Stormwater

Spanning 2,000 acres with more than 50 miles of trails, Wissahickon Valley Park in northwest Philadelphia offers a variety of recreational opportunities, from hiking and biking to bird watching and picnicking. We are a professor of history who co-authored a book on the Wissahickon Valley and an assistant professor of biology. We teach students at Chestnut Hill College, which sits directly across the street from this lush urban park, about the environmental history of the Wissahickon forest and the importance of preserving its biodiversity. We’re also developing a documentary on the Wissahickon funded by the Sisters of Saint Joseph. We want our students – and all Philadelphians – to understand the importance of protecting this urban ecosystem as a way to build climate resilience. Like many of the country’s other great urban parks – from Central Park in New York or Rock Creek Park in Washington to the smaller Phalen Park in St. Paul, Minnesota R...

“When it rains, it pours” once was a metaphor for bad things happening in clusters. Now it’s becoming a statement of fact about rainfall in a changing climate. Across the continental U.S., intense single-day precipitation events are growing more frequent, fueled by warming air that can hold increasing levels of moisture. Most recently, areas north of Houston received 12 to 20 inches (30 to 50 centimeters) of rain in several days in early May 2024, leading to swamped roads and evacuations. Earlier in the year, San Diego received 2.72 inches (7 centimeters) of rain on Jan. 22 that damaged nearly 600 homes and displaced about 1,200 people. Two weeks later, an atmospheric river dumped 5 to 10 inches (12 to 25 centimeters) of rain on Los Angeles, causing widespread mudslides and leaving more than a million people without power. Events like these have sparked interest in so-called sponge cities – a comprehensive approach to urban flood mitigation that uses i...

Heavy rainfall generated widespread flooding. in the Upper Midwest in late June 2024, putting at least one aging dam at risk. In southern Minnesota, the Blue Earth River cut a path around the Rapidan Dam in Rapidan Township, about 15 miles south of Mankato, on June 24, putting the structure at imminent risk of failing. Officials warned local residents that if the dam burst, the river could rise by 2 feet, but said that evacuations were not needed. This event comes a year after flooding in Vermont collapsed at least one dam and threatened others. Hiba Baroud, associate professor and associate chair in the department of civil and environmental engineering at Vanderbilt University, explains how flooding stresses dams in a changing climate. How serious is the risk when water flows over or around a dam? These conditions can result in erosion, which subsequently could lead to a dam breach or failure and a sudden, uncontrolled release of impounded water. The risk reflects the combin...

Heavy downpours and a thick snowpack in the Western mountains and Upper Midwest have put communities in several states at risk of flooding this spring – or already under water. Flooding is the costliest type of natural disaster in the U.S., responsible for about 90% of the damage from natural disasters each year. It happens almost every day somewhere in the country. Yet, much of the aging infrastructure meant to protect U.S. communities is in bad shape and, in some cases, failing. The American Society of Civil Engineers gave the nation’s dams, levees and stormwater infrastructure a D grade in its latest report card, in 2021. Help is coming. Congress authorized billions of dollars for infrastructure projects under the Infrastructure Investment and Jobs Act in 2021. But there’s a problem: New infrastructure planning frequently relies on historical flood patterns for its benchmarks rather than forecasts of changing risks as the climate warms. We study flood ris...