Stormwater 101

Explaining Stormwater

Stormwater is the runoff from rainfall and snow melt. In undeveloped areas such as grasslands and forests, much of the rainfall and snow melt soaks into the ground. Vegetation helps to slow runoff.

In urban areas, buildings and other impervious surfaces such as parking lots do not allow water to soak into the ground resulting in both increased amounts of runoff and faster flow. Along the way, runoff can pick up pollutants such as fertilizers and pesticides from yards, motor oil from leaking cars, pet waste, and dirt from construction sites. This can cause downstream waterways to become polluted.

Stormwater System & Sewer System

The city's stormwater drainage system is separate from the sanitary sewer system (indoor sinks, toilets, etc). The sanitary sewer system drains to the city's 2 wastewater treatment plants while the stormwater system drains to area streams, rivers, and lakes.

Parts of the Stormwater Drainage System

A variety of structures and land forms, both natural and artificial, are considered to be part of the stormwater drainage system, these include:
  • box culverts
  • detention basins
  • ditches
  • earth berms
  • grass and concrete channels
  • pipes
  • sinkholes
  • storm drains
  • streams
  • street gutters
All of these are part of the course which stormwater runoff travels on its way out of urban areas and into nearby streams, rivers, and lakes.

Importance of Stormwater Management

Good stormwater management benefits citizens and the community by reducing potential flood hazards and protecting area waterways. This includes stormwater capital improvement projects, requirements for development, and maintaining compliance with the City’s MS4 permit for water quality protection.