Kanan Dume Road is in danger of sliding into the canyon; however, only one lane is closed for now. A water line leak has closed another lane of PCH; work continues on Sunset Mesa landslide.
By Hans Laetz/Special to The Malibu Times
Slowly creeping landslides caused by this winter’s record-setting rainfall may snarl another key road into Malibu. Engineers are scrambling to keep Kanan Dume Road from sliding into a steep canyon nine miles north of the city limits.
Adding to the traffic nightmares on Pacific Coast Highway, the county Department of Public Works issued a press release late Tuesday afternoon announcing that it will be repairing a 30-inch water line that has been leaking at 18820 PCH near Topanga Canyon Boulevard. As a result, the number two southbound lane will be closed between the 19300 and 18600 areas of PCH until work is completed on the water line. It is estimated that the closure will be in effect until about 3 p.m. this Thursday. Also, water service to approximately 75 to 100 customers of Waterworks District 29 may have their service disrupted during this time.
As for the slide on Pacific Coast Highway near Sunset Mesa, the state received an emergency directive from the director of Caltrans in Sacramento and work began to remove debris and dirt Wednesday last week. The directive was needed because several landowners did not give permission (one refused outright, several were unsure about what to do) to Caltrans to traverse their property in order to remove dirt and debris.
Officials say work on the landslide was unaffected by weekend rain, although workers covered surplus dirt with tarps. State contractors planned to begin removing an estimated 20,000 cubic yards of debris with 14-hour-per-day truck relays by midweek.
County Department of Public Works engineers say a road cut and hillside is falling above Kanan Dume Road, about 500 feet north of the northernmost set of tunnels. Loose dirt is flowing under Kanan’s northbound lane’s pavement, which has severely buckled, said assistant district engineer Lance Grindle.
“The toe of this landslide seems to be hitting some immovable object under the road, which could be bedrock,” Grindle said. “This is causing the road to bulge and buckle from beneath.”
A worst-case scenario would be a gradual, but total, collapse of the road as it slides 150 feet down into a steep canyon to the west, Grindle said. But the engineer noted that the failure is on a road cut on the eastern flank, meaning traffic can safely use the western side of the roadway for now.
Detour signs, reduced speed limits and the closure of one of three lanes at the landslide have meant a minimum of motorist delays, however. “We’re checking it every day, and it’s safe now, but we cannot rule out complete closure of that road,” Grindle said.
If Kanan Dume is closed, traffic would be detoured onto a switch back and rockslide-riddled section of old Mulholland Highway between Sierra Creek and Rocky Flat.
Grindle said the landslide originates on private property, and county workers only have a Malibu post office box to contact. Permission from the owner-or a lengthy process to declare an emergency threat to public safety-have to occur before the landslide can be removed.
On the coast, half of the severe traffic backup problems on Pacific Coast Highway between Malibu and Santa Monica were eliminated when the state Department of Transportation squeezed in a third lane for reverse-flow use Friday morning.
The new reversible lane past the Charthouse Restaurant all but eliminated traffic delays heading south in the mornings, and north in the afternoons. But some motorists complained that the lane reversals should occur more often to relieve unlucky Santa Monica-bound motorists in the afternoon.
Friday evening, city-bound cars were backed up to the Carbon Canyon Fire Station. Delays approached two hours on the southbound lanes, while northbound traffic was freeflowing at the slide.
Some city residents had been clamoring for the reversible lane. Caltrans officials said they waited to make sure additional road width wasn’t necessary for dirt removal before adding it.
On Point Dume, city workers fell a day behind schedule on rebuilding Fernhill Drive when they were unable to work in the rain Saturday.
Replacement of a failed culvert and roadway could be completed by next Wednesday, said Malibu Public works Director Yugal Lall.
On the other side of Point Dume, a damaged drain on Birdview Drive has been repaired, and that road reopened.
City crews have also reopened Encinal Canyon Road one mile north of PCH. After some dirt was hauled away, cement railings were installed beneath a still-active landslide, and stop signs set out to regulate the one lane of traffic still open at the site.
Further west, Decker Canyon Road’s landslide has been removed and that road is open for normal traffic. And work continues with little traffic delay on the PCH culvert collapse north of Trancas Canyon Road.
Lall said the city is keeping an eye on 18 specific trouble areas that could cause landslides or other damage to public property. The most serious is a privately owned drain that broke on a hillside of Puerco Canyon, which threatens to inundate the 24900 block of Malibu Road with water and/or mud.
“We have sent out a notice to the private property owner to have that drain fixed,” Lall said.