Vermont StreamStats

Vermont StreamStats incorporates statewide regression equations for estimating instantaneous peak flows with annual exceedance probabilities of 50, 20, 10, 4, 2, 1, 0.5, and 0.2 percent. These peak flows have recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years, respectively. The report below documents the regression equations, the methods used to develop them and to measure the basin characteristics used in the equations, and the errors associated with estimates obtained from the equations. Users should familiarize themselves with this report before using StreamStats to obtain estimates of flows for ungaged sites in rural drainage basins.

• Olson, S.A., 2014, Estimation of flood discharges at selected annual exceedance probabilities for unregulated, rural streams in Vermont, with a section on Vermont regional skew regression, by Veilleux, A.G.: U.S. Geological Survey Scientific Investigations Report 2014–5078, 27 p. plus appendixes.

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

Estimating peak-flow frequency statistics based on the flows at nearby streamgages:

This page previously provided special instructions for estimating peak-flow frequencies for ungaged sites based on the flows at nearby streamgages. The described estimation method relied on functionality that was only available in StreamStats version 2. That functionality is under development in version 4. The instructions will be updated when the needed functionality is made available in version 4.