San Diego County Shoreline (Oceanside) Mitigation Study

Project Description
The San Diego County Shoreline (Oceanside) Mitigation Study is a U.S. Army Corps of Engineers (USACE) effort to mitigate for shoreline erosion and other impacts, resulting from the construction of Marine Corps Base Camp Pendleton Harbor. The construction of Camp Pendleton Harbor has interrupted sediment transport along the coast and contributed to erosion of southward beaches. The study will result in a recommended plan to mitigate impacts and restore shorelines to the conditions that existed before the harbor was constructed in 1942.

The study is authorized under Section 414 of the Water Resources Development Act (WRDA) 2000 (Pub. L. No. 106-541) and is 100-percent federally funded. The authorization directs USACE to develop and screen an array of alternatives, assess environmental impacts and evaluate the least cost alternative to identify a mitigation plan that is environmentally acceptable and meets the study’s objectives. The authorization is for the study only – additional authorization and funding will be required to move to construction.

Additional Information and Commenting
Additional information about the study can be found below in the Quick Guides (English and Spanish) and by watching the recording of the study team’s presentation from the virtual public meeting from Sept. 30, 2024. If you would like to be updated via email, please email SDCS@usace.army.mil with your request.

Public comments are a critical part of the study process. If you would like to provide comments on the study, you may do so through:

  • Email: Must be received by Thursday, October 31, 2024. San Diego County Shoreline Mitigation Study Email Address — SDCS@usace.army.mil.
  • Mail: Must be postmarked by Thursday, October 31, 2024:

U.S. Army Corps of Engineers
Los Angeles District
Planning Division
Attn: Kym Lyons
915 Wilshire Blvd., Suite 930
Los Angeles, CA 90017

Future public involvement opportunities will be scheduled after the release of the Draft Integrated Report and EIS anticipated for Spring 2026.


Quick Guide (English)

What is the San Diego County Shoreline Mitigation Study?
The San Diego County Shoreline (Oceanside) Mitigation Study is a U.S. Army Corps of Engineers (USACE) effort to mitigate for shoreline erosion and other impacts, resulting from the construction of Marine Corps Base Camp Pendleton Harbor. The construction of Camp Pendleton Harbor has interrupted sediment transport along the coast and contributed to erosion of southward beaches. The study will result in a recommended plan to mitigate impacts and restore shorelines to the conditions that existed before the harbor was constructed in 1942.

The study is authorized under Section 414 of the Water Resources Development Act (WRDA) 2000 (Pub. L. No. 106-541) and is 100-percent federally funded. The authorization directs USACE to develop and screen an array of alternatives, assess environmental impacts and evaluate the least cost alternative to identify a mitigation plan that is environmentally acceptable and meets the study’s objectives. The authorization is for the study only – additional authorization and funding will be required to move to construction.

Where are the study’s boundaries?
The study area runs six miles along the shoreline from the northern tip of Camp Pendleton Harbor and Del Mar Boat Basin to Agua Hedionda Lagoon in the south. This area includes beaches in Oceanside and Carlsbad, the mouth of the San Luis Rey River and Buena Vista Lagoon.

What is the timeline for the study?
The study builds on previous phases completed in 2003 (when initial National Environmental Policy Act (NEPA) public scoping was conducted and a broad array of potential measures developed) and 2016 (when a focused array of alternatives was identified at the Alternatives Milestone with additional public engagement). Breaks between these phases were the result of funding gaps requiring the study to pause. In addition to the opportunities for public engagement listed below, planned activities in 2025 include alternative development/evaluation and sediment sampling to ensure compatibility of sand sources for renourishing the beach with sand, which was lost because of the harbor’s construction.

Key study milestones are outlined below (dates subject to change):

  • Public Engagement – September 2024
  • Identify Tentatively Selected Plan (TSP) – Spring 2026
  • Release of Draft Integrated Report and Environmental Impact Statement (EIS) – Spring 2026
  • Final Integrated Report and EIS – Spring 2027

What alternatives are being considered to restore beach conditions?
The study team is developing two alternative plans to restore beach conditions: 1) Beach nourishment  and 2) Beach nourishment with groins . These “action”  alternatives were identified at the Alternatives Milestone after the 2016 NEPA public scoping meeting. Other potential measures, such as seawalls or revetments, alteration of harbor structures, and offshore reefs, were removed from further consideration based on criteria of completeness, effectiveness, efficiency and acceptability in meeting the study’s authorized purpose of identifying a least-cost mitigation plan. The study also will analyze a “no action” alternative to understand what the future would look like without a project and to compare against the action alternatives to make a recommendation.

How will alternatives be developed and evaluated?
The study team will formulate, analyze, evaluate and compare the action alternatives and the no action alternative, considering a project horizon of 50 years. This entails activities such as developing initial designs, coastal modeling to understand sediment transport, estimating costs, incorporating public, tribal, and agency comments and evaluating environmental impacts. Critical considerations include climate change, sea-level change, biological impacts, recreational uses (such as surfing), air and water quality, environmental justice, cultural sites and regional and local economies.  

How will a Recommended Plan be selected?
According to the study authorization and guidance, the least-cost feasible plan that is environmentally acceptable and meets the study objectives of mitigating shoreline impacts of Camp Pendleton Harbor will be identified as the Recommended Plan. This is distinct from a “usual” USACE study that evaluates alternatives based upon costs and benefits. The planning process and Recommended Plan will be documented in a Draft Integrated Report and Environmental Impact Statement (EIS), which will be made available for public review. A Final Integrated Report and EIS will be developed, and a recommendation made to the U.S. Congress.

What activities are out of the scope of the study?
The study is authorized by the U.S. Congress to meet specific objectives and USACE cannot go beyond that authorization. For example, the authorization specifies a least-cost plan to mitigate erosion and restore shorelines from impacts of Camp Pendleton Harbor over a project horizon of 50 years. More expensive alternatives, even those that might have other benefits, would not meet the purpose nor would alternatives that do not restore shorelines in the study area for the full 50-year project horizon.

What is the relationship between the study and City of Oceanside’s RE:BEACH?
The USACE mitigation study and the City of Oceanside’s RE:BEACH both include a focus on beach restoration in Oceanside; however, they also are distinct, i.e., the USACE mitigation study is federally led and authorized to mitigate erosion impacts versus RE:BEACH, which is locally led and focused on multiple benefits. Continued coordination is critical as both initiatives move forward.

How can I give input on the study? How can I learn more?
If you would like to be updated via email, please email SDCS@usace.army.mil. The next opportunities for public involvement are the September 2024 in-person and virtual meetings. Future public involvement opportunities will be scheduled after the release of the Draft Integrated Report and EIS in Spring 2026.