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Retreat on Remove
- Don Mosier | Rimini Road

The October 26th meeting of Del Mar’s Sea Level Rise Technical Advisory Committee considered a revised draft document that eliminated the “move or remove” option for residential houses when the annual risk of extreme flooding events reaches 15%. The recommendation to remove and relocate public infrastructure (the firehouse, public works buildings, and the 21st Street pump station) at this risk level was retained. In response to resident complaints about protection of the North Beach area from 15th Street to the San Dieguito River, the revised draft emphasized the historic importance of this district and placed more emphasis on sand replenishment, preservation and enhancement of sea walls, and protection of property. The word “retreat,” which inspired such angst among local residents, is still in the document but now has more conditions and is more focused on public property. Here is the new definition from the draft Executive Summary:

“Retreat strategies, which relocate existing development as necessary out of hazard areas and limit the construction of new development in vulnerable areas in a manner that considers property rights and avoids regulatory takings without just compensation. Examples where this strategy could be used for public property include relocation of public facilities, roads, and infrastructure. “
The adaptation strategies for sea level rise have been reorganized into region-specific chapters, with draft chapter 9 focused on North Beach. Here are the vulnerability assessment, adaptation options, and monitoring recommended in the draft document:

Vulnerability assessment:
Public access along the beach (horizontal access) will be lost due to beach erosion with 1 to 2 feet of sea-level rise.
Beach erosion and coastal storms will threaten sea wall integrity and increase flooding and storm damage.

Low-lying roads and properties in North Beach will be highly vulnerable to coastal and river flooding, including the blocks between Ocean Front and Camino Del Mar/Coast Blvd and the blocks directly east of Camino Del Mar/Coast Blvd.
The present low to moderate vulnerability to coastal flooding and wave damage will become a high vulnerability with 1 to 2 feet of sea-level rise, for low-lying roads and properties in North Beach, including the City’s 17th St Beach Safety Center.

Beach adaptation options:
Beach and dune nourishment
Raise/improve sea walls and revetments
Sand retention measures
Raise structures
Relocate public infrastructure

Beach adaptation monitoring:
Beach width
Flooding and storm damage frequency

Many, if not all, of the adaptation measures will require approval by the California Coastal Commission, which funded the grants used to generate the draft plans under consideration. The details listed above consider 1-2 feet of sea level rise, but the current sea level rise estimates for the end of the century are 3-6 feet. Protect, elevate, retreat, and relocate are all strategies that will become necessary at some point. But remove is gone.



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