SFO Airport Sinkhole ‘Emergency’ as Flight Volume Soars

SFO (Kyle Harmon / Flickr / CC)
Kyle Harmon / Flickr / CC

Federal and state transportation officials are warning that San Francisco Airport’s rapidly deteriorating seawall has created the risk of runway flooding and sinkholes as passenger volume soars.

San Francisco is legend for environmental hypocrisy, such as flooding the beautiful Hetch Hetchy Valley in the Sierras to obtain its own cheap water supply, and paving over a huge piece of the fragile San Francisco Bay to build SFO, the nation’s seventh busiest airport.

SFO serviced over 50 million passengers last year, including about 11.3 million international travelers. That was up 9 percent from the prior year. To support the boom, SFO is on a $5.7 billion borrowing spree to fund a new air-traffic control tower, major terminal renovations, new hotel, another long-term parking garage, security upgrades and energy-efficiency improvements.

But as a result of being built into the Bay, the airport location is subject to large daily tidal ranges (difference between high and low tide) that average approximately 5.8 feet during each month’s full moon. When the mud-laden tide of the Sacramento River waters sweeps down the bay during the rainy season, the Bay tidal bore has reached 8.8 feet.

So powerful is this wall of water that Oakland ferry captains still read the Sacramento newspapers in the winter to learn the height of the river upstream, in order to calculate the size of the tidal surge they must cope with a day or two later.

Understanding the risks of this daily challenge was a priority for newly hired San Francisco Airport Director Ivar Satero. That is why he declared in writing to SFO Commissioners in September that seawall repairs had become an emergency safety issue and repairs must be completed before December.

Although it would have required bypassing the traditional six-to-nine month public-sector bidding process, Satero stated, “If this repair is not completed before the rain season, the seawall may fail and flooding is likely to occur.” He added, “These circumstances constitute an imminent threat to Airport property which may interrupt aircraft arrival and departures and impact the general public.”

To emphasize his concerns, Satero forwarded the airport consultant’s assessment of the airport seawall’s integrity. The structural engineers found that seepage problems presented a meaningful risk of runway flooding and sinkholes due to erosion.

But inexplicably, the budget and finance committee of the San Francisco Board of Supervisors took another three months until December 6 before even scheduling a vote on to declare seawall erosion at SFO an emergency and expediting the $1.5 million the placement of around 2,000 feet of “riprap” rocks along seawall.

It appears that the delay in approving a relatively small amount of money for a safety issue happenedbecause SFO is currently in the midst of procuring environmental permits and design services for a $60 million Shoreline Protection Project that will shield the airport against a global warming sea rise in a 100-year flood.

The West Coast is currently being pounded by a “storm train,” according to Accuweather blog. Meteorologist Jim Andrews predicts, “The combination of storms through this weekend has the potential to bring the biggest amount of rain and mountain snow to California since the drought began several years ago.”

Accuweather forecasts that 3 inches of rain will fall just north of San Francisco in the next 36 hours, followed by another big storm later this week. The combination is expected to create flash flooding along the Sacramento River.

With that torrent of water mostly headed out to the ocean through the San Francisco Bay, SFO spokesman Doug Yakel warned that the erosion is continuing. The only good news he could offer was: “The wall has not failed, which is what we’re trying to stave off.”


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