Separate incidents of leaky pipes cause sinkage, closures at Alta Canyada and Foothill
Traffic near the intersection of Foothill Boulevard and Alta Canyada Road has been recently complicated by two unrelated incidents of leaky pipes, owned by separate entities, which have compromised portions of the roadway and caused sinking.
La Cañada Public Works Director Pat DeChellis confirmed last Thursday a recurring leak on Alta Canyada first discovered in January recently erupted into a geyser-like overflow of sediment-heavy water, indicating the possibility of erosion underneath.
The line ran from an overflow tank up in the foothills owned by Los Angeles County’s Parks and Recreation Department and used to aid irrigation at Descanso Gardens. DeChellis said whenever the valve was opened to let excess water flow through, it leaked out from a pipe under Alta Canyada just north of Foothill.
“It was coming up first out of the joint between the asphalt and the pavement,” he said. “And later it was coming up through the pavement itself. Last week it was a geyser.”
Chester Kano, a capital projects group manager for the county, said the source of the leak has been located and a 20-foot section of the pipe replaced. Now, crews are working on restoring the stability of Alta Canyada, which has been a challenge.
“It’s ultimately a much larger road repair, [rather] than a plumbing repair,” Kano said Wednesday. “The contractor says there are definitely some soft spots they have to correct.”
The road will remain closed until it is ready for repaving. Kano said an earlier estimate the work would be done by Friday is “unlikely,” due to soil conditions.
A second incident of a compromised pipe causing possible sinkhole conditions has occurred on the inner lane of eastbound Foothill Boulevard just west of Alta Canyada, where a 24-inch water pipe operated by Foothill Municipal Water District broke open on Easter Sunday.
FMWD General Manager Nina Jazmadarian said a work crew set up a traffic control area and began digging some 12 feet down into the road to find the source of the leak. La Cañada Irrigation and Crescenta Valley Water district customers had their water turned off and were hooked up to Glendale water supplies in the interim.
Last Thursday, a work crew was filling the holes it had made to access the 65-year-old pipeline. Although a portion of Foothill has been repaved and is currently open to traffic, the work caused a noticeable depression in the roadway.
“It looks like the road might have sunk a little bit,” Jazmadarian said. “We need to get together with the city about that.”
DeChellis said Foothill Municipal needs to provide a remediation plan and will have to survey conditions and hire a geotechnical expert. Restoring that portion of La Cañada’s main thoroughfare could take weeks, he added.
