CA - Preliminary Resiliency Concepts Prioritize Sand Nourishment at Critically Vulnerable Beaches
Additional sand nourishment and the utilization of artificial retention devices highlighted some of the solutions suggested to rescue critically vulnerable San Clemente beaches at a community meeting on Sept. 27.
Residents and other stakeholders gathered in the Council Chambers at City Hall to learn about and provide feedback regarding early concepts for coastal resiliency, in relation to the city’s ongoing Nature Based Coastal Resiliency Project Feasibility Study.
New Coastal Administrator Leslea Meyerhoff and Chris Webb, principal coastal scientist with the city’s contracted consultant, Moffatt & Nichol, spoke about the study’s objectives and progress. Community Development Director Cecilia Gallardo-Daly was also present to facilitate and answer other questions.
Webb noted the proven effectiveness of beach nourishment when enough sand is placed, saying that placing more sand north and south of the upcoming San Clemente Shoreline Protection Project would be ideal in order to keep sand within the city limits.
He also mentioned the expenses associated with bringing in sand and the possibility of sand damaging local ecosystems if it buries rocky outcrops and other features that create surf breaks.
“Let’s have nourishment in the mix, but let’s try to hold it in place with whatever kind of concepts (that) make sense,” he said. “Since there are these wave-dissipation natural structures down at Trestles that work great, those became an obvious model to us. …If we did exactly what’s there, I’ve got to believe it’s going to work.”
During the meeting, Webb also noted that the city would likely focus on implementing one project at a time and analyzing its success.
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The plan marked another step toward achieving the feasibility study’s objective of devising sand retention solutions to halt the trend of coastal erosion at city beaches.
Meyerhoff spoke about the study’s background, and Webb gave an in-depth presentation detailing the draft concepts for aiding eight sections of the San Clemente coastline that have been categorized as in stable, threatened or critical condition.
In June, Moffatt & Nichol sent a memo to city officials that marked four of the sections as critical “hotspots” for erosion—those being Shorecliffs, Capistrano Shores, Mariposa Beach and Cyprus Shores. Webb, his partner, coastal scientist Justin Peglow, and his team of scientists came to that conclusion after using five measurements to estimate the health of varying sections, or transects, in the city.
“We call things ‘critical’ if they have three critical components of the five, or if they have two of the critical components and two threatened,” said Webb. “If there’s two of those five components in the threatened category, they get a threatened (rating). And if none of that stuff’s happening, it gets a stable rating.”
After the analysis to complete the first identifying report was completed, the project team developed criteria by which to develop preliminary sand retention concepts, according to Meyerhoff.
They focused on the critical and threatened transects first, and considered the level of access to the public through public transportation or access to city Marine Safety Division personnel, the number of amenities and surf resources, the amount of existing native vegetation, and whether public safety was adversely affected by erosion at each location. Then, the team devised small, medium, and large concepts.
