ALLEMAN, Iowa (June 17, 2021) — Iowa Secretary of Agriculture Mike Naig joined state and federal government agencies, Polk County officials, conservation contractors and local landowners to kick off the Central Iowa water quality infrastructure project. The unique water quality project creates a new framework to streamline and scale up the adoption of saturated buffers and denitrifying bioreactors in Polk and Dallas Counties by simplifying the financing and construction processes for landowners.
At Kurt Lehman’s farm near Alleman, Naig thanked the project partners who helped design, build, fund and recruit landowners for the project. He also thanked the participating landowners for being conservation leaders.
“This project creates a model that allows us to speed up the pace at which we’re adding more soil health and water quality practices. These practices directly benefit the residents of Polk and Dallas Counties and our neighbors downstream,” said Secretary Naig. “Other communities are watching what’s happening here. We know that success here will lead to successful projects in other priority watersheds around the state.”
Johnathon Swanson, watershed management authority coordinator with Polk County Public Works, calls the streamlining of financing and construction a “fiscal agent” model that gives contractors access to sites through a temporary construction easement. “The easement allows contractors to access private lands and ensure the landowners and funding agencies’ expectations are met,” he said. “The easement payment to the landowner incentivized participation and helped generate interest in the project.”
Construction contractors broke ground on Phase 1 of the project last week, which is scheduled to take about a year to complete. Crews are installing 40 saturated buffers and 11 bioreactors on the edge of farm fields to help protect water quality and support recreational opportunities in the Des Moines and Raccoon Rivers.
Phase 2 of the project is expected to include another 150 sites and additional counties and partners moving forward.
Conservation practices at work
Saturated buffers have underground, lateral pipes that divert tile-drained water through a vegetated buffer. The vegetative buffer removes sediment, phosphorous and pesticide runoff, while creating wildlife habitat.
Bioreactors are excavated pits filled with woodchips that filter tile drainage water. As water from the tile line passes through the woodchips, denitrifying bacteria converts nitrates in the tile water into di-nitrogen gas.
Swanson said sites were selected using mapping tools that consider topography, stream bank height, and soil types to identify project sites that will have the greatest impact on water quality.
From there, organizers reached out to farmers and landowners living along Fourmile, Mud, Camp, Spring and Walnut Creeks to encourage them to get involved.
“Identifying multiple sites in one county made it easier and more attractive for contractors to bid on the project,” said Swanson, “which reduced the overall project costs.”
The Central Iowa Water Quality Infrastructure Project formed through strong collaboration between:
Polk Soil and Water Conservation District
Iowa Department of Agriculture and Land Stewardship