Sunday, December 7, 2014

Managing nature: moving sand along Ocean Beach, San Francisco

San Francisco Chronicle/Michael Cabanatua, 12/5/14.  "Why San Francisco is moving 42,000 tons of sand down Ocean Beach."

 .... "It’s part of an effort by the San Francisco Public Utilities Commission, working with the National Park Service,  to move 42,000 tons of sand — 30,000 cubic yards — from the north end of the wide beach to the south, which is where it came from in the first place. “We call it a sand bypass,” said Michael Carlin, deputy general manager of the commission.
“We pick up sand in one location and take it to another location.”

Waves, wind and winter weather suck sand from the south end, near the San Francisco Zoo, and deposit it on the north end, where it overwhelms the beach, creating problems for humans, wildlife and traffic. Sand clogs the stairwells between the Great Highway parking lots and the beach, making it difficult for some people to get to the beach. Wind causes the sand to pile up in the parking lots and along the highway, occasionally forcing closures. Sand drifts can also smother wildlife habitat.

The natural movement of the sand also creates problems on the south end, where its disappearance threatens to undermine the Lake Merced Transport Tunnel, a key part of the city’s wastewater system. Sand surrounding the tunnel protects it and prevents the city from having to build large concrete structures.  “We don’t quite understand all the science behind it, but we’re trying to figure out a long-term solution,” Carlin said."   Read article, includes 9 slides.

Note photographs:  upper left Embassy Suites Hotels (Hilton 3 link picture), lower left SF Youth Tours/Ocean Beach; upper right Art and Architecture, San Francisco,  lower right Sea and swank/Ocean Beach.

Posted by Kathy Meeh

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