The layers contained here are California State Agencies and Local Transportation Organizations. Each boundary contains the name, address and web site for each office. California Metropolitan Planning Organization (MPO) legislative boundaries, primarily for regional planning applications. MPO is a federally mandated and federally funded transportation policy-making organization in the United States that is made up of representatives from local government and governmental transportation authorities. https://gisdata-caltrans.opendata.arcgis.com/datasets/55975bdc89a9456382dbd1fbda98c45a_0 California Regional Transportation Planning Agencies (RTPA) legislative boundaries, primarily for regional planning applications. The State Water Board and the Regional Water Boards have been entrusted with broad duties and powers to preserve and enhance all beneficial uses of the state's immensely complex waterscape. https://gisdata-caltrans.opendata.arcgis.com/datasets/ccbb62df26b84974a87ab3c02b2b4e8d_0 Caltrans Districts The District boundary definitions are primarily based on the county boundaries. There are 12 Caltrans Districts in California. https://gisdata-caltrans.opendata.arcgis.com/datasets/a0f1da19bffe471ea89bd6a241e5604b_0 The California Department of Water Resources (DWR) is part of the California Natural Resources Agency and is responsible for the management and regulation of the State of California's water usage. California's 35 local Air Districts are responsible for regional air quality planning, monitoring, and stationary source and facility permitting. The districts administer air quality improvement grant programs and are CARB's primary partners in efforts to ensure that all Californians breathe clean air. The California State Water Resources Control Board (SWRCB) is one of six branches of the California Environmental Protection Agency. California's pioneering clean water act is the 1969 Porter-Cologne Water Quality Control Act (Porter-Cologne Act).[5] Through the Porter-Cologne Act, the State Water Board and the Regional Water Boards have been entrusted with broad duties and powers to preserve and enhance all beneficial uses of the state's immensely complex waterscape. The Porter-Cologne Act is recognized as one of the nation's strongest pieces of anti-pollution legislation, and was so influential that Congressional authors used sections of the Act as the basis for the Federal Clean Water Act. Many California State GIS layers can be downloaded at this URL https://gis.data.ca.gov/