Sealed surfaces such as roads, buildings and carparks prevent rainwater from filtering into the ground. Instead, rainwater runs off into the street and enters stormwater drains, carrying with it any pollutants, such as oil, fuel and rubbish which directly flows unfiltered into nearby streams and rivers. Washing cars on sealed surfaces washes pollutants directly into stormwater drains and into waterways.
We can reduce the sealed surfaces around us by using materials that will allow water to filter naturally such as gravel, bark, shells or pavers with gaps between them, or by maintaining grassy or treed areas. This is becoming even more important as infill housing creates hard surfaces where lawns and gardens once existed. We can also make informed choices about what chemicals we use and dispose of close to and in stormwater drains or on grassed areas such as lawns and to never drop litter outside.
Acknowledgement: Boffa Miskell