Alliance Water is a Regional Water Authority that was formed for the purpose of resolving the long-term water needs of its Participants. Alliance Water is comprised of the cities of Kyle, San Marcos and Buda, along with the Canyon Regional Water Authority which represents County Line Special Utility District (SUD), Crystal Clear SUD, Martindale WSC, and Green Valley SUD.
Hays Caldwell Public Utility Agency The City of San Marcos is a member of the Hays Caldwell Public Utility Agency (HCPUA). The purpose of the Agency is to resolve long-term water needs for it participants.
Edwards Aquifer Authority The City of San Marcos pumps groundwater from the Edwards Aquifer. The Edwards Aquifer Authority (EAA) manages and regulates the Aquifer.
Guadalupe-Blanco River Authority The City of San Marcos pumps surface water from Canyon Lake. These water rights are governed by the Guadalupe-Blanco River Authority (GBRA).