Restoring Indiana's Floodplains
Do Hoosiers still dream about the fair moonlight on the Wabash River? Do those dreams also include thousands of acres of new floodplain forest? Probably not, but they should. A new study is showing that restored floodplain forests are a remarkable investment for improving water quality.
The study, developed by a team of freshwater ecologists at the University of Notre Dame, is showing that the floodplain forests are helping to keep excess nutrients that leave Indiana rural and urban areas out of the Gulf of Mexico. It highlights the pivotal role that the Wabash River can play in reducing the infamous “dead zone” in the Gulf.
“Indiana has been identified as one of the states contributing the most excess nutrients to the Gulf of Mexico, and these nutrients come from a variety of sources, both urban and rural” says Mary McConnell, state director for The Nature Conservancy in Indiana. “But our work with the Natural Resources Conservation Service (NRCS), Soil and Water Conservation Districts, farmers and landowners along the Wabash River is a big part of the solution, and this study proves it.”
The study was underwritten by The Nature Conservancy and funded by the Walton Family Foundation, as part of their support for the Conservancy’s work on the Wabash River.
Although the Wabash River represents just about 3% of the total Mississippi River Basin area, it delivers a whopping 11% of the nitrogen that flows into the Gulf. Nitrogen pollution in the Gulf has created an oxygen-free dead zone, now the size of the state of Connecticut. The dead zone disrupts the valuable fishery of the Gulf, threatening commercial and recreational fisheries valued at almost $1 billion.
“The report shows that for a comparatively small investment, Indiana can have a big impact on water quality both in the state and down river,” says Professor Jennifer Tank at the University of Notre Dame. “Taxpayers, landowners, conservationists and resource managers should all be thrilled to see so much bang for the buck.”
The restored floodplain forests along the Wabash River are generating a remarkable return on investment for water quality, making Indiana one of the best places to invest in restoration efforts. The Notre Dame findings estimate that nearly 600 pounds of nitrogen are cleaned out of the river annually by every acre of floodplain that is restored.
“The Natural Resources Conservation Service (NRCS) has been restoring floodplains along the Wabash River since 1973,” said Jane Hardisty, State Conservationist at Indiana USDA-NRCS. “Nearly 30,000 acres of previously farmed floodplain has been restored to natural habitats and forest, and we’re seeing a great impact.”
In addition, the restored floodplain forests create new habitats for Indiana’s wildlife along the river. More importantly, these restored floodplains are cleaning the river during floods. As floodwaters enter the restored floodplain habitats, the currents slow down, allowing pollutants to settle out and be filtered and processed by plants and animals. The restored habitats, which represent just 0.3% of the lands drained by the Wabash, could be removing 7% of the nitrogen in the river.
Just as importantly, the floodplains also remove phosphorus (another nutrient that pollutes water) and sediment from the river as well. While these pollutants don’t threaten the Gulf as much as nitrogen, they still contribute to impaired water quality in the Wabash and the Ohio River. The restored acres could reduce sediments and phosphorus by 3% annually.
According to the study, Indiana has the potential to reduce the flow of pollutants to the Gulf even further by restoring even more floodplain.
“By restoring an additional 55,000 acres of floodplain along the Wabash, which is less than 1% of the river’s entire watershed, we could reduce the amount of nitrogen leaving the state by 20%,” said McConnell. “This is a reduction of 1,100 truckloads of nitrogen delivered to the Gulf of Mexico each year!”
Cities, landowners and farmers have voluntarily taken many positive actions throughout the entire watershed area to address water quality issues. Floodplain and wetland restoration, nutrient management and cover crops are helping to improve water quality.
Hardisty urges landowners along the Wabash River to take advantage of the financial incentives being offered by the NRCS to restore or improve habitat, conserve wetlands, control flooding and strengthen rural economies. Farm Bill programs such as the Agricultural Conservation Easement Program (Wetland Reserve Easements) and the Environmental Incentives Program provide options to enhance and protect natural resources on privately owned land.
In addition to Farm Bill programs, Hardisty encourages all farmers to think about incorporating soil health management practices into their operations. “This system of conservation practices, like using cover crops, no-till, and nutrient management simulates nature’s way of protecting the soil, increasing its water holding capacity and ability to filter pollutants,” she said.
Landowners who are interested in NRCS assistance should contact their District Conservationist at the local NRCS office.
The Nature Conservancy has prepared a video describing its work with the NRCS and farmers to improve water quality in the Wabash River.
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The Nature Conservancy is a leading conservation organization working around the world to protect ecologically important lands and waters for nature and people. To date, the Conservancy and its more than one million members have been responsible for the protection of more than 119 million acres of land and 5,000 miles of rivers worldwide. In Indiana, the Conservancy has worked for 50 years at over 195 sites to protect more than 80,000 acres. Working from eight offices across the State, the Conservancy works with local communities on issues of vital interest, including the quality and quantity of Indiana’s freshwater. Visit us on the web at nature.org/Indiana.