USGS Upgrades StreamStats for Pennsylvania

Watershed Delineation Improved

Surface drainage basin delineated for Yellow Breeches Creek, New Cumberland, Pennsylvania

Estimate Low-Flow for Any Stream in Pennsylvania

Low flow at Young Womans Creek near Renovo, on this day equal to the 7-day, 10-year low flow statistic for this gage.

By Pennsylvania Water Science Center October 1, 2020

The Pennsylvania Water Science Center (PaWSC) has upgraded StreamStats with the latest National Hydrography Dataset (NHD) flowlines and Watershed Boundary Dataset (WBD) drainage basins. More accurate basin delineations and basin characteristics, and improved estimates of streamflow are now available for any stream location in the Commonwealth of Pennsylvania.

StreamStats is a national web-based application developed by the USGS to provide water-resource-related information. Users can easily obtain descriptive information, basin characteristics, water-use information, and streamflow statistics for USGS streamgages and ungaged stream locations throughout Pennsylvania. Users select a location on any stream and StreamStats provides estimates of basin characteristics, streamflow statistics, and water-use information. PaWSC developed StreamStats for Pennsylvania in 2003 using flowlines and watershed boundaries that were the best available at that time. However, over the last two decades, better and more accurate stream flowlines and elevation models, which are used to determine watershed boundaries, have been developed. PaWSC recently used these flowlines and watershed boundaries to update StreamStats and provide more accurate basin characteristics which are used to estimate streamflows, such as the 7-day, 10-year low flow, which is the lowest 7 consecutive days of flow that could occur every 10 years. Water-resource managers use this statistic to manage water withdrawals from streams for the protection of instream habitats and ecology when streamflows are very low.

Photograph of broad weir notch with low flow, Young Womans Creek, Pennsylvania — (USGS, public domain.)

October 1^st starts the new hydrologic water year 2021 (10/1/2020 – 9/30/2021). Late September through mid-October is typically the season for the lowest streamflows in Pennsylvania and this season is starting out dry. Many western and north central Pennsylvania counties are under a State drought watch or warning and, in some places, historical low streamflows are occurring. Want to find out how low the streams are near you compared to historical observations? Check out the new and improved StreamStats in Pennsylvania and click on a stream near you.

Web Tool

Low streamflow at USGS streamgage Young Womans Creek near Renovo (01545600). At the time of the photograph, late September 2020, the streamflow was 1.5 cubic feet per second, which is equal to the 7-day, 10-year low flow statistic for this streamgage. Average streamflow around the beginning of October at this site is 12 cubic feet per second.