Coastal Regional Sediment Management Planning In Southern Monterey Bay, California
Philip Williams & Associates, 550 Kearny Street, Suite 900, San Francisco, CA 94108, USA
Current address: Royal Haskoning, Rightwell House, Bretton, Peterborough, PE3 8DW, UK ; email@example.com ; firstname.lastname@example.org
2 Naval Postgraduate School, 327 Spanagel Hall, Monterey, CA 93943, USA.
3 California Geological Survey, 135 Ridgway, Santa Rosa, CA 95401, USA.
4 Monterey Bay National Marine Sanctuary, 299 Foam Street, Monterey, CA 93940, USA.
The coastal dunes and beaches of southern Monterey Bay (the Bay) are eroding at approximately four feet per year, placing oceanfront property, infrastructure, and natural habitat at risk of loss. Erosion is exacerbated by mining operations that extract sand from the beach near the City of Marina. Recognising that much of California’s coastal erosion, sediment supply and demand issues can be attributed to human modification of natural processes at regional scales, Regional Sediment Management (RSM) is being pursued by the responsible agencies. This paper presents the findings of the Coastal RSM Plan developed to address erosion in the Bay. The Plan first evaluates the sedimentary processes, erosion rates and sensitive species and habitat along the coast. Those data sets are then combined with economic, ecological, and societal considerations, to identify critical areas of erosion and to propose RSM-based solutions. The Plan recommends three main RSM strategies for the Bay. (1) reduce or eliminate mining of sand from the beach at Marina. Sand mining creates a sediment sink which increases erosion potential and, if stopped, erosion rates would slow. (2) allow dune erosion to continue without human intervention along the undeveloped sections of the Bay. This erosion would continue to supply large volumes of sand to the beaches, providing benefits for sensitive species and habitats, recreation and tourism. (3) investigate beach nourishment to ameliorate erosion along the southern developed part of the Bay, where the majority of high risk facilities are located.
Key words: Sedimentary processes / coastal erosion / coastal habitats / regional sediment management / beach nourishment / sand mining
© Owned by the authors, published by EDP Sciences, 2011