DEL MAR, Calif. (KGTV) - San Diego’s North County Transit District detailed Friday the structural reinforcements made to the Del Mar bluffs following a “washout on the tracks.”
Two areas were washed out on the bluffs south of Seagrove Park following the Thanksgiving storm, the NCTD reported.
Jacobs Engineering and Leighton Consulting reviewed the cause of the track washouts. A preliminary report found the following contributing factors:
- Excessive stormwater run-on from the City of Del Mar’s residential streets and adjacent properties.
- Existing drainage facilities (earthen swale drainage ditches) to include culvert clean outs, stormwater overflow not channeled correctly built up and overflowed the main track just south of 13th Street causing erosion on the west side of the Cast-In-Drilled-Hole (CIDH) piles.
- Debris was observed on the ends of the ties and evidence of the drainage overflowing the track adjacent to the CIDH piles.
- Drainage channels were completely silted in at this location as well. Excessive silt was a result of overwhelmed inlets from heavy rain and excessive City of Del Mar run-on stormwater that mobilized right-of-way sediment and sediment migrated further, blocking inlets and filling in earthen trackside ditches.
At the southernmost point of erosion, two one-inch thick steel plates measuring eight by ten feet and concrete slurry were used as a temporary fix, the NCTD said.
The northern washout location will require engineers to analyze it, according to the NCTD. The repairs will be made no later than Jan. 11-12, a date previously scheduled to complete other rail work.
Until the repairs are finished, the NCTD said it will have an inspector stationed at the bluffs around the clock to ensure safety for passengers and train crews.
“This event highlights the fragile nature and lack of resiliency of the Del Mar Bluffs. It is critical that we advance projects to stabilize the Bluffs for the next 20 to 30 years so that the region can determine and implement a permanent solution. Over the last few years, we have all seen the impacts of sea level rise and we should expect that we will continue to see more weather-related events like this most recent rainstorm moving forward,” said NCTD Executive Director Matthew Tucker.
Tucker and San Diego Association of Governments (SANDAG) Executive Director Hasan Ikhrata issued a joint memorandum supporting projects to secure the bluffs. The statement requested an immediate grant of $5 million to support emergency repairs, in addition to another $24 million to support repairs through 2021, and up to $80 million in 2022.