Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Nature Based Coastal Adaptation topic
No spam. Unsubscribe anytime.
City receives draft feasibility study on offshore reefs and sand-retention pilot projects
Summary
Consultants presented a draft feasibility study for emergent and submerged breakwaters designed to retain sand at North Beach, Capistrano Shores and the State Beach; council accepted the report for public review and encouraged grant pursuit.
Consultants from Moffatt & Nichol presented a draft feasibility study to the San Clemente City Council on May 20 that evaluates offshore rock structures (emergent and submerged breakwaters) and associated sand placement to create durable, wider beaches at three pilot sites: North Beach, Capistrano Shores and the State Beach.
Moffatt & Nichol coastal scientist Chris Webb described how breakwaters create a shadow zone where sand collects, termed a "salient," and presented conceptual footprints and sand-volume estimates. The North Beach emergent reef concept was estimated to need roughly 400,000–600,000 cubic yards of sand to form a beach up to about 430 feet wide and occupy 8–12 acres; a Capistrano Shores submerged concept was modeled at a larger scale with estimated sand needs of about 1,400,000 cubic yards. Webb said combined costs for a broad program incorporating multiple actions could reach into the order of "a hundred million dollars" but that footprints and placement could be refined to lower cost.
Staff announced the draft report would be posted for a roughly 50-day public review and comment period, with a final report planned for November and a presentation to the California Coastal Commission in December. Council voted unanimously to receive and file the draft report and to proceed with public outreach and grant-seeking efforts; councilmembers and members of the public asked detailed questions about surf effects, habitat, navigational hazards and permitting risk. The consultant said emergent breakwaters are more effective at blocking wave energy but may have greater construction and material cost and that design steps would include refined numerical modeling and laboratory testing before permitting and construction.
Council members asked staff to continue coordination with OCTA and other prospective partners so that projects could align with the agency work now planned for emergency sand placement. The study team recommended North Beach as the initial pilot site because of access, parking and potential public benefit.
