhannon Buckhannon River at Hall River at Phillipi Valley Tygart Bonica Run on U.S. 250 near Phillipi Bonica Run on Route 38 near Phillipi Three Fork Creek near Grafton River at Fetterman Valley Tygart Run near Grafton Wickwire Right Fk. Walkersville Fork River at West Skin Creek near Brownsville Weston Fork R. blw Stonewall Jackson Dam nr West Fork River at Butcherville West Fork River at Clarksburg West Elk Creek at Quiet Dell Salem Fork at Fork River at Enterprise West Creek at Barrackville Buffalo Cobun Creek at Morgantown Deckers Creek at Morgantown

02014000 03050000 03050500 03050650 03051000 03051500 03052000 03052340 03052500 03053500 03054500 03055020 03055040 03056250 03056500 03056600 03057300 03057500 03058000 03058500 03059000 03059500 03060500 03061000 03061500 03062400 03062500 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water Table 1 29 - 10

.318 .211 .204 .197 .239 .138 .203 .172 .162 .187 .185 .206 .189 .176 .200 .190 .199 .197 .205 .210 .284 .143 .205 .223 .220 .237 .202 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 .846 1.836 4.136 3.195 3.416 3.615 2.379 4.043 3.957 4.422 1.906 3.032 4.541 3.875 4.644 4.665 3.850 2.826 1.370 3.636 1.501 1.072 3.192 3.737 3.568 2.592 3.958 second discharges, transformed Mean of log flood-frequency in cubic feet per

.967 .959 .796 .721 .316 .304 .439 .355 .846 .845 .548 .210 .596 .750 .280 .290 .099 .385 .579 .215 .057 .136 .356 .284 .160 -.010 -.110 skews, unitless and station Weighted WV Weighted

.466 .491 .347 .334 .350 .205 .425 .359 .399 .488 .239 .222 .471 .246 .398 .415 .206 .239 .259 .254 .272 .284 .051 .051 .149 .120 -.050 skews, unitless between Difference WV and US .351 .322 .342 .337 .316 .345 .334 .323 .311 .307 .280 .279 .276 .230 .219 .196 .164 .188 .316 .303 .294 .269 .276 .057 .004 -.055 -.022 unitless U.S. skew, U.S. skew, .817 .813 .689 .671 .666 .550 .759 .682 .710 .795 .519 .501 .747 .476 .617 .611 .114 .394 .555 .562 .548 .541 .560 .108 .055 .094 .098 unitless WV skew, WV skew, PA PA PA PA OH OH MD MD MD MD MD WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name Job Run near Wymer Job Run near Dry Fork at Hendricks Blackwater River near Davis Blackwater River at Davis WS-4 near Hendricks Fernow Shavers Fork at Cheat Bridge Run at Bowden Taylor Shavers Fork below Bowden Shavers Fork at Parsons Cheat River near Parsons Long Run near Parsons Creek near Rowlesburg Buffalo Cheat River at Rowlesburg Big Sandy Creek near Rockville Cheat River near Pisgah Cheat River near Morgantown Dunkard Creek at Shannopin Creek at Smithfield Georges at Deer Park Trib. R. Youghiogheny Little River near Oakland Youghiogheny near Hoyes Run Tributary Run Toliver near Friendsville Trib. R. Youghiogheny Bear Creek at Friendsville Chartiers Creek at Carnegie Mill Raccoon Creek at Moffatts Lisbon Creek at Little Beaver Creek near East Liverpool

03063950 03065000 03065400 03066000 03067100 03067500 03068610 03068800 03069000 03069500 03069850 03069880 03070000 03070500 03071000 03071500 03072000 03072590 03075450 03075500 03075600 03076505 03076600 03085500 03108000 03109000 03109500 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

111 110 112 113 114 115 116 117 118 119 109 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water 30 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia - 10

.196 .331 .294 .293 .242 .367 .211 .520 .239 .205 .333 .216 .377 .132 .306 .258 .286 .218 .230 .383 .194 .253 .357 .086 .239 .243 .135 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 .808 3.497 2.721 1.764 2.352 1.805 3.448 1.686 3.426 3.955 2.693 3.785 1.805 4.132 2.307 2.401 2.905 2.814 3.890 1.282 3.886 2.359 2.737 1.646 2.153 3.708 3.712 second discharges, transformed Mean of log flood-frequency in cubic feet per

.391 .048 .005 .108 .008 .000 .090 .218 .481 .196 .045 .252 .173 .450 -.040 -.110 -.130 -.060 -.040 -.070 -.130 -.250 -.190 -.340 -.260 -.010 -.170 skews, unitless and station Weighted WV Weighted

.040 .001 -.002 -.022 -.023 -.006 -.040 -.038 -.061 -.031 -.078 -.089 -.107 -.184 -.180 -.182 -.186 -.150 -.132 -.141 -.135 -.134 -.052 -.055 -.077 -.066 -.083 skews, unitless between Difference WV and US .048 .011 .016 .036 .042 .023 .026 .079 .071 .073 .076 .051 .041 .042 .042 .039 .020 .247 .227 -.025 -.013 -.012 -.012 -.013 -.002 -.007 -.002 unitless U.S. skew, U.S. skew, .015 .049 .005 .181 .144 -.015 -.034 -.035 -.019 -.029 -.040 -.045 -.036 -.066 -.081 -.105 -.109 -.109 -.110 -.099 -.091 -.099 -.093 -.095 -.059 -.057 -.057 unitless WV skew, WV skew, PA OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH OH WV WV WV WV WV WV WV WV State Streamgage-station name Yellow Creek near Hammondsville Yellow Consol Run at Bloomingdale Brush Run near Buffalo Branson Run at Georgetown South Fork Short Creek at Georgetown Little Piney Fork at Parlett Short Creek near Dillonvale near Harrisville Tributary Sloan Run Wheeling Creek below Blaine Wheeling Creek at Elm Grove Little Grave Creek near Glendale Armstrongs Mills Captina Creek at Woodsfield Run near Wood Middle Island Creek at Little Run near Friendly Buffalo Run near Friendly Little Buffalo Run near Little Buffalo Antioch Run near Trail Little Muskingum River at Bloomfield Graham Run near Bloomfield Little Muskingum River at Fay Wingott Moss Run near Barns Run near Summerfield near Dexter City Tributary Run Buffalo Creek at Devola Tupper Wildcat Little Kanawha River near Little Kanawha River near Burnsville

03111150 03111450 03111455 03111470 03111500 03111540 03111548 03110000 03110980 03112000 03113700 03114000 03114240 03114500 03114550 03114600 03114650 03115280 03115400 03115410 03115500 03115510 03115600 03115710 03150600 03151400 03151500 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water Table 1 31 - 10

.149 .247 .194 .180 .119 .175 .204 .146 .141 .119 .246 .164 .231 .182 .239 .246 .221 .228 .147 .244 .084 .146 .267 .217 .152 .213 .191 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 3.986 2.537 3.783 3.838 4.301 3.887 2.824 3.548 4.466 3.911 2.865 4.160 3.274 3.579 2.191 4.543 3.833 3.722 3.162 4.608 3.593 2.851 3.153 3.901 3.944 4.693 1.741 second discharges, transformed Mean of log flood-frequency in cubic feet per

.021 .086 .084 .565 .270 .674 .005 .584 .567 .553 -.010 -.300 -.260 -.270 -.150 -.080 -.210 -.290 -.240 -.130 -.420 -.160 -.290 -.070 -.240 -.460 -.170 skews, unitless and station Weighted WV Weighted

.040 .278 -.167 -.299 -.303 -.229 -.222 -.238 -.245 -.216 -.196 -.260 -.237 -.238 -.216 -.163 -.042 -.370 -.423 -.425 -.071 -.405 -.433 -.488 -.483 -.485 -.142 skews, unitless between Difference WV and US .181 .171 .173 .166 .147 .141 .127 .098 .084 .111 .099 .092 .086 .011 .086 .412 .404 .385 .381 .378 .366 .343 .335 .344 .345 .347 .357 unitless U.S. skew, U.S. skew, .014 .051 .370 .034 .307 .205 .635 -.128 -.130 -.063 -.075 -.097 -.118 -.118 -.112 -.149 -.138 -.146 -.130 -.077 -.038 -.044 -.039 -.090 -.153 -.139 -.140 unitless WV skew, WV skew, VA VA VA VA VA OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name Little Kanawha River at Glenville Buck Run near Leopold Leading Creek near Glenville Steer Creek near Grantsville Little Kanawha River at Grantsville Fk. Little Kanawha River at Rocksdale W. Run at Spencer Tanner Reedy Creek near Little Kanawha River at Palestine South Fork Hughes River at Macfarlan Big Island Run near Elizabeth Hughes River at Cisco Goose Creek near Petroleum Shade River near Chester Grasslick Run near Ripley New River at Eggleston Creek at Bane Walker Creek near Narrows Wolf Rich Creek near Peterstown New River at Glen Lyn Indian Creek at Mills Bluestone River at Bluefield Camp Creek near Bluestone River near Pipestem Bluestone River at Lilly New River at Bluestone Dam at Durbin Trib. Fk. Greenbrier River W.

03152000 03152200 03152500 03153000 03153500 03154000 03154250 03154500 03155000 03155200 03155450 03155500 03155525 03159540 03159700 03171500 03173000 03175500 03176400 03176500 03177500 03177700 03178500 03179000 03179500 03180000 03180350 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water 32 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia - 10

.210 .330 .266 .153 .163 .181 .165 .232 .169 .130 .296 .148 .361 .212 .235 .328 .189 .210 .188 .191 .233 .189 .204 .195 .172 .231 .149 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 3.687 1.862 1.992 1.019 3.708 4.273 3.980 3.409 4.527 2.441 2.118 4.568 2.782 4.898 3.091 1.472 4.957 4.975 3.914 4.057 2.911 3.695 3.944 4.415 4.397 2.234 3.779 second discharges, transformed Mean of log flood-frequency in cubic feet per

.380 .259 .043 .728 .460 .524 .017 .119 .127 .077 .206 .070 .379 .254 .343 .311 .656 .113 .514 .036 -.140 -.270 -.310 -.090 -.160 -.110 1.068 skews, unitless and station Weighted WV Weighted

.369 .276 .110 .075 .006 -.145 -.188 -.332 -.398 -.254 -.385 -.402 -.266 -.410 -.331 -.452 -.437 -.308 -.297 -.012 -.090 -.069 -.135 -.052 -.045 -.197 -.246 skews, unitless between Difference WV and US .359 .370 .378 .376 .367 .364 .381 .388 .364 .356 .361 .356 .352 .344 .305 .316 .293 .281 .301 .289 .334 .307 .310 .295 .279 .287 .296 unitless U.S. skew, U.S. skew, .728 .646 .488 .231 .179 .439 .049 .110 .090 .013 .289 .295 .244 .238 .175 .243 .234 .090 .050 -.010 -.029 -.041 -.058 -.147 -.121 -.015 -.016 unitless WV skew, WV skew, WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name Greenbrier River at Durbin Brush Run near Bartow Cooper Run near Green Bank Mack Butterball Hollow near Huntersville Knapp Creek at Marlinton Greenbrier River at Buckeye Anthony Anthony Creek near Second Creek near Alderson Greenbrier River at Alderson Griffith Creek near Buggar Lick at Pence Springs Greenbrier River at Hilldale Big Creek near Bellepoint New River at Hinton Piney Creek at Raleigh near Shady Springs Trib. Little Beaver Cr. New River at Caperton New River at Fayette River at Dyer Williams Gauley River at Camden on North Fk. Cranberry River near Hillsboro Cranberry River near Richwood Cherry River at Fenwick Gauley River near Craigsville Gauley River near Summersville Collison Creek near Nallen Meadow River at Nallen

03180500 03180530 03180680 03181900 03182000 03182500 03182700 03183000 03183500 03183550 03183570 03184000 03184200 03184500 03185000 03185020 03185500 03186000 03186500 03187000 03187300 03187500 03189000 03189100 03189500 03189650 03190000 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

211 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 212 213 214 215 216 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water Table 1 33 - 10

.372 .187 .155 .348 .279 .158 .198 .178 .203 .273 .179 .101 .187 .187 .159 .159 .154 .175 .251 .391 .275 .232 .256 .436 .273 .305 .241 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 3.231 3.958 2.506 2.379 3.420 4.624 4.576 5.089 1.267 2.393 4.082 4.049 3.395 3.403 4.299 2.961 4.446 2.347 1.840 3.332 2.571 4.021 2.081 1.864 3.965 2.622 4.006 second discharges, transformed Mean of log flood-frequency in cubic feet per

.215 .276 .085 .112 .319 .251 .104 .621 .500 .143 .478 .388 .287 .199 .418 .029 .060 .096 .263 .088 .105 -.170 -.070 -.120 -.230 -.070 -.260 skews, unitless and station Weighted WV Weighted

.112 .116 .006 .011 .072 -.203 -.221 -.195 -.198 -.180 -.078 -.083 -.313 -.349 -.047 -.171 -.015 -.254 -.256 -.360 -.306 -.313 -.334 -.321 -.345 -.296 -.321 skews, unitless between Difference WV and US .296 .277 .273 .262 .258 .242 .242 .253 .269 .351 .270 .260 .268 .265 .235 .233 .191 .174 .179 .241 .196 .184 .201 .195 .186 .183 .171 unitless U.S. skew, U.S. skew, .093 .056 .078 .064 .078 .164 .159 .304 .382 .376 .274 .276 .307 .062 .176 -.060 -.080 -.080 -.077 -.119 -.110 -.129 -.133 -.126 -.159 -.113 -.150 unitless WV skew, WV skew, WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name Anglins Creek near Nallen Meadow River near Mount Lookout Meadow Creek near Summersville Laurel Creek near Summersville Peters Creek near Lockwood Gauley River above Belva Gauley River at Belva Kanawha River at Falls Little Fork at Mossy Gilmer Run near Marlinton Springs Webster Elk River below Elk River at Centralia Right Fork Holly River at Guardian Left Fork Holly River near Replete Elk River at Sutton Granny Creek at Sutton Elk River at Queen Shoals Ashleycamp Run near Left Hand near Charleston Trib. Creek Twomile Elk Whitesville Clear Fork at Drawdy Creek near Peytona Ashford Big Coal River at Hunters Branch near Madison Low Gap Creek near Madison Little Coal River at Danville Rock Creek near Danville Little Coal River at Julian

03190100 03190400 03190500 03191400 03191500 03192000 03192500 03193000 03193725 03193830 03194700 03195000 03195100 03195250 03195500 03195600 03197000 03197150 03197900 03198350 03198450 03198500 03198780 03198800 03199000 03199300 03199400 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water 34 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia - 10

.174 .228 .189 .183 .179 .155 .229 .323 .191 .239 .343 .365 .200 .217 .252 .201 .229 .217 .337 .195 .183 .228 .224 .448 .277 .323 .369 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 4.300 1.926 3.826 3.317 2.955 2.406 2.490 2.111 3.790 2.667 3.911 2.541 3.638 4.294 4.380 4.345 3.808 2.066 2.826 3.244 3.536 3.811 3.810 2.922 3.955 3.946 1.796 second discharges, transformed Mean of log flood-frequency in cubic feet per

.049 .302 .308 .171 .042 .250 .335 .199 .000 .000 -.290 -.140 -.180 -.040 -.300 -.220 -.030 -.310 -.340 -.400 -.480 -.100 -.160 -.020 -.190 -.390 -.180 skews, unitless and station Weighted WV Weighted

.028 .217 .133 .036 -.273 -.176 -.234 -.134 -.153 -.143 -.051 -.492 -.466 -.493 -.471 -.450 -.428 -.322 -.145 -.174 -.105 -.063 -.058 -.357 -.369 -.354 -.256 skews, unitless between Difference WV and US .140 .118 .135 .099 .108 .103 .058 .019 .290 .265 .268 .255 .223 .200 .107 .093 .030 .055 .124 .088 .068 .066 .251 .238 .221 .187 -.017 unitless U.S. skew, U.S. skew, .007 .047 .200 .163 .091 .005 .008 -.133 -.058 -.099 -.035 -.045 -.040 -.202 -.201 -.225 -.216 -.227 -.228 -.215 -.052 -.050 -.017 -.106 -.131 -.133 -.069 unitless WV skew, WV skew, VA VA VA KY OH OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Streamgage-station name Coal River at Tornado Coal River at Little Scary Creek near Nitro Pocatalico River at Sissonville Hurricane Creek at Teays Poplar Fork at Teays Long Branch near Sixteenmile Creek near Pliny near Point Pleasant Trib. Threemile Creek Adamsville Raccoon Creek at Marsh Fork at Maben Guyandotte River near Baileysville Brier Creek at Fanrock Clear Fork at Guyandotte River at Man Guyandotte River at Logan Guyandotte River at Branchland Mud River near Milton Sandusky Creek near Burlington Fourpole Creek near Huntington Creek near Dunlow Twelvepole East Fork Creek near East Lynn Twelvepole E. Fk. Wayne Creek at Twelvepole Wayne Creek below Twelvepole Vasant Prater Creek at Levisa Fork near Grundy Levisa Fork at Big Rock Dicks Fork at Phyllis

03200500 03200600 03201000 03201405 03201410 03201420 03201440 03201480 03202000 03202245 03202400 03202480 03202750 03203000 03203600 03204000 03204500 03205995 03206450 03206600 03206800 03207000 03207020 03207400 03207500 03207800 03207962 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water Table 1 35 - 10

.216 .295 .305 .236 .203 .247 .227 .303 .336 .252 .261 .385 .268 .281 .268 .241 .219 .178 .168 .185 second Standard discharges, transformed flood-frequency in cubic feet per deviation of log of deviation

- 10 4.076 4.099 3.402 3.970 2.464 3.396 3.627 3.706 3.490 3.718 4.081 3.205 4.242 4.380 4.366 4.275 3.784 4.007 2.975 2.280 second discharges, transformed Mean of log flood-frequency in cubic feet per

.189 .430 .043 .116 .270 .249 .088 -.130 -.240 -.100 -.420 -.110 -.170 -.060 -.310 -.250 -.150 -.050 -.130 -.040 skews, unitless and station Weighted WV Weighted

.001 .251 .229 .394 .234 .292 -.309 -.281 -.179 -.186 -.217 -.082 -.470 -.423 -.438 -.433 -.360 -.319 -.307 -.252 skews, unitless between Difference WV and US .178 .223 .213 .213 .131 .153 .085 .047 .287 .269 .255 .256 .169 .133 .127 .087 .039 .024 -.024 -.006 unitless U.S. skew, U.S. skew, .034 .027 .132 .003 .298 .268 .370 .258 .286 -.131 -.058 -.064 -.183 -.154 -.183 -.177 -.191 -.186 -.180 -.165 unitless WV skew, WV skew, VA VA VA KY KY KY KY KY KY KY KY KY WV WV WV WV WV WV WV WV State Streamgage-station name Levisa Fork below Fishtrap Dam Russel Fork at Haysi Cranes Nest River near Clintwood Flannagan Dam near Haysi Pond R. blw. Bill D. Branch near Kite Johns Crek near Meta Lear Van Johns Creek near Paint Creek at Staffordsville Welch Fork at Tug Dry Fork at Beartown Fork at Litwar Tug Panther Creek near Williamson Fork at Tug Fork near Kermit Tug Fork at Kermit Tug Fork at Glenhayes Tug Yatesville Blaine Creek at Little Sandy River at Grayson E. Fk. Little Sandy River near Fallsburg Mile Branch near Rush

03211500 03208000 03208500 03208950 03209000 03209575 03210000 03212000 03212750 03212980 03213000 03213500 03213700 03214000 03214500 03214900 03215500 03216500 03216540 03216563 Streamgage station number Identification numbers, station streamgage-station names, and skew coefficients statistics for the 290 U.S. Geologi cal Survey streamgage stations on

271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 number Identification Table 1. Table and adjacent states.—Continued Virginia rural, unregulated streams in West Br., West; R., Right; W., KY, Kentucky; N., North; S., South; E., East; PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; Advisory Committee on the skew presented in Bulletin-17B by Interagency United States skew, near; U.S. skew, Spgs., Springs; Rt., Route; bl, below; nr, Tributary; Trib., Creek; Branch; Fk., Fork; Cr., Atkins and others (2009); shading indicates the 44 streamgage stations removed from consideration as part of regional regression analysis] skew determined by Virginia West skew, WV Data (1982); Water 36 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

-- .083 .445 .528 .537 .816 .980 .301 .546 .012 .169 .360 .005 .237 .033 .509 .325 .161 .030 .711 .235 .017 .536 .724 .833 .213 .820 level 0.175 1.000 Significance

Trend analysis Trend -- .071 .107 .104 .462 .065 .075 .308 .513 .046 .033 .000 .309 .046 tau -.239 -.093 -.056 -.030 -.007 -.081 -.100 -.495 -.088 -.231 -.187 -.143 -.092 -.052 -0.130 Kendall’s Kendall’s 1 ------Low outlier 1 1 1 1 2 1 1 3 2 1 3 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------second Override of outlier thresholds discharge, in cubic feet per High threshold ------83 130 130 130 130 130 130 Historic record 9 9 11 52 27 56 25 58 33 24 77 21 15 77 52 69 61 13 50 80 13 64 78 13 84 26 25 68 18 Number of years Systematic peaks bounding systematic 1955–2006 1955–1982 1950–2006 1924–1950 1949–2006 1949–1981 1925–1950 1931–2007 1948–1969 1936–1950 1930–2006 1930–1981 1939–2007 1936–2007 1965–1977 1940–2007 1924–2007 1965–1977 1944–2007 1999–2007 1924–2007 1965–1977 1900–2007 1928–2005 1948–1976 1999–2007 1967–1977 1939–2006 1965–1983 Water years Water

0.23 1.56 1.04 0.21 5.08 73.1 42.6 49.1 16.7 72.4 46.5 28.9 10.4 115 225 287 598 247 877 221 179 310 651 103 277 148 108 miles 3,114 1,461 in square Drainage area, MD MD MD MD MD MD MD MD MD MD MD MD MD WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 01595000 01595300 01595500 01596000 01596500 01597000 01598000 01599000 01599500 01600000 01601500 01603000 01604500 01605500 01605700 01606000 01606500 01606800 01607500 01607510 01608000 01608100 01608500 01609000 01609500 01609650 01609800 01610000 01610150 Streamgage

eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

1 2 3 4 5 6 7 8 9 11 10 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] Table 2 37

------.880 .511 .808 .967 .955 .788 .643 .715 .032 .004 .056 .552 .661 .200 .592 .305 .049 .262 .747 .681 level Significance

Trend analysis Trend ------.089 .048 .036 .194 .396 .170 .063 .156 .511 .085 .051 .043 tau -.033 -.143 -.018 -.015 -.013 -.077 -.282 -.080 Kendall’s Kendall’s 1 1 1 1 1 ------Low outlier 1 1 1 1 1 1 1 5 1 ------12 High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------36,000 second Override of outlier thresholds discharge, in cubic feet per High threshold ------67 55 40 25 119 146 172 Historic record 11 18 14 84 17 75 22 12 46 51 58 27 60 26 43 69 80 60 31 28 13 10 77 10 10 32 81 25 45 Number of years Systematic peaks bounding systematic 1968–2006 1936–1951 1923–2007 1948–1964 1929–2006 1965–1986 1965–1976 1961–2006 1929–2007 1944–2006 1950–1994 1948–2007 1949–2007 1964–2007 1929–2004 1966–1976 1928–2007 1947–2006 1943–1986 1949–1976 1949–1961 1966–1975 1927–2006 1966–1975 1967–1976 1967–2000 1926–2006 1950–1977 1961–2006 Water years Water

4.80 1.20 0.10 9.73 5.44 0.67 1.56 0.54 0.46 7.94 11.3 16.9 15.9 58.2 17.0 18.9 17.3 73.0 93.6 102 306 675 235 273 281 375 210 miles 4,075 5,950 in square Drainage area, VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA MD MD MD MD MD MD MD MD MD WV WV WV WV WV State station number 01611500 01610155 01610500 01612500 01613000 01613150 01613160 01613900 01614000 01615000 01616000 01616500 01617000 01617800 01618000 01619475 01619500 01620500 01621000 01621200 01621400 01621450 01622000 01622100 01622300 01622400 01632000 01632300 01632900 Streamgage eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] 38 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

------.039 .173 .157 .586 .130 .488 .010 .906 .213 .161 .389 .010 .259 .180 .172 .030 .209 .516 .516 .260 level Significance

Trend analysis Trend ------.533 .124 .074 .053 .211 .096 .105 .238 .104 .114 .166 .112 .044 .157 tau -.166 -.178 -.016 -.345 -.217 -.104 Kendall’s Kendall’s 1 1 1 1 1 ------Low outlier 1 1 1 4 2 1 1 1 1 2 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------second Override of outlier thresholds discharge, in cubic feet per High threshold ------69 91 91 75 119 172 138 138 120 120 120 Historic record 11 10 35 62 30 36 80 69 90 29 59 36 34 79 12 10 34 32 34 55 26 78 68 80 60 22 27 113 100 Number of years Systematic peaks bounding systematic 1966–1975 1972–2006 1944–2006 1947–1976 1971–2006 1926–2006 1938–2006 1896–2007 1948–1976 1948–2006 1971–2006 1895–2007 1966–2006 1910–2006 1966–1977 1966–1975 1972–2006 1975–2006 1974–1984 1951–1984 1925–1979 1966–1995 1929–2006 1929–2006 1916–2007 1945–2004 1964–2006 1908–2007 1916–1942 Water years Water

0.34 6.60 3.43 8.83 2.06 0.68 0.86 0.46 77.5 66.9 89.6 60.9 88.6 508 770 102 122 332 157 134 410 162 153 185 271 406 122 miles 3,041 9,651 in square Drainage area, VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA VA MD MD MD WV WV WV WV WV WV State station number 02011400 02011460 02011480 02011500 01632950 01632970 01633000 01633500 01633650 01634000 01634500 01636500 01637000 01637500 01638480 01638500 01643700 01644000 01644100 02009500 02012500 02012950 02013000 02014000 03050000 03050500 03050650 03051000 03051500 Streamgage

eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] Table 2 39

.097 .441 .169 .997 .072 .730 .584 .853 .852 .760 .488 .521 .229 .124 .858 .588 .970 .986 .863 .105 .178 .945 .117 .631 .133 .455 .040 .558 .449 level Significance

Trend analysis Trend .153 .121 .000 .151 .032 .077 .143 .013 .030 .132 .111 .329 .117 .137 tau -.135 -.091 -.121 -.026 -.072 -.128 -.123 -.016 -.077 -.002 -.013 -.188 -.159 -.121 -.070 Kendall’s Kendall’s 1 ------Low outlier 1 1 1 1 1 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------60,000 second Override of outlier thresholds discharge, in cubic feet per High threshold ------42 120 120 102 102 120 Historic record 56 19 61 93 67 12 14 23 31 13 15 40 43 74 60 27 18 65 83 37 36 12 67 12 86 55 21 16 18 Number of years Systematic peaks bounding systematic 1943–2007 1966–2007 1947–2007 1908–2007 1941–2007 1966–1977 1964–1977 1985–2007 1908–1938 1965–1977 1985–1999 1946–1985 1947–1989 1916–1989 1924–1983 1944–1970 1952–1969 1908–1989 1916–2007 1966–2002 1947–2007 1965–1977 1941–2007 1992–2007 1922–2007 1952–2006 1922–2007 1974–1998 1974–2007 Water years Water

2.33 0.60 3.15 2.33 8.32 1.08 0.15 5.06 11.0 14.3 96.8 28.8 25.7 84.6 63.2 54.7 85.9 57.6 116 148 277 914 101 181 384 759 349 151 miles 1,304 in square Drainage area, WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 03052000 03052340 03052500 03053500 03054500 03055020 03055040 03056250 03056500 03056600 03057300 03057500 03058000 03058500 03059000 03059500 03060500 03061000 03061500 03062400 03062500 03063950 03065000 03065400 03066000 03067100 03067500 03068610 03068800 Streamgage eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

88 89 90 91 92 93 94 95 96 97 98 99 111 110 112 113 114 115 116 100 101 102 103 104 105 106 107 108 109 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] 40 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

------.513 .023 .945 .016 .024 .564 .978 .943 .767 .295 .042 .798 .049 .025 .474 .342 .767 level Significance

Trend analysis Trend ------.052 .160 .180 .007 .067 .078 .146 tau -.030 -.355 -.041 -.004 -.155 -.032 -.141 -.189 -.200 -.037 Kendall’s Kendall’s 1 ------Low outlier 1 4 1 2 1 1 1 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------second Override of outlier thresholds discharge, in cubic feet per High threshold ------164 164 142 142 Historic record 11 11 74 94 12 24 74 93 47 16 66 15 12 65 22 12 43 84 80 35 91 66 10 21 10 65 10 23 34 Number of years Systematic peaks bounding systematic 1911–2001 1914–2007 1966–1977 1968–2007 1921–1996 1910–2007 1903–1958 1903–1926 1941–2006 1964–1978 1965–1976 1936–2006 1965–1986 1965–1976 1965–2007 1916–2006 1916–2006 1947–1981 1916–2006 1941–2006 1978–1987 1961–1985 1978–1990 1978–1990 1978–1987 1942–2006 1978–1987 1983–2006 1941–1974 Water years Water

0.95 0.57 0.53 0.22 6.19 0.04 1.31 1.57 0.34 12.2 16.3 48.9 10.3 10.9 97.7 213 722 939 200 229 134 257 178 496 147 123 281 miles 1,354 1,380 in square Drainage area, PA PA PA PA PA OH OH OH OH OH OH OH OH OH OH MD MD MD MD MD WV WV WV WV WV WV WV WV WV State station number 03111150 03111450 03111455 03111470 03111500 03111540 03111548 03110000 03110980 03112000 03069000 03069500 03069850 03069880 03070000 03070500 03071000 03071500 03072000 03072590 03075450 03075500 03075600 03076505 03076600 03085500 03108000 03109000 03109500 Streamgage

eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] Table 2 41

-- -- .451 .933 .210 .219 .373 .616 .594 .902 .897 .118 .235 .865 .712 .649 .450 .025 .456 .490 .127 .428 .118 .605 .112 .266 .592 level 1.000 1.000 Significance

Trend analysis Trend -- -- .009 .095 .212 .079 .066 .026 .444 .024 .045 .124 .462 .087 .067 .179 .217 .057 .330 .206 tau -.182 -.333 -.018 -.022 -.071 -.238 -.045 -.129 -.049 Kendall’s Kendall’s 1 1 1 ------Low outlier 1 1 1 1 4 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------second Override of outlier thresholds discharge, in cubic feet per High threshold ------95 51 Historic record 11 12 53 10 78 12 23 10 34 10 20 10 33 10 15 31 35 51 21 14 37 51 66 13 27 41 14 17 59 Number of years Systematic peaks bounding systematic 1970–1996 1927–2002 1978–1987 1916–1997 1966–1977 1967–1977 1969–2007 1978–1987 1959–2006 1978–1987 1916–1935 1978–1987 1947–1979 1978–1987 1966–1980 1975–2007 1939–1973 1929–1979 1970–2006 1938–1951 1939–1975 1929–1979 1929–2000 1970–1998 1952–1978 1939–1979 1938–1951 1965–1998 1930–1997 Water years Water

4.95 0.53 0.88 1.22 4.19 5.45 0.13 1.52 3.46 0.19 0.99 2.91 2.82 3.52 79.4 112 134 458 210 258 155 387 144 166 913 205 210 453 miles 1,516 in square Drainage area, OH OH OH OH OH OH OH OH OH OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 03113700 03114000 03114240 03114500 03114550 03114600 03114650 03115280 03115400 03115410 03115500 03115510 03115600 03115710 03150600 03151400 03151500 03152000 03152200 03152500 03153000 03153500 03154000 03154250 03154500 03155000 03155200 03155450 03155500 Streamgage eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] 42 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

------.283 .796 .541 .594 .735 .589 .530 .092 .985 .445 .118 .492 .171 .350 .360 .459 .441 .075 .213 .246 .635 .582 .783 .563 .303 level Significance

Trend analysis Trend ------.156 .178 .333 .005 .070 .217 .167 .118 .236 .205 .135 .138 .152 .136 .076 .047 tau -.289 -.029 -.141 -.044 -.027 -.167 -.309 -.031 -.191 Kendall’s Kendall’s 1 1 1 1 1 1 1 ------Low outlier 1 1 1 1 1 1 2 1 1 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------5,000 21,000 second Override of outlier thresholds discharge, in cubic feet per High threshold ------56 90 90 112 112 Historic record 11 11 10 41 13 25 69 77 10 24 10 15 29 57 27 25 12 64 13 13 19 78 30 12 12 72 17 12 112 Number of years Systematic peaks bounding systematic 1998–2007 1966–2006 1965–1977 1915–1939 1938–2006 1909–2006 1942–1951 1915–1938 1942–1951 1966–1980 1947–1998 1951–2007 1909–1948 1924–1948 1966–1977 1944–2007 1966–1977 1965–1977 1965–1977 1946–1998 1930–2007 1972–1982 1946–1998 1896–2007 1966–1977 1966–1977 1936–2007 1970–2007 1937–1948 Water years Water

0.70 1.13 1.28 1.52 0.10 3.84 2.31 8.27 25.3 50.6 39.7 32.0 80.8 156 299 223 189 395 438 133 108 540 144 miles 2,961 3,783 4,602 1,364 1,619 6,256 in square Drainage area, VA VA VA VA VA OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 03155525 03159540 03159700 03171500 03173000 03175500 03176400 03176500 03177500 03177700 03178500 03179000 03179500 03180000 03180350 03180500 03180530 03180680 03181900 03182000 03182500 03182700 03183000 03183500 03183550 03183570 03184000 03184200 03184500 Streamgage

eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] Table 2 43

------.870 .492 .117 .473 .108 .111 .109 .728 .338 .455 .251 .371 .241 .127 .948 .496 .098 .301 .005 .027 .254 .735 .342 level 1.000 1.000 Significance

Trend analysis Trend ------.021 .167 .121 .056 .275 .158 .171 .039 .100 .000 .073 .291 .279 .341 .242 .490 .173 .022 .149 .056 .146 tau -.333 -.101 -.009 -.081 Kendall’s Kendall’s 1 1 ------Low outlier 1 1 2 1 1 1 1 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------1,800 42,000 second Override of outlier thresholds discharge, in cubic feet per High threshold ------63 69 76 33 29 106 Historic record 9 11 36 12 20 35 78 77 19 49 43 41 45 12 51 39 17 37 36 14 71 12 18 76 29 10 30 22 23 Number of years Systematic peaks bounding systematic 1952–2007 1966–1977 1929–1948 1896–1948 1930–2007 1909–2000 1969–1998 1945–2007 1930–1982 1965–2007 1909–1965 1966–1977 1909–1971 1999–2007 1967–2007 1966–1976 1966–1998 1946–2007 1929–1964 1909–1930 1878–1948 1966–1977 1969–2007 1930–2007 1935–1963 1975–1987 1975–2007 1939–1960 1966–2004 Water years Water

0.62 9.78 2.78 4.22 3.88 0.33 1.80 6.39 52.7 80.4 23.5 40.2 51.9 46.5 128 236 150 529 680 287 365 266 281 542 miles 6,826 6,850 1,317 1,402 8,371 in square Drainage area, WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 03185000 03185020 03185500 03186000 03186500 03187000 03187300 03187500 03189000 03189100 03189500 03189650 03190000 03190100 03190400 03190500 03191400 03191500 03192000 03192500 03193000 03193725 03193830 03194700 03195000 03195100 03195250 03195500 03195600 Streamgage eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

211 204 205 206 207 208 209 210 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] 44 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

-- .149 .284 .945 .858 .325 .796 .537 .956 .835 .324 .858 .377 .271 .760 .754 .392 .112 .951 .044 .175 .545 .367 .631 .516 .600 .477 .470 .586 level Significance

Trend analysis Trend -- .179 .030 .067 .176 .019 .067 .258 .064 .094 .065 .078 .114 tau -.181 -.152 -.022 -.020 -.209 -.085 -.029 -.111 -.167 -.346 -.026 -.436 -.389 -.069 -.143 -.061 Kendall’s Kendall’s 1 1 1 1 1 ------Low outlier 1 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------second Override of outlier thresholds discharge, in cubic feet per High threshold ------31 Historic record 9 32 20 12 10 18 85 12 14 54 14 10 52 12 54 16 13 13 13 83 12 39 22 33 51 19 58 43 15 Number of years Systematic peaks bounding systematic 1929–1960 1966–2006 1964–1975 1997–2007 1965–1998 1909–2007 1966–1977 1963–1977 1931–1984 1979–2006 1975–1984 1909–2007 1966–1977 1909–1999 1999–2007 1992–2007 1965–1977 1965–1977 1965–1977 1916–2006 1978–2007 1969–2007 1970–2007 1975–2007 1929–1979 1961–1979 1916–1979 1938–1980 1978–2006 Water years Water

2.01 0.49 7.75 1.97 1.28 0.87 8.47 2.05 1.04 0.70 4.85 7.34 0.73 62.8 12.2 26.8 391 269 318 862 238 585 306 126 758 833 256 miles 1,145 1,224 in square Drainage area, OH OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 03197000 03197150 03197900 03198350 03198450 03198500 03198780 03198800 03199000 03199300 03199400 03200500 03200600 03201000 03201405 03201410 03201420 03201440 03201480 03202000 03202245 03202400 03202480 03202750 03203000 03203600 03204000 03204500 03205995 Streamgage

eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] Table 2 45

-- -- .618 .537 .592 .361 .359 .184 .377 .675 .634 .504 .820 .143 .350 .352 .945 .277 .554 .176 .506 .195 .771 .350 .451 .089 .695 .310 .891 level Significance

Trend analysis Trend -- -- .066 .139 .062 .095 .212 .062 .133 .175 .045 tau -.179 -.156 -.108 -.128 -.142 -.100 -.051 -.026 -.165 -.236 -.079 -.030 -.137 -.033 -.071 -.182 -.168 -.053 Kendall’s Kendall’s 1 1 1 1 1 1 1 ------Low outlier 1 1 1 ------High outlier Number of peaks ------second discharge, in cubic feet per Low threshold ------second Override of outlier thresholds discharge, in cubic feet per High threshold ------59 59 59 Historic record 9 9 11 43 10 31 36 27 43 39 31 80 42 39 66 12 32 22 22 56 46 40 51 81 12 49 30 19 12 Number of years Systematic peaks bounding systematic 1999–2007 1965–2007 1962–1971 1916–1966 1916–1971 1951–1977 1942–1995 1968–2006 1975–1984 1938–1968 1927–2006 1964–2006 1927–1965 1976–1986 1938–2006 1938–1949 1950–1981 1986–2007 1986–2007 1931–1986 1947–2007 1968–2007 1935–1985 1916–2007 1977–1995 1916–1981 1937–1967 1973–1991 1976–1987 Water years Water

4.02 0.82 3.17 0.94 38.5 20.0 66.5 56.3 31.0 12.2 139 291 300 239 297 392 286 221 206 103 174 209 504 936 217 400 miles 1,188 1,280 1,507 in square Drainage area, VA VA VA VA VA VA KY KY KY KY KY KY KY KY KY KY WV WV WV WV WV WV WV WV WV WV WV WV WV State station number 03211500 03206450 03206600 03206800 03207000 03207020 03207400 03207500 03207800 03207962 03208000 03208500 03208950 03209000 03209575 03210000 03212000 03212750 03212980 03213000 03213500 03213700 03214000 03214500 03214900 03215500 03216500 03216540 03216563 Streamgage eams in West Virginia and adjacent Virginia Flood-frequency statistics and drainage areas for the 290 U.S. Geological Survey streamgage stations on rural, unregulated str eams in West

262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 number Identification Table 2. Table states.—Continued KY, Kentucky; - -, no value; shading indicates the 44 streamgage stations PA, Pennsylvania; OH, Ohio; Virginia; VA, MD, Maryland; Virginia; West WV, [Identification number refers to the in figure 3; removed from consideration as part of the regional regression analysis] 46 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

8,670 5,230 5,090 5,140 8,020 11,400 11,700 11,200 22,300 18,200 19,800 10,500 68,600 48,200 55,800 65,800 59,500 60,900 10,200 12,900 32,000 27,000 28,100 12,700 18,100 15,200 12,300 500-year 114,000 116,000 131,000 (0.2% AOP)

), from the systematic the from ), s 6,550 9,150 8,180 7,960 9,160 3,810 4,090 3,990 6,430 9,870 8,920 11,900 17,700 14,600 15,800 50,600 38,200 43,200 50,700 47,100 48,000 10,300 23,900 21,500 22,100 10,000 14,400 89,700 91,400 200-year ), from the regionalized 100,000 r (0.5% AOP)

5,280 7,610 6,650 6,530 8,590 7,500 2,970 3,420 3,240 8,270 9,730 5,360 8,200 7,340 14,700 12,100 13,200 39,900 31,600 35,200 41,200 38,900 39,500 19,000 17,800 18,100 12,000 81,300 73,800 75,200 100-year (1% AOP)

9,820 4,220 6,200 5,290 5,300 7,000 6,010 2,290 2,790 2,570 6,750 9,740 7,790 4,400 6,680 5,880 12,100 10,900 31,200 25,600 28,400 33,100 31,500 32,000 15,000 14,400 14,600 65,000 59,600 60,700 50-year (2% AOP)

9,760 7,780 8,890 3,350 4,920 4,080 4,260 5,550 4,710 1,740 2,230 1,970 5,440 7,720 6,080 3,530 5,300 4,560 11,600 11,400 11,500 24,100 20,200 22,500 26,100 24,800 25,300 51,200 46,800 48,000 25-year (4% AOP)

7,130 5,390 6,590 2,430 3,420 2,750 3,100 3,850 3,270 1,180 1,550 1,300 8,050 7,890 7,970 3,960 5,340 4,220 2,520 3,680 3,030 16,800 13,900 15,900 18,500 17,000 17,800 36,100 32,000 33,600 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

840 898 Flood discharge, in cubic feet per second 1,110 5,390 3,840 5,080 1,870 2,440 1,990 9,850 2,350 2,750 2,410 5,860 5,610 5,780 3,000 3,810 3,090 1,850 2,630 2,080 5-year 11,900 12,400 13,600 12,100 13,100 26,600 22,600 24,700 (20% AOP)

481 622 494 2,110 3,280 2,120 3,170 1,240 1,360 1,250 7,580 5,410 7,390 8,020 6,620 7,790 1,480 1,520 1,480 3,420 3,090 3,370 1,860 1,870 1,020 1,460 1,080 2-year 15,600 12,300 14,800 (50% AOP)

376 477 384 760 801 1,110 2,600 1,620 2,530 1,050 1,030 1,050 6,160 4,100 6,010 6,270 5,020 6,100 1,200 1,160 1,200 2,690 2,350 2,640 1,490 1,600 1,490 9,330 11,600 1.5-year 12,200 (67% AOP)

993 818 638 799 847 717 839 250 297 254 985 425 686 455 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,700 1,640 4,440 2,490 4,280 4,050 3,040 3,900 1,790 1,440 1,740 1,010 1,010 7,960 5,620 7,410 1.1-year (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East East East Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w MD MD MD MD MD MD MD MD WV WV State station number 01595000 01595300 01595500 01596000 01596500 01597000 01598000 01599000 01599500 01600000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

1 2 3 4 5 6 7 8 9 10 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 47

145 125 130 915 656 701 381 462 449 62,400 52,300 57,000 27,100 47,500 36,600 70,600 39,600 50,900 84,900 63,600 72,200 68,200 24,500 40,400 500-year 113,000 156,000 138,000 153,000 121,000 136,000 (0.2% AOP)

), from the systematic the from ), s 112 103 105 613 534 550 278 377 359 45,600 41,400 43,500 88,600 22,000 37,600 28,900 50,300 31,400 39,000 61,500 50,300 55,200 95,200 45,200 19,500 30,000 200-year ), from the regionalized 110,000 123,000 107,000 103,000 r (0.5% AOP)

91.1 87.5 88.5 446 450 449 216 318 296 35,600 34,200 35,000 73,100 87,400 18,400 31,100 23,700 38,400 26,000 31,500 47,700 41,500 44,500 85,300 78,400 82,200 32,800 16,200 23,800 100-year (1% AOP) 101,000

73.6 72.7 73 319 371 356 166 263 239 27,600 27,700 27,600 59,700 81,500 69,800 15,300 25,200 18,900 28,800 21,100 25,000 36,700 33,600 35,300 65,300 63,200 64,500 23,500 13,200 18,600 50-year (2% AOP)

58.7 58.9 58.8 223 298 271 125 212 184 21,100 21,800 21,300 48,200 63,900 54,400 12,300 19,900 14,600 21,200 16,600 19,300 27,900 26,500 27,400 49,300 49,600 49,400 16,500 10,400 14,200 25-year (4% AOP)

42.3 42.1 42.2 82.7 211 119 133 170 150 8,910 9,840 7,190 9,320 11,500 14,400 15,000 14,500 35,500 43,700 37,700 13,700 13,500 13,000 18,900 18,200 18,700 32,900 34,000 33,100 10,000 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

31.9 30.7 31.5 84.2 57.5 77.9 153 107 109 Flood discharge, in cubic feet per second 6,560 9,700 6,940 9,070 8,130 8,920 6,550 5,120 6,340 5-year 10,400 10,600 10,400 27,300 30,800 27,900 13,700 12,900 13,500 23,200 24,000 23,300 (20% AOP)

19.8 17.6 19.4 38.7 86.6 45.7 30.6 61.8 36.9 6,070 5,840 6,060 3,670 5,330 3,750 4,520 4,470 4,520 8,050 7,060 7,980 3,280 2,820 3,250 2-year 17,600 16,800 17,500 13,100 13,100 13,100 (50% AOP)

16 13.7 15.6 27.1 67 31.7 22.9 47.9 27 4,820 4,430 4,800 2,730 4,040 2,780 3,270 3,390 3,280 6,430 5,350 6,370 9,880 2,440 2,150 2,430 1.5-year 14,500 12,600 14,400 10,200 10,200 (67% AOP)

8.9 11.2 10.8 14.7 42.6 17.8 13.8 30.6 16.6 a Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 3,310 2,690 3,280 7,590 1,520 2,460 1,560 1,840 2,070 1,850 4,500 3,240 4,420 6,660 5,950 6,630 1,510 1,310 1,500 1.1-year 10,500 10,300 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East East East Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w MD MD WV WV WV WV WV WV WV WV State station number 01601500 01603000 01604500 01605500 01605700 01606000 01606500 01606800 01607500 01607510 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

11 12 13 14 15 16 17 18 19 20 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 48 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

116 118 126 1,370 1,820 1,680 8,180 8,710 3,070 3,380 3,310 86,500 57,700 70,500 23,400 33,600 30,700 14,400 21,000 25,600 25,000 39,500 24,300 26,700 500-year 280,000 243,000 262,000 237,000 (0.2% AOP)

95.4 99.7 ), from the systematic the from ), s 113 1,110 1,470 1,350 6,560 6,950 2,420 2,730 2,650 61,200 45,700 53,200 19,100 26,700 24,400 10,700 17,200 20,300 19,900 30,200 19,400 21,200 200-year ), from the regionalized 203,000 191,000 197,000 191,000 r (0.5% AOP)

80.9 86.7 103 943 1,230 1,130 8,390 5,460 5,790 1,990 2,280 2,200 46,500 37,700 42,400 16,200 22,100 20,200 14,600 16,900 16,500 24,300 16,100 17,600 100-year (1% AOP) 157,000 156,000 157,000 161,000

93.4 67.3 74.8 792 922 1,010 6,470 4,460 4,730 1,620 1,870 1,790 34,900 30,500 33,100 13,600 17,900 16,300 12,300 13,700 13,400 19,200 13,000 14,400 50-year (2% AOP) 120,000 126,000 122,000 134,000

83.9 54.5 64.3 811 658 737 4,880 3,540 3,790 1,290 1,490 1,410 11,200 11,600 25,800 24,100 25,200 90,400 98,500 92,800 14,100 12,900 10,200 10,800 10,700 14,800 10,300 25-year 111,000 (4% AOP)

71.3 39 53.2 911 502 570 529 974 8,340 9,760 8,940 3,180 2,470 2,670 7,680 7,480 7,550 1,040 7,130 8,370 16,600 16,500 16,600 59,700 67,100 61,100 83,100 10,000 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

61.3 28.5 46.9 411 398 401 666 749 694 Flood discharge, in cubic feet per second 6,360 6,930 6,530 2,150 1,760 1,930 5,980 5,320 5,640 7,010 5,080 6,190 5-year 11,300 11,700 11,400 41,700 47,200 42,300 64,600 (20% AOP)

46.3 16.3 38.4 267 231 262 981 375 419 383 5,940 6,430 5,970 3,850 3,820 3,850 1,050 1,030 3,810 2,940 3,540 3,620 2,800 3,440 2-year 22,700 25,600 22,800 41,700 (50% AOP)

40.3 12.7 34 223 178 218 741 750 744 284 322 289 a 4,440 4,870 4,460 3,000 2,900 2,990 3,080 2,230 2,850 2,620 2,130 2,530 1.5-year 17,200 19,300 17,300 34,000 (67% AOP)

8.3 30.8 25.1 112 163 156 381 465 402 167 201 172 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on a AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 2,710 2,950 2,720 1,860 1,770 1,850 2,070 1,370 1,870 1,410 1,300 1,390 1.1-year 11,500 10,700 10,700 23,700 (90% AOP) r r r r r r r r r s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East East East Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w MD MD MD MD WV WV WV WV WV WV State station number 01608000 01608100 01608500 01609000 01609500 01609650 01609800 01610000 01610150 01610155 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

21 22 23 24 25 26 27 28 29 30 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 49

414 523 500 3,840 5,150 4,860 1,380 1,730 1,630 7,480 4,880 5,790 3,440 5,170 4,610 90,000 62,900 66,400 37,400 50,100 44,700 21,100 15,000 17,400 500-year 110,000 117,000 125,000 379,000 (0.2% AOP)

), from the systematic the from ), s 349 426 409 3,060 4,140 3,880 1,120 1,400 1,320 6,040 3,920 4,710 2,840 4,160 3,710 68,600 49,800 52,400 87,600 98,200 92,300 29,900 39,700 35,300 16,700 12,000 13,900 200-year ), from the regionalized 297,000 r (0.5% AOP)

949 304 359 346 2,540 3,450 3,210 1,180 1,100 5,040 3,270 3,990 9,930 2,420 3,470 3,080 11,700 54,900 41,100 43,300 72,700 80,800 76,000 25,000 32,800 29,000 13,800 100-year (1% AOP) 244,000

793 966 901 263 297 288 2,080 2,820 2,600 4,130 2,680 3,340 8,090 9,640 2,040 2,840 2,500 11,200 43,100 33,200 35,100 59,300 65,200 61,500 20,600 26,600 23,400 50-year (2% AOP) 199,000

653 773 720 226 239 235 1,680 2,250 2,040 3,310 2,130 2,750 8,860 6,410 7,830 1,680 2,260 1,980 33,100 26,200 27,900 47,300 51,200 48,500 16,700 20,900 18,400 25-year (4% AOP) 159,000

489 544 512 180 169 174 1,210 1,570 1,390 2,320 1,490 2,050 6,220 4,450 5,710 1,240 1,580 1,370 22,000 18,000 19,500 33,400 35,000 33,700 12,200 14,400 12,800 10-year 115,000 (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

901 979 377 392 381 148 123 137 935 985 Flood discharge, in cubic feet per second 1,130 1,660 1,070 1,530 9,250 9,420 4,480 3,170 4,240 1,130 5-year 15,100 12,700 14,000 24,100 24,700 24,200 86,800 10,200 (20% AOP)

69.6 96.1 524 628 542 237 221 235 105 856 597 832 544 631 554 7,420 6,980 7,310 5,590 5,610 5,590 2,420 1,760 2,370 2-year 13,000 13,500 13,000 53,100 (50% AOP)

89.9 53.9 82 411 403 481 414 190 170 188 604 458 593 484 418 5,190 5,290 5,210 9,490 9,520 4,400 4,250 4,390 1,780 1,340 1,750 1.5-year 10,200 42,300 (67% AOP)

68.4 34.4 60.2 a 245 300 253 126 107 124 298 285 297 973 824 964 237 301 243 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 5,110 2,600 3,210 2,720 6,120 5,150 2,820 2,580 2,800 1.1-year 28,400 (90% AOP) r r r r r r r r r s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East East East Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA VA MD MD MD MD WV WV WV State station number 01611500 01610500 01612500 01613000 01613150 01613160 01613900 01614000 01615000 01616000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

31 32 33 34 35 36 37 38 39 40 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 50 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

994 373 396 316 329 459 656 620 187 469 1,130 5,000 3,190 3,650 2,280 1,930 1,990 40,000 57,000 49,000 20,500 19,000 29,300 18,200 20,900 80,800 75,200 77,900 500-year 373,000 (0.2% AOP)

), from the systematic the from ), s 903 781 263 293 258 265 362 534 500 161 358 3,800 2,570 2,920 1,860 1,560 1,610 31,300 45,100 38,300 16,100 12,600 20,600 14,500 16,200 58,800 59,400 59,100 200-year ), from the regionalized 304,000 r (0.5% AOP)

754 641 199 231 218 221 298 450 416 143 289 9,140 3,060 2,150 2,430 1,590 1,310 1,360 25,700 37,300 31,100 13,200 15,600 12,100 13,200 45,800 49,000 47,200 100-year (1% AOP) 258,000

621 516 148 181 181 181 243 371 338 125 231 6,490 9,810 2,430 1,760 2,000 1,340 1,080 1,130 11,700 20,700 30,200 24,600 10,700 10,500 35,200 39,600 36,800 50-year (2% AOP) 217,000

504 406 108 860 932 139 146 144 194 298 265 109 181 8,570 4,500 8,680 7,770 8,180 1,900 1,410 1,620 1,120 16,300 23,800 18,900 26,600 31,200 28,000 25-year (4% AOP) 180,000

67.2 96 88.8 211 368 280 986 866 604 706 104 100 138 178 127 6,110 2,630 5,680 5,380 5,560 1,320 1,180 11,400 16,300 12,500 17,700 21,400 18,400 10-year 135,000 (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

44.3 69.8 75.3 72.1 73.8 93.3 278 198 956 708 884 691 435 569 102 153 123 Flood discharge, in cubic feet per second 8,230 8,700 4,510 1,640 3,980 3,830 3,940 5-year 11,600 12,400 15,100 12,700 105,000 (20% AOP)

21.3 41.1 42.9 41.5 58.5 86.6 64.6 53.0 54.7 167 103 727 547 397 526 471 245 407 4,480 6,350 4,590 2,600 2,250 2,120 2,230 6,810 8,290 6,880 2-year 66,900 (50% AOP)

73.3 15.1 32.6 33.3 32.7 44.6 67 48.6 45.2 42.8 131 499 422 305 409 396 188 345 3,320 4,810 3,390 2,000 1,770 1,620 1,750 5,190 6,270 5,230 1.5-year 53,900 (67% AOP)

8.2 83.3 37.9 22.2 21.3 22 26.9 42.6 29.8 33.7 a27.8 118 257 992 266 191 257 293 246 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,870 2,920 1,920 1,220 1,220 1,190 3,250 3,790 3,270 1.1-year 36,200 (90% AOP) r r r r r r r s s s s s s s s s s s s s s s w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East East East East East East East East Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA VA VA VA VA VA VA VA MD MD MD MD WV WV State station number 01616500 01617000 01617800 01618000 01619475 01619500 01620500 01621000 01621200 01621400 01621450 01622000 01622100 01622300 01622400 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 51

93.1 176 156 3,180 2,680 2,810 3,760 2,290 2,730 1,700 1,300 1,440 56,700 45,400 51,000 24,900 22,600 23,400 77,700 97,500 87,900 18,000 19,200 18,800 38,600 24,300 30,200 500-year 138,000 140,000 139,000 (0.2% AOP)

79.6 ), from the systematic the from ), s 144 128 2,160 2,160 2,160 2,750 1,850 2,150 1,240 1,050 1,120 46,200 36,000 41,200 19,200 18,000 18,500 63,000 77,000 69,900 14,000 15,300 14,800 29,100 19,400 23,700 200-year ), from the regionalized 110,000 102,000 105,000 r (0.5% AOP)

70 122 108 966 882 917 1,580 1,810 1,730 2,140 1,550 1,770 11,400 39,000 29,800 34,800 15,600 14,900 15,200 53,000 63,400 57,800 12,700 12,200 79,600 90,400 84,300 23,200 16,100 19,500 100-year (1% AOP)

61 89.1 736 726 731 101 1,140 1,480 1,340 1,640 1,270 1,430 9,120 9,810 32,400 24,100 29,000 12,300 12,100 12,200 43,900 51,200 46,900 10,300 61,500 72,900 65,800 18,100 13,000 15,800 50-year (2% AOP)

52.4 82 71.4 796 992 547 582 562 1,180 9,530 9,590 9,560 1,220 1,010 1,120 7,190 8,170 7,670 26,400 19,000 23,900 35,600 40,200 37,200 46,600 57,200 49,800 13,900 10,300 12,500 25-year (4% AOP)

41.6 58.5 50.4 470 831 594 786 712 761 350 410 367 6,380 6,630 6,460 5,030 5,660 5,250 9,250 7,130 8,720 19,200 13,100 17,800 25,800 27,600 26,200 30,900 39,100 32,500 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

33.7 42.6 37.2 294 598 359 527 512 524 233 296 245 Flood discharge, in cubic feet per second 9,300 4,380 4,720 4,450 3,650 4,030 3,740 6,400 5,080 6,190 5-year 14,300 13,600 19,100 19,500 19,200 21,500 27,600 22,200 (20% AOP)

22.8 24.4 23.2 111 115 129 335 146 255 288 258 167 5,110 8,090 7,910 2,130 2,610 2,170 2,050 2,230 2,070 3,250 2,800 3,220 2-year 11,400 11,600 10,800 10,600 10,800 15,000 (50% AOP)

87.4 98.2 18.8 19 18.8 77.3 80.2 258 179 221 182 129 6,060 3,870 5,950 1,470 1,980 1,500 8,120 8,050 8,120 1,560 1,700 1,570 8,420 8,530 2,340 2,130 2,330 11,400 1.5-year (67% AOP)

43.3 50.2 13 12.2 12.8 92.6 95.7 39.1 81.2 41.3 161 707 736 139 934 943 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on a AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 3,420 2,360 3,370 1,220 4,620 4,850 4,630 1,040 4,910 6,820 4,980 1,250 1,300 1,250 1.1-year (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East East East Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA VA VA VA VA VA VA VA VA State station number 01632000 01632300 01632900 01632950 01632970 01633000 01633500 01633650 01634000 01634500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

56 57 58 59 60 61 62 63 64 65 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 52 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

71.0 373 3,070 1,560 1,090 12,700 22,300 39,800 50,500 28,400 33,800 96,000 67,500 80,700 28,000 18,000 14,900 14,200 14,600 20,700 19,600 20,500 40,500 47,300 41,000 30,000 22,800 29,400 500-year 274,000 549,000 (0.2% AOP)

64.5 ), from the systematic the from ), s 308 794 8,710 2,420 1,080 17,500 31,400 38,100 22,600 26,800 70,600 53,400 61,900 21,600 14,300 13,000 12,200 12,700 18,300 16,900 18,100 35,700 41,000 36,100 24,800 19,600 24,500 200-year ), from the regionalized 216,000 453,000 r (0.5% AOP)

59.7 611 795 263 6,450 2,000 11,900 11,700 11,400 14,300 25,800 30,300 18,700 22,200 55,100 44,000 50,000 17,600 10,700 16,500 14,900 16,300 32,100 36,500 32,400 21,300 17,400 21,000 100-year (1% AOP) 178,000 387,000

55.0 566 221 457 4,690 1,630 9,780 9,340 11,600 20,800 23,600 15,200 18,200 42,300 35,600 39,600 14,200 10,400 10,000 14,700 13,000 14,500 28,500 32,200 28,700 18,000 15,200 17,800 50-year (2% AOP) 145,000 327,000

50.4 386 182 329 3,320 9,130 1,300 7,950 9,080 8,030 8,770 11,300 11,300 16,300 18,000 12,000 14,600 31,900 28,100 30,600 12,900 12,700 24,800 28,000 25,000 15,000 13,100 14,900 25-year 115,000 (4% AOP) 272,000

44.2 211 925 135 194 1,990 6,370 8,290 8,080 5,860 7,430 6,370 7,150 8,990 11,100 11,800 11,300 11,200 81,400 10,300 20,900 19,300 20,500 10,600 10,400 19,900 22,800 20,000 10,500 10-year 207,000 (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

39.3 118 116 680 102 Flood discharge, in cubic feet per second 1,260 4,580 7,780 8,030 5,900 7,430 6,030 4,490 6,170 5,150 5,950 8,700 7,310 8,580 8,660 8,580 8,660 5-year 59,200 14,300 13,600 14,200 16,000 18,800 16,100 161,000 (20% AOP)

32.0 37.7 60.8 39.7 553 387 2,480 3,870 3,890 3,250 3,810 7,260 7,470 7,270 3,650 2,820 4,360 3,480 4,220 5,940 5,000 5,890 5,270 5,900 5,280 2-year 32,800 10,300 13,300 10,400 (50% AOP) 102,000

29.1 20.6 47.1 22.4 a 375 295 1,830 2,690 2,710 2,470 2,690 5,260 5,660 5,280 2,900 2,280 3,660 2,880 3,540 4,860 4,150 4,820 8,140 8,210 4,100 4,910 4,120 11,200 1.5-year 24,500 81,800 (67% AOP)

6.06 7.3 a 24.4 29.1 a 184 176 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,020 1,300 1,340 1,510 1,360 2,920 3,430 2,940 1,940 1,560 2,620 2,010 2,510 3,240 2,940 3,220 4,960 8,160 5,030 2,520 3,490 2,540 1.1-year 14,000 54,000 (90% AOP) r r r r r r r s s s s s s s s s s s s s s s s w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate East East East East East East East East Region Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA VA VA VA VA VA VA VA VA VA VA MD MD MD WV State station number 02011400 02011460 02011480 02011500 01636500 01637000 01637500 01638480 01638500 01643700 01644000 01644100 02009500 02012500 02012950 02013000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 53

598 228 450 630 816 680 5,260 3,390 5,030 17,800 21,800 18,000 25,000 25,300 25,000 22,300 34,100 23,000 29,100 46,900 29,700 21,600 18,200 21,200 22,300 21,200 22,200 17,400 34,700 18,000 500-year (0.2% AOP)

), from the systematic the from ), s 425 188 336 536 679 574 4,190 2,860 4,040 15,300 18,800 15,500 21,400 21,800 21,400 19,400 29,500 20,000 25,800 40,700 26,300 18,100 15,700 17,800 19,200 18,300 19,200 16,100 30,000 16,600 200-year ), from the regionalized r (0.5% AOP)

325 160 266 471 584 500 3,500 2,490 3,390 13,500 16,600 13,700 18,900 19,300 18,900 17,400 26,200 17,900 23,300 36,200 23,800 15,800 13,800 15,500 17,000 16,100 17,000 15,000 26,700 15,400 100-year (1% AOP)

245 133 208 409 495 431 2,880 2,140 2,810 11,800 14,500 12,000 16,600 16,900 16,600 15,500 23,000 15,900 21,000 31,900 21,300 13,600 12,100 13,400 15,000 14,100 14,900 13,900 23,400 14,300 50-year (2% AOP)

183 109 161 351 412 366 2,340 1,810 2,290 11,500 11,400 10,100 12,500 10,200 14,300 14,600 14,400 13,700 20,000 14,000 18,700 27,800 19,000 10,400 13,000 12,200 12,900 12,800 20,400 13,000 25-year (4% AOP)

80.4 110 120 279 310 286 7,940 8,030 9,010 8,310 8,950 9,760 1,720 1,400 1,690 11,600 11,700 11,600 11,400 11,600 11,200 11,300 10,000 16,100 15,800 22,600 15,900 10,500 10,400 16,400 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

83.6 60.3 78.8 227 238 229 Flood discharge, in cubic feet per second 6,290 8,180 6,350 9,560 9,600 9,560 9,670 9,800 7,230 6,750 7,200 8,630 7,950 8,600 1,300 1,100 1,290 9,770 9,850 5-year 13,300 13,500 18,700 13,600 13,500 (20% AOP)

46.2 35.2 44.6 155 145 154 797 708 794 3,980 5,610 4,020 6,790 6,630 6,790 7,300 9,250 7,350 4,850 4,610 4,840 6,060 5,450 6,040 7,490 9,430 7,520 2-year 10,200 13,200 10,200 (50% AOP)

35.6 27 34.4 114 128 126 631 570 629 3,130 4,670 3,160 5,760 5,530 5,760 6,410 7,760 6,440 8,930 8,960 4,000 3,820 3,990 5,100 4,540 5,080 6,500 7,910 6,520 11,100 1.5-year (67% AOP)

23.3 16.4 22.2 90.4 72.3 87.5 411 412 380 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,920 3,310 1,950 4,270 3,940 4,260 5,090 5,590 5,100 6,970 8,080 6,990 2,800 2,690 2,790 3,690 3,210 3,670 4,850 5,700 4,870 1.1-year (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate Region Central Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA WV WV WV WV WV WV WV WV WV State station number 02014000 03050000 03050500 03050650 03051000 03051500 03052000 03052340 03052500 03053500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

82 83 84 85 86 87 88 89 90 91 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 54 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

404 281 346 816 927 1,700 1,030 1,420 1,000 6,370 7,140 6,700 2,870 6,620 3,480 11,600 68,600 88,700 69,600 17,700 15,200 17,200 10,700 16,400 19,600 24,100 20,100 500-year 117,000 101,000 103,000 (0.2% AOP)

), from the systematic the from ), s 333 232 286 863 842 679 777 6,110 1,320 1,140 5,470 5,730 2,650 5,660 3,140 9,340 60,300 77,400 61,100 15,200 13,000 14,800 87,900 89,400 14,100 10,100 17,400 20,900 17,800 200-year ), from the regionalized 103,000 r (0.5% AOP)

284 197 244 743 951 730 584 673 1,080 4,830 5,360 5,040 2,490 4,970 2,870 8,380 9,000 11,500 54,300 69,300 55,000 13,400 13,000 78,500 92,000 79,800 12,500 15,800 18,500 16,000 100-year (1% AOP)

238 165 206 871 631 784 624 495 576 4,220 4,640 4,380 2,310 4,300 2,600 7,450 7,930 11,700 11,400 48,500 61,500 49,100 10,000 69,500 81,900 70,700 10,900 14,100 16,200 14,300 50-year (2% AOP)

197 136 171 691 527 635 526 412 485 8,630 9,890 3,630 3,950 3,740 2,130 3,650 2,340 6,540 9,360 6,890 43,000 54,000 43,400 10,100 61,000 72,100 62,000 12,500 14,000 12,600 25-year (4% AOP)

147 100 129 489 398 463 405 310 375 8,170 6,860 7,980 2,890 3,060 2,940 1,870 2,830 1,980 5,370 7,360 5,560 11,100 35,700 44,300 36,000 50,200 59,500 50,900 10,300 10,400 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

75.5 99.9 112 359 307 347 318 238 296 Flood discharge, in cubic feet per second 6,720 5,550 6,580 2,340 2,400 2,350 1,650 2,210 1,700 4,480 5,850 4,580 8,620 8,850 8,630 5-year 30,200 37,100 30,400 42,200 50,000 42,600 (20% AOP)

66.8 44.4 61.3 208 189 205 202 145 190 4,720 3,760 4,640 1,570 1,500 1,560 1,290 1,380 1,300 3,190 3,750 3,220 6,070 5,750 6,060 2-year 22,300 26,700 22,400 30,900 36,500 31,100 (50% AOP)

51.5 34.2 47.4 114 160 149 158 161 152 3,110 3,990 3,920 1,280 1,180 1,260 1,130 1,080 1,130 2,690 2,990 2,710 5,060 4,610 5,050 1.5-year 19,300 22,800 19,400 26,600 31,300 26,800 (67% AOP)

31.1 20.9 28.4 99.4 95.2 98.6 72 97 104 864 739 837 867 678 848 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 2,910 2,180 2,840 1,950 1,930 1,950 3,520 3,010 3,500 1.1-year 14,600 17,000 14,700 20,200 23,500 20,300 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West Region Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03054500 03055020 03055040 03056250 03056500 03056600 03057300 03057500 03058000 03058500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

92 93 94 95 96 97 98 99 100 101 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 55

446 841 5,040 3,140 4,130 4,720 3,780 4,460 1,320 9,500 9,720 9,570 11,000 11,300 23,000 39,500 24,600 15,300 14,500 15,100 53,800 62,000 54,700 13,500 17,900 13,900 12,000 97,200 41,600 91,900 500-year (0.2% AOP)

), from the systematic the from ), s 861 369 609 4,240 2,660 3,510 3,520 3,210 3,440 8,700 9,040 7,390 8,300 7,670 21,300 34,500 22,600 12,700 12,500 12,700 48,200 54,300 48,800 12,200 15,500 12,500 10,300 73,100 36,100 69,900 200-year ), from the regionalized r (0.5% AOP)

615 316 472 9,110 3,660 2,320 3,060 2,790 2,800 2,790 7,180 7,550 6,060 7,280 6,420 11,100 11,300 11,500 20,000 30,700 21,000 10,900 10,900 43,900 48,600 44,400 13,700 58,600 32,100 56,500 100-year (1% AOP)

435 266 360 3,110 9,220 9,670 9,320 1,990 2,640 2,180 2,410 2,230 5,860 7,930 6,220 4,940 6,330 5,320 18,600 27,100 19,300 39,700 43,000 40,000 10,300 12,000 10,500 46,600 28,300 45,300 50-year (2% AOP)

303 220 270 7,650 8,290 7,790 2,590 1,680 2,240 9,340 9,410 1,680 2,040 1,750 4,700 6,780 5,010 3,980 5,410 4,340 17,100 23,500 17,600 35,400 37,500 35,500 10,300 36,700 24,600 35,900 25-year (4% AOP)

183 164 176 5,750 6,500 5,870 1,930 1,280 1,730 8,000 8,100 8,010 1,150 1,560 1,210 3,390 5,300 3,610 2,930 4,270 3,210 15,000 18,700 15,200 29,500 30,100 29,600 26,200 19,900 25,900 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

994 829 866 120 124 121 Flood discharge, in cubic feet per second 4,400 5,160 4,490 1,460 1,340 6,910 6,450 6,890 1,210 2,540 4,190 2,670 2,260 3,430 2,460 5-year 13,100 15,100 13,200 24,800 24,500 24,800 19,800 16,400 19,700 (20% AOP)

61 74.2 63.5 827 606 789 473 743 490 9,950 2,640 3,300 2,690 5,200 4,150 5,170 1,510 2,660 1,570 1,470 2,290 1,570 2-year 11,500 10,000 10,000 17,700 16,400 17,700 12,700 12,700 (50% AOP)

46.1 57.6 48.1 611 470 587 366 578 379 2,110 8,630 8,060 8,610 2,040 2,620 2,090 4,490 3,320 4,450 1,180 1,230 9,710 1,220 1,880 1,290 1.5-year 14,800 13,300 14,800 10,500 10,500 (67% AOP)

29.9 35.8 31.1 329 287 320 236 355 246 757 798 906 959 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 6,320 5,340 6,270 1,230 1,680 1,280 8,980 3,340 2,140 3,280 1,350 7,890 7,040 7,870 1,290 1.1-year 10,300 10,200 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West Region Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03059000 03059500 03060500 03061000 03061500 03062400 03062500 03063950 03065000 03065400 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

111 110 102 103 104 105 106 107 108 109 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 56 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

42.3 94.7 47.9 365 403 380 1,180 1,500 1,270 4,750 2,990 4,290 11,600 11,300 14,300 13,900 14,300 10,100 40,800 21,600 35,400 38,800 28,300 38,000 73,700 90,600 500-year 141,000 138,000 167,000 162,000 (0.2% AOP)

34.1 77.2 38.6 ), from the systematic the from ), s 963 300 333 313 8,640 9,890 1,260 1,050 4,000 2,520 3,620 11,300 11,900 11,400 10,300 34,800 18,600 30,300 31,600 24,400 31,100 64,200 79,000 200-year ), from the regionalized 112,000 109,000 136,000 132,000 r (0.5% AOP)

28.7 65.1 32.3 821 893 256 285 267 9,450 9,500 9,280 7,590 8,910 1,090 3,480 2,190 3,160 10,500 30,600 16,400 26,800 26,900 21,600 26,600 92,700 57,400 91,000 70,800 100-year 115,000 113,000 (1% AOP)

23.8 54 26.7 693 925 754 218 240 226 9,110 7,800 7,870 8,350 6,600 7,970 3,000 1,880 2,730 26,700 14,400 23,600 22,800 19,000 22,500 76,400 50,800 75,400 97,000 62,800 95,300 50-year (2% AOP)

19.5 43.8 21.6 578 775 626 183 198 188 6,380 7,830 6,440 7,440 5,650 7,080 2,550 1,590 2,330 23,100 12,400 20,500 19,100 16,400 19,000 62,500 44,500 61,800 80,800 55,200 79,700 25-year (4% AOP)

14.4 31.7 15.7 443 590 474 142 147 143 4,780 6,210 4,830 6,260 4,450 5,940 9,920 1,990 1,230 1,850 18,500 16,800 14,900 13,200 14,800 46,900 36,400 46,600 62,000 45,300 61,400 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

11 11.8 23.4 111 113 113 350 458 369 964 Flood discharge, in cubic feet per second 3,730 5,020 3,770 5,360 3,580 5,090 8,090 1,590 1,490 5-year 15,300 14,000 12,100 10,800 12,000 36,800 30,400 36,700 49,300 37,900 48,900 (20% AOP)

6.8 7.08 13.2 77.4 66.3 75 231 286 238 617 2,470 3,390 2,490 4,060 2,390 3,880 5,550 8,600 7,500 8,570 1,060 1,010 2-year 10,800 10,200 24,900 21,800 24,900 33,300 27,400 33,200 (50% AOP)

5.4 5.6 10 65.1 51.4 62.2 191 227 195 865 495 825 2,060 2,800 2,070 3,550 1,960 3,380 9,140 4,620 8,620 7,430 6,260 7,400 1.5-year 21,000 18,500 21,000 27,900 23,400 27,800 (67% AOP)

3.5 5.89 3.63 48.1 31.8 43.8 135 147 137 593 328 559 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,530 1,950 1,540 2,770 1,360 2,580 6,770 3,270 6,290 5,880 4,480 5,840 1.1-year 16,100 13,700 16,100 20,600 17,400 20,500 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate Region Central Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03066000 03067100 03067500 03068610 03068800 03069000 03069500 03069850 03069880 03070000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

112 113 114 115 116 117 118 119 120 121 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 57

96.5 33.2 330 2,900 4,900 3,680 6,260 2,270 2,580 2,360 34,700 26,900 34,300 24,900 28,100 25,300 21,800 26,100 30,300 26,500 19,700 23,800 20,100 37,700 46,800 38,500 500-year 194,000 121,000 187,000 162,000 (0.2% AOP)

82.6 29.5 ), from the systematic the from ), s 243 2,440 4,180 3,090 5,390 1,840 2,190 1,930 28,100 23,200 27,800 22,000 24,400 22,300 17,900 21,900 26,400 22,300 16,100 20,600 16,500 32,100 40,900 32,800 200-year ), from the regionalized 162,000 106,000 158,000 142,000 r (0.5% AOP)

72.7 26.8 190 2,120 3,650 2,670 4,760 1,560 1,900 1,640 23,800 20,500 23,600 94,800 19,800 21,700 20,000 15,200 19,000 23,400 19,300 13,600 18,300 14,000 28,200 36,500 28,800 100-year (1% AOP) 141,000 137,000 128,000

63.3 24.1 147 1,820 3,150 2,270 4,160 1,300 1,630 1,370 11,500 11,800 20,000 18,000 19,900 84,400 17,700 19,000 17,800 12,900 16,300 20,600 16,600 16,000 24,500 32,200 25,000 50-year 119,000 113,000 (2% AOP) 121,000

54.4 21.5 112 1,550 2,670 1,890 3,590 9,490 9,780 1,070 1,370 1,130 16,700 15,600 16,700 74,400 99,400 15,500 16,400 15,600 10,700 13,700 17,800 14,000 13,800 20,900 28,000 21,300 25-year (4% AOP) 103,000 101,000

43.1 75.5 18.1 798 835 1,210 2,060 1,420 8,170 2,860 7,180 7,360 1,040 12,900 12,500 12,900 80,300 61,400 79,300 81,000 12,700 13,000 12,700 10,600 14,100 10,800 10,900 16,600 22,400 16,800 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

34.8 53.6 15.5 974 613 806 635 Flood discharge, in cubic feet per second 1,600 1,100 6,420 2,310 8,380 8,490 5,590 8,740 5,710 5-year 11,300 10,300 10,300 10,300 64,300 51,700 63,800 66,900 10,400 10,500 10,400 13,300 18,100 13,500 (20% AOP)

11.7 23.2 29.8 656 990 703 381 488 389 7,140 7,090 7,140 7,150 6,820 7,140 4,200 1,550 5,400 7,420 5,450 3,590 5,680 3,640 8,960 9,020 2-year 43,100 37,700 43,000 46,300 12,000 (50% AOP)

19.0 22.9 10.1 542 774 575 303 378 309 6,080 5,920 6,080 5,860 5,490 5,850 3,430 1,260 4,340 5,980 4,380 2,910 4,560 2,950 7,350 9,740 7,400 1.5-year 35,500 32,300 35,400 38,300 (67% AOP)

7.79 a 12.9 14.4 381 479 400 851 198 229 201 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 4,670 4,230 4,660 3,920 3,600 3,900 2,390 2,850 3,930 2,880 1,980 2,970 2,010 5,050 6,490 5,090 1.1-year 24,800 24,300 24,800 26,400 (90% AOP) r r r r r r r r s s s s s s s s s s s s s s w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West Region Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w PA PA PA PA OH OH MD MD MD MD MD WV WV WV State station number 03070500 03071000 03071500 03072000 03072590 03075450 03075500 03075600 03076505 03076600 03085500 03108000 03109000 03109500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

122 123 124 125 126 127 128 129 130 131 132 133 134 135 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 58 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

55.4 811 422 926 663 674 509 568 3,380 1,120 1,390 4,180 2,230 2,990 14,300 21,000 15,000 10,600 13,000 16,000 13,900 34,400 32,200 33,900 25,400 19,700 24,400 33,500 44,400 34,500 500-year (0.2% AOP)

44.4 ), from the systematic the from ), s 341 775 540 947 612 988 535 423 465 2,810 9,270 3,370 1,880 2,490 11,800 11,000 11,800 18,100 12,500 13,800 29,900 28,000 29,500 21,900 17,100 21,100 30,400 38,800 31,100 200-year ), from the regionalized r (0.5% AOP)

37.0 286 668 454 824 487 744 441 363 394 2,410 8,310 9,620 2,810 1,640 2,150 10,200 16,100 10,800 12,200 10,300 26,700 24,900 26,300 19,300 15,100 18,700 28,000 34,600 28,500 100-year (1% AOP)

30.2 236 567 372 707 380 545 356 306 327 8,690 9,160 2,030 7,370 8,270 8,860 2,310 1,400 1,820 14,100 10,700 23,600 21,900 23,200 16,900 13,200 16,300 25,600 30,500 26,000 50-year (2% AOP)

24.1 191 471 296 597 289 385 280 253 265 7,320 7,690 1,680 6,430 7,000 9,150 7,460 1,850 1,180 1,520 11,400 12,100 20,500 18,900 20,200 14,500 14,100 23,300 26,500 23,500 25-year (4% AOP)

17.0 138 353 204 460 190 223 893 191 187 190 5,680 9,560 5,910 1,240 5,200 5,400 7,190 5,700 1,310 1,140 8,960 11,500 11,300 16,500 15,000 16,300 20,000 21,200 20,100 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

12.2 932 102 268 142 360 129 134 942 688 856 133 141 136 Flood discharge, in cubic feet per second 4,540 7,630 4,670 4,240 4,240 5,710 4,430 9,250 7,150 9,090 5-year 13,400 12,100 13,300 17,500 17,100 17,400 (20% AOP)

6.5 57.7 74.5 62.8 49.1 65 81.1 69.3 532 157 225 497 415 478 3,050 4,940 3,100 2,840 2,670 3,660 2,760 9,030 7,920 8,950 6,090 4,610 6,010 2-year 11,300 13,500 13,400 (50% AOP)

4.6 43.2 55.8 43.8 29.3 44.6 61.1 48.8 119 396 177 357 320 349 a 2,110 2,530 3,950 2,570 2,290 2,920 2,180 7,360 6,390 7,290 4,920 3,690 4,860 9,180 11,800 11,700 1.5-year (67% AOP)

2.4 24.5 69.9 34 21.8 10.4 20.7 35 24.9 110 219 183 193 186 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on a AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 6,110 1,800 2,570 1,830 1,490 1,320 1,880 1,380 4,900 4,210 4,840 3,220 2,390 3,160 9,210 9,070 1.1-year (90% AOP) r r r r r r r r s s s s s s s s s s s s s s w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w PA OH OH OH OH OH OH OH OH OH OH WV WV WV State station number 03111150 03111450 03111455 03111470 03111500 03111540 03111548 03110000 03110980 03112000 03113700 03114000 03114240 03114500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

136 137 138 139 140 141 142 143 144 145 146 147 148 149 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 59

83.3 712 909 883 184 201 195 779 769 774 1,240 1,210 1,010 4,080 2,000 3,120 3,150 2,380 2,680 1,410 1,020 1,160 6,090 48,600 26,500 42,400 27,500 30,400 28,400 500-year (0.2% AOP)

77.3 ), from the systematic the from ), s 594 770 739 860 150 166 159 856 966 642 643 642 1,050 1,040 3,550 1,690 2,710 2,620 2,010 2,260 1,140 4,700 38,500 23,000 34,500 24,100 26,400 24,800 200-year ), from the regionalized r (0.5% AOP)

72.8 511 914 672 922 637 753 126 141 135 965 738 829 549 553 551 3,150 1,460 2,410 2,260 1,750 1,960 3,800 32,000 20,500 29,200 21,600 23,500 22,100 100-year (1% AOP)

68.3 111 118 781 432 579 801 540 652 804 627 703 463 469 466 103 2,750 1,250 2,130 1,930 1,500 1,690 3,020 26,300 17,900 24,400 19,100 20,600 19,500 50-year (2% AOP)

82.7 96.2 89.8 63.7 653 358 493 684 449 557 659 522 586 385 389 386 2,350 1,050 1,850 1,620 1,260 1,430 2,330 21,300 15,500 20,200 16,700 17,800 17,000 25-year (4% AOP)

57.7 70.1 63.3 57.4 489 267 384 532 335 439 795 955 488 391 443 291 290 290 1,820 1,490 1,250 1,120 1,570 15,600 12,300 15,100 13,600 14,200 13,700 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

40.6 51.9 44.8 52.2 611 369 202 303 417 254 352 986 736 893 371 297 342 225 219 223 Flood discharge, in cubic feet per second 1,410 1,210 9,830 1,090 5-year 11,900 11,700 11,200 11,400 11,200 (20% AOP)

19.9 29.1 22.4 43.9 117 209 182 257 149 224 834 367 750 639 445 583 224 175 210 542 140 128 137 7,440 6,410 7,370 7,690 7,440 7,660 2-year (50% AOP)

88.9 13.5 21.5 15.6 40.4 97 111 113 154 135 198 172 624 283 564 517 344 467 175 133 163 381 108 5,980 5,150 5,920 6,350 6,000 6,310 1.5-year (67% AOP)

6.06 7.81 a 80.9 51.6 70.7 66 97 12 78 98 34.5 71 56.5 67 a 116 110 338 170 301 347 208 296 191 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on a AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 4,070 3,370 4,000 4,340 3,940 4,280 1.1-year (90% AOP) r r r r r r r r r s s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w OH OH OH OH OH OH OH OH WV WV WV State station number 03114550 03114600 03114650 03115280 03115400 03115410 03115500 03115510 03115600 03115710 03150600 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

150 151 152 153 154 155 156 157 158 159 160 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 60 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

1,800 1,570 1,700 2,460 1,540 1,920 9,620 11,800 34,600 17,500 29,100 21,700 13,600 25,800 39,700 27,600 18,700 20,700 19,500 19,800 22,700 20,400 40,300 70,100 43,600 22,800 26,100 23,200 14,000 10,500 500-year (0.2% AOP)

), from the systematic the from ), s 1,510 1,320 1,430 2,160 1,290 1,660 8,620 9,300 27,200 15,100 23,600 10,900 18,800 12,300 23,300 34,600 24,700 17,000 17,900 17,300 18,000 19,700 18,400 37,800 61,500 40,400 20,500 22,700 20,800 12,000 200-year ), from the regionalized r (0.5% AOP)

1,310 1,140 1,240 1,930 1,120 1,480 7,880 8,400 11,300 22,400 13,400 19,900 10,200 16,700 21,400 30,900 22,500 15,600 15,900 15,700 16,600 17,500 16,800 35,900 55,100 37,900 18,800 20,100 18,900 10,600 100-year (1% AOP)

976 955 9,480 1,120 1,060 1,710 1,310 7,150 9,260 7,530 11,700 18,300 16,700 14,600 10,300 19,500 27,200 20,400 14,100 13,900 14,000 15,200 15,300 15,200 33,800 48,800 35,200 17,000 17,700 17,100 50-year (2% AOP)

937 816 897 799 8,710 9,260 1,500 1,140 6,420 7,930 6,670 11,900 14,700 10,100 13,700 12,600 17,600 23,600 18,200 12,700 12,400 13,700 13,200 13,600 31,500 42,600 32,500 15,300 15,200 15,300 25-year (4% AOP)

715 616 688 603 941 7,910 7,620 9,930 7,890 9,430 1,210 5,450 6,220 5,550 11,500 11,400 10,700 10,200 15,000 18,800 15,300 10,600 10,300 10,400 28,200 34,300 28,600 12,800 12,100 12,800 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

556 472 538 992 461 791 Flood discharge, in cubic feet per second 8,040 6,290 7,820 6,700 7,920 6,820 8,880 7,520 8,570 9,790 8,320 9,640 9,660 4,680 4,930 4,710 5-year 12,900 15,200 13,100 25,300 27,900 25,400 10,800 10,800 (20% AOP)

344 281 334 671 275 554 4,900 4,050 4,830 5,190 5,130 5,190 9,690 9,700 6,200 4,860 5,980 7,010 5,390 6,900 7,790 6,290 7,730 3,520 3,150 3,490 2-year 10,000 20,200 18,700 20,100 (50% AOP)

211 269 216 261 547 447 4,110 3,890 3,230 3,840 4,540 4,510 8,350 8,100 8,340 5,100 3,890 4,900 5,850 4,330 5,740 6,540 5,060 6,480 3,050 2,500 3,010 1.5-year 18,000 15,300 17,900 (67% AOP)

166 129 158 363 126 273 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 2,580 2,080 2,530 3,440 2,670 3,370 6,230 5,370 6,180 3,380 2,530 3,200 4,010 2,810 3,900 4,580 3,310 4,510 2,310 1,600 2,230 1.1-year 14,000 10,300 13,800 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03151400 03151500 03152000 03152200 03152500 03153000 03153500 03154000 03154250 03154500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

161 162 163 164 165 166 167 168 169 170 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 61

908 612 733 3,170 1,780 2,450 9,150 6,550 7,630 68,300 98,000 72,500 16,200 26,500 19,900 40,400 44,100 40,900 16,900 21,800 17,800 29,600 36,900 30,000 18,400 29,300 18,900 500-year 284,000 (0.2% AOP)

), from the systematic the from ), s 737 510 606 2,770 1,500 2,120 7,700 5,600 6,500 63,100 86,200 66,300 15,300 23,000 18,000 36,500 38,500 36,800 13,900 18,900 14,700 25,300 31,900 25,700 16,600 25,300 17,000 200-year ), from the regionalized 214,000 r (0.5% AOP)

623 438 520 2,470 1,300 1,890 6,680 4,910 5,710 11,900 59,000 77,500 61,400 14,500 20,500 16,500 33,600 34,300 33,600 16,700 12,700 22,300 28,300 22,600 15,200 22,400 15,500 100-year (1% AOP) 171,000

520 370 440 1,110 2,170 1,670 5,730 4,250 4,950 54,800 68,900 56,500 13,700 17,900 15,100 30,600 30,300 30,500 10,100 14,700 10,800 19,400 24,900 19,700 13,700 19,700 14,000 50-year (2% AOP) 135,000

930 427 306 367 1,880 1,460 4,830 3,610 4,240 8,510 9,020 50,300 60,300 51,400 12,800 15,500 13,600 27,500 26,300 27,400 12,600 16,600 21,700 16,800 12,200 17,100 12,400 25-year (4% AOP) 106,000

704 319 227 280 1,490 1,190 3,730 2,790 3,340 6,610 9,970 6,930 11,500 11,700 43,900 48,900 44,400 12,300 23,300 21,000 23,100 74,200 13,100 17,500 13,200 10,100 13,700 10,200 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

540 981 245 172 219 Flood discharge, in cubic feet per second 9,830 1,180 2,930 2,190 2,680 5,310 7,960 5,500 8,260 8,350 5-year 11,200 38,500 40,000 38,600 10,300 10,200 19,900 17,000 19,700 54,700 10,400 14,400 10,600 (20% AOP)

99.4 748 323 649 151 137 8,260 6,410 7,960 1,860 1,370 1,730 3,650 5,160 3,720 6,800 6,860 5,470 7,800 5,510 2-year 11,200 29,600 27,100 29,500 14,600 14,500 32,800 10,100 (50% AOP)

75 585 249 507 120 108 9,110 7,330 5,150 6,960 1,480 1,070 1,380 3,080 4,130 3,130 5,460 8,460 5,510 4,340 6,520 4,380 1.5-year 25,700 22,300 25,500 12,400 12,300 26,100 (67% AOP)

78 43.3 65.9 350 149 291 955 670 864 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 6,110 5,700 3,370 5,170 8,870 6,060 8,710 2,290 2,680 2,320 3,540 3,590 2,640 4,680 2,680 1.1-year 19,200 15,200 18,900 17,800 (90% AOP) r r r r r r r r r s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West Region Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA VA OH WV WV WV WV WV WV State station number 03155000 03155200 03155450 03155500 03155525 03159540 03159700 03171500 03173000 03175500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

171 172 173 174 175 176 177 178 179 180 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 62 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

711 263 462 333 920 510 3,600 9,140 5,090 6,370 1,810 7,560 2,740 7,010 6,380 6,890 25,700 10,200 25,600 45,900 26,700 22,400 49,800 25,100 36,400 19,500 34,700 500-year 304,000 284,000 (0.2% AOP)

), from the systematic the from ), s 215 383 272 673 422 552 3,300 7,800 4,510 6,100 9,320 1,650 6,430 2,420 6,050 5,420 5,940 22,200 23,300 39,800 24,200 20,400 43,200 22,700 27,000 16,800 26,000 200-year ), from the regionalized 233,000 226,000 r (0.5% AOP)

183 327 230 524 362 449 3,060 6,840 4,070 5,880 8,640 1,520 5,640 2,180 5,340 4,740 5,240 19,600 21,500 35,400 22,300 19,000 38,500 20,900 21,400 14,800 20,800 100-year (1% AOP) 189,000 188,000

154 276 193 402 305 360 2,820 5,940 3,630 5,640 7,940 1,400 4,880 1,940 4,650 4,100 4,560 17,200 19,600 31,200 20,200 17,400 33,900 19,000 16,800 13,000 16,500 50-year (2% AOP) 152,000 156,000

129 228 158 302 252 282 2,570 5,080 3,200 5,380 7,210 1,270 4,170 1,690 3,970 3,500 3,890 11,200 14,900 17,600 27,200 18,100 15,900 29,600 17,100 13,100 13,000 25-year (4% AOP) 120,000 127,000

98.8 118 170 197 188 194 2,220 4,000 2,620 4,980 6,200 1,090 3,270 1,370 3,080 2,730 3,030 9,300 8,930 9,280 85,500 12,000 14,700 22,100 15,000 13,600 24,000 14,400 94,500 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

78.5 89.9 942 129 135 143 138 Flood discharge, in cubic feet per second 1,930 3,210 2,180 4,610 9,780 5,400 2,610 1,130 2,400 2,180 2,380 6,990 7,260 7,000 5-year 11,800 63,600 12,200 18,200 12,400 19,900 12,300 73,100 (20% AOP)

52.9 77.2 57.1 69.3 86 72.6 713 795 1,460 2,140 1,560 3,950 6,750 4,280 1,730 1,460 1,430 1,460 8,270 8,370 8,870 9,100 4,470 4,970 4,480 2-year 38,400 12,900 14,100 47,100 (50% AOP)

44.3 60 47 50.5 67 53.5 616 679 1,260 1,750 1,330 3,630 5,630 3,860 1,410 1,120 1,170 1,120 6,640 6,720 7,620 7,800 3,730 4,120 3,740 11,900 1.5-year 30,600 10,800 38,600 (67% AOP)

32.4 37.3 33.4 28.5 41.8 31.2 937 982 461 965 510 639 793 650 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,210 3,040 4,020 3,180 4,120 7,880 4,200 5,590 8,670 5,740 2,840 2,920 2,840 1.1-year a 20,700 27,300 (90% AOP) r r r r r r r r r s s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate Region Central Central Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA WV WV WV WV WV WV WV WV WV State station number 03176400 03176500 03177500 03177700 03178500 03179000 03179500 03180000 03180350 03180500 03180530 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

181 182 183 184 185 186 187 188 189 190 191 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 63

29.3 68.8 42.8 693 583 648 594 784 810 935 1,210 1,030 21,000 16,600 19,900 78,800 58,700 77,600 36,500 20,800 32,300 12,100 13,200 12,200 96,600 97,300 500-year 121,000 104,000 139,000 106,000 (0.2% AOP)

26.2 55.9 36.4 ), from the systematic the from ), s 551 484 524 555 697 820 675 759 1,010 11,300 17,300 14,200 16,600 65,800 51,000 64,900 30,700 17,900 27,400 10,200 10,400 87,100 87,700 92,700 93,900 200-year ), from the regionalized 106,000 122,000 r (0.5% AOP)

23.9 47.1 31.9 457 415 441 523 871 632 680 580 640 8,950 9,950 9,090 14,900 12,600 14,300 56,900 45,500 56,300 26,700 15,800 24,000 79,900 95,400 80,400 84,400 85,400 100-year (1% AOP) 109,000

21.7 38.9 27.6 375 350 366 490 741 568 556 491 531 7,720 8,670 7,850 11,000 12,700 12,300 48,800 40,200 48,400 23,100 13,800 20,900 72,600 84,900 73,000 76,200 97,500 77,100 50-year (2% AOP)

19.4 31.5 23.4 302 290 298 454 619 504 445 409 432 9,440 6,560 7,450 6,670 11,900 10,700 10,500 41,400 35,100 41,100 19,800 18,100 65,200 74,800 65,500 68,200 86,100 68,800 25-year (4% AOP)

16.4 22.6 18.3 218 217 218 402 469 421 317 308 314 8,430 7,510 8,270 9,540 5,090 5,900 5,170 32,600 28,600 32,400 15,800 14,600 55,000 61,800 55,200 57,500 71,300 57,900 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

14 16.6 14.8 163 166 164 357 363 358 232 236 233 Flood discharge, in cubic feet per second 6,860 6,090 6,760 7,770 4,020 4,770 4,080 5-year 26,300 23,700 26,200 13,000 12,200 46,800 52,000 46,800 49,200 60,100 49,400 (20% AOP)

9.28 95.6 96.4 10.4 10.1 100 280 225 269 130 144 133 4,880 4,140 4,810 9,240 5,320 8,810 2,560 3,210 2,600 2-year 18,200 16,900 18,200 33,900 37,900 33,900 36,700 44,100 36,800 (50% AOP)

9 6.98 8.52 73.9 78 74.6 96.9 99.7 113 246 178 232 4,200 3,430 4,130 7,910 4,430 7,540 2,030 2,650 2,060 1.5-year 15,300 14,300 15,300 28,600 32,500 28,600 31,700 37,900 31,800 (67% AOP)

6.7 4.07 5.93 45.7 48.9 46.3 55.4 71.7 58.5 114 187 169 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 3,280 2,410 3,180 6,020 3,130 5,650 1,290 1,850 1,320 1.1-year 11,300 11,300 10,500 20,300 24,500 20,400 24,000 28,600 24,100 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate Region Central Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03180680 03181900 03182000 03182500 03182700 03183000 03183500 03183550 03183570 03184000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

192 193 194 195 196 197 198 199 200 201 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 64 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

197 288 232 7,130 2,200 5,040 6,140 9,440 6,520 4,780 2,520 4,020 34,700 18,900 33,400 46,300 30,600 45,100 20,400 13,200 19,500 49,300 21,500 45,100 57,700 96,000 500-year 365,000 302,000 345,000 101,000 (0.2% AOP)

), from the systematic the from ), s 167 238 193 5,450 1,850 3,990 5,160 8,050 5,480 3,850 2,120 3,290 11,300 29,100 16,300 28,000 39,200 26,400 38,300 17,200 16,500 39,100 18,500 36,200 86,600 50,100 82,900 200-year ), from the regionalized 306,000 268,000 304,000 r (0.5% AOP)

144 203 166 4,370 1,610 3,300 4,470 7,070 4,750 3,240 1,840 2,810 9,910 25,200 14,400 24,400 34,400 23,500 33,600 15,000 14,400 32,600 16,300 30,400 76,600 44,700 73,500 100-year (1% AOP) 265,000 242,000 274,000

123 170 140 3,440 1,380 2,690 3,830 6,140 4,060 2,700 1,580 2,370 8,630 21,700 12,600 21,000 29,800 20,600 29,200 13,000 12,500 26,900 14,300 25,400 67,100 39,500 64,500 50-year (2% AOP) 227,000 216,000 244,000

115 102 140 2,650 1,160 2,150 3,220 5,250 3,410 2,210 1,330 1,970 7,420 11,100 18,400 10,800 17,900 25,500 17,900 25,100 10,700 22,000 12,300 20,900 58,000 34,500 56,000 25-year (4% AOP) 192,000 191,000 214,000

75.8 84 888 103 1,770 1,520 2,480 4,140 2,610 8,650 1,650 1,020 1,500 8,760 5,880 8,520 9,870 14,500 14,200 20,200 14,400 19,900 16,400 15,800 46,400 28,100 45,100 10-year 149,000 157,000 174,000 (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

56.4 77.6 61.8 694 800 Flood discharge, in cubic feet per second 1,210 1,100 1,940 3,320 2,030 7,030 1,270 1,170 7,090 4,750 6,930 8,040 5-year 11,700 11,500 11,800 16,400 16,200 12,800 12,400 37,800 23,300 37,000 119,000 131,000 142,000 (20% AOP)

30.8 45.7 33.5 599 439 576 790 508 751 1,230 2,210 1,270 7,980 4,800 7,890 8,200 4,850 3,200 4,770 8,360 5,520 8,220 2-year 11,200 11,100 77,700 91,000 95,700 25,800 16,600 25,500 (50% AOP)

22.1 35.2 24.3 411 420 351 972 632 407 603 1,810 1,000 6,670 3,990 6,600 9,290 6,860 9,230 4,040 2,640 3,980 6,920 4,590 6,810 1.5-year 63,200 75,400 77,600 21,300 14,000 21,000 (67% AOP)

11 21.6 12.9 210 230 213 619 646 419 268 396 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,250 4,810 2,810 4,740 6,570 4,920 6,520 2,890 1,840 2,840 5,030 3,250 4,930 1.1-year 42,700 51,700 50,500 14,700 10,300 14,500 (90% AOP) r r r r r r r r r s s s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate Region Central Central Central Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV WV WV State station number 03184200 03184500 03185000 03185020 03185500 03186000 03186500 03187000 03187300 03187500 03189000 03189100 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

211 202 203 204 205 206 207 208 209 210 212 213 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 65

736 937 810 833 5,010 1,300 1,000 2,620 1,220 2,060 7,630 99,600 70,300 96,600 16,400 35,700 17,500 25,000 12,800 36,100 43,100 36,800 18,200 16,100 500-year 118,000 138,000 136,000 161,000 124,000 152,000 (0.2% AOP)

), from the systematic the from ), s 637 781 689 760 878 4,240 1,090 2,020 1,020 1,640 6,500 83,400 61,200 81,200 14,700 30,900 15,700 18,300 10,100 30,700 37,400 31,300 14,700 13,100 200-year ), from the regionalized 118,000 120,000 103,000 136,000 109,000 129,000 r (0.5% AOP)

564 672 603 704 939 788 878 3,710 8,340 1,630 1,360 5,690 11,100 72,400 54,700 70,700 13,500 27,400 14,300 14,300 26,900 33,200 27,500 12,300 92,800 97,500 100-year 118,000 114,000 (1% AOP) 107,000 105,000

494 571 521 646 799 700 747 1,110 3,200 6,800 1,290 4,930 9,310 62,300 48,400 61,100 12,300 24,100 12,900 10,900 23,400 29,300 23,900 10,200 94,500 82,600 93,400 86,800 98,900 50-year (2% AOP) 102,000

425 475 442 587 668 615 998 624 882 8,100 2,720 5,450 8,280 4,210 7,660 11,000 11,500 53,200 42,400 52,300 21,000 20,000 25,500 20,500 82,700 72,700 81,900 86,900 76,500 85,000 25-year (4% AOP)

336 359 343 504 508 505 674 473 622 2,110 9,350 9,680 5,190 3,890 6,020 3,300 5,680 42,100 34,700 41,600 16,900 15,900 20,700 16,200 67,800 60,000 67,300 68,300 63,200 67,500 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

269 276 270 434 393 423 469 366 447 Flood discharge, in cubic feet per second 8,020 8,230 3,460 1,680 2,840 4,490 2,640 4,310 5-year 34,300 28,900 34,000 13,900 13,000 17,100 13,200 56,800 50,500 56,400 54,900 53,200 54,700 (20% AOP)

173 169 172 324 244 307 237 227 236 6,000 9,730 6,090 1,650 1,090 1,520 8,910 9,020 2,600 1,750 2,550 2-year 24,100 20,700 24,000 12,000 41,300 36,800 41,100 37,000 38,900 37,200 (50% AOP)

137 133 136 886 278 193 260 168 179 169 5,180 8,160 5,250 1,150 1,090 7,430 7,520 1,970 1,430 1,940 1.5-year 20,500 17,500 20,400 10,100 35,500 31,500 35,400 30,500 33,300 30,700 (67% AOP)

86.2 85 85.9 86.3 90.2 115 581 598 585 202 124 182 977 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 3,880 5,890 3,940 5,310 7,340 5,390 1,160 1,150 1.1-year 15,500 13,000 15,400 26,800 23,700 26,700 21,300 25,100 21,600 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate Region Central Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03189500 03189650 03190000 03190100 03190400 03190500 03191400 03191500 03192000 03192500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

214 215 216 217 218 219 220 221 222 223 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 66 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

75.2 176 109 666 718 900 2,430 1,620 9,330 8,560 2,850 1,800 2,550 1,230 11,000 50,600 33,600 49,400 22,800 10,300 10,700 10,300 64,700 58,800 63,700 93,000 81,400 90,500 500-year 387,000 (0.2% AOP)

64.5 91.3 ), from the systematic the from ), s 144 553 634 773 1,800 1,250 9,090 7,960 8,660 8,940 7,290 8,650 2,500 1,510 2,220 1,030 42,100 29,100 41,200 21,100 56,200 51,100 55,400 80,000 71,500 78,300 200-year ), from the regionalized 344,000 r (0.5% AOP)

56.8 78.5 122 475 572 892 680 1,410 1,020 7,820 6,980 7,520 7,750 6,400 7,520 2,250 1,310 1,990 36,400 25,800 35,700 19,700 50,200 45,600 49,500 71,000 64,200 69,700 100-year (1% AOP) 312,000

49.5 66.5 511 402 824 759 591 102 1,100 6,670 6,060 6,460 6,670 5,550 6,490 2,010 1,120 1,770 31,200 22,700 30,700 18,400 44,500 40,300 43,900 62,500 56,900 61,500 50-year (2% AOP) 281,000

42.6 83.5 55.2 840 333 656 938 452 633 506 5,630 5,190 5,480 5,670 4,740 5,530 1,770 1,560 26,500 19,700 26,100 17,000 39,000 35,200 38,500 54,500 49,700 53,800 25-year (4% AOP) 249,000

33.8 61 41.4 571 250 471 716 373 476 399 4,380 4,090 4,300 4,450 3,730 4,360 1,470 1,300 20,800 15,900 20,600 15,200 32,100 28,700 31,700 44,600 40,200 44,000 10-year 207,000 (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

27.3 45.6 31.8 408 191 352 558 312 363 322 Flood discharge, in cubic feet per second 3,520 3,280 3,460 3,590 2,990 3,530 1,240 1,100 5-year 16,800 13,100 16,700 13,600 26,900 23,800 26,600 37,300 32,800 36,900 174,000 (20% AOP)

18.3 26.3 19.8 116 211 232 902 350 821 222 215 221 9,100 2,400 2,180 2,360 2,460 1,980 2,430 2-year 11,700 11,600 11,100 19,600 16,900 19,400 27,200 22,100 26,900 (50% AOP) 123,000

15 20.1 16 91 180 164 773 279 702 187 164 183 9,850 7,630 9,800 2,010 1,790 1,970 2,060 1,620 2,030 1.5-year 10,100 16,800 14,300 16,700 23,500 18,100 23,100 (67% AOP) 103,000

10.2 12.1 10.6 57 97 116 104 577 182 507 133 125 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 7,320 5,490 7,270 8,340 1,470 1,230 1,420 1,490 1,120 1,460 1.1-year 72,300 12,600 10,500 12,500 18,100 12,300 17,600 (90% AOP) r r r r r r r r r s s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West Region Central Central Central Central Central Central Central Central Central ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV WV State station number 03193000 03193725 03193830 03194700 03195000 03195100 03195250 03195500 03195600 03197000 03197150 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

224 225 226 227 228 229 230 231 232 233 234 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 67

381 483 436 607 886 995 912 951 2,830 3,000 2,900 1,210 2,540 4,050 3,170 11,900 31,900 19,500 51,600 40,000 50,300 53,300 31,300 49,200 53,800 34,900 43,600 55,000 67,500 56,600 500-year (0.2% AOP)

), from the systematic the from ), s 317 402 362 517 742 781 763 772 2,230 2,540 2,350 1,020 2,160 3,440 2,680 23,700 10,300 15,800 43,300 34,900 42,400 44,600 27,200 41,600 44,800 30,400 37,300 50,200 59,100 51,300 200-year ), from the regionalized r (0.5% AOP)

273 344 309 453 880 638 637 658 647 9,070 1,840 2,210 1,980 1,880 3,010 2,310 18,600 13,300 37,500 31,100 36,900 38,500 24,200 36,100 38,500 27,100 32,800 46,500 53,000 47,300 100-year (1% AOP)

231 290 260 391 748 538 507 558 530 7,890 1,490 1,900 1,630 1,610 2,590 1,960 11,000 14,300 32,200 27,400 31,800 32,700 21,200 31,000 32,700 23,800 28,500 42,600 46,900 43,100 50-year (2% AOP)

193 240 214 331 624 442 391 464 420 6,750 8,870 1,190 1,600 1,320 1,340 2,190 1,620 10,700 27,100 23,700 26,900 27,300 18,400 26,100 27,300 20,600 24,500 38,600 40,900 38,800 25-year (4% AOP)

146 177 158 852 941 255 469 323 258 347 287 6,880 5,280 6,280 1,220 1,010 1,680 1,190 20,900 19,000 20,800 20,500 14,600 19,900 20,800 16,400 19,200 32,900 32,900 32,900 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

112 119 133 629 945 687 199 358 240 172 263 195 762 874 Flood discharge, in cubic feet per second 4,570 4,170 4,450 1,300 5-year 11,700 16,400 15,300 16,300 15,700 15,400 16,100 13,200 15,300 28,100 26,800 28,000 (20% AOP)

68.8 76.6 70.7 76 88.3 362 575 389 122 212 139 154 432 801 484 2,120 2,650 2,220 9,290 7,670 9,220 8,670 9,740 2-year 10,400 10,100 10,400 10,000 20,300 18,000 20,200 (50% AOP)

53.7 57.6 54.7 94.4 49 58.9 117 277 446 298 162 107 317 625 358 1,440 2,100 1,550 8,280 8,160 8,280 7,080 6,190 7,040 7,920 7,000 7,740 1.5-year 17,100 14,700 17,000 (67% AOP)

33.1 33 33.1 56.2 95.5 65.5 19.8 68.7 27.5 683 807 168 272 184 167 384 202 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 4,110 4,110 1,340 5,320 5,410 5,320 4,070 5,010 4,620 4,920 9,890 1.1-year 11,800 11,700 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w WV WV WV WV WV WV WV WV WV WV State station number 03197900 03198350 03198450 03198500 03198780 03198800 03199000 03199300 03199400 03200500 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

235 236 237 238 239 240 241 242 243 244 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 68 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

395 706 547 626 899 795 898 612 729 6,350 6,810 6,610 1,890 3,180 2,390 1,240 1,700 1,130 2,540 2,200 2,350 21,800 28,800 22,800 25,700 76,600 34,000 65,300 500-year (0.2% AOP)

), from the systematic the from ), s 611 335 590 456 578 783 664 944 750 510 5,710 5,820 5,770 1,720 2,700 2,090 1,050 1,390 2,090 1,860 1,970 19,400 25,000 20,200 21,700 60,800 29,600 53,100 200-year ), from the regionalized r (0.5% AOP)

292 507 391 540 903 697 572 817 644 438 528 5,110 5,220 5,160 1,590 2,350 1,870 1,180 1,790 1,610 1,700 17,600 22,300 18,200 18,900 50,200 26,400 44,800 100-year (1% AOP)

252 429 330 500 769 612 989 484 701 543 370 450 4,720 4,420 4,570 1,460 2,020 1,660 1,510 1,380 1,450 15,900 19,500 16,300 16,300 40,600 23,200 37,100 50-year (2% AOP)

214 356 271 458 641 530 817 402 595 447 306 377 4,220 3,760 3,990 1,320 1,700 1,450 1,260 1,160 1,210 14,000 16,900 14,300 13,900 32,200 20,100 30,100 25-year (4% AOP)

166 265 200 397 482 427 615 300 469 328 227 285 949 880 923 3,530 2,910 3,260 1,140 1,300 1,180 11,600 11,800 11,000 13,400 22,300 16,000 21,500 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

131 200 151 980 986 345 368 352 476 227 379 243 172 218 735 678 717 Flood discharge, in cubic feet per second 9,680 9,740 2,970 2,280 2,720 1,010 8,850 5-year 10,700 15,900 12,800 15,600 (20% AOP)

84 91 99.4 116 734 614 712 259 218 249 301 133 250 133 124 458 409 447 6,760 7,020 6,770 2,100 1,420 1,910 6,030 8,180 8,430 8,190 2-year (50% AOP)

67 88.2 71.6 95.8 75 90.6 631 476 602 222 166 209 241 101 198 363 315 352 a 5,590 5,650 5,590 1,750 1,120 1,570 5,010 5,820 6,810 5,870 1.5-year (67% AOP)

43.1 51.2 45.4 98 59 48.9 43.3 47.2 700 463 291 419 159 140 160 121 232 190 220 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on a AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 3,810 3,710 3,800 1,200 1,020 3,570 2,960 4,490 3,050 1.1-year (90% AOP) r r r r r r r r r s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w OH WV WV WV WV WV WV WV WV WV State station number 03200600 03201000 03201405 03201410 03201420 03201440 03201480 03202000 03202245 03202400 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

245 246 247 248 249 250 251 252 253 254 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 69

599 629 614 2,850 2,890 2,860 5,700 1,940 2,970 5,850 8,650 6,350 16,800 18,900 17,300 67,300 62,000 66,500 96,700 66,000 85,900 64,400 85,100 66,600 34,300 30,200 33,500 12,800 20,200 15,200 500-year (0.2% AOP)

), from the systematic the from ), s 491 524 507 2,370 2,450 2,400 4,600 1,640 2,500 5,200 7,410 5,590 11,000 14,500 16,400 14,900 60,600 54,300 59,700 86,100 57,800 76,500 59,200 74,800 60,900 28,200 26,300 27,900 17,500 13,000 200-year ), from the regionalized r (0.5% AOP)

419 450 434 2,020 2,130 2,060 3,850 1,420 2,170 4,720 6,520 5,020 9,720 11,400 12,900 14,500 13,200 55,300 48,600 54,400 77,900 51,800 69,400 55,100 67,100 56,300 24,100 23,400 24,000 15,500 100-year (1% AOP)

354 381 366 1,690 1,830 1,740 3,160 1,220 1,870 4,230 5,660 4,460 8,520 9,910 11,300 11,600 12,700 49,900 43,000 49,000 69,500 45,800 62,300 50,600 59,600 51,500 20,300 20,500 20,300 13,600 50-year (2% AOP)

294 315 303 1,380 1,540 1,420 9,810 2,530 1,020 1,580 3,750 4,820 3,900 7,380 8,440 11,700 10,900 10,000 44,300 37,400 43,500 60,900 40,000 55,100 45,900 52,100 46,400 16,900 17,700 17,000 25-year (4% AOP)

988 224 234 227 772 1,180 1,030 7,870 8,590 7,960 1,790 1,230 3,090 3,750 3,160 5,940 9,200 6,590 36,500 30,100 36,000 49,000 32,200 45,300 38,900 42,100 39,100 12,800 14,100 12,900 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

712 909 745 175 177 176 593 968 Flood discharge, in cubic feet per second 6,400 6,840 6,450 9,940 1,290 2,560 2,950 2,600 4,870 7,330 5,260 5-year 11,300 30,100 24,500 29,800 39,400 26,100 37,100 32,900 34,400 33,000 10,000 (20% AOP)

111 113 363 553 383 102 678 356 567 4,340 4,410 4,350 6,290 7,400 6,340 1,770 1,860 1,780 3,390 4,740 3,540 2-year 20,200 16,400 20,000 24,900 17,500 24,100 23,000 23,200 23,000 (50% AOP)

91.8 77.4 88.6 251 428 269 484 274 414 3,560 3,530 3,560 5,040 5,960 5,080 1,460 1,460 1,460 2,830 3,790 2,940 1.5-year 16,300 13,300 16,200 19,300 14,300 18,700 18,700 19,000 18,700 (67% AOP)

62.6 44.7 57.4 115 260 132 246 165 215 980 923 975 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on a AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 2,410 2,280 2,400 8,970 9,640 3,330 3,920 3,370 2,020 2,460 2,090 1.1-year 11,200 11,000 10,200 10,100 12,000 12,900 12,000 (90% AOP) r r r r r r r r r r s s s s s s s s s s w w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w OH WV WV WV WV WV WV WV WV WV State station number 03202480 03202750 03203000 03203600 03204000 03204500 03205995 03206450 03206600 03206800 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

255 256 257 258 259 260 261 262 263 264 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 70 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

597 679 648 5,610 9,960 29,300 28,200 33,600 29,200 12,900 42,100 28,900 39,300 75,100 33,400 64,000 46,300 40,100 44,800 72,800 32,500 66,800 22,300 12,400 19,800 41,600 27,400 38,200 500-year (0.2% AOP)

), from the systematic the from ), s 481 567 532 9,960 4,790 8,000 25,000 24,200 29,200 25,000 37,000 25,100 34,600 60,000 29,000 52,400 40,500 34,900 39,200 61,900 28,300 57,200 17,400 10,700 15,800 35,800 23,800 33,100 200-year ), from the regionalized r (0.5% AOP)

402 487 451 8,000 4,190 6,650 9,430 22,000 21,300 26,000 22,100 33,100 22,300 31,000 49,800 25,800 44,400 36,200 31,200 35,100 54,000 25,200 50,200 14,200 13,200 31,600 21,200 29,400 100-year (1% AOP)

328 412 374 6,270 3,620 5,420 8,210 11,400 19,000 18,500 22,900 19,200 29,200 19,600 27,500 40,700 22,700 37,000 32,000 27,400 31,100 46,300 22,100 43,400 10,800 27,600 18,600 25,800 50-year (2% AOP)

261 341 302 4,760 3,070 4,290 9,010 7,020 8,670 16,200 15,900 19,800 16,400 25,200 16,900 23,900 32,500 19,700 30,200 27,900 23,800 27,100 38,900 19,200 36,800 23,600 16,000 22,300 25-year (4% AOP)

182 254 213 3,070 2,370 2,920 6,280 5,490 6,180 12,700 12,500 15,700 12,800 19,800 13,400 19,000 22,900 15,600 22,000 22,400 19,000 21,900 29,400 15,200 28,300 18,600 12,700 17,800 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

128 192 151 Flood discharge, in cubic feet per second 9,980 2,010 1,850 1,980 4,520 4,350 4,510 5-year 10,100 12,700 10,200 15,500 10,800 15,100 16,500 12,600 16,200 18,200 15,300 17,900 22,400 12,200 21,800 14,800 10,200 14,300 (20% AOP)

64.1 75.8 112 863 888 6,480 6,470 8,310 6,560 1,150 9,390 7,040 9,250 8,840 8,250 8,810 8,030 2,470 2,770 2,490 9,410 6,650 9,220 2-year 12,100 10,100 12,000 12,900 12,700 (50% AOP)

44.3 84.4 53.7 551 901 578 5,160 5,180 6,710 5,250 7,090 5,670 7,010 6,410 6,660 6,420 9,710 8,180 9,600 9,590 6,470 9,490 1,830 2,200 1,850 7,440 5,350 7,300 1.5-year (67% AOP)

20.8 48.9 28.4 219 560 247 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 3,300 3,330 4,420 3,400 3,890 3,720 3,880 3,400 4,390 3,460 6,260 5,420 6,180 5,190 4,260 5,150 1,040 1,400 1,060 4,630 3,500 4,530 1.1-year (90% AOP) r r r r r r r r r s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w VA VA VA VA VA VA KY KY WV WV State station number 03207000 03207020 03207400 03207500 03207800 03207962 03208000 03208500 03208950 03209000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

265 266 267 268 269 270 271 272 273 274 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Table 3 71

1,420 1,660 1,550 9,600 9,810 7,490 11,100 17,700 26,200 21,200 32,700 16,600 27,600 27,000 23,400 25,800 22,300 26,400 23,500 56,700 47,300 55,300 17,400 14,700 71,200 99,300 500-year 106,000 148,000 (0.2% AOP)

), from the systematic the from ), s 1,170 1,400 1,290 8,600 9,560 8,730 6,420 11,900 15,400 22,700 18,300 27,400 14,300 23,500 21,600 20,300 21,200 19,700 23,000 20,600 49,200 41,300 48,000 13,800 87,700 62,500 82,900 200-year ), from the regionalized 123,000 r (0.5% AOP)

995 1,210 1,100 7,820 8,420 7,900 5,640 11,400 13,700 20,200 16,100 23,500 12,700 20,500 18,000 18,000 18,000 17,600 20,400 18,400 43,600 36,900 42,700 10,000 74,800 56,000 71,500 100-year (1% AOP) 105,000

841 934 1,030 7,010 7,330 7,050 9,200 4,880 8,260 11,100 12,000 17,700 14,000 19,900 17,600 14,700 15,800 15,000 15,600 17,900 16,200 38,100 32,600 37,400 62,900 49,600 60,800 88,800 50-year (2% AOP)

702 865 775 6,180 6,260 6,180 9,490 7,220 4,150 6,640 11,900 11,700 10,300 15,300 16,500 14,900 13,600 12,200 13,500 15,400 13,900 32,700 28,300 32,200 51,900 43,300 50,700 73,500 25-year (4% AOP)

538 654 582 5,000 4,890 5,000 8,210 9,220 7,460 8,270 8,690 4,920 3,220 4,680 11,400 11,000 12,100 12,200 10,800 10,700 12,200 25,500 22,600 25,300 38,600 34,900 38,200 54,700 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

425 501 449 Flood discharge, in cubic feet per second 4,050 3,860 4,040 6,590 9,700 7,220 9,170 5,930 8,740 5,930 8,600 6,260 8,570 9,800 8,730 3,400 2,530 3,310 5-year 20,100 18,300 20,000 29,300 28,400 29,200 41,400 (20% AOP)

282 299 286 3,110 2,590 2,450 2,580 4,270 6,320 4,560 5,180 3,810 5,060 5,580 3,300 5,380 6,380 5,470 1,640 1,580 1,640 2-year 12,300 12,100 12,300 17,400 19,100 17,500 24,100 (50% AOP)

232 230 232 2,020 1,940 2,020 3,410 5,080 3,640 3,820 3,040 3,760 2,230 4,480 2,390 4,170 5,130 4,250 9,490 9,850 9,500 1,120 1,250 1,130 1.5-year 13,300 15,600 13,400 18,200 (67% AOP)

164 137 156 508 782 525 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 1,180 1,230 1,180 2,150 3,320 2,360 2,060 1,960 2,050 1,140 2,920 1,290 2,440 3,360 2,540 5,500 6,570 5,550 7,950 8,090 1.1-year 10,500 10,400 (90% AOP) r r r r r r r r r s s s s s s s s s s w w w w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w KY KY KY KY WV WV WV WV WV WV State station number 03211500 03209575 03210000 03212000 03212750 03212980 03213000 03213500 03213700 03214000 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

275 276 277 278 279 280 281 282 283 284 number Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] 72 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

- 678 743 714 3,230 4,050 3,540 87,600 90,400 97,600 93,200 27,800 27,100 27,700 37,800 40,600 38,400 500-year 125,000 121,000 (0.2% AOP)

), from the systematic the from ), s 590 621 607 2,800 3,440 3,030 77,000 76,900 85,900 80,200 23,500 23,500 23,500 32,300 35,400 33,000 200-year ), from the regionalized 106,000 103,000 r (0.5% AOP)

527 534 531 2,490 3,010 2,670 92,200 69,200 90,100 67,200 77,200 70,800 20,500 20,900 20,500 28,500 31,600 29,200 100-year (1% AOP)

465 452 459 2,200 2,590 2,330 79,200 61,400 77,700 58,000 68,600 61,500 17,600 18,400 17,700 24,900 27,800 25,500 50-year (2% AOP)

406 375 391 1,920 2,190 2,000 66,600 53,700 65,700 49,300 60,100 52,400 15,000 15,800 15,100 21,600 24,100 22,000 25-year (4% AOP)

330 280 309 1,560 1,680 1,590 11,700 11,700 50,800 43,400 50,400 38,200 48,700 40,600 12,600 17,300 19,300 17,600 10-year (10% AOP) ge and equivalent years of record. Shading indicates the 44 streamgage stations removed

211 272 250 Flood discharge, in cubic feet per second 9,260 9,320 1,300 1,300 1,300 5-year 39,200 35,500 39,100 30,000 39,800 31,800 10,100 14,200 15,500 14,400 (20% AOP)

929 801 910 190 123 171 6,020 6,560 6,040 9,970 9,990 2-year 23,600 24,000 23,600 18,900 27,000 19,900 10,300 (50% AOP)

93 789 625 764 158 139 4,860 5,280 4,880 8,390 8,300 8,380 1.5-year 18,000 19,700 18,000 14,900 22,200 15,700 (67% AOP)

54 90 111 582 384 540 Advisory Committee on Water Data (1982) with the West Virginia skew (Atkins and others, 2009); second line (Q Virginia West Data (1982) with the Water Advisory Committee on AOP, annual-occurrence probability; WV, West Virginia; MD, Maryland; VA, Virginia; OH, Ohio; PA, Pennsylvania; KY, Kentucky; East, Pennsylvania; KY, OH, Ohio; PA, Virginia; VA, MD, Maryland; Virginia; West WV, annual-occurrence probability; AOP, 9,240 3,210 3,450 3,220 6,090 5,510 6,030 1.1-year 10,500 13,400 10,600 15,200 10,100 (90% AOP) r r r r r r s s s s s s w w w w w w Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q type Estimate West West West West West West Region ), from weighting (1) the systematic and historical record using guidelines established by the Interagency Advisory Committee on Water Data (1982) with the West Virginia Virginia West Data (1982) with the Water Advisory Committee on by the Interagency record using guidelines established ), from weighting (1) the systematic and historical w KY KY KY KY WV WV State station number 03214500 03214900 03215500 03216500 03216540 03216563 Streamgage Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West Virginia and adjacent states.—Continued Virginia Flood-frequency discharges for the 290 U.S. Geological Survey streamgage stations on rural, unregulated streams in West

285 286 287 288 289 290 number Discharge was computed outside the PeakFQ computer program (Flynn and others, 2006) using the HARTIV subroutine (Kirby, 1980) and by computing the antilog of the discharge from equation 1 (Inter 1980) and by computing the antilog of discharge subroutine (Kirby, was computed outside the PeakFQ computer program (Flynn and others, 2006) using HARTIV Discharge a Identification Table 3. Table [Identification number refers to the in figure 3; %, percent; (Q line first order: estimate-type following the in presented are discharges Flood-frequency Region. Plateaus Western West, Region; Mountains Central Central, Region; Panhandle Eastern and historical record using guidelines established by the Interagency regression equation; and third line (Q skew (Atkins and others, 2009) (2) the regionalized regression equation, using number of years peak dischar from consideration as part of the regional regression analysis] Data, 1982, p. 9–10). Water Advisory Committee on agency Table 5 73 VA VA VA VA VA MD MD MD MD MD MD WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Station name Downstream station North Br. Potomac River at Kitzmiller North Br. Potomac River near Cumberland N. Br. Potomac River at Bloomington North Br. North Branch Potomac River at Pinto Potomac River near Cumberland N. Br. Potomac River near Cumberland N. Br. Potomac River near Petersburg S. Br. Potomac River near Springfield S. Br. Potomac River near Springfield S. Br. Potomac R. near Moorefield S. Fk. Br. Little Cacapon River near Levels Cacapon River near Great Opequon Creek near Martinsburg N. Fk. Shenandoah R. at Mount Jackson N. Fk. Shenandoah River near Strasburg N. Fk. Shenandoah River near Strasburg Goose Creek near Leesburg Back Creek near Mountain Grove River near Elkins Valley Tygart River at Fetterman Valley Tygart River at Belington Valley Tygart River at Phillipi Valley Tygart River at Fetterman Valley Tygart River at Fetterman Valley Tygart Audra Middle Fork River at Bonica Run on Route 38 near Phillipi Weston Fork R. blw Stonewall Jackson Dam nr West Fork River at Enterprise West Fork River at Butcherville West Fork River at Clarksburg West

station number 01611500 02011500 01595500 01603000 01596000 01600000 01603000 01603000 01606500 01608500 01608500 01608000 01609800 01616500 01633000 01634000 01634000 01644000 03050500 03056500 03051000 03054500 03056500 03056500 03052000 03055040 03058000 03061000 03058500 03059000 Streamgage - 3 4 12 10 12 12 17 23 23 21 27 32 41 61 64 64 72 78 84 96 86 92 96 96 88 94 100 105 101 102 Identi number fication VA VA VA VA VA VA MD MD MD MD MD MD WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State WV, West Virginia; VA, Virginia; PA, Pennsylvania; OH, Ohio; KY, Kentucky; N., North; S., South; E., East; R., River; Br., Branch; Fk., Kentucky; N., North; S., South; E., East; R., River; Br., Pennsylvania; OH, Ohio; KY, PA, Virginia; VA, Virginia; West WV, Station name Upstream station North Branch Potomac River at Steyer North Branch Potomac River at Steyer Potomac River at Kitzmiller North Br. Potomac River at Bloomington North Br. Potomac River at Bloomington North Br. North Branch Potomac River at Pinto South Branch Potomac River at Franklin South Branch Potomac River at Franklin Potomac River near Petersburg S. Br. Potomac R. at Brandywine S. Fk. Br. Little Cacapon River at Frenchburg Spring Yellow Cacapon River at Opequon Creek near Berryville N. Fk. Shenandoah R. at Cootes Store N. Fk. Shenandoah R. at Cootes Store N. Fk. Shenandoah R. at Mount Jackson Goose Creek near Middleburg at Rt. 600 near Mountain Grove Back Cr. River near Dailey Valley Tygart River near Dailey Valley Tygart River near Elkins Valley Tygart River at Belington Valley Tygart River at Belington Valley Tygart River at Phillipi Valley Tygart Middle Fork River at Midvale Bonica Run on U.S. 250 near Phillipi Walkersville Fork River at West Walkersville Fork River at West Weston Fork R. blw Stonewall Jackson Dam nr West Fork River at Butcherville West

station number 02011480 01595000 01595000 01595500 01596000 01596000 01600000 01605500 01605500 01606500 01607500 01609650 01610500 01615000 01632000 01632000 01633000 01643700 03050000 03050000 03050500 03051000 03051000 03054500 03051500 03055020 03057300 03057300 03058000 03058500 Streamgage - 1 1 3 4 4 10 14 14 17 19 26 31 39 56 56 61 71 77 83 83 84 86 86 92 87 93 98 98 100 101 Identi number fication Description of the 88 pairs of U.S. Geological Survey streamgage stations in West Virginia and adjacent states that were evaluated to quantify “near” for application Virginia Description of the 88 pairs U.S. Geological Survey streamgage stations in West

1 2 3 4 5 6 7 8 9 11 10 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Pair number Table 5. Table of the drainage-area ratio method in this study.—Continued [Identification number refers to the in figure 3; MD, Maryland; below] near; blw, Fork; nr, 74 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Station name Downstream station West Fork River at Enterprise West Fork River at Enterprise West Cheat River near Parsons Cheat River near Pisgah Cheat River at Rowlesburg Cheat River near Pisgah Cheat River near Pisgah Blackwater River at Davis Shavers Fork below Bowden Cheat River near Parsons Cheat River near Parsons Little Muskingum River at Fay Little Kanawha River near Burnsville Little Kanawha River at Palestine Little Kanawha River at Glenville Little Kanawha River at Grantsville Little Kanawha River at Palestine Little Kanawha River at Palestine Hughes River at Cisco Bluestone River near Pipestem Bluestone River at Lilly Bluestone River at Lilly Greenbrier River at Buckeye Greenbrier River at Hilldale Alderson Greenbrier River at Greenbrier River at Hilldale Greenbrier River at Hilldale Gauley River at Camden on Gauley River near Craigsville Gauley River at Belva

station number 03115500 03061000 03061000 03069500 03071000 03070000 03071000 03071000 03066000 03068800 03069500 03069500 03151500 03155000 03152000 03153500 03155000 03155000 03155500 03179000 03179500 03179500 03182500 03184000 03183500 03184000 03184000 03187000 03189100 03192500 Streamgage - 118 112 116 118 118 105 105 123 121 123 123 156 162 171 163 167 171 171 174 186 187 187 195 201 198 201 201 209 213 223 Identi number fication VA VA OH WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State WV, West Virginia; VA, Virginia; PA, Pennsylvania; OH, Ohio; KY, Kentucky; N., North; S., South; E., East; R., River; Br., Branch; Fk., Kentucky; N., North; S., South; E., East; R., River; Br., Pennsylvania; OH, Ohio; KY, PA, Virginia; VA, Virginia; West WV, Station name Upstream station West Fork River at Butcherville West Fork River at Clarksburg West Dry Fork at Hendricks Dry Fork at Hendricks Cheat River near Parsons Cheat River near Parsons Cheat River at Rowlesburg Blackwater River near Davis Shavers Fork at Cheat Bridge Shavers Fork at Cheat Bridge Shavers Fork below Bowden Little Muskingum River at Bloomfield Wildcat Little Kanawha River near Wildcat Little Kanawha River near Little Kanawha River near Burnsville Little Kanawha River at Glenville Little Kanawha River at Glenville Little Kanawha River at Grantsville South Fork Hughes River at Macfarlan Bluestone River at Bluefield Bluestone River at Bluefield Bluestone River near Pipestem Greenbrier River at Durbin Greenbrier River at Durbin Greenbrier River at Buckeye Greenbrier River at Buckeye Alderson Greenbrier River at River at Dyer Williams Gauley River at Camden on Gauley River at Camden on

station number 03115400 03058500 03059000 03065000 03065000 03069500 03069500 03070000 03065400 03067500 03067500 03068800 03151400 03151400 03151500 03152000 03152000 03153500 03155200 03177700 03177700 03179000 03180500 03180500 03182500 03182500 03183500 03186500 03187000 03187000 Streamgage - 111 110 110 118 118 114 114 116 101 102 121 154 161 161 162 163 163 167 172 184 184 186 190 190 195 195 198 208 209 209 Identi number fication Description of the 88 pairs of U.S. Geological Survey streamgage stations in West Virginia and adjacent states that were evaluated to quantify “near” for application Virginia Description of the 88 pairs U.S. Geological Survey streamgage stations in West

31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Pair number Table 5. Table of the drainage-area ratio method in this study.—Continued [Identification number refers to the in figure 3; MD, Maryland; below] near; blw, Fork; nr, Table 5 75 VA KY KY KY WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State Station name Downstream station Gauley River near Summersville Gauley River above Belva Gauley River at Belva Gauley River at Belva Meadow River near Mount Lookout Elk River at Sutton Elk River at Queen Shoals Elk River at Queen Shoals Tornado Coal River at Little Coal River at Julian Guyandotte River at Man Guyandotte River at Branchland Guyandotte River at Logan Guyandotte River at Branchland Guyandotte River at Branchland Creek near East Lynn Twelvepole E. Fk. Wayne Creek below Twelvepole Wayne Creek below Twelvepole Levisa Fork at Big Rock Levisa Fork below Fishtrap Dam Levisa Fork below Fishtrap Dam Lear Van Johns Creek near Fork at Litwar Tug Fork at Glenhayes Tug Williamson Fork at Tug Fork at Kermit Tug Fork at Glenhayes Tug Fork at Glenhayes Tug

station number 03211500 03189500 03192000 03192500 03192500 03190400 03195500 03197000 03197000 03200500 03199400 03203000 03204000 03203600 03204000 03204000 03206800 03207020 03207020 03207800 03208000 03208000 03213000 03214900 03213700 03214500 03214900 03214900 Streamgage - 214 222 223 223 218 231 233 233 244 243 257 259 258 259 259 264 266 266 269 271 271 277 281 286 283 285 286 286 Identi number fication VA VA VA KY WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV WV State WV, West Virginia; VA, Virginia; PA, Pennsylvania; OH, Ohio; KY, Kentucky; N., North; S., South; E., East; R., River; Br., Branch; Fk., Kentucky; N., North; S., South; E., East; R., River; Br., Pennsylvania; OH, Ohio; KY, PA, Virginia; VA, Virginia; West WV, Station name Upstream station Gauley River near Craigsville Gauley River near Summersville Gauley River near Summersville Gauley River above Belva Meadow River at Nallen Springs Webster Elk River below Springs Webster Elk River below Elk River at Sutton Ashford Big Coal River at Little Coal River at Danville Guyandotte River near Baileysville Guyandotte River near Baileysville Guyandotte River at Man Guyandotte River at Man Guyandotte River at Logan Creek near Dunlow Twelvepole East Fork Creek near Dunlow Twelvepole East Fork Creek near East Lynn Twelvepole E. Fk. Levisa Fork near Grundy Levisa Fork near Grundy Levisa Fork at Big Rock Johns Crek near Meta Welch Fork at Tug Welch Fork at Tug Fork at Litwar Tug Williamson Fork at Tug Williamson Fork at Tug Fork at Kermit Tug

station number 03189100 03189500 03189500 03192000 03190000 03194700 03194700 03195500 03198500 03199000 03202400 03202400 03203000 03203000 03203600 03206600 03206600 03206800 03207500 03207500 03207800 03210000 03212750 03212750 03213000 03213700 03213700 03214500 Streamgage - 213 214 214 222 216 227 227 231 238 241 254 254 257 257 258 263 263 264 268 268 269 276 279 279 281 283 283 285 Identi number fication Description of the 88 pairs of U.S. Geological Survey streamgage stations in West Virginia and adjacent states that were evaluated to quantify “near” for application Virginia Description of the 88 pairs U.S. Geological Survey streamgage stations in West

61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 Pair number Table 5. Table of the drainage-area ratio method in this study.—Continued [Identification number refers to the in figure 3; MD, Maryland; below] near; blw, Fork; nr, 76 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

(This page intentionally left blank.) Appendix 1 78 Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia

Appendix 1. Matrices Used to Compute Individual Standard Errors of Prediction

[PK(n_n), peak discharge for the (n.n)-year recurrence interval; PK(n), peak discharge for the (n)-year recurrence interval; %, percent; AOP, annual-occurrence probability; γ2, standard error of the model squared; numbers are given in scientific notation where 0.32483E-01 is 0.032483]

Eastern Panhandle Region Central Mountains Region Western Plateaus Region

PK1_1(90%AOP) γ2 = 0.32483E-01 PK1_1(90%AOP) γ2 = 0.27978E-01 PK1_1(90%AOP) γ2 = 0.25715E-01 0.36765E-02 -0.13943E-02 0.26613E-02 -0.98361E-03 0.21782E-02 -0.77332E-03 -0.13943E-02 0.79153E-03 -0.98361E-03 0.47958E-03 -0.77332E-03 0.38325E-03

PK1_5(67%AOP) γ2 = 0.22559E-01 PK1_5(67%AOP) γ2 = 0.21308E-01 PK1_5(67%AOP) γ2 = 0.19963E-01 0.26813E-02 -0.98579E-03 0.20667E-02 -0.75807E-03 0.16074E-02 -0.56593E-03 -0.98579E-03 0.55605E-03 -0.75807E-03 0.36705E-03 -0.56593E-03 0.28053E-03

PK2(50%AOP) γ2 = 0.18489E-01 PK2(50%AOP) γ2 = 0.19922E-01 PK2(50%AOP) γ2 = 0.17940E-01 0.24610E-02 -0.86628E-03 0.20406E-02 -0.74156E-03 0.14888E-02 -0.51918E-03 -0.86628E-03 0.48293E-03 -0.74156E-03 0.35478E-03 -0.51918E-03 0.25507E-03

PK5(20%AOP) γ2 = 0.11967E-01 PK5(20%AOP) γ2 = 0.20745E-01 PK5(20%AOP) γ2 = 0.15490E-01 0.24958E-02 -0.76020E-03 0.24841E-02 -0.88266E-03 0.15374E-02 -0.52302E-03 -0.76020E-03 0.41065E-03 -0.88266E-03 0.41029E-03 -0.52302E-03 0.24868E-03

PK10(10%AOP) γ2 = 0.92526E-02 PK10(10%AOP) γ2 = 0.23263E-01 PK10(10%AOP) γ2 = 0.15120E-01 0.27016E-02 -0.75370E-03 0.29889E-02 -0.10523E-02 0.17035E-02 -0.57249E-03 -0.75370E-03 0.40192E-03 -0.10523E-02 0.48398E-03 -0.57249E-03 0.26724E-03

PK25(4%AOP) γ2 = 0.71876E-02 PK25(4%AOP) γ2 = 0.27815E-01 PK25(4%AOP) γ2 = 0.15624E-01 0.30780E-02 -0.79872E-03 0.37621E-02 -0.13163E-02 0.19906E-02 -0.66264E-03 -0.79872E-03 0.42199E-03 -0.13163E-02 0.60165E-03 -0.66264E-03 0.30467E-03

PK50(2%AOP) γ2 = 0.64308E-02 PK50(2%AOP) γ2 = 0.31932E-01 PK50(2%AOP) γ2 = 0.16517E-01 0.34417E-02 -0.86987E-03 0.44057E-02 -0.15382E-02 0.22400E-02 -0.74298E-03 -0.86987E-03 0.45750E-03 -0.15382E-02 0.70196E-03 -0.74298E-03 0.33935E-03

PK100(1%AOP) γ2 = 0.61728E-02 PK100(1%AOP) γ2 = 0.36527E-01 PK100(1%AOP) γ2 = 0.17743E-01 0.38754E-02 -0.96990E-03 0.50907E-02 -0.17758E-02 0.25100E-02 -0.83124E-03 -0.96990E-03 0.50843E-03 -0.17758E-02 0.81032E-03 -0.83124E-03 0.37818E-03

PK200(0.5%AOP) γ2 = 0.63080E-02 PK200(0.5%AOP) γ2 = 0.41553E-01 PK200(0.5%AOP) γ2 = 0.19246E-01 0.43778E-02 -0.10963E-02 0.58123E-02 -0.20274E-02 0.27968E-02 -0.92609E-03 -0.10963E-02 0.57352E-03 -0.20274E-02 0.92586E-03 -0.92609E-03 0.42049E-03

PK500(0.2%AOP) γ2 = 0.69967E-02 PK500(0.2%AOP) γ2 = 0.48810E-01 PK500(0.2%AOP) γ2 = 0.21600E-01 0.51444E-02 -0.13012E-02 0.68170E-02 -0.23795E-02 0.31977E-02 -0.10601E-02 -0.13012E-02 0.68008E-03 -0.23795E-02 0.10887E-02 -0.10601E-02 0.48102E-03 For additional information, write to: Director U.S. Geological Survey West Virginia Water Science Center 11 Dunbar Street Charleston, WV 25301 or visit our Web site at: http://wv.usgs.gov/

Document prepared by the West Trenton Publishing Service Center Wiiley, J.B. and Atkins, J.T.—Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia—Scientific Investigations Report 2010–5033 Printed on recycled paper