Stormwater is precipitation (from either a rain event or snow melt) that falls on impervious surfaces, like streets or the roof of our house, and flows over them to storm drains that eventually lead to lakes and rivers.
Picture: 9 Mile Creek Watershed District
Water flowing over hard surfaces cannot infiltrate, therefore it moves faster causing more damage and picks up pollutants along the way. Common pollutants include yard waste, motor oil, leaf litter, trash, and salt used during the winter. Runoff containing these pollutants and flowing into storm drains is NOT treated before entering our local water bodies. Lake Winona, Garvin Brook, and the Whitewater River are a few of our locally impaired waters.
Keeping water on the land and intercepting it before it hits impervious surfaces helps to infiltrate it back to the earth. Pollutants can be absorbed and filtered out by plants and groundwater can be recharged.