Paul Brown made a keynote presentation on how cities are approaching the future role of technologies and structural engineering in their communities.1 Though not an engineer himself, Brown has worked with many municipalities over several decades on how to approach engineering, design, and construction.
Spurred by the 2017 hurricanes Harvey, Irma, Jose, and Maria (which had recently occurred at the time of this workshop), Brown opened his talk with two observations. First, the likelihood of more extreme and unprecedented weather events has increased due to steadily rising temperatures and subsequent climatic non-stationarity. Building resilience and recovering from more extreme and frequent disruptions is among the greatest challenges that cities now face. Brown emphasized that recovery takes years and more events are likely to occur before recovery is accomplished—a cycle that can result in the “slow death” of a city. Second, hurricanes like Harvey are reminders of how “enormous” natural disasters can be. Brown asserted that, in the context of an event like Hurricane Harvey, none of the current best practices could have protected Harris County, Texas or Houston from destruction. Despite reports that a lack of progressive policies in Houston was to blame, he maintained that no U.S. metropolitan area could have absorbed the amount of water that fell on the Houston region.
Current urban systems were designed and developed during a time of climate stationarity. Brown drew from a 2008 article in Science, which defines stationarity as the idea that “natural systems fluctuate within an unchanging envelope of variability,” and that stationarity “is a foundational concept that permeates training and practice in water resource engineering.”2 In the past, climate stationarity allowed for rational investments in large-scale infrastructure. This infrastructure was designed to function under predictable, average, and extreme conditions; decisions were made based on a tolerance for quantified risk. Because of the uncertainty now faced from a changing climate, the future frequency of a similar event cannot be predicted. Non-stationarity poses a real challenge to planners, engineers, insurance providers, and policy makers, all of whom rely on predictions of future risk to make decisions and recommendations. As Earth
1 A version of this keynote is available at: https://urbanh2oplanner.com/dev_v1/wp-content/uploads/2017/12/NAS-Resilience-Keynote-FINAL.pdf.
2 Stouffer, R.J., P. C. D. Milly, J. Betancourt, M. Falkenmark, R.M. Hirsch, Z.W. Kundzewicz, and D.P. Lettenmaier. 2018. Stationarity is Dead: Wither Water Management? Science 319(5863): 573-574.
transforms into a time where stationarity is in effect “dead,” Brown said he was uncertain resilience efforts can truly prepare for future unprecedented events.
Even so, Brown asserted that cities need engineers, architects, and builders to help reinvent urban policies, decision-making, and governance, and to make city components more durable, less energy-intensive, and smarter for the new era. Currently, cities face multi-pronged threats to their infrastructure, not only from increasingly frequent and extreme weather events, but neglected and deteriorating facilities, rapid population growth, and widening economic inequalities. Additionally, the established rigid framework of building codes and design standards can hamper the discovery of new solutions. While absolute and worldwide standards benefit public health and safety under normal conditions, they also inhibit innovative adaptations to infrastructure. Brown indicated he supports the transition of codes to a performance-based standard.
Brown asked: what is a resilient city? With reference to water, he cited Howard Neukrug, Brown’s colleague and former commissioner of the Philadelphia water department, who described the water sector’s situation as follows: “Rising tides, water scarcity, floods, legacy and emerging contaminants, extreme storms, the threat of terrorism, non-stationarity, and piping systems built in the 19th century combined with 20th century technologies have left us with little choice but to actively renew our thinking about the relation of water to our cities, our budgets, and our future.”3 This implies that every city is a unique and complex combination of interests and forces with diverse expectations. Resilience will mean something unique in all of them—an emerging capacity to adapt—not a static design solution.
Brown further noted Spiro Kostof’s work, which focuses on the urban process rather than urban design, an approach Brown shares. Cities evolve due to collaborations and conflicts between constituents—citizens, elected officials, local authorities, stakeholders, and businesses. Brown observed that engineers, architects, and builders often become too attached to the idea that resilience is a design problem and “…forget that cities are people, places, and processes that depend on the built environment, but are not defined by it.” Lastly, he referred to Luis Bettencourt, who observed, “Despite the increasing importance of cities in human societies... our ability to understand them scientifically and manage them in practice has remained limited. The greatest difficulties to any scientific approach to cities have resulted from their interdependent facets, as social, economic, infrastructural, and spatial complex systems that exist in similar but changing forms over a huge range of scales.”4 Bettencourt said he believed that cities are their “own thing” and there is no analogy for a city found in nature.
Despite Bettencourt’s view, Brown concluded by metaphorically comparing the city to a land-based crustacean. Like the crustacean, cities nest in locations accessible to water; thus, subjecting themselves to the threat of “drowning,” or flooding. City infrastructure, the domain of engineers, architects, and builders, is like the crustacean’s exoskeleton and the complex network of arteries that transport food, goods, and waste in and out of its “guts.” The living heart and body of the city is inside the exoskeleton, and the living city takes that exoskeleton for granted. So what happens if this habitat, the exoskeleton, experiences an event that needs to change shape quickly? Luckily, cities possess a remarkable capacity for change, Brown said. When radical habitat changes make it necessary for the city to become resilient, Brown argued that it begins
3 Neukrog, H., and D. Lind. 2020. Transforming New Jersey’s Water Infrastructure: A Call to Action and Innovation. Jersey Water Works. https://cpb-usw2.wpmucdn.com/web.sas.upenn.edu/dist/5/391/files/2017/11/JWWs-Final-copy-2b096nb.pdf.
4 L. Bettencourt. 2013. The Origins of Scaling in Cities. Science 6139(340):1438-1441.
from the inside out. These changes must be “progressive changes in the city’s DNA, not cosmetic surgery on its [the city’s or crustacean’s] shell.” In this case, Brown encouraged the need to actively research and re-engineer the adaptation process for multi-purposed, durable, flexible, and possibly regenerative systems. He pointed to the Department of Defense’s definition of system reliance as one that is “trusted and effective out of the box, can be used in a wide range of contexts, is easily adapted to many others through reconfiguration and replacement, and has a graceful and detectable degradation of function.”5
In urban water infrastructure, Brown promoted the need for increased levels of public engagement, understanding, participation, and “love” for water. Southern California’s “H2love,”6 a public service campaign, is working to change public concern and participation in this way. While campaigns like H2love demonstrate methods of promoting community change, Brown identified more complex questions for creating urban resilience, such as: how to balance the standardization of codes and practices with the benefits of innovation and locally developed solutions; whether performance-based codes can be established to facilitate that balance; the degree to which operational decisions rely on artificial intelligence; and how to protect against hacking and cyber-attacks, among others.
In closing, Brown described the need for resilience at the city level as a “bittersweet acknowledgement” because to acknowledge this need is to accept the inadequacy of existing infrastructure. Advances in structural, mechanical, and civil engineering primarily occur in response to the failure of engineered structures. For this reason, Brown stressed resilience as a key component of sustainability. Unlike possibly unattainable and unaffordable promises of protection, resilience relies on humility and wisdom to provide for survival and rapid recovery. He emphasized that rapid adoption of adaptive innovation during the recovery process produces resilience, and noted the Netherlands as an example for wide-ranging engineering approaches to frequent inundation. Lastly, Brown advised those in the room to be the responsible enablers of sound decision making under uncertainty, and to recognize that people and community are the sources of urban resilience; everything else should be designed to be safe and reusable when damaged.
5 R. Neches. 2011. Engineered Resilient Systems (ERS) S&T Priority Description and Roadmap. ODASD SE, Advanced Engineering Initiatives. https://pdfs.semanticscholar.org/b6d0/66afc7c4a9c021b8f0ba9ecb4883bd58140f.pdf.
6 More information about the H2love campaign is available at: https://patch.com/california/beverlyhills/water-agency-launches-summer-h2love-campaign-aimed-water-conservation.