It is hard to imagine the world we live in will become radically different over the next 25 to 75 years. All narratives about technology aside (automated vehicles, anti-aging organ transplants, etc.), the planet we rely on to support the way we live is itself going to be different and those changes are already taking place. This isn’t based on a projection alone — it is a conclusion that can be drawn from current data. We now have almost twice as much carbon dioxide in our atmosphere than we have had for more than 400,000 years. No matter what we do about carbon levels over the coming decades, the consequences are unstoppable and that includes rising sea levels which are expected to increase exponentially.
This past year, the Rockefeller Foundation sponsored the “Resilient by Design Bay Area Challenge,” a Bay Area design and planning competition created to identify regionally appropriate adaptation strategies. The College of Environmental Design participated as a member of the All Bay Collective (ABC), one of the ten teams competing in the challenge, ensuring that faculty whose work is pushing the envelope of adaptation options, and students whose professional future will deal with these changes, had both a voice and a learning opportunity in this event.
CED students contributed their innovative energy through seminars, studios, and colloquia, where they worked together with professionals in identifying key sites and strategies for creating a more resilient, just, and sustainable environment. Along with Nicholas de Monchaux, Associate Professor of Architecture and Urban Design at CED, our design partners included AECOM, CMG Landscape Architecture, and David Baker Architects, along with Silvestrum, SKEO, and a dozen engaged community organizations from “deep East” Oakland.
We tested cutting-edge ideas and learned an enormous amount in the process. Two insights were crucial. First, that an entirely different way of thinking about redeveloping a city near the shore is both necessary and feasible — one that accepts the inevitability of higher water and designs for it. Second, that designers and planners must advocate for community-based land trusts as an ownership strategy if we want “adaptation” to mean something other than “displacement” for communities of color. These two strategies don’t have to be used on the same parcels to achieve adaptation with equity, but they can be if there are supportive governance and financial contexts.
A “Tidal City” Design Strategy
The physical design strategy we pursued was one that introduces new landforms, relying on earthwork as the key “shape-changer” for an urban district. To quote Seattle landscape architect Rich Haag, the essence of landscape architecture is to “dig hole, make mound.” It is common to hear of adaptation strategies for flooding that require building a mound, requiring fantastical amounts of fill to become a regional solution. But if we balance cut and fill, we can generate a new typology using a mosaic of levees and ponds that would achieve several goals at once. It would allow the groundwater to rise, driven by rising salt water. It would provide space for mixed-use developments, some of which float on shared decking in the ponds, and others that are built on terraces or “superdikes” raised above the ever-higher tide line. The floating buildings would be naturally protected from increasing liquefaction risks as groundwater rises on fill soils. Mid-rise buildings on terraces and superdikes would require deep foundations, but be valuable enough to justify them. Wetlands and other habitat areas can be incorporated into this mosaic of levees and ponds, with large wetlands on the edge and small corridors passing through the interior.
We called this type of district a “Tidal City,” conceived as a fabric of strategies on a gradient of ever-higher water, perhaps starting with canals to drain high groundwater from existing blocks and evolving into ponds and levees as sea levels continue to rise. The flexibility of balancing cut and fill means the approach can be “rolled back” as urban land becomes flooded farther and farther inland, filling older ponds near the shore to turn them back into coastal wetlands. This proposal for adaptation in place can also be seen as a long-term form of managed retreat that re-works the old, contaminated soils of an urban and industrial landscape as it moves landward, reconstructed in phases that respond to the as-yet-unknown upper limits of sea level rise. The floating architecture might use prefabricated structures to maximize the mobility of those assets, like the Steigereiland district of Amsterdam, however these would float only on artificial, managed ponds, where tides can be muted and waves eliminated, not on the waters of the San Francisco Bay. The same ponds can be managed to help improve water quality as rainwater runs off the land, through filtration parks and eventually into the Bay.
Establishing New Forms of Ownership
No matter how we imagined the development of new urban districts, the only way we could honestly say that housing units would remain affordable was by introducing forms of collective ownership. We concluded that establishing a seat at the negotiating table for communities of color, where people tend to have less wealth as a result of systemic racism, meant recognizing that landowners have much more influence on change. A land/housing trust can set its own rents and govern its own future. Oakland has an existing land trust for housing that can grow exponentially through new private investments, incentivized by our new tax laws (“opportunity zone” maps are expected to guide these investments, and East Oakland has been designated as one). If the trusts use one of California’s current governance tools — the Geologic Hazard Abatement District — they can accomplish the earthwork they need to adapt with minimal permitting restrictions and tap into a shared insurance pool. Adaptation in place also creates opportunity for new locally-owned businesses that provide new transportation options, environmental monitoring, park maintenance services, and play on-going construction roles.
In sum, we woke up to two facts. First, an entire urban mixed-use district can float safely and beautifully if its landscape armature allows that to happen. And second, no matter how well-designed these districts are, investments in redevelopment will accelerate displacement unless existing communities of color in places like East Oakland can gain health, wealth, and stability from the investments, and are able to manage those investments in their own interest. See our report, including the underlying research on groundwater flooding impacts that became a driver for our floodable development strategies.