LOCAL Bluffs off PCH have a long history of landslides
CITY HALL — Long feared as dangerous and unstable, the Palisades bluffs are constantly eroding and need $10 million in repairs, officials have concluded.
That was the key finding of a geotechnical study delivered to the City Council on Tuesday. Scientists recommended draining the bluffs of as much water as possible, while perhaps paving over the crumbling rim and evicting the resident ground squirrels.
Details of the project still need to be hammered out before plans are reviewed by local and state boards, as well as the public.
After hearing an overview of five possible approaches, the City Council directed staffers to find a permanent solution if possible, with cost being a secondary concern.
Ranging from 30 to 150 feet high, the Palisades bluffs distinguishes the western edge of Santa Monica, where they rise directly above the Pacific Coast Highway. Landslides have occurred on the Palisades bluffs for at least 130 years, officials said. “The first reported landslides along the bluffs were reported by travelers, stagecoach travelers, traveling between Santa Monica and Topanga Canyon in the 1870s and 1880s,” said Anthony Antich, an engineer in City Hall. Antich chronicled the history of the bluffs, which over the years have suffered from several slides and “rim failures,” leaving debris covering PCH.
In the 1930s and 1950s, city workers did some work to limit erosion, but Antich said the tunnels they drilled into the hillside to help drain ground water were not used and are now inoperable. The new report called upon more than 50 years of studies and highlighted several different approaches, all with varying costs and impacts on residents and motorists.
“Someone once mentioned that God wants this bluff in the ocean, because that’s what nature will do if we don’t do anything to try and change that.” — said City Councilman Bob Holbrook, who recalled two slides — one that buried motorists
“It’s a serious thing, landslides,”
At a minimum, scientists recommended draining the bluffs of water. Different “dewatering systems” include drilling perforated tubes upward into the bluffs, building a 10-foot-diameter tunnel underneath Palisades Park — so workers can find and remove pockets of water — and drilling a series of vertical pipes from above, which would intercept ground water moving west towards the edge of the bluffs.
A second approach involves manipulating the bluffs’ surface. Antich said a clear, cement-like application could be applied that would hold together the bluffs. He also said grout could be wedged into cracks to keep them from widening and gullies could be filled.
The other three options include what’s called “soil nailing,” where 20-foot nails would be hammered into the bluff face, constructing a 15-foot-wide pathway along part or all of the rim, and getting rid of ground squirrels and damaging vegetation. Ice plant, for example, gets heavy when its wet and can rip off portions of the bluffs, Antich said.
How City Hall will pay for the project won’t be decided until a final plan is adopted by the council, perhaps as early as this fall. Officials already have set aside $1.3 million of redevelopment funds and another $6 million in grant money from the federal government, according to City Hall documents. The project is expected to cost about $7.5 million, plus another $2.5 million in soft costs — though those estimates could change depending on the final plan.
Council members said the most important thing is that the job is done right.
“This is a long-term investment in a signature part of our city — and we will regret it for a long time if we don’t do it right when we do it,” said City Councilman Kevin McKeown.
“This is a long-term investment in a signature part of our city.” — KEVIN MCKEOWN City Councilman
Originally published in the Santa Monica Daily Press print edition on April 29, 2004. Read the original PDF.