Consultants recommend multipurpose offshore breakwaters, prefill sand to retain beach sand in San Clemente

Consultants with Moffatt & Nichol presented a draft Nature‑Based Feasibility Study to the Coastal Advisory Committee on May 15, outlining offshore breakwater/reef concepts intended to trap sand and lengthen the interval between nourishment cycles. The firm proposed pilot projects at North Beach, Capistrano Shores and the south end of the city, and gave preliminary estimates of filled areas, sand volumes and costs for each concept.

Why it matters: The study seeks to move San Clemente from repeated short‑term sand placements toward infrastructure that retains sand longer, potentially reducing long‑term replenishment frequency and protecting shoreline infrastructure, recreation and habitat.

Key consultant findings and concepts - North Beach “dog‑bone” breakwater: a multipurpose emergent structure the consultants sketched as roughly one quarter mile long with a roughly 700‑foot planform width. Moffatt & Nichol reported that a prefill of 400,000–600,000 cubic yards (they cited 500,000 cy as an illustrative midpoint) would likely be required to create an 8–13 acre beach in the structure’s lee. The consultants said such a feature would…