GSI/Natural drainage techniques
GSI/Natural drainage systems manage stormwater by allowing it to soak into the ground or evaporate into the air. There are a number of ways to do this on streets and on private property:
- Roadside rain gardens are low areas that absorb large amounts of stormwater from streets and sidewalks. They are planted with deep-rooted plants and grasses. These gardens temporarily hold and clean stormwater. The water soaks into the ground, evaporates, or slowly drains into the sewer system after a storm has passed. They are often located in parking lots, median strips, or planter strips in residential neighborhoods.
- Permeable pavement is hard but porous material that allows stormwater to soak through into the ground below. Bicycles and cars can travel on permeable pavement.
- Cisterns and rain barrels store rain to reduce the amount of water entering the sewer system. In the summer, this water can be used for watering.
- Green roofs are made of shallow layers of soil, low-growing vegetation, subsurface drainage, and a waterproof membrane. They look natural while slowing stormwater.
- Tree boxes are street trees designed to store and filter stormwater. They work well in small spaces and provide multiple benefits including reducing air pollution and absorbing carbon dioxide.
Landscape choices people and businesses can make
People can use these GSI/natural drainage techniques in their businesses and homes too. Some property owners can get a RainWise rebate that will pay for these features.
Learn more about what you can do.