Stormwater runoff is the water that flows over hard surfaces, such as roads and roofs, during a rain event.
In developed areas, impervious surfaces such as pavement and roofs prevent precipitation from naturally soaking into the ground. Instead, water runs rapidly into storm drains, sewer systems and drainage ditches and can cause:
As stormwater runs along impervious surfaces, it collects a great deal of pollutants and litter. Unfortunately, this polluted runoff does not get treated after it flows into storm drains; it simply winds up in streams, rivers, and lakes.
Stream bank erosion
Increased turbidity (muddiness created by stirred up sediment) from erosion
Combined storm and sanitary sewer system overflows
Contaminated streams, rivers and coastal water
What is a Stormdrain System?
Photo credits to fairfaxcounty.gov
The storm water system is a network of structures, channels and underground pipes that carry stormwater to ponds, lakes, streams and rivers. The network consists of both public and private systems. It's an integral part of the stormwater management system in the city that is designed to control the quantity, quality, timing, and distribution of storm runoff.
Stormdrain systems are an integral part of the stormwater management in the county that is designed to control the quantity, quality, timing and distribution of storm runoff into local streams and waterways.
It is important to note that the stormwater management system is not part of the wastewater system, which carries water and waste from drains (sinks, bathtubs, showers, etc.) and toilets to a treatment plant to be treated and filtered. Stormwater does not flow to a treatment plant.