SAN DIEGO (AP) City experts failed repeatedly to diagnose the conditions that precipitated an Oct. 3 landslide in La Jolla, documents released by Mayor Jerry Sanders show.
A homeowner reported a broken water line on Soledad Mountain Road in July, according to e-mails and other correspondence made public Oct. 10.
The first sign of trouble came in a July phone call from resident Thomas Crabbe to Jim Barrett, director of the city’s Water Department.
Rob Hawk, the city’s chief geologist, said he learned about the July 18 sewer break on July 23 when a city official told him about Crabbe’s concerns. The next day he checked a crack in the street that Crabbe had reported.
“I didn’t see any indications of large-scale earth movement,” Hawk said. “Large-scale means no evidence of a landslide. But clearly something was moving around because the pavement was deflected.”
Crews began checking Sept. 20 to see if water could be escaping from city pipes and causing the soil to shift, but the trench lines were dry. Hawk said examinations of two holes of more than 100 ft. (30.5 m) and one of 56 ft. (17 m) drilled after the slide showed no signs of significant water leakage.
Two homes were destroyed and four severely damaged in the slide, which forced the evacuation of 111 homes overnight. Five other houses beneath the slide zone weren’t damaged but are blocked by debris.
The collapse came just hours after engineers hired to inspect an earth slippage that was first spotted in July warned residents not to sleep in their homes because of the potential for instability.
The landslide cut a 50-yd.-long (45 m) chasm in a four-lane street that serves as a thoroughfare between Pacific Beach and the tourist area of La Jolla. A 20-ft.-deep (6 m) fissure was cut like a slice of cake out of the hillside overlooking Interstate 5 hundreds of feet below.
No one was injured in the slide that tore away a chunk of a hilltop neighborhood and caused an estimated $48 million in damages, according to city officials.
The amount includes $26 million for broken sewer and water mains, and $22 million for private property losses in the upscale La Jolla neighborhood, officials announced Oct. 6.
The initial estimate will likely change as geologists continue their investigation into why the land gave way, city homeland security program manager Donna Faller said.
Crews spent Oct. 6 digging a 16-ft.-deep (4.8 m) hole for a new manhole and sewer line to service the undamaged homes on Soledad Mountain Road.
Geologists have found the neighborhood to be prone to landslides. At least three significant slides have occurred between 1961 and 1994, including a major failure in 1961 that destroyed seven homes under construction.