Water supply planning.

(1) Existing law requires a city or county that determines a project, as defined, is subject to the California Environmental Quality Act to identify certain water systems that may supply water for the project and to request those public water systems to prepare and approve a specified water supply assessment. Under existing law, if no public water system is identified, the city or county is required to prepare and approve the water supply assessment. Existing law provides that if, as a result of its assessment, the public water system or city or county concludes that its water supplies are, or will be, insufficient, the public water system or city or county is required to provide its plans for acquiring additional water supplies, as prescribed. Existing law, the Sustainable Groundwater Management Act, requires all groundwater basins designated as high- or medium-priority basins by the Department of Water Resources that are designated as basins subject to critical conditions of overdraft to be managed under a groundwater sustainability plan or coordinated groundwater sustainability plans by January 31, 2020, and requires all other groundwater basins designated as high- or medium-priority basins to be managed under a groundwater sustainability plan or coordinated groundwater sustainability plans by January 31, 2022, except as specified. The act authorizes the State Water Resources Control Board to designate a basin as a probationary basin if the state board makes a certain determination and to develop an interim plan for the probationary basin. This bill would require a city or county that determines a project is subject to the California Environmental Quality Act to identify any water system whose service area includes the project site and any water system adjacent to the project site. This bill would provide that hauled water is not a source of water for the purposes of a water supply assessment, as specified. This bill would, if a water supply for a proposed project includes groundwater, require certain additional information to be included in the water supply assessment. By imposing additional duties on cities and counties, this bill would impose a state-mandated local program. (2) Existing law, the Subdivision Map Act, establishes a statewide regulatory framework for controlling the subdividing of land. The act generally requires a subdivider to submit, and have approved by the city, county, or city and county in which the land is situated, a tentative map for subdivisions of land, as specified. Existing law requires a city or county to deny approval of a tentative map, or parcel map for which a tentative map was not required, if it makes certain findings relating to the proposed subdivision. Existing law requires a city or county to include as a condition in any tentative map that includes a subdivision a requirement that a sufficient water supply be available. Existing law requires proof of the availability of a sufficient water supply, as prescribed, and that the written verification of a public water system's ability or inability to provide a sufficient water supply be supported by substantial evidence. This bill would revise the definition of sufficient water supply to include additional factors relating to a proposed subdivision that relies in whole or in part on groundwater. (3) The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement. This bill would provide that no reimbursement is required by this act for a specified reason.