Hydrogeologic Provinces for California based upon established groundwater basins and watershed polygons.

These data were released prior to the October 1, 2016 effective date for the USGS’s policy dictating the review, approval, and release of scientific data as referenced in USGS Survey Manual Chapter 502.8 Fundamental Science Practices: Review and Approval of Scientific Data for Release. Ten hydrogeologic provinces of California are represented by a region- class feature called "provinces" within this digital data set. These provinces were identified and defined in the USGS Water Resource Investigation Report (WRIR) 03-4166 (Belitz and others, 2003) titled, "Framework for a Ground-water Quality Monitoring and Assessment Plan for California". Hydrogeologic provinces are generalized areas where hydrology and/or geology have similar characteristics. [...]