THE DIRT

By Kristina Hill, Affil. ASLA

Over the next hundred years, average global sea levels are expected to rise faster than they have in the last 8,000 years. By 2050, storm surges and high tides could flood homes, subways, and roads that are currently one or two feet higher in elevation than the homes, subways, and roads that have already flooded over the last twenty years in New Orleans, New York, Zhengzhou, and Boston. Hundreds of millions of people living in coastal cities and rural areas will be affected, even if communities stop burning fossil fuels completely today.

Adaptation to climate change is essential. But do landscape architects and planners understand the most important impacts of higher seas, assuming the goal is to design for adaptation without accidentally blowing it? And how will communities prioritize and achieve the social goals of adaptation in a systematically unequal society? Who will pay, who will benefit, and how can communities take the first steps? As this figure based on innovative planning in the UK reveals, there’s a long lead time before coastal communities can live in safety, so those first steps need to happen now.

Carolyn Kousky, Billy Fleming, ASLA, and Alan M. Berger, the editors of the new book A Blueprint for Coastal Adaptation: Uniting Design, Economics and Policy, set out to answer these questions. In their introductory essay, they make the claim that landscape architects and planners already have most of the tools needed to help communities adapt. The challenge, in their view, is the lack of action. They close the last paragraph of their introduction with the (overly?) triumphant claim that if we start now, “the future is ours.” Ouch. Remind me who “we” are? And is it a good thing for anyone to claim possession of the future, which will have its own claims? I realize this introductory chapter is a pitch, not a research paper, and the chapters themselves are far more self-reflective. But I want to start by putting this review in context, simply because the book is so important.

As a scholar and designer in the field of landscape architecture, I ask myself every day whether design professionals have the synthetic understanding needed to advise urban decision makers to act. For example, while the authors in this anthology consider flooding driven by saltwater, rainwater, and rivers overflowing their channels, not a single essay grapples with the risk that shallow coastal groundwater will rise through the soil and/or move laterally into river channels in response to rising seawater. Recent research indicates that groundwater-driven flooding may cause more water-related failures of urban infrastructure and buildings than seawater and that it will add to river and rainwater flooding. If landscape architects and planners haven’t considered the compounded physical and ecological risks created by rising coastal groundwater, it’s premature for us to give professional advice on adaptation.

To be “professional,” our advice has to go beyond selling a proposal. That advice has to reflect the shared knowledge of a field, or it won’t meet the standard of professionalism; at that point, we might as well be selling used cars. If we recommend spending billions of dollars to use levees to keep the sea out, our shared knowledge tells us that we will also need to pump the rainwater and groundwater out from behind the levees and design the protected district to be resilient to catastrophic failures of coastal structures. Levees and movable gates won’t keep coastal land from flooding by themselves, especially where the rock or sand under a city is very permeable.

The upshot is that the mantra of “sponge cities” or “sponge wetlands” won’t work in high groundwater conditions, because the “sponge” will already be full of groundwater. The really bad news is that changes in the elevation or flow direction of coastal groundwater could end up sending us to a dystopian ‘80’s theme party. New flows of groundwater can mobilize soil pollution that was capped in the 1980’s or 1990’s and carry it under buildings where people will be exposed to old pollution in new ways. Most cities don’t even have maps of their shallow water table. Rising groundwater will corrode and shift building foundations, fill old sewer pipes and basements, corrode electrical conduits, and make extreme shaking more likely in an earthquake. Groundwater management must be part of any viable climate adaptation strategy.

The ambition of the editors to consider the trifecta of hurdles in funding, policy, and design is what makes this book eminently worth reading. Although no one confronts coastal groundwater impacts, the authors in this book provide a robust set of useful ideas, many of which have been tested in practice.

On the design side, Matthijs Bouw, associate professor of practice at the Weitzman School of Design at the University of Pennsylvania, presents useful examples from his professional design experience in New York and Boston clearly and intelligently.

It was (and is) hard for a European firm to encounter and adjust to the state of American infrastructure. Adaptation is made more difficult by the fact that American cities coast on bridge and pipe investments made 100+ years ago and have cultivated a strategy of neglect since then. Bouw’s description of a more abstract ideas competition in San Francisco is less effective than his other examples, but together his experiences allow him to sincerely observe that adaptation with equity is in doubt in the U.S., where we continue to live under the long shadow of systemic racism and growing economic inequality.

Karen M’Closkey and Keith VanDerSys, co-founders of PEG office of landscape architecture, use their experience in the same California ideas competition as the basis for an argument that adaptation will also be a housing problem, as lower-income renters will need new options. They do an excellent job of bringing in the bigger national picture, suggesting policy avenues and making it clear that the gravity and scale of the housing problem is impossible to solve with design tools alone. All of these design chapters are well-referenced and thoughtfully written.

Susannah Drake, FASLA, founder of DLANDStudio, and Rafi Segal, associate professor of architecture and urbanism at MIT, describe their proposals for coastal New Jersey and Long Island and Jamaica Bay, New York, more in the style of a manifesto or a competition submission. They have an interesting core of ideas and intriguing claims, but without a critical frame, deeper references, or details, the chapter reads more as a point of departure than a fully-reasoned landscape architecture strategy. For example, their image of dense housing inserted at the edge of a marsh reveals the fundamental conflict between human housing needs and the needs of coastal ecosystems.

There is no question that putting housing in that location would degrade the quality of the habitat for the egret shown in the image. As we get real about climate, we also need to face the fact that real tradeoffs result from developing coastal ecosystems. This proposal shows an opportunity for landscape architecture to lead adaptation through an ambitious use of land form as an armature for adaptation, instead of concrete and steel walls.

The same site, Jamaica Bay, is also the subject of a proposal in another chapter led by Catherine Seavitt Nordenson, ASLA, professor and director of graduate landscape architecture program at the Spitzer School of Architecture, The City College of New York, which is also provocative but isn’t presented with enough detail to understand how the ecosystems of the Bay would not suffer from introducing new tide gates or how higher groundwater would be managed at the edge of the Bay. As in the Segal and Drake proposal, some separation (physical, temporal or behavioral) would be needed between marshes and lagoons that are managed for housing or recreation and marshes and lagoons that are intended to support diverse ecosystems. It’s a complex landscape, so perhaps this is considered but not described.

On the planning and finance side, several chapters deserve particularly careful reading. Joyce Coffee, founder of Climate Resilient Consulting, and Sarah Dobie, a PhD student at the Taubman College at the University of Michigan, describe strategies at the municipal scale, contrasting the retreat by attrition that is occurring in a small town in Louisiana with Miami Beach’s efforts to raise its streets to adapt in place. Their frank and clear presentation stresses the glaring differences between a community whose tax base and land area are shrinking and a city where a growing population and continued investment is expanding its capacity to adapt in place. It’s not as clear that they have translated the cases into recommendations, which raises the question of whether we know how to prioritize the goals of adaptation. What outcomes are acceptable and to whom?

Thomas Ruppert, a coastal planning specialist at Sea Grant Florida, examines the genuinely frightening prospect that abandoned coastal properties will cause pollution hazards and concludes that current legal tools are insufficient to prevent this dystopian outcome. Carlos Martin, senior fellow at the Urban Institute, makes a spirited case for public funding for adaptation as public works, and Allison Lassiter, an assistant professor at the Weitzman School of Design at Penn, describes the risks of sea level rise for urban drinking water in Philadelphia, which draws its water from the tidal Delaware River, along with New York. Fadi Masoud, assistant professor and director of the Centre for Landscape Research at the University of Toronto, and David Vega-Barachowitz, director of urban Design at WXY architecture + urban design, take a speculative approach to zoning, describing environmental overlay zones as a strategy for implementing incremental change and making it clear that designers should understand the history and legal context of zoning before altering it.

The real stand-out chapter in this section is by Shannon Cunniff, scientific advisor at Stone Living Lab, and her co-authors. They present environmental impact bonds as a new financing tool that has already been used in Washington D.C., Baltimore, and Atlanta, and considered in many others. To the extent that cities continue to rely on private capital to pay for adaptation, or simply to accelerate innovative pilot projects, impact bonds are a very useful strategy. Taking this one chapter seriously could make the difference between kick starting adaptation or failing by delay.

Overall, the book has a strong emphasis on conditions and strategies in the Mid-Atlantic and Gulf coasts. This is a limitation for translating some of the design ideas to the west coast, because different regions have different problems (earthquakes vs. hurricanes, karst geology vs. granite, etc.). The book also doesn’t include innovations from design or financing that have been adopted in California or the Pacific Northwest, outside of the rather abstract recent ideas competition in the San Francisco Bay area. But it’s strong on arguments for the East coast and Gulf.

The editors have taken a light-handed approach. Each chapter is encountered on its own without a broader synthesis or set of recommendations at the scale of a section or the book, leaving the reader challenged to identify gaps and draw conclusions by themselves. For example, in spite of the editors’ hopes, it’s not clear that any of the authors have a strategy for increasing social equity in U.S. cities while adapting to flooding. In that sense, some of the limits in this anthology reflect the genuine boundaries of what has been tried and even proposed. To achieve greater equity, several of the authors seem to conclude that we will need more radical strategies.

Everyone should read this book to see how the field of landscape architecture might help cities adapt to a changing climate, particularly with new federally-funded infrastructure investments. Each chapter of this book reaches beyond the conventional limits of our professional knowledge, by degrees or by leaps. But the most important bar this anthology has set for other books about adaptation is to place questions about funding and policy side-by-side with design proposals. For setting that bar higher, we should all thank the editors. Every future book on this topic should accept that challenge and rise to it. Without progressive new policies that can direct the sources and uses of funds for adaptation, even the best designs for adaptation will only reinforce the unequal status quo.

Kristina Hill, Affil. ASLA, is the director of the Institute of Urban and Regional Development and associate professor of landscape architecture & environmental planning and urban design at the University of California at Berkeley College of Environmental Design. She is writing a book about adaptation to sea level rise.