Preserving Our Beaches: How Retention Saves Oceanside Sand

By Steve Maschue, Bob Ashton Save Oceanside Sand

Oceanside, a picturesque beach town established in 1888, has always been known for its beautiful shores and vibrant coastal life. However, over the years, the natural sources of sand that replenished our beaches have been disrupted, leading to a decline in their size and health. In response, local advocates, Save Oceanside Sand, have championed the concept of retention as a solution to preserve our beloved coastline. In this article, we explore the importance of sand retention, highlight successful examples from other communities, and shed light on Oceanside’s ongoing efforts to implement a sand retention project.

Historically, Oceanside’s beaches thrived due to natural sand sources from the Santa Margarita River and the San Luis Rey River. However, human interventions such as damming, flood control, sand mining, and the construction of the Camp Pendleton Boat Basin disrupted the natural flow of sand to our shores. Consequently, our beaches have suffered from erosion, with more than 2 miles of our 3.7mile shoreline devoid of dry sand. This loss not only affects the natural habitat and access to the beach but also compromises the resilience of our coastal infrastructure.

To combat the diminishing coastline, the US Army Corps of Engineers has conducted major beach nourishment projects over the past 80 years, depositing over 19 million cubic yards of sand onto Oceanside’s beaches. However, the results have been short-lived, with the sand disappearing within months to years. These large-scale nourishment events have proven to be environmentally disruptive, requiring the mobilization of dredges and heavy equipment. The process also harms the nearshore ecosystem, leading to the loss of invertebrates and other marine creatures, which, in turn, affects shorebird populations. It is clear that beach nourishment alone is an unsustainable and wasteful process.

When waves, tides, and currents carry sand away from our beaches, it enters a “river of sand” that flows down the shoreline. Unfortunately, a significant amount of this sand is lost forever when it passes by the Carlsbad Canyon. While occasional south swells do bring some sand back to our shores, it is not enough to counterbalance the ongoing erosion. This problem requires a man-made solution.

Recognizing the shortcomings of frequent beach nourishment, many communities worldwide have implemented sand retention strategies. These approaches include the construction of offshore reefs, dunes, artificial headlands, jetties, groins, and living shorelines. By utilizing sand retention structures, these communities have reduced the need for constant replenishment while improving habitat, access, and safety.

Newport Beach faced a similar situation in the 1960s when they lost a significant portion of their beach, endangering nearby properties. To address this, they installed sand retention devices known as groins. These structures have provided long-lasting shoreline resilience, improved habitat, and enhanced recreational opportunities. Newport Beach serves as a prime example of how a modest investment in retention can save millions of dollars in replenishment costs.

It is important to note that designing a sand retention structure is a complex undertaking that requires scientific and engineering expertise. Each structure must be tailored to the specific section of shoreline it aims to retain, taking into account factors such as permitting, cost, effectiveness, and mitigating impacts on surf, access, habitat, and downdrift effects.

The City of Oceanside is fully committed to implementing sand retention solutions to preserve our beaches. Currently, the Oceanside Sand Nourishment and Retention Pilot Project is in its second phase, with ongoing plans for the construction of an innovative, multi-benefit sand retention project. While the final design and components are yet to be determined, the city’s mission statement for this project emphasizes its commitment to both local and regional benefits.

The concept of “retention saves replenishment” is crucial in safeguarding our coastal treasures. Oceanside, like many other communities, recognizes the importance of sand retention structures in maintaining healthy beaches, enhancing habitat, and preserving access for all. By investing in retention, we can create a sustainable future for our coastline, where the beauty of our shores can be enjoyed by future generations.

Learn more at the Oceanside Coastal Management Web page: https:// www.ci.oceanside.ca.us/government/ public-works/beaches-pier/coastalmanagement