Stormwater ponds are designed to be catch basins for developed areas. Stormwater ponds collect rainwater (stormwater runoff) that runs over impermeable surfaces such as parking lots, roads, and buildings.
Daily activities cause pollutants such as dirt, oil, fertilizers, and litter to collect on impermeable surfaces and get washed into local waterways. Pollutants can be harmful to habitats and wildlife downstream if they are allowed into the ecosystem. With stormwater management ponds in place, rainwater can collect, and sediment and pollutants can settle out before the water is released back into the watershed.
When it comes to stormwater ponds, Harford Streams goes about them in two ways:
1. Reconstructing existing stormwater ponds
2. Constructing new stormwater ponds
Reconstructing existing stormwater ponds: reconstruction of a stormwater pond occurs when the pond is already in place, part of the Best Management Practice, but is not functioning as it is meant to because of structural problems. Concrete pipes may show cracking and joints may fail, gate valves can become rusted and corroded, and sediment can accumulate.
Reconstruction can also include converting an existing dry pond to a wet pond. A dry pond is designed to hold water for a short period of time before allowing the water to discharge to a nearby stream. Dry ponds control peak flows of runoff, help improve water quality and lessen the effects of erosion. Wet ponds frequently have smaller pools, plants and a wetland area.
Stream reconstruction of an existing stormwater pond at Ring Factory Elementary School (2014-2018)