Updating Pennsylvania Streamgage Datums

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The USGS Pennsylvania Water Science Center (PaWSC) will be converting the geodetic vertical elevations for our network of streamgages to the current datum of North American Vertical Datum of 1988 (NAVD88). Prior to a change in geodetic vertical elevation (gage datum) at a streamgage, USGS will provide a 90-day notification to users of the data.

Current and accurate geodetic vertical elevations provide a universally based datum that benefits Federal, State, and local agencies, along with engineers, academics, and others that use water-level information. These updates are also part of preparations for a future transition to the North American-Pacific Geopotential Datum of 2022 (NAPGD2022).

This update in geodetic vertical datum does not affect the location of the streamgage, nor the observed local gage height (stage) or discharge recorded at the streamgage. 

A list of streamgages with previous and upcoming datum changes can be found below. This table will be updated as additional datum changes are finalized.

For more information on the streamgage datum conversion process, contact Marla Stuckey (mstuckey@usgs.gov).