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

Bolsa Chica Lowlands Restoration Monitoring2007 Annual ReportTransect 423+89 occurred between the berm and the waterline. Because the beach face becamesteeper in October 2007, however, the MSL shoreline position was more landward than in October2005.Figure 2-14. Long-Term Subaerial Volume Changes, May 1963 to October 2007.Long-Term Shorezone Volume Changes (1963 to 2007): As described previously, the shorezoneencompasses the entire littoral zone from the back beach to the depth of closure. Figure 2-16shows the net long-term shorezone volume changes between May 1963 and October 2007 at eachof the Bolsa Chica area transects. The comparison utilizes the May 1963 and October 2007surveys because the shorezone volume is not subject to seasonal bias. Shorezone volume gainsprevailed at each of the seven Bolsa Chica area transects. The gains ranged from 129 m 3 /m atTransect 378+29 to 1189 m 3 /m at Transect 318+30.The shorezone volume gains reflect not only the influence of the Surfside/Sunset nourishmentactivities, but also the ebb bar that was placed offshore of the entrance channel as part of therestoration project. The ebb bar, which was created by placing approximately 929,326 m 3 of sandoffshore, is evident in the 2007 profiles at Transects 311+22, 318+30 and 333+30. The time seriesplot in Appendix 2-D shows substantial volume gains at each of these transects between 2002 and2007.Merkel & Associates, Inc. 85