As work continues on a 200-foot-long wall to keep a slipping hillside off train tracks, Orange County Transportation Authority planners are proposing spending millions of dollars more on wall construction and armoring with rocks along San Clemente’s coastline to protect the rail line.
The added armoring would include a half-mile-long retaining wall in the North Beach area and placing more boulders along other troubled areas of beach, work that comes with an estimated price tag of $200 million and could be done as early as this summer, according to OCTA staff.
The details were revealed at meetings this month, including Monday, March 11, when an overview by staff was presented to the OCTA Board of Directors.
Several people at the meetings wondered whether armoring the coastline is the right action or if sand is a better immediate solution to protect the rail line and help the community.
OCTA Program Manager Dan Phu gave a presentation at the meetings highlighting the transportation agency’s struggles in recent years along the rail line where it runs beachfront for a 7-mile stretch of South Orange coast, much of which sits 200 feet or less from the ocean.
Since 2021, there have been five closures of the rail line through San Clemente due to landslides and the ocean’s waves battering the tracks, costing OCTA and the state about $37 million in emergency repairs.
The latest happened at Mariposa Point in January, when a landslide destroyed a pedestrian bridge along the city’s popular beach path and debris dumped onto the tracks. Only limited passenger service through to San Diego has been offered in the last few days.
OCTA officials said they expect installation of the resulting 200-foot-long and 10- to 15-foot tall catchment wall to be completed by the end of the month. It is a $10 million project.
While the OCTA has two studies underway looking at how long-term the rail line can be protected against the effects of erosion and climate change – or maybe even moved inland – work needs to be done sooner to add protection to “hot spot” areas to address already vulnerable sections of the coast, Phu told OCTA board members.
Seven areas need monitoring, with four of those needing immediate action, he said.
The north end of the city needs added rock revetments for protection and an area of North Beach has steep bluffs with potential to impact the rail line, with poor track-side drainage and the possibility of liquefaction of the ground. OCTA proposes a half-mile long wall to keep any sliding of the bluff from falling onto the tracks near where the wall is currently being built at Mariposa Point.
An exact location for a wall has yet to be been determined, but it would be located near where the existing San Clemente Pedestrian Beach Trail lies to the east of the railroad tracks, said OCTA spokesman Eric Carpenter.
In the area from the Mariposa Bridge to Linda Lane, sensors should be installed to monitor for potential movement, Phu said.
Also, next to the rip rap added in response to a landslide at Cyprus Shore, more “engineered revetment” with larger boulders on top should be added where erosion has created a shelf near Calafia State Beach and should be “reinforced as needed” to stabilize tracks, Phu said.
The first step in coming months will be to secure funding and permitting from involved regulatory agencies, such as the California Coastal Commission. And then a contract would need to be secured to design and build the measures; construction could take place within five to 15 months, officials said.
The plan comes with a price tag “roughly somewhere in the ballpark of $200 million,” Phu said, and when asked where the money could come from, Carpenter noted the OCTA would be seeking additional state and federal funding sources.
Katrina Foley, who represents the Fifth District on the OC Board of Supervisors and also serves on the OCTA board, said there is one thing “glaringly missing” from the study – sand.
“I guess I’m concerned our focus is predominantly on rip rap as a solution,” she said. “My biggest concern is that we don’t have a plan for sand.”
Sand is widely believed to act as a buffer between the ocean’s waves and coastal infrastructure, such as the railroad, but getting permitting to bring the material in can be a years-long endeavor. Putting down rocks as a barrier is a seemingly easier fix, with agencies often asking for forgiveness from the Coastal Commission after-the-fact, but can come with negative impacts on the beach landscape.
When waves strike a hard structure such as boulders or sea walls, they refract and create a backwash that pulls sand away from the shoreline and out to sea, said UC Irvine professor Brett Sanders, who specializes in coastal civil engineering and wave dynamics.
While historically sand has kept the ocean away from those hard structures, problematic erosion in the past decade has allowed waves to batter onto rocks put in place to protect the rail line, scouring the sand and eroding the beach even further, Sanders said.
Then more rocks are put in as more sand is chomped away and the ocean inches closer, Foley noted. “It’s sort of like a circle we are in here. We keep armoring, the beaches erode … the beaches are gone.”
Suzie Whitelaw, a geologist and president of Save Our Beaches San Clemente, argued the addition of sand to recreate the beach in front of the tracks would cost a fraction of the $200 million the OCTA is talking about needing to spend on rocks and seawalls.
If a wide sandy beach is established and maintained, there is no need for the proposed revetments, she said.
Rip rap exacerbating erosion is “one school of thought,” and not necessarily the opinion of OCTA’s team, said Phu.
“We’re reserving judgment. I think what we want to do is have enough information before we can make a judgment on whether or not rip rap causes beach erosion,” he said. “We want to take a deeper dive into that.”
Sanders argued expanding revetments may worse the problems of beach loss and undermine future efforts to restore the beach.
“Within the field of coastal engineering, it is firmly established that armoring the coastline to protect inland infrastructure leads to increased erosion directly, immediately in front of the armoring,” Sanders said.
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The sea reaching the base of cliffs with no sand buffer also means trouble for hillsides, he said. Once waves strike the toe of a cliff and erode the base of the slope, it can collapse, especially during wet seasons like the past two winters that have saturated hills, he said.
The OCTA has heard the feedback about the importance of incorporating sand to protect the rail and the agency is in agreement that sand should be studied as part of the solution for the next 10 to 30 years, Carpenter said.
“For the immediate future, OCTA is charged with protecting the rail right-of-way to keep trains moving, and reinforcing these areas is our top priority in the next several months before the next storm season,” he said in an e-mail. “At the same time, we will continue to work with partners and the community to find longer-term solutions.”
The railway is part of the 351-mile Los Angeles-San Diego-San Luis Obispo Rail Corridor, or LOSSAN, and is used by both passenger and freight trains.
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