Historically, nature always seems to get the best of San Francisco engineering. For example, when the Spanish built the original Presidio, it collapsed after only two years—fog and adobe construction are a poor combination.
Now, beachgoers have stumbled on another casualty of an ongoing structural contest with the ocean: The remains of a decades-old stairwell and seawalls, long since overwhelmed and buried by the shifting sands of Ocean Beach, now briefly exposed again.
The Chronicle reports that a roughly 50-foot long, three-foot high concrete wall was sighted first about a month ago, rising out of the sand near the end of Taraval Street. Nearby were the splintered remains of a wooden barrier as well. The paper speculates that the aged structures were unearthed by winter storms, although the ocean is always churning up and changing the composition of the beach. That’s why the walls were put there to begin with, and also why they were buried.
San Francisco historians at the Western Neighborhoods Project say that what we are seeing here are past, failed attempts at combating beach erosion. In the 1930s, the city built a wooden seawall to shield the Great Highway from waves, but it was done in by a violent storm in ‘39.
They followed it up with a concrete seawall in the 1940s. This was less vulnerable to the weather, but was eventually smothered in sand, and has been under the feet of unsuspecting beachgoers all this time.
The nearby stairs are the end part of a 1920s-era pedestrian tunnel that used to run under the Highway. But the tunnel was decommissioned in the 1970s, and the natural processes of the beach have since filled it in. Now the old cobblestone steps have popped up for the first time in over 40 years.
The city is presently (and eternally) trying to manage beach erosion via the borderline existentialist practice of ferrying tons of sand from place to place. The visual aid of past, doomed city efforts to accomplish similar goals presumably does nothing for city workers' morale. But at least it looks cool.
- Old Ruins Emerging on Beach [Chronicle]
- Ocean Beach Archaeology [Western Neighborhoods Project]
- Existentialist Public Utilities Commission Moves Tons of Sand [San Francisco Magazine]