El Niño finally arrived in the San Francisco Bay Area this winter. The local hills turned green, and reservoirs and creeks were filled from the abundant rainfall. But the accompanying ocean storm surges off the Pacific Ocean pounded the coast, causing the erosion of beachside bluffs all along the San Francisco peninsula, and punching a hole in the seawall fronting the Beach Boulevard Boardwalk in Pacifica, an oceanside community about ten miles south of San Francisco.
Particularly strong El Niño ocean storm surges in late January caused a break in the seawall, and wave action washed out sand and earth from behind the wall and under the adjoining sidewalk, until both the wall and sidewalk eventually collapsed. The area of the breach was fenced off, and a local emergency declared for housing and businesses alongside the ocean. The gap in the seawall was stabilized with rip rap, until repairs can begin when the weather improves.
This was not the first time ocean surges have damaged the boardwalk. Severe storms from the El Niño of 1997-98 also broke down the seawall, and forced the closure of the boardwalk for several months.
Large El Niño storm waves hollowed out the sand and earth from below and behind the seawall, which led to the collapse of over fifty feet of the Boardwalk’s stone and asphalt sidewalk, and eventually the wall itself. Large rocks temporarily fill the hole until the seawall and sidewalk can be repaired this coming summer.
Concrete, poured over the riprap revetment at the base of the seawall, were both in response to the severe damage to the wall caused by the El Niño of 1997-98.
Note the rusted metal straps that were used to hold in place the concrete slabs that make up the wall itself.
A distant view of the breach in the Beach Boardwalk seawall. It was originally built in two phases, from 1985 to 1988.
Broken seawall, with the Pacifica Pier in the distance.
Sandbags guard the front yard of a home along the Beach Boardwalk in Pacifica.
The cordoned-off area around the breach in the Beach Boardwalk seawall. There isn’t much room to spare from seawall to front door. Note the sandbags along the front of the green house on the right.
On a lighter note, if you have to build a seawall, you might as well decorate it with some dolphins.
Images:
All images were taken by Devon Low on February 15, 2016.