FLOODSDallas Is Only the Latest Flood Disaster: How Cities Can Learn from Today’s Climate Crises to Prepare for Tomorrow
Floods are complex events, and they are about more than just heavy rain. Each community has its own unique geography and climate that can exacerbate flooding, so preparing to deal with future floods has to be tailored to the community. Recent floods provide case studies that can help cities everywhere manage the increasing risk.
Powerful storms across the South, following flash floods in Dallas, Death Valley, St. Louis, Yellowstone and Appalachia, have left cities across the U.S. questioning their own security in a warming climate.
Dallas was hit with nearly 15 inches of rain that turned roads into rivers and poured into homes starting Aug. 21, 2022. Neighborhoods in Jackson, Mississippi, were inundated a few days later as the Pearl River rose and a water treatment plant breakdown left the city without clean drinking water. In late July, extreme storms struck the mountains of eastern Kentucky, sending rivers sweeping through valley towns and triggering mudslides that killed more than three dozen people.
Floods are complex events, and they are about more than just heavy rain. Each community has its own unique geography and climate that can exacerbate flooding, so preparing to deal with future floods has to be tailored to the community.
I work with a center at the University of Michigan that helps communities turn climate knowledge into projects that can reduce the harm of future climate disasters. The recent floods provide case studies that can help cities everywhere manage the increasing risk.
Flood Risks Are Rising
The first thing the recent floods tell us is that the climate is changing.
In the past, it might have made sense to consider a flood a rare and random event – communities could just build back. But the statistical distribution of weather events and natural disasters is shifting.
What might have been a 1-in-500-year event may become a 1-in-100-year event, on the way to becoming a 1-in-50-year event. Hurricane Harvey in 2017 delivered Houston’s third 500-year flood in the span of three years. Ellicott City, Maryland saw catastrophic floods in 2016 and 2018, and the town flooded again in June 2022.
Basic physics points to the rising risks ahead: Global greenhouse gas emissions are increasing global average temperatures. Warming leads to increasing precipitation and more intense downpours, and this increases flood potential.
Communities Aren’t Prepared
Recent floods are revealing vulnerabilities in how communities are designed and managed.
Pavement is a major contributor to urban flooding, because water cannot be absorbed and it runs off quickly. Similarly, after a forest fire or extended drought, water runs off of soil rather than soaking in. This can overwhelm drainage systems and pile up debris that can clog pipes and culverts.
Failures in maintaining infrastructure, such as levees and storm drains, are a common contributor to flooding.
