Using Green Infrastructure To Reduce Flooding
Consecutive waves of heavy rain in places like San Francisco have resulted in sewer overflows and the more densely populated areas of New Jersey have witnessed the rise of creeks and rivers over their banks. Serious storm systems can easily overwhelm the capacity of many storm sewer systems, and smaller storms may still cause flooded basements, businesses, and main thoroughfares.
In a way, the repeated crisis of localized flooding is the inevitable result of the manner through which storm sewer systems have historically been built, designed to move rainfall away from our communities through the use of gutter, tunnels, and ditches. As more land gets paved over with parking lots and rooftops, more rainfall ends up flowing into the storm sewer system in ever increasing volumes.
FEMA estimates that at least a quarter of all economic damages caused by flooding are the result of problems with the urban drainage system. With that in mind, many new engineering companies are looking at natural solutions when it comes to protecting communities from large-scale flooding, as well as building new communities to prevent recurring localized flood damage.
The idea is to find different ways to build office parks, shopping centers, and residential neighborhoods to prevent rainfall from draining off into overworked sewers and streams. Hard surfaces such as road and rooftops interrupt the natural water cycle, namely by preventing water from infiltrating into the ground or being used by trees and plants. Green infrastructure counteracts this problem, preventing flooding from occurring by slowing the rate of runoff and capturing the rainwater where it falls.
This approach has already proven itself to be effective at the neighborhood level, with experiments in neighborhoods in Toledo OH yielding positive results. When the project was completed in 2012, residents reported no basement flooding, even when a major storm brought more than seven inches of rain to the area.
Scenarios such as this make an effective case for the advantages of a green infrastructure, especially with cities and towns dealing with shifting precipitation patterns and a rapidly changing climate. Green infrastructure offers a very cost-effective approach to protecting clean water and mitigating the effects of localized flooding.
Advancements in technology and green infrastructure concepts will no doubt go a long way towards reducing the amount of long-term flood damage to homes, neighborhoods, and businesses across the country in the coming years.