What is a watershed?
A watershed is simply an area of land that drains to a central body of water. The rainwater that falls within the watershed is funneled to a body of water based on the shape and elevation of the land.
It doesn’t matter where you live, everyone lives in a watershed. Each watershed’s residents, businesses and industries are responsible for the health of the watershed’s water resources. The community must consider its actions and resulting impacts on water resources because “we all live downstream.”
Here’s our watershed, the Lower DuPage River watershed:
The Lower DuPage River watershed covers 168 square miles and encompasses portions of 13 municipalities. The majority of the watershed is within Will County, although portions of the watershed are included in DuPage, Grundy, and Kendall Counties. There are 166 stream miles within the watershed.
Healthy Watershed = Healthy Rivers = Clean Water
What we do on the land affects the health of our waterways. This is primarily due to stormwater runoff, rainwater that hits the ground and instead of seeping into the ground, flows over it–bringing pesticides, fertilizer, road salt, and whatever else is on the ground into our waterways. The fertilizer we put on our lawns in the summer and the salt we put on the roads in the winter can all end up in our local streams and rivers.
Land Use in Our Watershed
Different kind of land use affects what stormwater runoff brings into our rivers. For instance, pesticides and fertilizers will be a bigger concern for waterways near agriculture. Open spaces can protect waterways by allowing rainfall to sink into the ground where it lands, instead of running off. Below is a chart of land use in the Lower DuPage River watershed:
| Land Use | Acres | Percent in Watershed |
| Agricultural Land | 28,786 | 26.72% |
| Commercial and Services | 4,338 | 4.03% |
| Industrial, Warehouse, and Wholesale Trade | 5,596 | 5.19% |
| Institutional | 2,916 | 2.71% |
| Open Space | 8,771 | 8.14% |
| Residential | 34,951 | 32.44% |
| Transportation, Communication, and Utilities | 2,848 | 2.64% |
| Vacant, Wetlands, or Under Construction | 15,871 | 14.73% |
| Water | 3,652 | 3.39% |
2016 Stream Impairments and Specific Assessment Information – Illinois EPA assesses streams to determine whether they are meeting the designated uses, and to identify the causes and sources of the impairments. The table below shows information about streams in the Lower DuPage River Watershed that Illinois EPA assesses.
2016 Integrated Report – Appendix B-2: Specific Assessment Information for Streams
| Name | AUID | Designated Use | Causes | Sources | ||
| Du Page River | IL_GB-01 | Not Supporting: Aquatic Life, Fish Consumption | Other flow regime alterations; Phosphorus (Total); Changes in stream depth and velocity patterns; Mercury; Polychlorinated biphenyls | Dam or impoundment; Municipal point source discharges; Channelization; Source unknown | ||
| Fully Supporting: Aesthetic Quality | ||||||
| Du Page River | IL_GB-11 | Not Supporting: Aquatic Life, Fish Consumption, Primary Contact | Alteration in stream-side or littoral vegetative covers; Arsenic; Chloride; Methoxychlor; Other flow regime alterations; Polychlorinated biphenyls; Sedimentation/Siltation; Phosphorus (Total); Aquatic plants (Macrophytes); Mercury; Fecal coliform | Loss of riparian habitat; Contaminated sediments; Municipal point source discharges; Urban runoff/Storm sewers; Impacts from hydrostructure flow regulation/modification; Site clearance (land development or redevelopment); Upstream impoundments (e.g., Pl-566 NRCS structures); Dam or impoundment; Atmospheric deposition – toxics; Source unknown | ||
| Fully Supporting: Aesthetic Quality | ||||||
| Du Page River | IL_GB-16 | Not Supporting: Aquatic Life, Fish Consumption, Primary Contact | Other flow regime alterations; Oxygen, Dissolved; Phosphorus (Total); Mercury; Polychlorinated biphenyls; Fecal coliform | Impacts from hydrostructure flow regulation/modification; Municipal point source discharges; Site clearance (land development or redevelopment); Urban runoff/Storm sewers; Atmospheric deposition – toxics; Source unknown | ||
| Fully Supporting: Aesthetic Quality | ||||||
| Illinois & Michigan Canal | IL_GBA | Not Supporting: Fish Consumption | Mercury | Atmospheric deposition – toxics; Source unknown | ||
| Lily Cache Creek | IL_GBE-01 | N/A | N/A | |||
| Fully Supporting: Aquatic Life, Aesthetic Quality | ||||||
| Lily Cache Creek | IL_GBE-02 | Not Supporting: Aquatic Life | Cause Unknown | N/A | ||
| Mink Creek | IL_GBEA | N/A | N/A | |||
| Rock Run | IL_GBAA-01 | Not Supporting: Aquatic Life | Cause Unknown | N/A | ||
| Spring Brook | IL_GBKA | Not Supporting: Aquatic Life, Primary Contact | Alteration in stream-side or littoral vegetative covers; Chloride; Oxygen, Dissolved; Phsophorus (Total); Fecal coliform | Channelization; Agriculture; Urban runoff/Storm sewers; Source unknown | ||
| Spring Brook | IL_GBKA-01 | Not Supporting: Aquatic Life, Primary Contact | Alteration in stream-side or littoral vegetative covers; Phosphorus (Total); Loss of instream cover; Fecal coliform | Channelization; Municipal point source discharges; Source unknown |
