Evaluation of Reference Gages for Passby Flow Determinations and Monitoring in the Susquehanna River Basin

The Commission has released a new report to evaluate the effectiveness of using reference gages for implementing passby flows at ungaged withdrawal sites.

On certain water withdrawal projects, the Commission limits the amount of water a user can withdraw to avoid adverse impacts to the water resources of the Basin. When possible, streamflow conditions are monitored by United States Geological Survey (USGS) gages within the watershed where the withdrawal is located. However, in many instances, the Commission establishes passby flows for withdrawals from ungaged streams and must monitor streamflow conditions using reference gages located in another watershed. In doing so, reference gages are selected based on hydrologic similarities between the gaged and ungaged watersheds.

Publication No. 305

Technical Report (34 pages, file size = 1.33MB)

Fact Sheet