Can (and should) blufftop real estate be saved from natural erosion?
What are the real costs of saving blufftop real estate from natural erosion?
As the bluffs continue to erode under the apartment buildings in Pacifica, the potential futility and cost to the public of armoring the coastside becomes more clear.
Engineers have come up with some potential solutions to erosion that is threatening several Pacifica apartment buildings, reports Julia Scott in the County Times.
These will likely include a plan to stitch the top of the bluff together by installing a series of long "nails," or steel rods, deep inside the bluff, securing them in place with industrial-sized applications of grout, and then stretching a long concrete wall across the outside of the bluff that would be camouflaged to look like the natural face of the cliff. In addition, O’Connor wants to permanently protect the bottom of the cliff with a thick steel retaining wall sunk 30 feet into the beach. It would extend five or six feet above the beach, preventing the ocean from undermining the boulders already there. [...]
Neither [Esplanade co-owner Farshid] Samsami nor his wife returned calls Tuesday. Considering the cost of the boulders was estimated at $400,000, a long-term fix could easily surpass $1 million, although costs will be shared among the owners of all four buildings if they agree to a partnership.
"They can’t just leave it unrepaired because it’s going to threaten the neighbors and the road. They do have some responsibility to prevent this from impinging on others," O’Connor said.
Just before Christmas, Scott wrote an excellent summary of the issues involved in saving land and buildings that would wind up under water if nature were allowed to run its course.
The real question is whether this building and many others on the California coast should be continuously protected by artificial means rather than let Mother Nature take her course.
Esplanade Apartments has benefited from a loophole in the Coastal Act that allows all buildings constructed before 1972 to erect sea walls and other forms of protection if no other option exists. Today, plans for new buildings on the waterfront are approved by the Coastal Commission only if they allow for 50 years of natural bluff “retreat.”
Esplanade Apartments has capitalized on this rule for many years, most recently installing piles of riprap at the bottom of the cliff in 2003 and again this week, according to Ruby Pap, coastal planner with the Coastal Commission’s San Francisco office.
The soil in Pacifica is easily saturated and prone to landslides. In that sense, any feat of engineering only delays the inevitable.
“This is going to be happening more and more with the winter El Niños and climate change and bigger storms. This is a very hazardous area, so it may not last for many years. I am concerned this is not going to be a good long-term fix for these property owners,” said Pap.
The Coastal Commission is charged with ensuring public access to beaches, but that duty can conflict with constructed sea walls and the like. In some cases such projects accelerate the rate at which the ocean eats away at the beach below the sea wall, rendering some beaches impassable in wintertime, according to O’Connor, the engineer.
“Whether you install a sea wall or rock riprap and you slow the threat to the bluff or dune, the shoreline is still retreating seaward so at some point the beach will eventually disappear.”
Ultimately, the Coastal Commission must rule whether the proposed project can survive for 50 years.