At City Water, Light and Power, protecting Springfield’s drinking water starts long before water reaches our treatment plant. It begins throughout the 265-square-mile Lake Springfield watershed.
As part of our ongoing efforts to protect the community’s source water, CWLP is working with local agricultural partners to incorporate nature-based solutions into water quality protection. One of those solutions is the construction of treatment wetlands designed to remove excess nutrients and other pollutants from agricultural tile drainage water before they can reach Lake Springfield.
These efforts are an important part of protecting the source water that CWLP relies on to provide safe, reliable drinking water to approximately 165,000 customers.
Bringing Source Water Protection to the Field
On June 24, 2026, CWLP, with the Wetlands Initiative (TWI), Staley Farms, Illinois Natural Resource Conservation Service, and the Sangamon County Soil & Water Conservation District, hosted more than 100 people for a field day at a farm near Loami, giving attendees an opportunity to see the layout of two wetlands being constructed to remove nutrients, sediment, and pesticides from agricultural drainage water.
These projects are particularly important because agriculture makes up approximately 74% of Lake Springfield’s 265-square-mile drainage area, and an estimated 94% of cropland soils within the watershed are tile-drained.
Agricultural drainage systems help move excess water away from fields, but surface and subsurface runoff can also carry nutrients, pesticides, and sediment. Without practices in place to capture or reduce these pollutants, they can eventually make their way into streams and waterways that feed Lake Springfield.
Why Reducing Nutrients and Sediment Matters
Protecting water quality within the watershed can also help support the drinking water treatment process.
High levels of nutrients entering Lake Springfield can contribute to increased algae growth, which can create taste and odor concerns and make the treatment process more complex. Sediment and other particles entering the lake must also be removed during treatment and may require additional chemicals to handle the increased treatment plant loading
By addressing these pollutants closer to their source, conservation practices such as constructed wetlands can help improve water quality before it reaches the lake.
How Constructed Wetlands Work
Constructed treatment wetlands use natural biological and chemical processes to help remove pollutants from agricultural drainage water.
Water from tile drainage systems is directed into the wetland, where it moves through an environment designed to slow the flow and allow natural processes involving plants, soils and microorganisms to take place. These processes can reduce nutrient, sediment, and pesticide levels before the water continues downstream.
During the June field day, attendees participated in self-guided tours of the wetland area and learned how the wetlands are designed and constructed, how they remove nutrients, sediment, and pesticides, and how their effectiveness and efficiency can be measured.
Connecting Farmers and Landowners with Resources
The field day also brought together approximately 20 technical service providers who were available to answer questions about conservation practices that can help reduce nutrient, pesticide and sediment losses from cropland throughout the Lake Springfield watershed.
Attendees learned about both in-field and edge-of-field practices that can be incorporated into agricultural operations. Technical experts also provided information about funding opportunities and other resources available to farmers and landowners interested in implementing conservation practices within their agricultural tile drainage systems.
For CWLP, projects like these represent an important partnership between source water protection and agriculture. By working with farmers, landowners, conservation professionals and other partners throughout the watershed, we can address water quality challenges before they reach Lake Springfield.
Protecting Springfield’s drinking water is a shared effort, and conservation practices throughout the watershed are one more tool to help protect Lake Springfield and the community it serves for generations to come.
