A curb cut is a rainwater harvesting feature that allows stormwater to flow into parkways or planting beds in parking lots, instead of running down the street, picking up pollution that ends up in the ocean. Curb cuts allow runoff to be directed into pervious areas and filtered through the soil. They can help to direct, slow, spread and sink stormwater, irrigate water wise plants, and prevent flooding. Although the term ‘curb cut’ is commonly used to describe the practice, the actual form can be created by cutting into a curb or by boring into it- which alleviates a concern about people tripping on or around the cut. Curb cores clog easier than cuts and do not capture as much water. A successful strategy to prevent tripping that I prefer is to place a flagstone or similar object over the cut and to create a stepping stone path from there.
For every inch of rainfall…a 10-foot wide paved street will drain 27,800 gallons of rainfall per mile. This water could be directed to help irrigate street trees and other plants in parkways. Curb cuts are most efficient when directed into eddy or backwater basins that allow the stormwater to easily infiltrate into the soil, and when full, use the basin inlet as the overflow, allowing the water to continue down the street.
Creating curb cuts is a stormwater management practice that has been approved for residents to implement in municipalities close to home, including Ventura, Panorama City, and Culver City, and recently in some areas of Santa Barbara County in public areas. They can be put into parking lots, and some lots in our county have implemented the practice, on private property. The Wake Center, REI, Five Points, and Whole Foods are four examples of parking lots that use curb cuts.
As a community we can join together to advocate for best practices for curb cuts in the public right of way, and for expanding the use of these rainwater harvesting features. Learn more in our webinar on Monday, February 8, 2021.