Out of 31 municipalities the U.S. Government Accountability Office researched recently, 26 reported that green infrastructure was more challenging to develop and maintain than gray infrastructure like concrete sewers. However, 25 of them still used green infrastructure despite its difficulties.

Some reported that they were unfamiliar with green infrastructure yet they continued to use it because of its additional benefits and the opportunity to educate the community about it. But 15 municipalities reported that less than five percent of their stormwater drained into green infrastructure.

And almost all of them used green infrastructure because of Clean Water Act permits or combined sewer overflow (CSOs) consent decrees.

Combined sewers are a type of gray infrastructure that collect sewage, wastewater and rainwater runoff in the same pipe and transport it to a treatment plant. Pollution can occur when heavy rain or snowmelt creates an excess of toxic storm water causing it to drain into nearby bodies of water.

To learn more about green infrastructure, visit https://www.epa.gov/green-infrastructure.