PWS boundary and reg agency map

Use Constraints: This mapping tool is for reference and guidance purposes only and is not a binding legal document to be used for legal determinations. The data provided may contain errors, inconsistencies, or may not in all cases appropriately represent the current boundaries of PWSs in California. The data in this map are subject to change at any time and should not be used as the sole source for decision making. By using this data, the user acknowledges all limitations of the data and agrees to accept all errors stemming from its use. Description: This mapping tool provides a representation of the general PWS boundaries for water service, wholesaler and jurisdictional areas. The boundaries were created originally by collection via crowd sourcing by CDPH through the Boundary Layer Tool, retired as of June 30, 2020. State Water Resources Control Board – Division of Drinking Water is currently in the process of verifying the accuracy of these boundaries and working on a tool for maintaining the current boundaries and collecting boundaries for PWS that were not in the original dataset. Map Layers · CA Drinking Water System Area Boundaries (SABL) – representation of the general water system boundaries maintained by the State Water Board. This layer contains polygons with associated data on the water system and boundary of the area served. · DDW District Office Locations – represents the office locations of the DDW District overseeing the water system in that county. Address and contact information are attributes of this dataset. · LPA Office Locations – represents the office locations of the Local Primacy Agency overseeing the water system in that county. Address and contact information are attributes of this dataset California County – represents the boundaries of the counties in California included as a reference layer in order to perform analysis with the Drinking Water System Area Boundary Layer. Source: California Department of Technology | Layer: California County Boundaries and Identifiers (ID:1). · California State Senate Districts and Membership 2025-2030 – represents the boundaries of the current CA state senate districts included as a reference layer in order to perform analysis with the Drinking Water System Area Boundary Layer. Source: California Department of Technology | Layer: CA_State_Senate_Districts (ID:0). California State Assembly Districts and Membership 2024-2026 – represents the boundaries of the current CA state assembly districts included as a reference layer in order to perform analysis with the Drinking Water System Area Boundary Layer. Source: California Department of Technology | Layer: CA_State_Senate_Districts (ID:0) United States Congressional Districts – represents the district boundaries of the U.S. House of Representatives included as a reference layer in order to perform analysis with the Drinking Water System Area Boundary Layer. Source: NTAD (National Transportation Atlas Database | Layer: Congressional Districts (ID:0). Informational Pop-up Box for SABL: · Water System Number – PWSID, or unique identifier for each water system · Water System Name – name of water system · Regulating Agency – agency overseeing the water system · System Type – classification of water system. · Population the approximate population served by the water system · Boundary Type – the type of water system boundary being displayed · Address Line 1 – the street or mailing address on file for the water system · Address Line 2 – additional line for street or mailing address on file for the water system, if applicable · City – city where water system located or receives mail · County – county where water system is located · Verification Status – the verification status of the water system boundary · Verified by – if the boundary is verified, the person responsible for the verification Date Created and Sources: This web app was most recently updated in March 2026. Click on layers in list below to see data created date and data source, indicated in the overview/metadata page.