The portion of the Great Highway south of Sloat Boulevard should reopen to one lane of southbound traffic in late October, after months of being restricted to two northbound lanes following severe erosion last winter.

Construction crews with heavy equipment work on drainage systems on the Great Highway in preparation for realigning traffic lanes and reopening the southernmost section of the Great Highway to southbound traffic. The Great Highway has been partially closed since last winter, when erosion undercut parking areas and parts of the road.

Crews working for contractor Ghilotti Brothers started repairing storm drains along that section of road the week after Labor Day. Once that portion of the $600,000 project is completed, they will move the center median and guardrail, and lay new pavement for a single southbound lane. They also will install concrete “K-rail” barriers on the western side of the road.

“We expect to be completed some time in late October, about the 20th or so,” said Manager of Capital Planning Frank Filice of the San Francisco Department of Public Works.

Erosion in the winter of 2009-2010 caused parts of the bluff fronting Ocean Beach to fall away, and undercut the westernmost parking areas and shoulder of the Great Highway, leaving asphalt overhanging the sand below and plunging the southbound shoulder guardrail over the edge and onto the beach.

Work on the road and on erosion control had stopped over the summer, in part because bank swallows, birds listed by the state as a threatened species, had occupied nest holes in the sheer face of the bluff.

Filice said the City also wanted to use the time to distribute information to the public and governmental agencies about the consequences of erosion and potential measures to address it.

The work now underway on the southern Great Highway extension is only to realign the road to accommodate traffic in both directions, said Filice, but the City has filed a permit application with the California Coastal Commission that would allow the Department of Public Works to take short-term measures to halt erosion of the bluff, and protect the road and wastewater pipes that run underneath it.

The Oceanside Water Pollution Control Plant, just east of the Great Highway near Lake Merced, treats wastewater and stormwater from the west side of the city and pumps the treated water into the ocean several miles offshore.

Filice said he had submitted the permit application to the Coastal Commission on Sept. 16, and hopes the commission will touch on the issue when it meets in San Francisco in December. “I would like to get some answers and get this thing vetted within the next four or five months,” Filice said.

Filice said he doesn’t expect that any measures the City would take under this permit would amount to a long-term way of dealing with coastal erosion. Instead, he said, they are intended to temporarily keep things more or less where they are while longer-term strategies are considered.

The Golden Gate National Recreation Area, which manages Ocean Beach, posts signs advising beach visitors to stay back from coastal bluffs where bank swallows nest in the summer.

That’s not the course the Golden Gate National Recreation Area would take, said George Durgerian, a public-affairs ranger with the GGNRA, an arm of the National Park Service that manages most of the beach. “Our preference is to let the natural processes work,” he said.

Nevertheless, Durgerian acknowledged that the GGNRA recognizes that San Francisco can declare emergencies that give it broad latitude to protect the infrastructure it has built nearby. The City is “between a rock and a hard place,” Durgerian said, the infrastructure responsibilities conflicting with what he surmised was an understanding that erosion-control measures ultimately will be futile.

But Josh Berry, environmental director for Save the Waves, a group dedicated to preserving surfing spots and the coastal environment, says that sometimes short-term fixes such as those proposed by DPW create at least as many problems as they solve. Piles of rocks and rubble, for instance, aren’t the protective barriers they appear to be, he said, but instead redirect the erosion and actually contribute to it as they are jostled around by powerful waves. “The rocks are literally acting like a sandpaper,” Berry said.

The way Berry sees it, there’s only one way this is going to end: “Ultimately, that sewer plant, or at least the pipe that moves under the road, is going to have to move.”

Click here to see the plan by the Department of Public Works for how the updated portion of the Greaty Highway will look.

NOTE: Long-term strategies for Ocean Beach are what the Ocean Beach Master Plan is all about. Read more about this effort to guide the future of the area.