AIA Cloudbursts Lecture

In February, I attended AIA’s panel discussion titled Cloudbursts and NYC: Strategies for Design, Mitigation, and Implementation. Before this talk, I was unfamiliar with the term cloudbursts which I now know is similar to its cousin atmospheric river. What caught my interest in the event was the focus on recent hurricanes such as Henri and Ida’s impact on New York City’s physical infrastructure.

Climate change is rapidly changing our environment with increasingly intense sudden rainfall (the definition of cloudburst) that inundate and overwhelm our waste water management systems but also overall rising sea levels that put our low lying neighborhoods at more risk. At least 11 people died in basements due to flooding in 2021 as well as causing massive damage to our roadways and public transportation. The panel featured speakers across the sector from the mayor’s office, the NY Department of Environmental Protection, and a local landscape architect that all spoke to their unique perspective on how the city is responding to cloudbursts.

One of the things that struck me about this panel was the initial focus by the Mayor’s office on not mitigation but response. Erika Jozwiak spoke about how in the aftermath of Hurricane Henri and Ida they updated NYC’s flash flood response to prioritize at-risk areas that not only consider flood zones but low lying areas at risk of sea level rise. She said it was key to educate the public of flood risks and that the city’s strategy was to “plan, prepare, monitor, and recover”. The city is also now building a large data collection with over 500 sensors in at-risk flood zones so they can know minute by minute if an area is at risk of flooding.

The second trend I noticed was how intergovernmental the work of mitigating becomes. While Alan Cohn spoke for the Department of Environmental Protection as the Managing Director of Integrated Water Management, he spoke of projects that had to be intimately partnered with NYCHA, NYC Department of Parks, and NYC Department of Design and Construction. The actual mitigation work comes in largely two camps - green or gray layers of infrastructure. Green layers include trees that can absorb up to 150 gallons, rain gardens, and green roofs. The green layer is largely meant to absorb the torrential rain, and reduce the strain on the sewer system. Gray layers of infrastructure try to store or transfer the water for example either in large pipes below ground or a sunken outdoor basketball court that can hold water temporarily. Many of these projects are in flight on a pilot level. Much of the green layer and gray layer infrastructure that the city can quickly address is public property like public housing or parks. Mr. Cohn said they select initial cloudburst hubs by their current physical vulnerability, social vulnerability, and feasibility (is there projects already in the making they can help address).

Since flooding doesn’t differentiate between who owns the land, I wondered what private property owners could do in conjunction with the city to help mitigate cloudburst impact. How could the state further incentivize this behavior? I specifically thought of tenants who have little control in how their living situations are managed but are directly impacted by lack of cloudburst management. One partnership opportunity could be with insurance companies that currently underwrite these properties. By educating insurance companies on the value of investing in green layers of infrastructure, in turn they can create incentives to their policyholders to make their properties more resilient.

Lastly, I thought of the cost of maintenance. Many of the green layer infrastructure proposed by the panel needs to be carefully managed and maintained to be effective at managing the impact of cloudbursts. But the city currently spends less than 1% on NYC Department of Parks. In the wake of COVID, their 2022 budget was slashed compared to 2020. How can we ensure we can successfully manage cloudbursts if we don’t manage the core green infrastructure that mitigates it?