2007 Annual Monitoring Report (pdf 16MB) - Bolsa Chica Lowlands ...

Bolsa Chica Lowlands Restoration Monitoring2007 Annual Reportjetties at Anaheim Bay (for the U.S. Navy Weapons Station, Seal Beach), and numerous flood controlmeasures. Coastal erosion was particularly severe in Surfside-Sunset Beach and West Newport Beach.249+30Historical TransectNewly-Established TransectNew Entrance Channel311+22318+30333+30350+71378+292 km423+89Figure 2-8. Location map.In response to the loss of private and public property caused by erosion, the U.SACE, in concert withthe State of California and the County of Orange, has undertaken periodic beach nourishmentoperations in the Huntington Beach cell since 1964. The majority of the sand nourishment has beenplaced at Surfside-Sunset Beach, immediately upcoast of the Bolsa Chica study area. Table 2-4summarizes the beach nourishment history at Surfside-Sunset Beach.The beaches along the Bolsa Chica study area benefited as the downdrift recipient of the Surfside-Sunset nourishment material. During the 34-year period between 1963 and 1997, the beachesadvanced at four of the five historical transects included in the Bolsa Chica monitoring program.Mean sea level (MSL) shoreline advance ranged from 14 m at Transect 423+89 to 71 m at Transect350+71. The only occurrence of shoreline retreat during the 34-yr period was a loss of 18 m atTransect 378+28, located at Huntington Cliffs. The volume of sand above MSL increased in parallelMerkel & Associates, Inc. 73