2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...

Bolsa Chica Lowlands Restoration Monitoring
2008 Annual Report
at the time of the October 2008 survey was 107 m (Transect 423+89), while the narrowest beach width
was 26 m (Transect 378+29). The beach width at Transect 318+30 (immediately north of the entrance
channel) exceeded historical beach width envelope at the time of both the May and October 2008
surveys. Further north at Transect 311+22, the May 2008 beach width exceeded the envelope, while
the October 2008 beach width was within 2 m of the historical maximum. The beach width at Transect
423+89 also exceed the envelope in May 2008.
Long-Term Shoreline Changes (1963 to 2008): The time series plots in Appendix 2-C indicate a trend
of long-term shoreline advance at six of the seven Bolsa Chica area transects during the 45-year period
between 1963 and 2008. The exception was Transect 378+29, where beach widths were relatively
stable during this period with no apparent trend.
Figure 2-12 shows the net long-term beach width changes in the Bolsa Chica study area between May
1963 and May 2008. To avoid a seasonal bias, the comparison utilizes the May 2008 survey rather
than the more recent October 2008 survey. Shoreline advance predominated, with gains ranging from
10 m at Transect 350+71 to 73 m at Transect 318+30. Shoreline retreat occurred at only one location,
a loss of 12 m at Transect 378+29.
Figure 2-12. Long-Term beach width changes, May 1963 to May 2008
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