Friday, August 12, 2011

Projected Sea Level Rise for Ocean Beach - Why Managed Retreat as a Long Term Strategy


The Future of Ocean Beach? The beach at Sharp Park (Pacifica) is disappearing under a pile of armor. Click photo to see close-up.


Dear Surfriders and Friends,

Many may be surprised to hear that there is a looming threat of beach loss at central Ocean Beach. Below are a few links to scientific reports that have informed this projection. They deal with sea level rise. According to the Pacific Institute report, sea levels off the CA coast have risen 8 inches over the last 100 years. By 2100, sea level rise is predicted to rise another 1.0-1.4 meters (4’-5’). Although sea level rise projections are estimates, the trend lines behind this projection are serious. We should prepare for significant impacts. Middle Ocean Beach has been eroding for some time. We should expect beach loss to continue. However, as compared to Sloat, there is a greater opportunity to slow it down with sand nourishment and strategic sand management practices. This should allow us to buy time for proper planning.

Surfrider believes the sooner we embrace a strategy of Managed Retreat, the better off we will all be – taxpayers, beach users, and ecology. An encroaching high tide line is part of a natural process. If our city chooses to hold fast to existing boundaries, we can expect to see results like we have in the photo above. This is a group of revetments recently placed on the beach at Sharp Park, in the neighboring town of Pacifica. It's not a pretty picture. They are wiping out their beach.

This ia a graphic derived from the statewide study showing the potential erosion by 2100 based on 4.6’ of sea level rise. http://www.pwa-ltd.com/about/about_news.html#OPC_Report

The report by PWA:
http://www.pwa-ltd.com/about/news-CoastalErosion/PWA_OPC_Methods_final.pdf

Here is a link to the Pacific Institute report that this work fed into:
http://www.pacinst.org/reports/sea_level_rise/

Here is the State Adaptation Strategy that was affected by this work:
http://www.climatechange.ca.gov/adaptation/

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