S.F. waterfront development must prepare for rising seas Height limits have diverted attention from need to prepare for higher tides

Phillipe Lochman stretches near China Basin Park and Pier 48. Bayfront water levels are forecast to rise 1 foot by 2050. Phillipe Lochman stretches near China Basin Park and Pier 48. Bayfront water levels are forecast to rise 1 foot by 2050. Photo: Tim Hussin, Special To The Chronicle Photo: Tim Hussin, Special To The Chronicle Image 1 of / 9 Caption Close S.F. waterfront development must prepare for rising seas 1 / 9 Back to Gallery

Now that San Francisco voters have said they want final say on waterfront development, we'll see if they have the courage and smarts to tackle the real job at hand - facing up to the need to deal with rising sea levels.

That means moving beyond the fixation on height that has been a political organizing tool here for decades, and focusing instead on how development can be used to help San Francisco adapt to environmental pressures unlike any that have come before.

The long-range view was absent from the debate over Proposition B, which voters approved last week and which locks in the current height limits on land owned by the Port of San Francisco. From here on, any proposed project that includes taller buildings must go on the ballot for, literally, an up or down vote.

This needn't be a bad thing, but it requires looking ahead rather than refighting battles from the past. By contrast, the Prop. B campaign had the undertone of antidevelopment crusades from the 1970s and '80s, the sort that takes great pride in stopping things - or, in this case, letting the bay shoreline mostly stay the way it is.

The catch is, that's not an option.

Seas to rise 3 to 4 feet

The National Research Council, an offshoot of the National Academy of Sciences, estimates that by 2050 the bay will be at levels roughly 1 foot higher than today. Look ahead to 2100 and most likely projections by the council add another 3 to 4 feet.

These numbers are the basis for current shoreline planning by local governments; other statistical forecasts are more severe. Whatever proves to be the case, only the most adamant denier of climate science can ignore the evidence that in the relationship between land and water, the latter has the upper hand.

We don't need to keep the bay from shrinking, the threat that rallied people in the 1960s to create the Bay Conservation and Development Commission. We need to be nimble as it expands.

In the case of San Francisco's northeast shoreline, there's little room for error. The natural topography was subsumed by the growing city after the Gold Rush, marshes buried beneath whatever material was nearby, including hills leveled to provide soil.

What keeps the land and bay apart today is an artificial constraint: the seawall of rubble and concrete built between 1878 and 1915 from Fisherman's Wharf to Pier 50, south of Mission Creek. On one side is valuable real estate. On the other, a bay with no hint of beaches or reeds or dunes.

"It was a complicated shoreline, with promontories and narrow creeks, then we filled it out pretty much to the deeper water," said Robin Grossinger, a scientist at the San Francisco Estuary Institute. "Which makes sense - that's where the ships could pull in - but it ties our hands a little bit."

Waves break over seawall

The simplistic conclusion would be to leave the remaining port properties alone. Let the 16-acre parking lot south of Mission Creek remain a parking lot for Giants fans. Let the dilapidated industrial blocks of Pier 70 remain a patchwork of mostly empty structures, scrap yards and asphalt.

Without some form of intervention, though, conditions will decay as the water rises. This gradual progression already has begun, sending waves over the seawall onto the Embarcadero during high winter tides. At the very least the seawall needs to be made seismically stable, an endeavor that could easily top $1 billion. When planning for that begins at some point in the next five years, we'll need to look at where the seawall will need to be raised as well.

South of Mission Creek, there's an opportunity to use multi-acre projects to improve conditions along the shoreline. Designs could include raised sites that double as berms, and parks that double as detention basins for storm water.

But this requires large-scale planning that accepts the complexity of a volatile future. Compare that to the regularity with which Prop. B leaders looking to scare voters would conjure up images of Fontana Towers - a pair of buildings next to Aquatic Park completed in 1960, 15 years before most of today's San Franciscans were even born.

One promising initiative that could serve as a model is along Mission Creek: Several city agencies are working with the conservation and development commission, the planning advocacy group SPUR and the Delta Alliance of the Netherlands. The idea is to approach the half-mile-long passage holistically, including possible changes to the shape and breadth of the shoreline.

Status quo is risky

"The problem is not one that any single entity or property owner can 'solve' alone," said Laura Tam, a sustainable development specialist at SPUR. "The status quo will put us in a position of greater vulnerability if we just let things go."

A similar note is sounded by senior planner Joe LaClair of the Bay Conservation and Development Commission, the state agency created in the 1960s in part to review and approve any projects along the shore. He's also involved in the study, a draft of which should be completed by October.

"Density in the right places can be designed to be resilient and, perhaps, help pay for expensive shoreline protection elsewhere," LaClair said. "We want to demonstrate that San Francisco is ready to grapple with the issue of sea level rise and resilience planning."

The Bay Area isn't the only region in a bind; that's one reason for the interest in Mission Creek from the Netherlands, a nation where much of the population lives below sea level. Thinking beyond the here and now is what smart governments do. But the responsibility rests with all of us. Our grandchildren will know whether we were equal to the task.