La Jolla Shores sinkhole under investigation
Acknowledging that little is yet known about the sinkhole situation that occured Jan. 6 at the western end of Avenida de la Playa in La Jolla Shores — including what went wrong and when it would be fixed — City of San Diego field engineer Steve Lindsay attended the La Jolla Shores Association (LJSA) Jan. 13 meeting to share what information he did have with trustees.
“During the last storm event, the end of Avenida de la Playa kind of exploded on us and collapsed,” Lindsay said, explaining that the street dropped by two feet, exposing a gasline and creating a sinkhole. “The obvious culprit was the super high storm surge the likes of which we haven’t seen in a while … But we need to figure out what the failure mechanism or mechanisms was that caused the damage.”
While Lindsay didn’t want to speculate on a timeline without more information, he approximated it would take four to six weeks to repair the street. He added that because the city considers the area an “emergency site,” funding is available for the repair.
As part of Sewer and Water Job 809 — to repair the sewer and water lines throughout the Shores, including Avenida de la Playa — crews are working at the end of Vallecitos next to Kellogg Park. Once they are done, Lindsay said, they will move over to Avenida de la Playa and get to work.
First, the city has trucks with vacuuming capabilities that will be used to clean out the sand and debris that could interfere with the investigation. However, he said, “all the trucks are tied up, because there are a lot of places in the city that experienced damage in the last storm.”
Once the area is vacuumed out, crews will “peel back” the street that was damaged to take a look and see if there is any other evidence as to what might have gone wrong. “We don’t want to rush into this, pour the street exactly as it was, and then have the same issues,” he said.
One early discovery is that the street was reinforced two-and-a-half feet down, but there was an additional few feet that could have been reinforced, but were not.
Another observation Lindsay noted was that the box culvert structure that protects the storm drain might not be as watertight as city engineers presumed. “The joints were supposed to be water tight, but we saw some leakage that caused additional damage and undermined the street,” he said, adding that the box culvert was modeled to withstand a “10 year storm,” one so strong it only happens once every 10 years.
“We’re not going to take the culvert out, but we need to make the joints water tight if we determine they are not,” he said. “We’ll do that as soon as possible.”
Sewer and Water Job 809 has been underway, block by block, since December 2013, with breaks for the summer construction moratorium. The Avenida de la Playa section that collapsed was repaved May 2015. The project was scheduled for completion in March, but the sinkhole likely added two months to the project.
In other Shores Association news:
• Say ‘cheese,’ er, ‘moo’: Health Fox, executive director of the La Jolla Historical Society, announced staff would be re-creating the historic photo of cows on the beach in La Jolla Shores.
“Many people have seen this photo of cows on the beach in front of the La Jolla Beach & Tennis Club,” he said, showing the board an enlargement of the 1906 photograph. “This year marks the 110th anniversary of this photo. Our project is to commission the creation of a new photograph of cows on the beach for 2016.”
Fox explained the Historical Society commissioned a photographer to create the photo and recruited 11 cows from Van Ommering Dairy Farm in Lakeside. The cows will be transported to the beach and handled by students in the Future Farmer’s of America program.
The date scheduled for the photo shoot is Sunday, March 13 at around 7 a.m., Fox said because sunrise is scheduled for 7:01 a.m. and low tide is predicted at 7:31 a.m., which would give the cows some time to get used to the new environment and provide adequate light, with minimal interference from beachgoers.
LJSA voted to support the project unanimously, and lifeguard Lt. Rich Stropky said while the project had the tentative support of lifeguards, they needed to confirm with the City Attorney’s office before giving their thumbs up.
• What’s up for 2016: LJSA Chair Nick LeBeouf said his goal for the coming year is to better collaborate with other Shores advocacy groups. “There are a lot of people who want to help the community,” LeBeouf said. “We have the La Jolla Shores Business Association, La Jolla Shores Surfing Association, Friends of La Jolla Shores, etc. Sometimes it feels like we stand alone … and I’d like to see more of a joint effort with projects and getting people involved. The more people involved, the better our community will be. That’s what I’d like to see in 2106.”
— La Jolla Shores Association next meets 6 p.m. Wednesday, Feb. 10 at 8840 Biological Grade. ljsa.org
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