Erosion expected to strip economic value of Ocean Beach

Map showing potential Ocean Beach erosion due to sea level rise

Ocean Beach stands to lose almost all of its beach area following a range of sea level rise scenarios, according to a new study. Ocean Beach between Lawton Street to the south and Lincoln Way to the north are shown in this image from economists at San Francisco State University. Image courtesy San Francisco State University.

San Francisco’s Ocean Beach could lose 92 percent of its beach area, drop tens of millions of dollars in economic value and sustain hundreds of millions of dollars in damages due to erosion caused by rising seas, according to a new study.

The new study by San Francisco State University predicts that as sea level rise, increased erosion and storm damage could cause $540 million in damages, plus tens of millions of dollars in lost tourism dollars and tax revenue.

Based on a sea level rise estimate of 4.6 feet (1.4 meters) by 2100, Ocean Beach could lose:

  • $19.6 million in damages caused by a 100-year coastal flood damaging homes and contents. This is an increase of 200 percent from the present day risk of a 100-year flood, which is $6.5 million.
  • $82 million in tourism spending and local and state tax revenue losses (accumulated between now and 2100) caused by a narrower, eroded beach attracting fewer visitors.
  • $16.5 million in habitat and recreation losses, caused by erosion reducing the beach area by 92 percent (53 acres lost). Ocean Beach provides a habitat for native species such as the Western Snowy Plover, a bird that is federally listed as a threatened species.
  • $540 million caused by land, buildings and infrastructure being lost or damaged by erosion and subsidence.

The study, led by SFSU economist Philip G. King, was funded by the California Department of Boating and Waterways. In a statement released with the study, King and co-authors Aaron McGregor and Justin Whittet said they hope the study will help agencies responsible for local planning and beach management determine how to respond to rising seas.

“Understanding the kind of impact sea level rise will have is important for deciding what adaptive action to take,” King said. “Seawalls have become the de facto policy for dealing with erosion and sea level rise but our findings suggest that other policies such as beach nourishment or where possible, allowing the coastline to retreat, could be more cost effective.”

The SFSU study examined Ocean Beach only north of Sloat Boulevard, but impacts from increased erosion already have been felt south of Sloat. There, sand has been stripped from the beach, parts of the Great Highway have fallen into the sea and the city has installed walls of boulders in an attempt to protect the Oceanside Water Pollution Control Plant, which processes waste water from most of western San Francisco.

San Francisco’s efforts to armor the southern part of Ocean Beach as an erosion-control measure have proved controversial. In August, the California Coastal Protection Network sued the city, seeking to force the city to remove rock piles and other structures the group says were placed improperly on Ocean Beach.

The study is not available online, but is available through San Francisco State University’s communications department.

 

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6 Comments

  1. Our website is at http://www.sloaterosionob.blogspot.com
    The 2 most recent posts deal with sea level rise and our Managed Retreat plan.

  2. Im not an expert on erosion, but I do know our beach is constantly replentished by sediments flushing out the goldengate.. and according to this article Bruun’s rule only applies to beaches that replentish sands by eroding the upper beach.. .http://www.coastalwiki.org/coastalwiki/Effect_of_climate_change_on_coastline_evolution

    Im sure there are locations along the coastline where this is true (eg sloat and south of there), but not for the stretch shown above… the rivers flowing out the golden gate dump sand on the bars every spring and summer, constantly replentishing the beach… then the on shore winds blow it inland building up the dunes… remember your history when all the sunset and richmond districts were sand dunes

  3. One small, but significant correction: The City is placing rock revetments south of Sloat to primarily protect the Great Highway and a sewer transport box that lies underneath it. The plant itself is not in any immediate danger. This is important. The south Sloat section of the Great Highway and sewer box can be easily re-routed inland. The entire wastewater plant is another story. Surfrider San Francisco with the help of our engineering consultants at ESA and Associates has put forth an erosion response plan for the next 50 years. For south of Sloat, we are caling for a relocation of the road and the underlying transport box should be done asap. This would allow restoration of the beach via a sand dune barrier. For the rest of Ocean Beach, we advocate sand nourishment as a way to slow the effects of sea level rise and to provide time for additional planning. See our blog for more information.

  4. It always struck me as kind of worthless and my life was in it.

  5. Thanks Tom for this story. I have requested a copy of the study but am thinking if you or the University can figure out a way to post it on the web it would be easier for everyone and save trees!

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  1. Ocean Beach erosion grabs Gray Lady's gaze | The Ocean Beach Bulletin

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