Defying the Tides
By John King
San Francisco Chronicle
9 September 2016
Photo courtesy San Francisco Chronicle

The steep mountains of dirt where Candlestick Park once stood exemplify the concerns around climate change that are beginning to reshape some of the most valuable land on San Francisco’s waterfront. The trucked-in soil sitting in Candlestick Park will soon be the foundation for a future shopping center and housing units that are scheduled to open in 2019, and will be located as much as 10 feet above the former level of the entrance to the stadium -- a height intended as a safe perch above the rising sea for another century or more.

As many as 24,000 new housing units and parks could fill four tracts of land at various sites around San Francisco’s shoreline, but come with serious environmental risk: Most government forecasts say tides in the bay could rise as much as 66 inches by 2100. This scenario has caused some experts to warn against any new bayfront developments, yet the demand for housing throughout the city has both city officials and developers scrambling to find solutions.

San Francisco plans to revitalize four new sites across the city, including Candlestick Point, Treasure Island, a 14-acre parking lot south of AT&T Park and a former steel works at Pier 70 below Potrero Hill. The four shoreline developments could together add 24,000 housing units to the city with a upwards of one-third of them being affordable.

While major developments are planned to be completed in the next 10 to 15 years, agencies like the Port of San Francisco are beginning to design for rising tides now. The new Crane Cove Park at the north end of Pier 70 — which starts work next fall — will be laid out so that higher tides and storm surges can easily coexist with recreation spaces. The park’s transition involves a concept called “managed retreat,” where the shoreline’s slope would be terraced in a procession of paths and native plants, culminating in a landscaped stop located above even the most extreme sea-rise projections for year 2100.

When it comes to rising sea levels, Associate Professor of Landscape Architecture & Environmental Planning Kristina Hill believes it’s better to be safe than sorry: While city planners have mandated that new developments sit at a minimum of 66 inches above today’s flood line, she argues that projections of sea level rise are likely to be raised again.

“All of the science is pointing toward a higher number, and sooner,” Hill said. “We will likely have less time to do more than we now think we need to do.”

If these projects are completed successfully, however, they can be used as models for new forms of waterfront growth keyed to the awareness that tides and shorelines are no longer static or predictable.