Curb cuts allow water flowing in street gutters to be diverted into road side retention and infiltration bioswales. The water is held to slow down the accumulation of runoff in the street and limit the amount of pollution washed into rivers and lakes nearby. When one of the bioswales fills, the water simply stops flowing into it and will instead pass the curb cut, requiring relatively little adjustment to the function of water drainage on the roadway itself.
Capturing stormwater runoff reduces the likelihood of flash flooding and limits the accumulation of chemicals and other pollutants. Curb cuts have very little impact on the function of the roadway but allow these critical water capture infrastructures to be implemented without impacting the roadway themselves.
Water features require more consistent maintenance than regular roadways and are an extra cost to construct. The bioswales are often planted with hardy native plants that may not be perceived as pretty by the community.
Example 1: EPA
EPA Stormwater Management Handbook
Description: The stormwater management handbook addresses designs for all green infrastructure best practices. However, curb cuts can be found on page 103.
Example 2: Michigan
Michigan Best Management Practices - Chapter 7
Description: Michigan's document outlining the best practices for low-impact development in general. Curb cuts are addressed on page 136.