Great Highway might not be crumbling into the ocean if The City had moved more aggressively on permanent solutions proposed years ago by its own task force, beach advocates say.
They also say a plan endorsed Tuesday night by city officials to build a long rock wall along the most-eroded section of the bluff is environmentally insensitive and will, in the long run, cause more problems than it solves.
City officials say they too are frustrated with the slow progress of a long-term solution to the erosion problem, but add they have been actively moving toward a permanent solution. They say the rock wall is the only affordable way to protect the beach from a potential disastrous sewage spill.
In recent weeks, the bluffs along Great Highway south of Sloat Boulevard have yielded to powerful waves stirred up by this year’s El Niño weather system in the Pacific Ocean. In the most-extreme areas, the bluffs have retreated more than 70 feet from where they were in a 2007 assessment. In one area, the guardrail of Great Highway has crumbled off the road.
Worse, the waves are now within 20 feet of a mammoth sewage tunnel that lies deep under Great Highway, Department of Public Works project manager Frank Filice said. He said if left untended, and if waves through the rest of winter are anything like they were the past few weeks, that 14-foot-wide tunnel could be breached, spilling as much as 10 million gallons of raw sewage onto the beach.
A rock retaining wall will shore up the bluffs at a cost of about $2.6 million, according to Public Works Director Ed Reiskin. On Tuesday night, the Board of Supervisors approved a proclamation of local emergency order for one week, which allows Reiskin to begin the process of contracting someone to build the wall. The order requires him to come back to the board next week and explain progress.
But advocate Dean LaTourrette, director of coastal advocate organization Save the Waves, said the rock wall could cause further erosion in the long run, and the bad erosion now being seen could partly be caused by the rock walls installed in the 1990s just to the north. The walls also can create a safety hazard and impact wildlife habitat, he said.
In 2003, the Ocean Beach Task Force said that The City should consider several proposed long-term solutions, including a strategic retreat from the coastline, moving the sewage tunnel and road further away from the bluffs.
Public Works has yet to assess this option, Filice said. Instead, the department has been working with the National Park Service on another solution: building a large sand dune in front of the eroding bluffs on top of the rock revetment.
LaTourrette described the proposed solutions as “a waste of time and money for everybody.”
“They’re just throwing rocks into the ocean and hoping to change Mother Nature,” he said.
900 Feet of bluff badly eroded in recent weeks
70 Amount, in feet, some parts of the bluff have receded since 2007
14 Diameter, in feet, of Lake Merced transport tunnel under Great Highway
10 Million Gallons of sewage carried by tunnel
20 Distance, in feet, of bluff between waves and sewage tunnel
$2.6 million Cost of building a rock revetment along the eroded area
Source: Department of Public Works