Opinion: Cities Need Green Infrastructure to Weather Future Storms

In an opinion piece in Next City, Franco Montalto touts the benefits of the ‘sponge city’ approach to flood mitigation that more and more cities are undertaking to protect their residents and infrastructure from catastrophic floods.

According to Montalto, “If this concept is to evolve into the new standard for urban design, city officials and developers will need to find ways to scale up and accelerate this work.”

Montalto explains that most U.S. stormwater management systems are not designed to handle all of the runoff created during a large storm. Now, cities are shifting to ‘green infrastructure’ to manage stormwater and direct it back into the ground rather than shuttling it out to rivers or oceans. This comes with its own challenges. “In the best cases, green infrastructure has been installed on publicly owned land and required on new or redesigned large-scale developments. It has proved much more challenging to incorporate green infrastructure on smaller, privately owned land parcels, which collectively make up a significant percentage of urban watershed areas.” In some areas, stormwater management is not even required as part of new development.

Montalto outlines some strategies cities can use to prevent flooding that include permeable asphalt, green roofs, rain gardens, and parks and green spaces designed to flood safely. Montalto also suggests ways to fund these efforts, pointing to collaborations between cities and nonprofit organizations as one option. “Cities could also offer incentives for retrofitting and scaling up existing stormwater management systems on private land. A trading system could be set up to sell the residual capacity to nearby property owners who lack onsite stormwater management opportunities.”