Sea level gives rise to ideas
The article, “Line in the Sand,” in the Sept. 20 issue says sea levels are rising, and we need to rethink our relationship with the coast.
The San Francisco Bay is part of the coast, and sea levels will rise enough to flood large parts of the Bay Area, including parts of Marin and Sonoma counties.
Retreat works on the ocean coast, but will not work as well along the San Francisco Bay, with its people, buildings and polluted sites. What to do?
There are several possibilities, which include 1. Retreat, 2. Do nothing, 3. Build levees, 4. Protect key infrastructure like San Francisco’s Ferry Building, for which there is a proposal to raise it eight feet.
There is a more radical solution that is worth evaluating: Build a structure across the Golden Gate Bridge to keep high tides and sea level rise from inundating the land around the bay. This is very expensive. And does it have a negative environmental impact? Surely. But its cost and environmental impact may be less than any of the alternatives. Retreat works well on the ocean for vacation areas but poorly for the entire bay, where there is lots of housing on low lying ground.
If nothing is done, housing and infrastructure are lost, and the polluted sites go into the bay. Protecting key infrastructure results in a few islands above the deluge, leaving the rest of us to swim. Levees are only as good as the weakest point and are very expensive as well. The Golden Gate is narrow, and it may be possible to control the water flow through it.
Protective structures against high water have been built in London and Venice. One low structure across the Golden Gate could protect millions of people, properties and cities, as well as leave polluted sites untouched. Locks and fish ladders would be included. It would close at high tides and open at lower tides to let water flow out. The bay would become a freshwater reservoir and solve the area’s water problems.
This is not a perfect solution, but its huge cost and environmental impact may be less than any of the alternatives. It should be seriously studied by our leaders and considered by the citizens.
John W. Cruz lives in Sebastopol.
