Posted on September 15, 2025
Key piece of equipment for large projects would be too costly to buy and maintain, experts say
A do-it-yourself option appears to be off the table as agencies continue searching for ways to place more sand on Southern California’s eroding beaches.
San Diego County’s regional planners for several years have considered purchasing their own ocean-going hopper dredge, a critical piece of equipment for shoreline replenishment projects.
Obtaining and scheduling one of the few hopper dredges available for the work is the single most expensive and time-consuming element of most big sand projects, experts said. Most of the dredges are privately owned and primarily located on the East Coast, which has more navigable rivers and harbors than the West Coast.
“There has been a lot of discussion about purchasing a dredge,” said Alan Alcorn of Moffatt and Nichol, a San Diego consulting firm that has worked on numerous sand replenishment projects.
Alcorn joined experts from the U.S. Army Corps of Engineers and the San Diego Association of Governments for a recent panel discussion of dredging at a meeting of SANDAG’s Shoreline Preservation Working Group.
The operation of a hopper dredge is a huge endeavor, Alcorn said. For one thing, its work usually is scheduled months or years in advance.
“It’s not like a back hoe,” he said. “This is something that has to be used frequently. It has to be maintained by qualified people, parts are hard to get. It requires a full-time dedicated crew.”
A single hopper dredge operation uses a full-time crew averaging 17 people, experts said. The engine consumes 5,000 to 10,000 gallons of fuel per day, and its emissions must conform to California’s air quality standards.
State and federal laws prohibit the work during the nesting seasons for endangered species of birds and during the spawning season for grunion, a fish species that lays its eggs on the beach.
The purchase of a dredge is a significant investment and is at least 25% of the costs in any job, said Lynn Nietfeld, senior vice president at Great Lakes Dredge and Dock in Illinois.
Each new vessel is assembled based on the buyer’s order, she said. Construction can take up to two years and cost between $150 million and $250 million.
Also, every dredging job requires pipeline to carry the sand, Niefeld said. For each job, the sections of pipe must be trucked or towed to the job site, assembled, then disassembled and removed.
“It’s a lot of pipeline,” she said. “It’s high-risk activity, putting it together and placing it on the beach. It requires a lot of people to do it safely.”
The only government agency that owns hopper dredges is the U.S. Army Corps of Engineers, which has four of them. Two of those are on the West Coast, usually in the Seattle area, and two are on the East Coast.
The dredges tend to stay on their own coast, except in rare cases of a dire need or emergency. To go from one side of the continent to the other requires a trip through the Panama Canal, which can take weeks and cost millions of dollars.
The Corps of Engineers’ fleet is relatively small compared to those owned by private companies, said Chuck Mesa, chief of coastal engineering for the Corps of Engineers, Los Angeles District.
Many Southern California dredging projects use a cutter dredge or a clamshell dredge, Mesa said.
Both types are smaller than a hopper dredge, he said. They typically stay inside the harbor or lagoon. One uses a cutter head to stir up sand on the harbor or lagoon floor and pump it with seawater through pipes to the nearby beach. The other uses a clamshell to scoop up the sand.
An ocean-going hopper dredge pulls sand from deposits on the seafloor, usually at depths of 30 feet or more. It stores the sand in the vessel’s hull and, when full, takes the sand to a destination beach where it is piped onto the shore.
Much of the San Diego County coastline is maintained with sand taken from lagoons, harbors and rivers.
Also, except for the annual dredging of the Oceanside Harbor entrance, most of those projects occur only every few years at best. Carlsbad’s Agua Hedionda lagoon is cleaned out the most frequently, every four or five years, formerly to keep seawater flowing to the Encina power plant and now for the Carlsbad desalination plant.
Batiquitos Lagoon, also in Carlsbad, is dredged less often as environmental mitigation for the Port of Los Angeles. Sand also has been placed on the beaches from the environmental work at the San Elijo and San Dieguito lagoons. But all of those projects are small enough to be done without the large hopper dredge.
The idea of purchasing a hopper dredge surfaced again as part of SANDAG’s proposal for another regional sand replenishment. The two previous regional projects used hopper dredges and the most recent, completed in 2012, pulled 1.5 million cubic yards of sand from ocean deposits and placed it on beaches in Oceanside, Carlsbad, Encinitas and Imperial Beach.
More recently, the Corps of Engineers hired a contractor with a hopper dredge for two separate federal projects in the region last year. One placed offshore sand on beaches in Encinitas and Solana Beach, and the other in San Clemente. Both those projects are intended to continue with periodic replenishments over the next 50 years.
SANDAG is in the initial stages of planning what would be its largest shoreline replenishment project yet, including for the first time San Clemente and Dana Point in southern Orange County.
The huge project is one of several reasons SANDAG wanted to take a closer look at the possibility of buying a dredge, possibly in a partnership with other public agencies. However, based on the information presented, members of the shoreline preservation group said that appears to be impractical.
“What I’ve heard today … should dissuade us from buying, owning and and operating a dredge,” said working group member Dan Malcomb, a commissioner for the Port of San Diego, adding that it would be “extremely costly and complex.”
“It wouldn’t be a good idea from my standpoint,” Malcomb said.
The group’s chair, Kristi Becker, a Solana Beach City Council member, said she agreed with Malcomb.
Pipes and equipment at Fletcher Cove in Solana Beach during a 2024 sand replenishment project.
