Strategies for Managing Sea Level Rise (The Urbanist Journal)
What it is: A large dam, gate, or lock — or a series of them — that manages tidal flows in and out of San Francisco Bay.
This strategy could be used at the Golden Gate, or in smaller, strategic parts of the Bay that are somewhat enclosed to begin with. The barrier could be fixed in place and allow managed flow through a portal for water exchange, tidal function and navigation. Alternatively, it could be temporarily deployed just to head off the worst flooding during a storm surge.
- Maeslant Barrier: A set of horizontal, pivoting gates on the Rhine River at the Port of Rotterdam, Netherlands, it is expected to be closed about every 10 years to hold off a surge of more than three meters.
- Thames Barrier: A series of river gates, it was built in the 1970s to protect vulnerable London from storm surges. In 1990, the Thames Barrier closed once or twice a year on average, while in 2003 it closed 14 times. It is expected to be useful only for another 50 years because of sea level rise.
- Venice MOSE: About 80 mobile barriers in the lagoon of Venice, Italy, that will lie on the sea floor but inflate during high tides. It is expected to be completed in 2012, and to operate as much as 100 times a year.
- Bay Arc: An idea for a giant net that would fold underwater at the Golden Gate and be raised to prevent major ocean storm surges from entering the Bay.