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Repairs needed after bluff collapse threatens tracks

A crew from the Scripps Institution of Oceanography at UCSD gathers data Monday at a bluff that collapsed in Del Mar.
A crew from the Scripps Institution of Oceanography gathers data Monday at a bluff that collapsed early Sunday in Del Mar. Residences can be seen on the bluff top just south of Fourth Street.
(Bill Wechter)

Regional agencies working on plan to safeguard rail line

A large bluff failure Sunday morning near the railroad tracks in Del Mar will require emergency repairs, transit officials said Monday, March 1.

The collapse reached within 35 feet of the edge of the railroad ties at the closest point, said Sean Loofbourrow, North County Transit District’s chief of safety.

“One train was delayed approximately 7 minutes, Amtrak 768, for the initial inspection,” Loofbourrow said by email Monday, March 1. “There is a speed restriction in place (15 mph for passenger trains) while NCTD and SANDAG determine the scope and timing of any potential repair.”

The collapse occurred just south of Fourth Street near Del Mar’s border with Torrey Pines State Beach. Drone video shot afterward showed a wide section of the cliff sheared off from the railroad level to the beach, leaving a pile of sandstone and rubble at the high-tide line.

Sheriff’s deputies cordoned off the beach near the collapse, and rescue dogs were brought in to search for anyone buried in the rubble. Nothing was found, and there were no reports of anyone injured or missing.

NCTD and San Diego Association of Governments officials met Monday afternoon, March 1, to discuss ways to safeguard the bluff-top tracks.

“We are working with SANDAG and our consultants to determine the scope and timing of repairs,” said NCTD Executive Director Matt Tucker in an email.

SANDAG, a regional planning agency, has been working with NCTD and other agencies for decades to stabilize the 1.7 miles of track on the Del Mar bluffs, where the cliffs are increasingly threatened by coastal erosion.

Studies show the bluffs disappear at the average rate of six inches per year. However, episodic events are the greatest threat, in which large sections break off, sometimes in perfect weather with no warning. Three women in a family sitting at Grandview Beach in Encinitas were killed by a collapse in August 2019.

Storm-water run-off during the heavy rains of Thanksgiving week in 2019 caused a failure that threatened the tracks and delayed trains until repairs could be completed a month later in a section just north of Sunday’s collapse.

Officials initially requested $5 million for the emergency construction, but only a portion of the money was spent, mostly to build a steel-reinforced concrete retaining wall that took several days. Some of the repair work was held over for a previously scheduled bluff stabilization project that was completed in 2020.

The stretch of tracks in Del Mar was originally installed more than 100 years ago.

Studies are underway, including soil samples to be taken this month, for a new inland route to be built through tunnels beneath the city. However, re-routing the tracks is expected to cost several billion dollars and require decades to complete.

A Coaster train travels the Del Mar Bluffs in December 2019.
(John Gibbins/The San Diego Union-Tribune)

A six-stage project to stabilize the tracks where they are began more than 20 years ago. The fourth phase of that work, completed in December, included the installation of additional concrete-and-steel support columns called soldier piles, bringing the total to more than 230. It also involved the replacement of a drainage channel atop the bluff and other work.

No support columns were visible in the area that collapsed Sunday morning.

The fifth phase of bluff stabilization work, with more support columns, drainage structures and bluff armoring, is expected to begin in 2023. No starting date has been scheduled for the sixth phase, which is designed to delay bluff retreat until an alternate route can be built.

The most likely plan for repairs is to advance some of the work planned for phase five, said John Haggerty, director of engineering and construction at SANDAG, late Monday.

“We are going to have to speed up the process,” Haggerty said. “We are still trying to figure out when it will start. We are working on the design. Then we have to find a contractor ... and the materials.”

The area that collapsed includes a retaining wall that probably was installed when the railroad was built in 1912, he said.

“There probably was quite a bit of beach there at the time,” he said.

Del Mar is the weak link in the 351-mile rail corridor between San Diego, Los Angeles and San Luis Obispo. Much of the corridor has been double-tracked, with a second set of tracks to allow trains to pass each other. But Del Mar is one of the few sections where there is no room for a second line, creating a bottle-neck where trains go slowly.

Prior to the COVID-19 pandemic, the so-called LOSSAN corridor carried 7.6 million passengers and $1 billion in goods and services annually. Freight trains coming from the port at San Diego, usually traveling at night, carry 10 percent of all new foreign cars sold in the western United States.

Transit officials say the number of trains on the corridor will double by 2030, increasing the need for a safe and swift passage through Del Mar.

Most of the funding for the bluff stabilization projects comes from state and federal grants.

The California Transportation Commission awarded $108 million in December to SANDAG and NCTD as partial funding for several projects on the LOSSAN corridor in San Diego County including the Del Mar bluff stabilization, the construction of a Coaster passenger platform at the San Diego Convention Center, and other rail improvements.

— Phil Diehl is a reporter for The San Diego Union-Tribune


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