Watershed project benefits Wapello County
The success of the Buckeye Creek Water Quality Improvement and Flood Reduction Project in Wapello County underscores just how beneficial environmentally responsible land practices can be in Iowa.
The REAP-funded watershed project reduces sediment flow into Buckeye Creek by more than 8,700 tons annually through more than nine miles of locally contracted, farmable, broad-based, tile-intake terraces and 17 grade stabilization structure “ponds” that permeate the 10,800-acre watershed.
REAP funding, through a Water Protection Fund grant from the Iowa Department of Agriculture and Land Stewardship, along with other state and federal funds, allowed 60 of the 79 landowners to participate. By investing their own funds to pay for at least 25 percent of the cost, they were able to reduce erosion of precious topsoil.
“Not only are you getting the environmental benefit, but it saves the county money on road costs,” said project coordinator Ryan Rasmussen. The area is no longer a concern for road flooding, grader ditches silting full, or deteriorating bridges due to high water.
The combination of terraces and grade stabilization structures has reduced area flooding dramatically.
Commissioner Neil McMullin recalled on April 17 when the Buckeye Creek watershed had to deal with eight inches of rain in just six hours.
“The new system of terraces and grade stabilization structures managed Mother Nature just as they were intended. Less than two feet of water made it to the emergency overflow area of the 23-acre structure that swelled to capacity,” McMullin said.
Buckeye Creek was named Iowa’s Watershed of the Year in 2011 by the Conservation Districts of Iowa, topping 41 other Iowa watersheds.
Tile-intake terraces were constructed by pushing soil from the farm field into earthen berms, helping to prevent water from channelizing as it moves down hillsides and cutting through the earth causing erosion and the loss of topsoil.
Longer field slopes increase water speed and soil erosion; however, terraces can intersect these slopes and shorten their length resulting in less soil being lost.
Terraces intercept the water allowing it to pool where larger soil particles drop out before the water exits underground through tile. Terrace benefits include reducing the flow of sediment into grade stabilization structures and other water bodies by 75 percent, substantially increasing their lifespan, and protecting water quality.
Four landowners were partners in the construction of Buckeye Creek’s primary grade stabilization structure which has a 23-acre pool and collects the drainage from 1,408 acres. Constructing earthen dams across ditches in low-lying areas create structures such as the one in this project that trap 90 percent of sediment caused by runoff.
All ground above these structures drains into them, where sediment settles at the bottom and stays. The structures also store additional water during heavy rainfall, letting un-silted water out at a controlled pace and thereby significantly reducing flood damage to roads and farmland in the area. The project’s 17 grade stabilization structures range in drainage areas from 10 to 1,400 acres.
In its 25 years, REAP has benefited every county in Iowa by supporting 14,535 projects. REAP has funded these projects with $264 million in state investments, leveraging two to three times the amount in private, local and federal dollars.
Collectively, the projects have improved the quality of life for all Iowans with better soil and water quality; added outdoor recreation opportunities; sustained economic development; enhanced knowledge and understanding of ecological and environmental assets, and preserved cultural and historic treasures.