Stormwater may seem like a non-issue to many people. Some may wonder why we should be concerned about stormwater at all. After all, it seems like it is just something that takes care of itself: as long as there are gravity and air, stormwater will continue to run downhill and eventually evaporate. However, stormwater can be a major source of pollution. Consider for a moment:

What happens to the rain after it hits the roof of your house? It goes into the gutters. Okay, but then where does it go? It flows through your downspout, runs across your driveway, and through your yard. Okay, but then where does it go?

Well, some of it seeps into your yard and some of it runs into your street, along the curb and gutter, and into the storm sewer. True. Stormwater is created by precipitation and runoff from land, pavements, building rooftops, and other surfaces. Some of the water does seep into the ground and some of it enters the storm sewer system. The storm sewer system is a way for the water to get to ponds, other storm sewer pipes, and also into our local bodies of water, including the Mississippi River.


However, on the way to the water bodies, stormwater runoff accumulates pollutants such as oil and grease, pesticides, sediment, litter, chemicals, nutrients, metals, and bacteria as it travels across land. Heavy precipitation or snow melt also can cause sewer overflows, which may lead to contamination of other water sources. Pollution prevention is a major reason why we want to manage our stormwater.

The U.S. Environmental Protection Agency controls storm water and sewer overflow discharges through its National Pollutant Discharge Elimination System (NPDES). NPDES created guidelines for municipalities and other agencies for minimizing or reducing stormwater pollution; the permit is administered by individual states. The Minnesota Pollution Control Agency (MPCA) issued permits to the City of Cottage Grove and other units of government that allows them to discharge stormwater to waters of the state, after meeting certain requirements.

Non Degradation

Pursuant with the City of Cottage Grove Municipal Separate Storm Sewer System (MS4) General Permit, the City of Cottage Grove has completed its Nondegradation Review. The City's Nondegradation Review includes a nondegradation analysis (Loading Assessment) and documents how the City intends to address nondegradation rules (Nondegradation Report and Proposed Storm Water Pollution Prevention Plan (SWPPP) Modifications), as outlined in the MS4 General Permit. A copy of the document is available at the front desk of the City of Cottage Grove Public Works Facility.

The following are some links of other organizations that address Stormwater Pollution and its prevention:

  1. Useful Links
  2. Definitions of Terms