PACIFICA — Lots of people visit the Pacifica Pier to watch the waves crash far below their feet. Little did they know that for years, the ocean has also been taking pieces of the neighborhood along with it.
The extent of the damage was a total mystery until early this week, when city officials cut up a large section of concrete in the sidewalk in front of the Pacifica Pier and discovered a huge, gaping sinkhole underneath — deep enough to stack three rusty cars.
“We didn’t know (the sinkhole) was there until the concrete started bouncing under people’s feet,” said Public Works Director Scott Holmes. Public Works employees have since cordoned off the area and opened up the top of the hole to get a better look, but they’re still not sure how far underground it goes. Holmes put the measurements at 30 feet wide and 11 feet long, reaching all the way from the edge of the sidewalk along Beach Boulevard to the place where the ocean meets the shore at the base of Pacifica Pier. The pier itself remains open.
Locals must now step carefully around the equivalent of a small construction site at the base of the pier — that is, if they dare walk by at all. On Thursday, Beach Boulevard was doused in seawater as wave after wave pounded the seawall and sprayed across the street, sprinkling the cars parked in front of homes 50 feet away. Any passerby was likely to get soaked.”I watch the rail as I walk along. It’s very wet,” said local resident David La Trobe, observing the scene in his hiking boots.
Crews will begin fixing the sinkhole this Monday, and will most likely fill it with a base of gravel and sand, said Holmes. He said the repairs would be paid for through a grant awarded by the Federal Emergency Management Agency after the City of Pacifica declared a state of emergency following last winter’s storms.
Sinkholes are common along Beach Boulevard, although rarely do they go undetected for so long, according to Holmes. He said the city had already detected two smaller gaps developing under the sidewalk closer to Paloma Avenue, a quarter-mile away. The last big problem developed after the El Nio winter storms of 1998, when part of the seawall was so weak that it pulled away from the street and collapsed into the ocean. The water rushing in created a sinkhole about 30 feet north of the current one, according to Holmes.
He called the sinkhole problem “a constant headache.” But said that once they were poured with the concrete mixture, the holes would disappear for the duration.
“We keep filling in the voids, and we will fix everything sooner or later,” said Holmes.
Back at the base of the pier, Public Works engineer Victor Dominguez removed a thin wood board weighed down with sandbags. He pointed into the dark hole, at the bottom of which the tide could be seen licking the rocks underground.
“This was completely full of dirt,” he said. “The waves came in and have been eating it away more and more.”
His boss, Public Works parks supervisor Ron Fasconda, explained that over time, the force of the waves had eroded the protective metal sheet at the base of Pacifica Pier. The water then worked its way behind the concrete-reinforced rocks piled up behind it and started digging the sand and dirt out from underneath the sidewalk. He said the repairs would only take a couple of days once begun.
The pier itself has been eroding for decades. City officials have spent $2.5 million on repairs to the rusting structure since the 1980s, according to Holmes. The first four piles that front the place where the sinkhole began are in particularly bad shape and have been repaired before. The city will begin work on the pier with some grant money it received from the California Coastal Conservancy this spring, although the money will not go toward replacing the metal barrier that used to keep the water out from under the sidewalk.
But all the money in the world could not stop the onslaught of the ocean at high tide, say officials. Workers in the city’s Engineering Department are constantly replacing 2- and 4-ton boulders they add along the beach to shore up the seawall. The rocks eventually sink under their own weight and wash out to sea, where they are rescued and put back in place.
“You’re looking at a pretty ferocious ocean that is keeping workers busy trying to hold the line,” said Holmes. “Whether you’re going to win the battle or not depends on how much effort you put into it.”
By Julia Scott of the Oakland Tribune