BEACH NOURISHMENT CONSTRUCTION AT TWELVE SAN DIEGO COUNTY, CALIFORNIA RECEIVER BEACH SITES

摘要

The first regional beach nourishment project in California was complete for twelve receiver beach sites within San Diego County during September 2001. This project was eight years in the planning, funding, engineering, permit processing and final design phases prior to the initiation of the construction during April 2001. The San Diego Association of Governments (SANDAG), a joint powers organization oversaw the planning and administration of this successful project that received funding from federal, state, and local government sources. The final design and construction methodology are discussed within this paper. Dredging and filling was performed by a trailing suction hopper dredge which utilized six ocean borrow sites and traveled to the individual twelve receiver beaches stretching between Oceanside and Imperial Beach, which is approximately 75 kilometers in shoreline distance. At the receiver beach, the dredge attached to a moored floating section of plastic/rubber pipeline that was attached to a submerged steel pipeline extending from approximately the -7.6 meter MLLW depth contour to the shoreline. The individual volumes of the beach fills ranged from 76,850 to 321,600 cubic meters and were placed over a net of 8.23 kilometers of shoreline at the twelve locations. The six offshore borrow sites were dispersed from near the Mexican Border to the North San Diego County Line and were located roughly one and a half kilometers offshore in 14 to 27 meters of water depth.