Posted on April 12, 2023
Carlsbad could be the next coastal North County city to join the San Diego Association of Governments’ proposal to launch a third regional beach sand replenishment project.
SANDAG asked Carlsbad to shoulder a proportional share of the $200,000 cost for a planning, feasibility and economic analysis needed to start the project, which would pull sand from the ocean and spread it on beaches from Oceanside to Imperial Beach.
So far, the Oceanside, Encinitas, Solana Beach and Imperial Beach city councils have agreed to help fund the analysis, SANDAG regional planner Courtney Pesce said Tuesday in a presentation to Carlsbad’s Beach Preservation Commission. Del Mar and Coronado have scheduled discussions for upcoming council meetings.
The Carlsbad commission voted unanimously to recommend the Carlsbad City Council agree to pay the city’s share of the initial costs, estimated at $64,677 based on its 6.5 miles of shoreline. Carlsbad’s share could go down if additional cities participate, Pesce said.
A second phase of the project, consisting of the engineering and environmental work, is expected to cost $3 million, she said. Construction and monitoring of the replenishment would be the third and final phase, estimated at $37 million. Most of those costs should be covered by state and federal grants, with a small part to be shared by the cities involved in the project.
The regional beach sand project would be San Diego County’s third, said Keith Greer, SANDAG’s environmental planning manager.
The first, completed in 2001, was spurred by the U.S. Navy’s San Diego Harbor dredging project. It placed 2.2 million cubic yards of sand, primarily from the harbor, on beaches the length of the county at a cost of $18 million, of which 60 percent was funded by federal grants and 40 percent by state grants, Greer said.
Regional beach sand projects
SANDAG is working with coastal cities on a possible third regional sand project that is expected to cost about $37 million.
The second, completed in 2012, placed 1.4 million cubic yards of sand taken from offshore deposits on beaches at a cost of $26 million. The state paid for 85 percent of that project, with the local jurisdictions contributing 15 percent.
State and federal agencies have declined SANDAG’s requests to fund the initial stage of a third regional project, so the cities involved are being asked to contribute. However, state and federal money should be available for most of the other costs.
Coastal cities have Oceanside to thank for the agency’s efforts to launch a third project, Greer said.
The “genesis for this” was Oceanside’s proposal to build a series of 600-foot-long rock groins, like jetties, to hold sand on the beach, he said. That idea created “a lot of concern” about negative effects the groins could have on cities downstream in the coastal currents that flow primarily to the south.
“We need to do this on a regional basis,” Greer said, because all the coastal cities are in a similar situation.
“Everybody wants the same thing, which is sand on the beach,” he said. “How you get that sand on the beach, that’s where people have different perspectives.”
Encinitas and Solana Beach have been working together for more than 10 years on a sand project with the U.S. Army Corps of Engineers. That project has obtained funding and approval and is scheduled to begin next year.
The Encinitas-Solana Beach project is a long-range effort designed to replenish beaches in the two cities every five to seven years for the next 50 years. Greer said all the coastal jurisdictions need to realize that beach replenishment is only temporary.
“You’ve got to start thinking of the sand as a maintenance project,” he said. “It’s not going to be a one-time thing. You need a cycle of maintenance, periodically.”
SANDAG hopes to coordinate with the Encinitas-Solana Beach replenishment to reduce the costs of the regional project, Greer said.
One of the biggest expenses is the use of a special dredge, like a floating crane, to extract the sand and send it to shore. The 2012 project required bringing a dredge from the East Coast, through the Panama Canal, which increased the overall costs by $5 million.
“Now there is a new one in Portland they can get,” Greer said. “That’s part of the planning studies we hope to have addressed.”
With the right timing the same dredge can be used for both the regional and the Encinitas-Solana Beach projects, he said.
San Diego County beaches have seen sand replenishment projects since at least the 1950s. However, most of these have been efforts to maintain the area’s lagoon and harbors and did not take sand from the ocean.
San Diego Gas & Electric Co. began dredging the Agua Hedionda Lagoon in Carlsbad in the 1950s to keep the lagoon deep enough for the Encina power plant to draw seawater for cooling.
SDG&E continued the dredging once every few years, placing the sand on Carlsbad State Beach until recently, when NRG Energy built a new power plant that doesn’t require seawater cooling. Since then, Poseidon Water has continued the dredging to keep the lagoon open for its desalination plant.
The Army Corps of Engineers has dredged the Oceanside harbor annually since it was built in the 1960s to keep the entrance clear for navigation. That sand has always been put on the beach south of the harbor, but Oceanside beaches south of the city’s pier get little of that material and have eroded to narrow, cobblestone strips in recent years.
Oceanside’s annual dredging is scheduled to begin within the next week, and this year’s goal is 500,000 cubic yards of material, about twice what was placed on the city’s beaches last year. The work usually concludes in time for the Memorial Day weekend.
“We will try to go as far south as possible,” said Army Corps of Engineers Public Affairs Specialist Stephen Baack on Friday. “With this year’s storms and heavy precipitation, there was more erosion than normal.”
Other coastal cities get occasional sand replenishment from lagoon restoration and other opportunities such as building excavations.
All of Southern California’s beaches have experienced increasing erosion, widely seen as an unavoidable consequence of climate change.