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

Bolsa Chica Lowlands Restoration Monitoring2007 Annual ReportINTRODUCTIONBACKGROUNDThe Bolsa Chica Lowlands are located in Orange County, California, between Bolsa Chica Mesa onthe northwest and Huntington Beach on the southeast (Figure 0-1). In 1996, eight state and federalagencies entered into an agreement to conduct wetland acquisition and restoration at the Lowlands.Following project planning, land purchase, restoration design, permit acquisition, and publication of aFinal Environmental Impact Statement/Final Environmental Impact Report, restoration constructionbegan October 6, 2004. The project involved the creation of a Full Tidal Basin and restoration ofMuted Tidal Basins by constructing an ocean inlet north of Huntington Mesa.To create the Full Tidal Basin, approximately 1.57 million m 3 of material were excavated from withinthe Bolsa Chica Lowlands to create a basin of a general depth of –1m NAVD, bounded by intertidalflats. The excavated sand was distributed on the adjacent beaches from March to June 2006 (102,500m 3 , divided evenly to the north and south of the future inlet) as well as placed offshore from November2005 to May 2006 to form an ebb bar (929,326 m 3 ) outside of the future inlet. Approximately 531,354m 3 of material was placed to form the basin levees and three nesting areas. Remaining material washauled off-site. Jetties were constructed to form the ocean inlet to the basin from March through Juneof 2006.The Full Tidal Basin was opened to the ocean on August 24, 2006. The basin was designed to support71.0 hectares (ha) (175.5 acres) of non-wetland waters, 49.6 ha (122.6 acres) of tidal flats, and 7.7 ha(19.1 acres) of pickleweed. In order to keep the inlet open, maintenance dredging is anticipated to beneeded on a biennial basis, with dredged sand to be placed on down-coast beaches.Water control structures and culverts through the levee were installed to allow regular but muted tidalinfluence from the Full Tidal Basin to three Muted Tidal Basins (Figure 0-1), to support 51.1 ha (126.3acres) of salt marsh habitat, and create 17.1 ha (42.3 acres) of tidal flats, 12.3 ha (30.5 acres) ofcordgrass habitat, and 0.7 ha (1.4 acres) of non-wetland waters. The Muted Tidal Basins were notopened to the Full Tidal Basin during the first year of the monitoring program, though all arescheduled to be opened in 2008. The restoration project involved no changes to the Future Full TidalBasin, which is currently an active oil production field, or the Seasonal Ponds (Figure 0-1).MONITORING PROGRAMThe follow-up monitoring of the restoration generally conforms to the Bolsa Chica LowlandRestoration Project Biological Monitoring and Follow-up Plan prepared by the U.S. Fish and WildlifeService in 2001 (Monitoring Plan)(USFWS, 2001a). The Monitoring Plan notes that the purpose ofthe monitoring program is to document the habitat improvements for fish and wildlife, the success ofrevegetation efforts, and the use of the site by endangered species. Additional monitoring elements inthe Monitoring Plan are intended to insure that the inlet is properly maintained, constructed nestingareas have adequate maintenance, any impacts to sensitive plant species are offset, and thatconstruction impacts to Belding’s Savannah sparrow are minimized.Merkel & Associates, Inc. 9