Background Agencies & Legislation Continue Search California's beaches, coastal bluffs, bays, estuaries, and other shoreline features are altered according to geologic conditions, the availability of beach sand, the wave and current energy impinging on the coast, and other physical processes that affect sand movement and retention. A constant supply of sand is necessary for beaches to form and be maintained along this shoreline. Many human activities reduce the supply of sand that reaches the ocean and, in turn, deprive beaches of replenishment. These activities include dam construction, river channelization, and other developments. Lack of sand creates greater vulnerability for shorelines that have always been subject to varying levels of erosion. In the long-term, sand supply from inland sources may be increased through re-design of existing structures or altering water management practices. However, short-term management of shoreline erosion will likely continue to focus at the land/sea interface along the California coastline. Sand is transported along the coast (long shore transport) by wave-induced nearshore currents, providing vital sand flow for California beaches. Construction of breakwaters, jetties, or groin fields to protect harbor entrances, maintain beaches, or protect coastal structures have had both positive and negative affects on sand movement along the shoreline. Protective structures trap sand and allow beaches to expand upcoast from the device, but can interrupt the flow of sand to other beaches. The structures protecting Santa Barbara and Oceanside harbors are two well-known examples of protective structures in California that provide benefits to the community, but also increase downcoast erosion. However, in many cases, few adverse affects have been documented and the major impact appears to be the increased width of narrow beaches, providing recreational opportunities and property protection. Other forces, such as intense storms, can cause serious shoreline retreat (storms in 1982, 1983, 1995 and 1998 caused major damage to California's beaches). Such events occasionally force coastal residents, local governments, or State agencies to dump boulders (rip-rap) in front of threatened structures during emergency attempts to save property. Such emergency measures can be costly, ineffective, and result in unintended effects (including reduced shoreline access), although they can be effective if properly engineered and permitted by agencies of jurisdiction.

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This file last modified on: Tuesday, January 24, 2006.
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