Del Mar, CA – Following the washout on the tracks located on the Del Mar Bluffs (Bluffs) that occurred during the final days of November, the North County Transit District (NCTD), following its normal protocols, requested field inspection reports from consultants Jacobs Engineering and Leighton Consulting, Inc. A report from each consultant has been received and can be found following this advisory.
During the rainstorm on Thursday, November 28, 2019 and Friday, November 29, 2019, erosion washouts occurred at two locations on the Del Mar Bluffs just south of Seagrove Park along NCTD’s right-of-way. A temporary fix with two new one-inch thick 8’ x 10’ steel plates and concrete slurry has been completed at the southernmost erosion point located at railroad milepost (MP) 244.30. The second track washout area located at railroad milepost 244.25 requires engineering analysis to determine the repairs that will be made not later than the January 11-12, 2020 during the absolute work window rail closure that was previously scheduled to support other major regional projects. Until those repairs are complete, NCTD will have an inspector on site 24/7 to monitor the Bluffs in order to ensure safety for our passengers and train crews.
NCTD and SANDAG’s consulting firms, Jacobs Engineering and Leighton Consulting, Inc., have reviewed the cause of the track washouts and provided preliminary field inspection reports to NCTD. The Jacobs report notes several immediate contributions to the washouts including the following:
- 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] at MP 244.25 (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.
For both locations, a combination of the above-referenced factors contributed to the damage and collapse. In response to the findings and recommendations from the consultant firms, NCTD has implemented enhanced inspection protocols and plans to procure supplemental resources to assist in managing the challenges on the Bluffs.
NCTD Executive Director Matthew Tucker stated, “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.”
Matthew Tucker and San Diego Association of Governments (SANDAG) Executive Director Hasan Ikhrata have released a joint memorandum that outlines their requested actions that support advancing projects that will secure the Bluffs to support the continued operations of daily freight and passenger rail operations.
For more information on Del Mar Bluffs projects, visit www.keepsandiegomoving.com.