Oceanside beaches are part of a naturally eroding sandstone bluff coastline that stretches from Dana Point to La Jolla. Rivers and streams which have supplied beaches with coarse sand have been diverted or dammed. Coastal bluffs have been developed and protected with sea walls and large rocks restricting the natural addition of sandstone to the beaches. Waves, tides, currents, and severe storms sweep sand off the beach. Some of this sand is deposited on other beaches, but most of it is swept out to sea to settle in offshore canyons. Our naturally wide beaches are shrinking and, in some areas disappearing.

Multiple structures built throughout the 20th century impacted and continue to reduce Oceanside's sand supply:

• The damming of Lake Henshaw in 1922

• The breakwater and boat basin for Camp Pendleton in 1940's

• The Oceanside Harbor in the 1960s

Combined, these structures contribute to severe coastal erosion and beach sand loss in Oceanside.

While it’s true that some people feel that coastal structures are harmful, coastal scientists, engineers, and planners do not generally agree with this blanket generalization. Coastal structures are not new, nor experimental, as they have been employed effectively for decades throughout the state and worldwide.

Artificial reefs, living shorelines, and groins may protect a public beach, and preserve beaches for many of their most important uses: low-cost recreation, coastal storm damage reduction and beach habitat. Widening and stabilizing beaches along the Southern California shoreline would protect existing structures and beaches from erosion and have an overall positive effect.

California Coastal engineering experts and renowned coastal scientists have cited that while there are a number of important design considerations and precautions associated with retention systems, they basically mimic natural littoral drift barriers and become artificial headlands.

As such, they trap sand and either create beaches where they previously did not exist or stabilize or widen existing beaches.

Scientists have stated that a well-design retention system with effectively, incorporated downdrift mitigation design features, addresses concerns of natural littoral drift flowing, both to the south and north.

The proposed Oceanside solution includes design features that will mitigate the potential negative impact on downdrift beaches.

Prefilling/nourishing the area between the built structures with sand is key to reaching an equilibrium state where sand will naturally bypass around the groin(s). Also, a proposed preliminary design of a sand bypass system may be part of the solution. The sand bypass recovers sand that generally would not otherwise be available. It would be a permanent system to bring sand from the North of Oceanside to the South, and beyond. This sand would typically end up in the mouth of the Oceanside harbor or its usual terminus in the offshore canyons.

Oceanside City Officials, have repeatedly stated on the record, that any sand replenishment and retention pilot project would NOT be approved if it has a detrimental impact on neighboring downdrift cities.

Continued expensive major replenishment events are not affordable nor sustainable. Dredge, pump, repeat…the same old story.

While beach nourishment (replenishment) events are considered an ecologically sound option for beach restoration, nourishment events also bring about significant changes in the sandy beach ecosystem. A large proportion of flora and fauna are destroyed by adding a thick layer of nourishment sand. (Speybroeck et al., 2006)

The engineers/scientists agree that living shoreline is not a sound option for the breaking wave  energy/physics of the Oceanside shoreline. There is a potential that once a substantial back beach is  established using replenishment and retention, a living shoreline could be considered for installation to  further anchor and protect the city assets and shoreline infrastructure. The living shoreline structure is  protective device vs retention device. A living shoreline such as in Cardiff is essentially an armored  shoreline/revetment buried by replenished sand. See below a cross section of the Cardiff Living Shoreline: 

Yes. Section 30235 of the Coastal Act states that “revetments, breakwaters, groins, harbor channels, seawalls, cliff retaining walls, and other such construction that alters natural shoreline processes shall be permitted when required to serve coastal-dependent uses or to protect existing structures or public beaches in danger from erosion, and when designed to eliminate or mitigate adverse impacts on local shoreline sand supply”.

Oceanside cannot accept managed retreat as an option. Although a nice-sounding idea to the coastal "purists", managed retreat is not feasible anywhere on the Oceanside shoreline. Where do we relocate the potentially targeted structures to? Even if we took the funding for the first part of the replenishment/retention plan, $51M – could you at best purchase 6-8 shorefront structures? Better to protect our shoreline with a broad back sandy beach.

The replenishment and retention system should have a regional view and dovetail with current and  future regional sediment management plans. Any engineered solution for the Oceanside shoreline will incorporate design features that address and mitigate downdrift beach/shoreline impact(s).