Flow Statistics for Pennsylvania Streams
Streamflow statistics for ungaged streams in Pennsylvania with no significant regulation can be determined using StreamStats for Pennsylvania. The following statistics can be determined: peak flows (50, 20, 10, 2, 1, and 0.2 percent annual exceedance flood), low flows (7day, 10year; 7day, 2year; 30day, 10year; 30day, 2year; and the 90day, 10year low flows), base flows (10year, 25year, and 50year base flows), and mean flows (mean annual flow, harmonic mean flow). The reports below document the regression equations available in StreamStats for Pennsylvania and the errors associated with the estimates obtained from the equations.
 Roland, M.A., and Stuckey, M.H., 2008, Regression equations for estimating flood flows at selected recurrence intervals for ungaged streams in Pennsylvania: U.S. Geological Survey Scientific Investigations Report 20085102, 57 p.
 Stuckey, M.H., 2006, Lowflow, baseflow, and meanflow regression equations for Pennsylvania streams: .U.S. Geological Survey Scientific Investigations Report 20065130, 84 p.
Streamflow statistics for streamgages can also be found using StreamStats for Pennsylvania or in published USGS reports (see links below). For guidance on techniques regarding weighting and transference of statistics, see Techniques for Estimating Magnitude and Frequency of Peak Flows for Pennsylvania Streams, USGS Water Resources Investigations Report 004189 by Stuckey and Reed; and documentation found at USGS LowFlow Statistics for Pennsylvania Streams web application. The mostcurrent methods and results of statistical analyses for lowflow statistics from regulated streams are described in Comparison of Methods for Computing Streamflow Statistics for Pennsylvania Streams, USGS Water Resources Investigations Report 994068 by Ehlke and Reed.
If you are interested in:

PeakFlow Statistics
 at or near a streamgage on an unregulated stream (USGS SIR 20085102, Appendix 2)
 at an ungaged location on an unregulated stream (USGS StreamStats web application)
 at selected streamgages on regulated streams (USGS SIR 20085102, Appendix 3)
 LowFlow Statistics
 at or near a streamgage on an unregulated stream (USGS SIR 20065130, Appendix 4)
 at an ungaged location on an unregulated stream (USGS StreamStats web application)
 at an ungaged location on an unregulated stream that exceeds the suggested limits of regression equations (USGS SIR 20065130, Table 5) presented in StreamStats web page (USGSPA Lowflow Statistics web application)
 at selected streamgages on regulated streams (USGS WRIR 994068, Appendix 1)
 BaseFlow and MeanFlow Statistics
 at or near a streamgage on an unregulated stream (USGS SIR 20065130, Appendix 5)
 at an ungaged location on an unregulated stream (USGS StreamStats web application)
 MeanFlow Statistics:
 at selected streamgages on regulated streams (USGS WRIR 994068, Appendix 1)