Streams are an integral part of our ecosystem. They provide a source of drinking water and an important habitat for aquatic life, but they also drain our agricultural lands to allow better crop production. In Episode 65 of the Illinois Nutrient Loss Reduction Podcast, we take a deeper look at the importance of stable streambanks in keeping waterways clean and protecting farmlands with Dr. Andrew Margenot from University of Illinois, Trevor Toland, a landowner from western Illinois, and Jeff Boeckler of NorthWater Consulting.
Importance of stable streams
Andrew Margenot is an Associate Professor of Crop Science at University of Illinois. He studies soils and how human activities can improve or degrade the foundation of all cropping systems. His laboratory is currently conducting research to monitor and quantify soil loss from stream banks.
Margenot explains that stream banks move and meander over time, which is a natural process but leads to streambank erosion. Human actions can accelerate erosion. When the banks erode, that soil enters the waterway. The sediments contain nutrients, phosphorus (P) in particular. Excessive streambank erosion leads to excessive amounts of P entering the waterways, which can cause eutrophication and hypoxia downstream.
The link between phosphorus and streambanks
Most of Illinois’ soil comes from loess, which is a fine, silty powder from glaciers and has high fertility, especially phosphorus. Soil loss from streambanks comes from deeper in the soil profile or column rather than the top few inches like what is lost through soil erosion of a farm field. The natural P in the streambank sediment is magnitudes higher than what is applied as fertilizer.
Phosphorus and the NLRS
The Nutrient Loss Reduction Strategy (NLRS) currently focuses on nutrient loss coming from point sources, urban stormwater, and agricultural non-point sources. Currently, streambank erosion is being counted as agricultural non-point sources, when it is not. Margenot emphasizes that non-point source isn’t synonymous with agriculture and research coming out of his lab indicates that streambanks may contribute around 30% of the P leaving the state. Mitigating streambank erosion will help move us closer to reaching the goals outlined in the NLRS.
When to consider streambank stabilization
At North Water Consulting, an environmental and geosciences consulting firm, Jeff Boeckler works to improve water resources in Illinois, across the United States, and Central America. Boeckler’s advice for landowners is to be vigilant when it comes to their streambanks. Often it is out of sight, out of mind. Often landowners don’t pursue streambank stabilization until it causes problems with homes or property, such as significant losses of land due to bank cutting. From Boeckler’s perspective, as a person who works with public water supplies, it is important to keep as much of the eroded sediment out of the reservoir as possible. He says reaching out to a local Soil and Water Conservation District or private engineering firm is the best way to get started.
Landowner options
If a landowner has excessive streambank erosion on their property, Margenot says there are two courses of action they can take. One would be to armor the banks with materials such as rock, concrete, vegetation, or even dead trees. Another option would be to manage the water with wetlands before it enters the stream. For both practices, Margenot emphasizes the most important part is to slow down the water. Boeckler said that in his limited experience, he leans toward utilizing rock stabilization because it lasts longer.
Stabilization in action
Trevor Toland, a farmer in Macomb Township, raises beef cattle on permanent pasture and manages some cropland and hardwood forest. The LaMoine River, the sixth largest tributary of the Illinois River, meanders through his property. After heavy rains, Toland noticed flooding and parts of the river bypassing its curves and creating new channels, so in 2007 he had a stabilization project installed on his land.
The stabilization project consisted of three 250-foot sections of stream that were armored with rock. While it was an extensive project that required collaboration between engineers, the US Army Corps of Engineers, and other contractors, Toland got 75% of the project funded through cost share.
Overall, Toland has been extremely satisfied with the results of the project. He says, “I just never would have believed how significant of a change it has made.” He encourages other landowners that while the process to get stabilization on his land was slow, the improvements he has seen since then have been worth it.
Funding opportunities
Boeckler explains that improving streambanks on your land can be challenging. It is a costly endeavor, especially for private landowners. Fortunately, there are limited grant opportunities through the Illinois Environmental Protection Agency, Illinois Department of Natural Resources, and other governmental agencies.
To listen to the full interviews, check out the NLRS Podcast Episode 65.
About the authors
Rachel Curry is an Agriculture and Agribusiness Educator focusing on agriculture and watershed education and is a part of the Illinois Extension's Nutrient Loss Reduction Strategy implementation team. Rachel earned a B.A. in Environmental Studies from Knox College and an M.S. in Environmental Science and Soil Science from Iowa State University with an emphasis on soil fertility. Her work focuses on education and outreach regarding the Illinois Nutrient Loss Reduction Strategy and agricultural conservation practices to reduce nutrient loss and improve water quality and soil health throughout Illinois.
Nicole Haverback is a Watershed Outreach Associate and a part of the Illinois Extension's Nutrient Loss Reduction Strategy implementation team. Nicole earned a B.S. in Agriculture and Rural Policy Studies from Iowa State University. She coordinates watershed and planning activities to reduce nutrient losses from priority watersheds, provides expertise on best management practices for nutrient loss, and conducts outreach on agricultural conservation practices outlined in the Illinois Nutrient Loss Reduction Strategy.
Emma Eldridge is a Watershed Outreach Associate and part of the Illinois Extension Nutrient Loss Reduction Strategy implementation team, serving the Little Wabash and Embarras watersheds, designated as phosphorus-priority watersheds in the NLRS. Emma earned a B.A. in Environmental Studies from McKendree University and an M.S. in Forestry from Southern Illinois University Carbondale. She coordinates watershed and planning activities to reduce phosphorus losses from identified priority watersheds, provides expertise on best management practices, and conducts outreach on agricultural conservation practices outlined in the Illinois Nutrient Loss Reduction Strategy.
About the blog
At Illinois Extension, we’re working to improve water quality at home and downstream. Every month, our Watershed Outreach Associates will bring you stories highlighting agricultural conservation practices, current research projects and results, and from the field farmer interviews. The Nutrient Loss Reduction blog covers conservation practices recommended by the Illinois Nutrient Loss Reduction Strategy, timely updates, farm safety, and new decision tools to help farmers and producers reduce the nutrients leaving their field. Want to get notified when new blog posts are available? Subscribe at go.illinois.edu/SubscribeINLRS.