If popular culture is any measure of collective obsession, people are apparently transfixed by natural calamities. Since 1972, the entertainment industry has produced at least 44 feature films and TV dramas about hydrologic or climatologic disaster (excluding all the earthquake, epidemic, nuclear, and bioterror flicks). A majority of these films are American and appeared after 2000. For a nation fascinated by imaginary catastrophes, though, the U.S. has done alarmingly little to prepare for real ones—the ones that climatologists know are coming.
“With this topic of resilience, we’re where we were with the topic of energy in the 1970s,” says Donald Watson, FAIA, a principal at Trumbull, Conn.–based EarthRise Design, co-author with Michele Adams of Design for Flooding (Wiley, 2010), and a pioneer in environmentally responsive architecture for the past five decades. Watson was among the first American architects to approach conservation, sustainability, and resilience—concerns that were cutting-edge when Watson began his career in the 1960s, and that have since been advanced by the AIA, the U.S. Green Building Council, and others on a professionwide scale. Now, Watson champions disaster preparation, viewing it as essential to “resilience in its deepest sense” and calls for collaborations between architects, engineers, insurers, planners, and building owners to accommodate inevitable challenges to the design professions.
The global trend toward urbanization has made disaster preparation even more important: Urban density gives people a light environmental effect per capita, but because major cities have generally developed near water, sea-level rise in a more urbanized future puts more people at risk. Design strategies can help reconcile these benefits and risks, though, particularly if they use and preserve natural defenses: Wetlands and woodlands, for example, have remarkable absorptive capacity. Pervious pavements, swales, plantings, and terraced reservoirs aid absorption and evapotranspiration; uninterrupted hardscape and heavily managed lawns have the opposite effect, increasing stormwater runoff and exacerbating damage. Defenses such as levees and bulkheads, as Hurricane Katrina proved, are essential but fallible. Lance Jay Brown, FAIA, who, with Illya Azaroff, AIA, co-chairs AIA New York’s year-old Design for Risk and Reconstruction committee (DfRR), attributes some of the recent interest in flood-resilient design to post-9/11 awareness of catastrophic risks as immediate, not remote.
Calculations by insurers support precautionary measures. Klaus Jacob, a geophysicist and urban environmental disaster expert at Columbia University’s Earth Institute, contended at a panel organized by DfRR last October that $1 spent on hazard mitigation saves an estimated $4 in destruction deferred. A 2010 Swiss Re/Entergy study of Gulf Coast assets finds that cumulative expected losses could reach $350 billion by 2030, and makes a conservative projection that $50 billion in adaptation through code upgrades, wetlands restoration, beach nourishment, roof-cover retrofits, and other “no regrets” measures would spare $135 billion in annual losses over that same time period. Extreme climate-change scenarios, the Swiss Re report adds, raise risk profiles so that a “once in 100 years” event would be closer to a “once in 40.”
New York’s Balancing ActArchitects and planners in several coastal cities have joined engineers in planning for the worst. Among cities at risk, New York has the advantage of multiple nonprofit, academic, and public-sector institutions aware of the need for independent local plans. So DfRR and the city’s Department of City Planning jointly sponsored the Freeboard Charrette on March 23 to develop new designs for vulnerable urban sites.
The charrette built on several related efforts, including a 2008 competition sponsored by the city’s Office of Emergency Management—“What If New York City … ”—which was an exercise in emergency-housing design in the event of a Category 3 hurricane. A 2010 exhibition at the Museum of Modern Art, “Rising Currents,” introduced the public to soft-adaptation strategies for New York’s harbor and coastline. The city’s PlaNYC 2030 and Vision 2020 waterfront plan include extensive wetlands restoration, flood-insurance map upgrades, and storm-sewer construction.
As City Planning’s Michael Marrella told the charrette group, the city’s model predicts sea levels to rise 2 to 5 inches by 2020, and 12 to 23 inches by 2080. This would submerge large coastal segments of the city—not “the Hollywood doom-and-gloom scenario” of universal inundation, but a higher-base-flood elevation that would worsen the temporary hazard that a 1 percent storm poses to subways, sewers, and streets. The impossibility of evacuating most of the city means that retreat is a less realistic strategy here than accommodation (raising critical mechanical systems above base flood elevation and designing exposed areas to let water enter and recede) and protective structures, both hard (seawalls, revetments, and watertight gates) and soft (graduated edge structures, reducing tidal speed and force).
San Francisco’s Trade-offs On the Pacific coast, accelerating erosion (especially harsh during El Niño years) has become dramatic enough to threaten Ocean Beach, a magnet for tourists, wildlife, and city residents. The south end of the beach is thinning; two years ago, a bluff receded 40 feet in a single season. Moreover, the risk affects not just treasured views and recreation but vital sewer and wastewater facilities along with the Great Highway, a 3.5-mile, 1929-era road above the sewer pipe. Where damage involves rising levels and the power of tides, hardening one area can raise risk in another.
Having produced several reports on regional sea-level rise, the nonprofit think tank San Francisco Planning and Urban Research Association (SPUR) offers a new master plan to orchestrate mitigation at the site. “A fundamental challenge at Ocean Beach is jurisdictional,” says Benjamin Grant, SPUR’s public realm and urban design program manager. The beach is part of Golden Gate National Recreation Area; the infrastructure adjacent to the coast is owned by the San Francisco Public Utilities Commission; regulatory purview belongs to the California Coastal Commission. Further complicating the picture are multiple nearby city parks and open spaces. “There hasn’t been one logical client entity that’s charged with looking at the future of the whole beach, as a place,” Grant says.
SPUR’s plan is threefold: “managed retreat” through rerouting and narrowing of the Great Highway; targeted hardening of the sewer pipe beneath a lower cobblestone structure; and “sacrificial beach nourishment” to dissipate wave energy, using sand that the U.S. Army Corps of Engineers annually dredges from the Golden Gate ship channel. SPUR’s planners have opted for strategic trade-offs between advocates of “armoring the hell out of the whole thing” and advocates of abandoning the existing infrastructure. “In a way, we’re the tip of the spear,” Grant says. “What we’re seeing at Ocean Beach is a taste of what we’re likely to see much more broadly as sea-level rise sets in.”
New Orleans’s Comprehensive PlanHurricane Katrina made New Orleans and other Gulf communities the national test cases for this field of planning and design. “The first lesson from New Orleans is: You can’t move a community,” says David Dixon, FAIA, principal at Boston’s Goody Clancy and a part of the team behind the United New Orleans Plan (UNOP), the city’s recently adopted master plan, and the related Comprehensive Zoning Ordinance (CZO) currently going through drafts and hearings. “You can’t move a city; it’s almost impossible in America today to move a neighborhood.”
After former Mayor Ray Nagin and the Urban Land Institute’s 2006 green-dot plan to reshape settlement patterns aroused ferocious opposition in affected neighborhoods, officials and planners learned that mandatory abandonment of homes, even for beneficial features such as parks, was a nonstarter. UNOP, funded by the Rockefeller Foundation but driven by grassroots input, established every neighborhood’s right to survival and protection. These principles were revisited and affirmed in the new master plan, which thanks to a city-charter amendment passed in 2008, will have the force of law.
Another lesson learned is the need for more-accurate property valuation. “Now that we know what it costs to rebuild after a storm,” Dixon says, “we have some pretty good numbers for what it costs to build New Orleans. And we know what percentage of those costs, or what share of those costs, at least the last time around, was borne by insurance companies. So if your house is not elevated, for instance, your premiums are much higher.”
“New Orleans is actually relatively safer today than it was before Hurricane Katrina,” he notes. “It is a city that is going to be protected, as is the Netherlands, by manmade interventions and man-led interventions, meaning restoring wetlands.”
But the most decisive change may be cultural. “Before Katrina, New Orleans had begun a comprehensive plan that got pretty much withered,” Dixon says. “It was not a city that took planning seriously; land-use decisions, building decisions, city-infrastructure investment decisions were all political.” UNOP helped change the atmosphere, building on a tradition of community-based activism to create a new culture of participatory community-based planning. Dixon concludes that “it’s about getting people comfortable with planning” so the process can be flexible, responsive, and, above all, effective.