Too often the fact is ignored that the way we use the land directly affects the quality of lakes, streams and other water resources. Why? We know that direct sources of contamination can affect the water: A single business experiencing a chemical spill, a toxic dump, a gas station with leaking storage tank, a home with a failing septic system. These are all example of point source pollution, where the pollution affecting the water can be attributed to an identifiable source. However, the majority of pollution in the local waterways is attributed to a different factor.

When we experience rain events, water flows overland and into various wetlands, streams, lakes and constructed basins. This is known as stormwater. As the stormwater flows across the land, it carries with it what it finds on the ground. This could mean dirt or sediment, garbage, pet waste, lawn fertilizers and numerous other substances that pollute the water. Furthermore, the storm water is flowing from all over the land at once, making it difficult to pinpoint a specific source of the pollution. This type of pollution is known as non-point source pollution.

The amount and type of non-point source pollution can be directly linked to land use.

This is because as water that flows overland, it drains a specific area of land known as the watershed. A watershed is all the land area over which water drains into a certain stream system. In Genesee County , the water flows into smaller stream systems such as Swartz Creek or Gilkey Creek, and these smaller streams flow into the Flint River . The whole system is known as the Flint River Watershed. For more information on the Flint River Watershed, visit the Flint River Watershed Coalition at www.flintriver.org

[Image- watershed]

The land use within each watershed affects the quantity and quality of the storm water that flows over it. More residential and commercial land use means more impervious surfaces in forms such as rooftops, driveways, parking lots and roads over which storm water flows at a faster rate with more opportunity of picking up contaminants. Increase in the speed that stormwater travels over impervious surface can lead to increases in flooding. Construction sites and barren land can wash dirt or sediment into the waterways. Agriculture and residential lawns that have been treated with pesticides and herbicides are also sources of chemicals that can travel into the steams. How the land is being used affects the pollutants and the overall water quality of our water resources.

Genesee County is currently involved in initiating Phase II the National Pollutant Discharge System (NPDES) Storm Water Program to address the problem of non-point source pollution. For more information this program and learn more about how your activities can affect water quality, visit the Genesee Water Quality Consortium at www.KeepItClear.com.

For more information on the effects of land use on water quality and innovative land use strategies for Michigan’s NPDES Phase II Stormwater Management read the publication titled “Smart Growth for Clean Water” developed by the Michigan Environmental Council. http://www.mecprotects.org/SGAmichiganFINAL.pdf

You can also check out the Water Quality section of our Links page for more information.

Glossary of Definitions

Point-source pollution –
Water contamination that degrades water quality and originates from discrete locations such as discharge pipes, drainage ditches, wells, concentrated livestock operations, or floating craft. 

Non-point source pollution - Water contamination that originates from a broad area (such as leaching of agricultural chemicals from crop land) and enters the water resource diffusely over a large area.

Stormwater - Refers to rainwater as well as water from washing cars, overwatering lawns, and other sources. Stormwater washes down storm drains on the curbs of roads and leads directly into lakes, rivers, and streams untreated. Stormwater can carry pollution directly into our natural water resources.

Watershed - The land area drained by a river or stream, also known as a drainage basin.

Impervious surfaces - Incapable of being penetrated: a material impervious to water. Ie. Rooftops, cement, asphalt, etc.