Impervious Surface
An impervious surface cannot absorb water, meaning water flows off the material. Some examples are concrete sidewalks, roadways, and rooftops.
The more impervious surface there is in a watershed, the more runoff of stormwater there will be during a rain event because the rain is not soaking into the ground. This means that any pollutants that are present on our roadways will be carried away with stormwater to our rivers and Lake Erie, untreated.