Surface Water

surface water

In order to maintain a healthy river basin, “environmental flows” must be managed.  Environmental flows refer to the flow of both quantity and rate of water flow required to maintain healthy streams and rivers.

River and stream levels within the Blanco watershed are clearly displayed in sub-basin map (JPEG).  Five USGS streamflow gages (JPEG) within this basin provide numbers for the daily stream flow. Stream gage data from 1950 to 2009 provide the information necessary to determine the average amount of monthly surface water flow. The monthly average stream flow (JPEG) and average annual stream flow (JPEG) data was recorded at USGS station 8171000 and station 41983.

Flood plain maps showing the 100-year flood plain are available from the Texas Natural Resources Information System (TNRIS) in all studies counties except Caldwell and Gonzales counties (TNRIS 2008). Digital data for Caldwell and Gonzales counties can be found through the First American Flood Data Services seen here in the flood plains map of the Blanco River watershed (JPEG).