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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 Adobe Acrobat PDF Documentthat come with the SWSA report are specific to your water system. The capture zones were created using computer algorithms based upon the hydrogeology of the area and each respective well's construction. When some of this information was missing, a half-mile diameter circle, a Adobe Acrobat PDF Documentfixed radiusAdobe Acrobat PDF Document, was automatically delineated as the capture zone.

The PWS Adobe Acrobat PDF Document 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.