Wildlife Benefit From Restored Kiowa Marsh Wetland Habitat
Project Improves Degraded Iowa Drinking Water Source.
EARLY, Iowa –-(AmmoLand.com)- Ducks Unlimited and the Iowa Department of Natural Resources recently restored a marsh that will help improve downstream drinking water for Des Moines area residents.
With funding from the Environmental Protection Agency’s 319 Program, Iowa DNR and DU restored a 45-acre wetland on the Kiowa Marsh Wildlife Management Area in Sac County. The marsh is located in the Indian Creek watershed, which flows directly into the North Raccoon River, a major water source for Iowa’s largest and most populated city.
“Wetlands serve as Mother Nature’s kidneys. They are able to absorb and filter excess sediments and nutrients from entering downstream watersheds,” said Eric Lindstrom, DU regional biologist for Iowa. “By restoring Kiowa Marsh, not only are we providing critical wildlife habitat, but we are also helping to reduce the amount of pollution that enters downstream waters.”
Iowa’s Raccoon River fails to meet state drinking water standards due to high nitrate, phosphorus and E. coli levels. In fact, the river has the highest average nitrate concentration of any of the 42 largest tributaries in the entire Mississippi River Basin.
“The Raccoon River provides critical drinking water for more than 450,000 Iowans or roughly one-sixth of the state’s entire population,” said Chris Jones, Des Moines Water Works laboratory supervisor. DMWW, a public utility, treats water directly from the Raccoon River and its aquifer near downtown Des Moines and helps purify it for human and industrial use.
“On average, we will operate our nitrate removal system approximately 40-50 days per year, but the Raccoon River facility has operated as many as 106 days in a single year,” Jones said.
Once a drained shallow wetland, Kiowa Marsh is now part of a 1,200-acre public WMA owned and managed by the Iowa DNR and U.S. Fish and Wildlife Service. To restore natural wetland functions back to the marsh, DU engineers designed and constructed an earthen levee and installed a box culvert structure to periodically manipulate water levels. This structure was also designed with a fish barrier to deter non-native fish, like common carp, from entering and destroying the ecological balance of the wetland.
Two small excavated wetlands were also created upstream to filter runoff going into two drainage ditches that empty into the marsh. Lindstrom says these man-made drainages have for years served as a superhighway for soil particles and nutrient runoff that enter Kiowa Marsh and eventually flow into downstream creeks, rivers and reservoirs.
The total cost of these restoration efforts was nearly $300,000 and will pay back significant dividends to Des Moines area water users. Using high-tech computer mapping and modeling software, the Iowa DNR is able to evaluate downstream water quality benefits of these wetland restoration efforts. Their modeling results predict that the restored wetlands will reduce sediment delivery to Indian Creek by approximately 652 tons/year and will help trap and recycle an estimated 847 tons of phosphorus per year.
“Kiowa Marsh represents a win-win project with dual wildlife and water quality benefits for Iowans that use the Raccoon River drainage system, said Mike Mahn, Iowa DNR Area Wildlife Manager. “By itself, it may seem somewhat inconsequential, but as one project in a suite of other positive land use changes that can occur throughout the watershed, we will begin to see substantial improvements in downstream water quality.”
Ducks Unlimited is the world’s largest non-profit organization dedicated to conserving North America’s continually disappearing waterfowl habitats. Established in 1937, Ducks Unlimited has conserved more than 13 million acres thanks to contributions from more than a million supporters across the continent. Guided by science and dedicated to program efficiency, DU works toward the vision of wetlands sufficient to fill the skies with waterfowl today, tomorrow and forever.