Regional Board Boundaries

The California State Water Resources Control Board (State Water Board) and the nine Regional Water Quality Control Boards (Regional Water Boards), collectively known as the California Water Boards (Water Boards), are dedicated to a single vision: abundant clean water for human uses and environmental protection to sustain California’s future. Under the federal Clean Water Act (CWA) and the state’s pioneering Porter-Cologne Water Quality Control Act, the State and Regional Water Boards have regulatory responsibility for protecting the water quality of nearly 1.6 million acres of lakes, 1.3 million acres of bays and estuaries, 211,000 miles of rivers and streams, and about 1,100 miles of California coastline. The State Water Board is located in Sacramento. There are nine Regional Water Boards, the boundaries of which are generally based on watersheds, also known as hydrologic areas. The nine Regional Water Boards are referred to by specific names, which are: (1) North Coast, (2) San Francisco Bay, (3) Central Coast, (4) Los Angeles, (5) Central Valley, (6) Lahontan, (7) Colorado River Basin, (8) Santa Ana, and (9) San Diego. Due to their size, and/or geographic spread, the Central Valley Board has three offices and the Lahontan Board has two offices. In addition, the Drinking Water Program has fourteen District offices spread throughout the state. This map service shows the jurisdictional boundaries of the nine Regional Water Boards and the locations of their administrative offices. The official legal definitions of Regional Water Quality Control Board jurisdictions may be found in the Section 13200 of the California Water Code. For more information, please visit the California Water Boards website at https://www.waterboards.ca.gov.