Skip to Content
Questions or Comments:

How to Interpret Source Water Susceptibility Assessment (SWSA) Maps

Information on how to read the SWSA maps. Explains the colors and circles on the maps.

The Public Water System (PWS)   well capture zone maps  fixed radius

The PWS intake capture zone maps consist of the area of primary influence (API) and the watershed. Nearby PWSs may share the same API and/or watershed. The API is based upon a 1000-foot buffer from a waterbody shoreline. It may extend upstream for PWS intakes drawing from rivers or streams. How far upstream the API extends depends upon a two-hour time of travel. The API boundaries were determined by characteristics that are specific to the TCEQ’s source water assessments. The API applied the same characteristics for boundary determination for each PWS. The watershed boundaries were determined by the natural topography specific to the particular PWS being assessed.