North Thompson River Water Quality Project

The North Thompson River Watershed is an 111,600 acre watershed located in southeast Adair County, southwest Madison County, and northeast Union County in central Iowa. This area is 60 to 70 percent intensively row cropped (corn and soybeans) and has potential soil erosion rates of 11 to 15 tons/acre/year. The lower reaches of the Thompson River in Union County and West Branch Creek in Madison County frequently flood.

The overall goal of this project is to improve water quality in the North Thompson River and its watershed. We are working towards this goal by reducing sediment through the use of Best Management Practices (BMPs).

We are currently focusing our efforts on priority areas in 18 of the 32 subwatersheds, totaling 65,090 acres. Only tracts located in the identified priority subwatersheds are eligible for funding through the watershed project at this time, but we are planning on opening more subwatersheds for funding later in 2017.

Best Management Practices and Financial Assistance

75% cost share* assistance is available through the Watershed Protection Fund (WSPF) for conservation practices in the priority areas that qualify, including:

  • Grade stabilization structures
  • Water and Sediment Control Structures
  • Terraces
  • Grassed Waterways

*Percentage based on your county’s average rates, not the contractor’s prices.

There is also cost share available for cover crops, and there are incentives for filter and buffer strips through the Buffer Initiative Program (one-time payment of $200/acre).

In addition to WSPF, there are several other sources of funding for conservation practices, including: the Iowa Financial Incentives Program (IFIP), Resource Enhancement And Protection (REAP), Iowa Buffer Initiative, Conservation Reserve Program (CRP), Environmental Quality Incentives Program (EQIP), and the Local Water Protection Program (LWPP) for low interest loans.

This project has already made a positive impact on the environment!

As of 2016, $1,245,387.00 of WSPF funding has been expended over the life of the water quality project to trap 24,790 tons of sediment per year resulting in a cost ratio of $50.23 per ton.

Grade Stabilization Structures such as this one improve water quality by preventing erosion from gullies and trapping sediment.

The North Thompson River Water Quality Project has been made possible by funding provided by the Iowa Department of Agriculture and Land Stewardship–Division of Soil Conservation and Water Quality (IDALS-DSCWQ), the Water Protection Fund (WPF), and the Watershed Protection Fund (WSPF).

1st Priority = Purple
2nd Priority = Pink
3rd Priority = Turquoise

More Information:

Map of Potential Sheet & Rill Erosion in the Watershed
Map of North Thompson River Watershed
Map of Priority Subwatersheds in Madison County


December 2019 Newsletter

To learn more, contact:

Tonna Damewood, Project Coordinator

Union County SWCD (Creston)
641-782-4218 ext. 3

Adair County SWCD (Greenfield)
641-343-7033 ext. 3

Madison County SWCD (Winterset)
515-462-2961 ext. 3