DES MOINES, Iowa – The last of Iowa’s remaining agricultural drainage wells were recently closed. It has taken more than 25 years to close the 300 drainage structures, with the goal of improving the state’s water quality.

“The closure of Iowa’s ag drainage wells represents a significant milestone in our efforts to improve Iowa’s water quality,” said Iowa Agriculture Secretary Mike Naig. “Improving water quality takes time, commitment, and dedicated funding, but this demonstrates that when there is a strategy and funding in place, this impactful work can get done successfully.”

This innovative project followed six years of planning or construction around the closures, resulting in the closing of the final seven agricultural drainage wells on Nov. 19, with the drainage re-directed into a water quality wetland spanning 137 acres.

On Nov. 19, Naig visited the final Humboldt County agricultural drainage well closure project near Gilmore City, which involved eight different properties with 13 different landowners that all had to agree for this project to move forward.

Michael Anderson, Iowa Department of Natural Resources senior environmental engineer, water supply engineering section, told Farm World, “The landowners were very cooperative in this process. This represented one of the more successful joint agency programs we have seen in Iowa.”

According to the Iowa Department of Agriculture and Land Stewardship, agricultural drainage wells were drilled into fractured limestone and connected to farm field drainage tiles (a system of pipes that removes excess water from the soil of farm fields).

Most of the state’s agricultural drainage wells were constructed by private landowners and farmers in the mid-1900s to discharge tile drainage into underground aquifers (a body of permeable rock which can contain or transmit groundwater), producing a direct conduit for storm water to enter groundwater, while the landowner or neighbors also used the same aquifers for their drinking water.

In 1987, the Iowa Legislature enacted the Iowa Groundwater Protection Act, which required that agricultural drainage wells be studied; the Iowa Department of Agriculture and Land Stewardship developed an inventory, and it was determined that the state had about 300 agricultural drainage wells.

“Inventory on the wells began in 1988, and the initial permits were issued in 1998,” Anderson said. “A total of 306 agricultural drainage well permits were eventually issued.”

In 1997, the Iowa Department of Agriculture and Land Stewardship received its first appropriation directed toward closing agricultural drainage wells, which was used to close 37 agricultural drainage wells in Pocahontas County.

As funding became available over the years, the Iowa Department of Agriculture and Land Stewardship continually worked to close as many as possible per year. In total, the department has received approximately $25 million in state appropriations from the Iowa Legislature, with the last appropriation in Fiscal Year 2021. These public funds have been paired with nearly $12 million in landowner and partner contributions.

The Iowa Department of Agriculture and Land Stewardship added that approximately one-third of the wells were closed either by landowners or with funding from the Watershed Improvement Review Board, or were determined to be non-functioning. This left 195 agricultural drainage wells to be closed, with 178 of them located in Humboldt, Pocahontas or Wright counties.

When asked why the majority of the wells were located in Humboldt, Pocahontas, and Wright counties, Anderson said, “My speculation is that they were drilled that way because of the natural topography (the arrangement of the natural and artificial physical features of an area) of that area of Iowa (the flatter Des Moines Lobe geological surface).”

Naig, said, “I want to thank everyone who has played a role throughout this ongoing effort: farmers, landowners, engineers, conservation professionals, legislators, and many other engaged public and private partners, including the Soil and Water Conservation Districts and County Boards of Supervisors.

“I’m pleased that we can now close this chapter even as we continue to push forward with our many other water quality and conservation initiatives across the state,” he added.