Pioneering multi-purpose reef for California's eroded coastline

Finding the solution that works for everyone has been challenging. Common engineering solutions, which are typically not socially and politically favored, caused the city to think beyond traditional, single-benefit solutions.  

Technical design was only part of the picture, as stakeholders across the community  and region had a range of goals as well as concerns. Neighboring communities worried about downdrift impacts. Surfers feared impacts to wave quality. Residents wanted beaches back but weren't sure how to get there without compromising other values. Any viable solution had to be developed with these groups, not just presented to them at the end. 

GHD in coordination with Resilient Cities Catalyst and the city facilitated an international design competition that became as much about community dialogue as technical innovation. We assembled a jury of regulators, stakeholders and local leaders, then invited three firms to compete: ICM from Australia, a partnership of Deltares and MVRDV from the Netherlands and SCAPE from New York. 

Over eight months, we worked with the design teams through three public workshops to refine concepts based on community, stakeholder and regional input. More than 700 people engaged through in-person workshops, online surveys and pop-up events at farmers' markets and surf contests. Each design was tested against the same criteria: sand retention, surf resources, habitat, scalability, cost and community benefit. 

The winning concept from ICM proposed an offshore artificial reef and two onshore headlands that act as "living speedbumps,” intended to let sand accumulate between structures to slow, not stop, the longshore transport of sand. The design also includes bringing a lot of sand to city beaches – a total of  900,000 cubic yards of beach nourishment is proposed along with the structures. The concept was designed to widen the dry beach, enhance surf conditions and restore nearshore sandy beach and intertidal habitat. Critically, it's designed to be adaptable or removable if monitoring shows it's not performing as intended.

This will be the first multipurpose sand retention reef of its kind in the United States. The project is designed to protect Oceanside's beaches, which add $2.8 billion annually to the city’s economy, while  restoring public beach access. What started as a coastal erosion challenge has developed into a pilot demonstration project with relevance well beyond the city of Oceanside. 

The competition itself became the win. Initial opposition from neighboring communities shifted to support or neutrality. Community members who were initially cautious became advocates because their input shaped the design. The project's selection as the San Diego Association of Governments’ regional pilot demonstrated the broader relevance of this approach to coastal restoration challenges 

The technical innovation matters, too. We applied a state-of-the-art numerical model developed by the University of Southern California and tested a physical model of the design at the O.H. Hinsdale Wave Research Laboratory at Oregon State University, which houses the only large-scale directional wave basin on the West Coast. The 1:35 scale physical model of Oceanside's coastline and the project was tested under multiple oceanographic conditions to validate wave dynamics, current patterns and sediment movement. 

The project received significant state grant support, with the California Coastal Commission awarding $1.8 million grant to the City in April 2025 to fund baseline monitoring, community outreach, and updates to city planning documents.  

As of early 2026, the project is finalizing advanced numerical modeling and physical wave-basin testing to optimize performance before final environmental review and construction. GHD is supporting the city through the environmental review and regulatory process and developing a Programmatic Environmental Impact Report for the project. Environmental approvals and permitting application submission are anticipated to be completed through the end of 2026 and early 2027. Securing construction funding and final regulatory approvals will be necessary before construction can begin. 

When construction begins, Oceanside gets its beach back while proving that innovation, stakeholder engagement, monitoring and adaptive management can solve problems that traditional engineering alone could not.