West Virginia StreamStats

StreamStats for West Virginia can be used to estimate the magnitude of flow statistics for rural, unregulated, ungaged streams in West Virginia. Peak flows can be estimated at the 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence intervals. Annual low flows can be estimated at the 1-, 3-, 7-, 14-, and 30-day average 2-, 5-, and 10-year recurrence intervals, and for the 1-day, 3-year and 4-day, 3-year biologically based low flow frequency values. Estimates can also be made of the harmonic mean and the 10-, 25-, 50-, 75-, and 90-percent exceedance flow durations. Seasonal values can also be estimated for the 1-day, 10 year (1Q10), 7-day, 10 year (7Q10), and 30-day, 5-year (30Q5) low flows, the harmonic mean, and 50-percent flow duration.

In addition to streamflow statistics, basin characteristics for a variety of land cover, elevation, precipitation, soils, streams, and geology are available for download with watershed delineations. The reports below present the equations used to estimate the flow statistics, describe the errors associated with the estimates, describe the methods used to develop the equations and to measure the basin characteristics used in the equations, and describe other methods to estimate flow statistics for gaged streams. Users should familiarize themselves with the reports before using StreamStats to obtain estimates of streamflow statistics for ungaged sites.

• Wiley, J.B., 2006, Low flow analysis and selected flow statistics representative of the period 1930–2002 for streamflow-gaging stations in or near West Virginia: U.S. Geological Survey Scientific Investigations Report 2006-5002, 190 p.
• Wiley, J.B.., 2008, Estimating selected streamflow statistics representative of 1930–2002 in West Virginia: (ver. 1.1, May 2021): U.S. Geological Survey Scientific Investigations Report 2008–5105, 24 p., https://doi.org/10.3133/sir20085105. 
• Wiley, J.B., and Atkins, J.T., Jr., 2010a, Estimation of flood frequency discharges for rural, unregulated streams in West Virginia: U.S. Geological Survey Scientific Investigations Report 2010–5033, 78 p.
• Wiley, J.B., and Atkins, J.T., Jr., 2010, Estimation of selected seasonal streamflow statistics representative of 1930-2002 in West Virginia (ver. 1.1, May 2021): U.S. Geological Survey Scientific Investigations Report 2010–5185, 20 p., https://doi.org/10.3133/sir20105185.

Click on this link to obtain general information on the West Virginia application, as well as specific sources and computation methods for basin characteristics. 

**Users are cautioned against using the equations outside of the ranges of values of the independent variables used to develop the equations, as potential errors are unknown in these cases. For the peak-flow equations drainage area was the only significant independent variable. Valid drainage areas range from 0.21 to 1,461 mi² in the Eastern Panhandle, from 0.10 to 1,619 mi² in the Central Mountains, and from 0.13 to 1,516 mi² in the Western Plateaus (Wiley and Atkins, 2010a). Three independent variables, drainage area, longitude of the centroid, and mean annual precipitation from 1971-2000, were significant in equations for determining the selected low-flow, flow-duration, and harmonic mean statistics for the three regions in West Virginia. Drainage area was significant and ranged from 16.3 to 1,516 mi² in the North Region, 2.78 to 1,619 mi² in the South-Central Region, and 8.83 to 3,041 mi² in the Eastern Panhandle Region. Longitude of the centroid, expressed as a positive number, was significant in the North Region, where it ranged from 79.618 to 82.023 decimal degrees. Mean annual precipitation from 1971-2000 was significant for annual flow-duration statistics and several seasonal-flow statistics in the South-Central Region, where it ranged from 40.6 to 59.4 in.; and for several seasonal-flow statistics in the Eastern Panhandle Region, where it ranged from 38.4 to 51.0 in. Users are also cautioned that karst, coal mining, and urban development can make regional regression estimates unrepresentative and inaccurate for affected streams. 

Computations of peak-flow, low-flow, flow-duration, and other discharge statistics listed above have been updated at many gaged locations across West Virginia (Wiley, 2006; Wiley and Atkins, 2010a). These data can be viewed by clicking on the Query Streamgages button on the Exploration Tools list and then clicking on a streamgage icon. Select the "StreamStats gage page" link in the pop-up window for a tabulation of the data that is available at the station.