California Bays and Estuaries Policy

The Water Quality Control Policy for the Enclosed Bays and Estuaries of California is published by the California State Water Resources Control Board as guidelines to prevent water quality degradation. The policy is revised as needed.

The Pacific coast of California has few natural harbors in comparison to similar lengths of the Atlantic coast of the United States.Humboldt Bay, Bodega Harbor, Tomales Bay, Drakes Estero, San Francisco Bay, Morro Bay, Los Angeles - Long Beach Harbor, Upper Newport Bay, Newport Back Bay, Mission Bay, and San Diego Bay are identified by the policy. The policy also applies to smaller areas of ocean water within headlands or harbor works when the distance between those features is less than 75 percent of the greatest dimension of the enclosed portion.

Mixing zones for fresh and ocean waters at the mouths of the Smith River, Klamath River, Mad River, Eel River, Noyo River, Russian River, and Sacramento–San Joaquin River Delta are identified as estuaries. The policy also applies to coastal lagoons and mouths of streams temporarily separated from the ocean by sandbars.

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