Is Development on San Francisco’s Treasure Island Viable?

Professor Tanu Sankalia discusses the history of Treasure Island and how earthquake risk, toxic contamination, and sea-level rise still imperil plans for large-scale, capital intensive, development on the island.


The man-made, low-lying, Treasure Island in the middle of San Francisco Bay. Photo copyright Barrie Rokeach 2017.

Few Bay Area residents are entirely aware of Treasure Island’s presence, and fewer still know its history: when it was built, how it has been used over the past decades, and what are plans for its future. Despite its very central location in the San Francisco Bay, this flat, low-lying, man-made island has remained at the periphery of most people’s local and geographical consciousness.

As an architect and urban planner, Treasure Island first caught my attention when plans for its redevelopment were unveiled in 2005. The project was promoted as a cutting-edge sustainable development, especially at a time in the early 2000s when sustainability had caught on rapidly among architecture and planning firms. Yet I was intrigued as to how a multi-billion dollar development that consumed great resources, required massive new infrastructure, and was proposed on what appeared to be a risky site (more about this later), could actually be sustainable.

Over the last eight years, my research on the planning and design history of the redevelopment project, together with contributions from a group of excellent scholars on a range of historic and contemporary issues concerning the island, has recently culminated in a co-edited book, Lynne Horiuchi and Tanu Sankalia, Eds., Urban Reinventions: San Francisco’s Treasure Island published by the University of Hawaii Press. While our work focuses on a single site and underscores its local significance, it also reaches out to topics of global importance such as the Pacific Rim, New Deal, world’s fairs, World War II, Cold War military industrial complex, nuclear contamination, sustainability, and eco-cities, among others. This research has also informed my teaching as I have been able to use Treasure Island as a case study in the urban planning and design course I teach in the Masters of Science in Environmental Management (MSEM) program at USF.

The Army Corps of Engineers built Treasure Island between 1936-1937 with New Deal money. It was constructed concurrently with the San Francisco-Oakland Bay Bridge and the Golden Gate Bridge, to serve as San Francisco’s airport, at a time of major transportation infrastructure expansion. Between 1939-1940 the island hosted the Golden Gate International Exposition (GGIE), which shifted the focus of world’s fairs as venues of science and industry to representations of international unity exemplified in the idea of a Pacific Rim interconnected through commerce and trade. World War II scuttled this utopian imagination, and in early 1942 Treasure Island was converted into an active naval base that cycled 4.5 million US soldiers on their way to and back from the Pacific theater of war. After World War II, Naval Station Treasure Island focused on training and distribution activities until it was officially closed in 1997. In 2011, the City and County of San Francisco Board of Supervisors approved a redevelopment project for a new sustainable city of 19,000 residents, which critics and commentators see as an example of twenty-first century, “ecotopian” urbanism.

Underlying Treasure Island’s historical narrative, our research found that since its conception, the island has remained a contested site with federal and local agencies vying for its control. These agencies have recurrently shaped the physical character of the island (what we call urban reinventions) through ambitious projects like the airport, world’s fair, military base and now, eco-city. But despite these important historical lessons, which are crucial in understanding how cities and communities conceive projects, the material risks—earthquakes, toxic soil and rising seas—surrounding its latest grand vision are rather pressing.

Treasure Island was built on the shoals of the natural Yerba Buena Island from dredged bay mud filled into a trough enclosed by a sea wall made of large boulders. The shoals, which function as bedrock into which tall buildings must pierce their foundations, are deeper away from the island. Although most buildings in the proposed plan are clustered where the shoals are shallower, there is considerable infrastructure on parts of the island that geotechnical reports (produced in the first reuse plan of 1996) indicate to be unstable. Given the island’s proximity to some of the Bay Area’s largest earthquake faults, a significant tremor can cause the landfill to function like jelly.

Toxic soil remains a major concern on Treasure Island. The US Navy established a Damage Control School in 1947 during its tenure on the island to train naval personnel in decontamination procedures in the event of an atomic, chemical or biological attack. For training purposes they built a mock training ship—the USS Pandemonium—from scrap metal, which was periodically contaminated with cesium-137 and a diluted solution of radioactive bromine-82. In 1971, they dragged this mock ship from the northwest to the southeast of the island further spreading radioactive substances across the island. According to the Department of Toxic Substances Control, the state agency charged with monitoring toxic cleanup at Treasure Island, the island’s soils contain a long list of toxic chemical substances harmful to humans including plutonium and radium. Furthermore, the current Historical Radiological Assessment report that the Navy must produce to guide management and remediation of toxic soils states that the island’s soils simply cannot return to their pre-military state.

Almost twenty years after the redevelopment process for the island was initiated, we have greater awareness about climate change, global warming, and one of its major effects—sea level rise. Maps produced by the Bay Conservation and Development Commission (BCDC) and the San Francisco Public Press show Treasure Island and the edges of San Francisco Bay under threat from rising seas and storm surges. There are plans to raise the entire island and build a higher, stronger seawall to protect against this danger. Still there is little evidence—especially considering the example of Miami Beach, which is constantly inundated despite its massive seawalls and giant pumps—that such measures will actually succeed.

The Bay Area indeed needs more housing, which Treasure Island’s development could well deliver. There are also many good ideas such as manmade wetlands, urban agriculture and energy efficient buildings, in the redevelopment plans. But they well may be great ideas in the wrong place. Why jeopardize billions of dollars in development and risk the lives of almost twenty thousand residents on an unstable, contaminated, low-lying island site?

Looking back to the very construction of Treasure Island and its recurrent urban reinventions, I am reminded of the German writer W.G. Sebald’s prescient observation that “it is often our mightiest projects that most obviously betray the degree of our insecurity.” It is in moments of vulnerability that governments, cities, and communities take on ambitious and, often, risky projects. In recognizing this risk, it still may not be too late to rethink the viability of development on Treasure Island.

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