Iowans have similar interests in cleaning up and protecting water resources, river clean-up volunteers in Floyd County learned last week.
While the volunteers canoed and kayaked their way down the Cedar River collecting debris from the river, a wetland was being constructed nearby, which will help de-nitrify water flowing through farms and streams and eventually into the Gulf of Mexico.
More than 470 volunteers traveled their way down the river as part of the Iowa Department of Natural Resources’ (DNR) Project AWARE (A Watershed Awareness River Expedition).
The wetland project being constructed on Dean and Linda Tjaden’s previous crop ground is being constructed through the Conservation Reserve Enhancement Program (CREP).
It’s a joint effort of the Iowa Department of Agriculture and Land Stewardship (IDALS) and the U.S. Department of Agriculture (USDA), in cooperation with local soil and water conservation districts, which provide incentives to landowners who voluntarily establish wetlands for water quality improvement in heavily tiled regions in Iowa.
After exiting the river for the day, busloads of volunteers stopped at the construction site to learn about the CREP wetland project.
The 6.2-acre wetland pool, which was once used to grow corn, soybeans and hay, will remove the equivalent of 327 row-cropped acres of nitrates if the wetland is proven to be 40 percent efficient. At 70 percent efficiency, it would be equivalent to removing nitrates from 572 acres, according to Brandon Dittman, CREP field coordinator for the water resources bureau at IDALS.
"It’s a very, very, very miniscule footprint for a huge amount of benefit," Dittman said.
However, CREP watershed projects aren’t open to all farmers. There is a set of criteria in which IDALS uses to determine the right site for the project.
Finding the sweet spot
There are requirements regarding the amount of water feeding the watershed, the depth of the wetland area, a buffer-to-wetland ratio and other considerations.
"Research has determined that there’s a sweet spot. You want to make your wetland pool a certain size based on the amount of water that drains to the wetland pool. You want it to be mostly shallow water — less than 3 feet deep where those naturally occurring anaerobic microbes occur in the soil. That’s where we get that denitrification from those anerobic microbes," Dittman said.
The Tjadens, Floyd County Farm Bureau members, said they were happy to receive the letter indicating their land was right for a CREP wetland.
"I know a lot of people that would like to do something like this, but they’re not fortunate enough to have the ground that’s right for the project. So we are very honored to be able to have this," said Linda Tjaden, a Floyd County supervisor.
The stop at the CREP wetland was an opportunity for Dittman and the Tjadens to explain the project and learn about the similarities they shared with the AWARE volunteers.
"We’re working to clean the water just as they (volunteers) are," Dean Tjaden said. "This is Hyers Creek. This goes into the Cedar River, which goes into the Mississippi River and then to the Gulf. In a small way, we’re attempting to clean the water to eliminate that hypoxia zone in the Gulf of Mexico."