California Code, Public Resources Code - PRC § 30103

(a) “Coastal zone” means that land and water area of the State of California from the Oregon border to the border of the Republic of Mexico, specified on the maps identified and set forth in Section 17 of Chapter 1330 of the Statutes of 1976, extending seaward to the state's outer limit of jurisdiction, including all offshore islands, and extending inland generally 1,000 yards from the mean high tide line of the sea. In significant coastal estuarine, habitat, and recreational areas it extends inland to the first major ridgeline paralleling the sea or five miles from the mean high tide line of the sea, whichever is less, and in developed urban areas the zone generally extends inland less than 1,000 yards. The coastal zone does not include the area of jurisdiction of the San Francisco Bay Conservation and Development Commission, established pursuant to Title 7.2 (commencing with Section 66600) of the Government Code, nor any area contiguous thereto, including any river, stream, tributary, creek, or flood control or drainage channel flowing into such area.

(b) The commission shall, within 60 days after its first meeting, prepare and adopt a detailed map, on a scale of one inch equals 24,000 inches for the coastal zone and shall file a copy of the map with the county clerk of each coastal county. The purpose of this provision is to provide greater detail than is provided by the maps identified in Section 17 of Chapter 1330 of the Statutes of 1976. The commission may adjust the inland boundary of the coastal zone the minimum landward distance necessary up to a maximum of 100 yards except as otherwise provided in this subdivision, or the minimum distance seaward necessary up to a maximum of 200 yards, to avoid bisecting any single lot or parcel or to conform it to readily identifiable natural or manmade features. Where a landward adjustment is requested by the local government and agreed to by the property owner, the maximum distance shall be 200 yards.