Oxbow restoration improves water quality, habitat


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An aerial view of existing oxbows along a waterway in Northern Iowa. (G. Witteveen/flickr)
Jenna Ladd | May 25, 2017

Conversations about water quality improvement on agricultural land usually include talk of terraces, wetland restoration and curbed pesticide application. One strategy, oxbow restoration, is often left out.

Prior to European-Americans converting Iowa’s prairies into cropland, most of the waterways that flow through the state regularly took long twists and turns. In order to maximize agricultural space, farmers straightened creeks in the 20th century. IIHR researcher Dr. Chris Jones said that this causes water to move quickly downstream, increasing nutrient runoff, erosion and the likelihood of flooding downstream.

Jones is one part of an effort to restore an oxbow in Morgan Creek Park in Linn County. In an interview, he explained that oxbow restoration is a cheaper conservation method because most oxbows were located on land that is not usable for farming anyway. He said, “It’s very cheap habitat—$10,000 to $15,000 to restore one of these.”

Jones, along with UI Dr. Keith Schilling and graduate student Bryce Haines, hope to measure the water quality benefits of oxbow restoration. The researchers have installed water level monitoring wells near the project on Morgan Creek, the first of its kind in eastern Iowa. Linn County Conservation has reintroduced native plants to the area, which is close to one of the park’s hiking trails. Jones said, “It’ll provide opportunities for people to look at birds.”

Schilling has already seen the positive impact oxbow restoration can have on a watershed. His research team restored an oxbow along White Fox Creek in the Boone watershed last year. Schilling reported that the oxbow removed 45 percent of the nitrate flowing into the stream from surrounding farmland, which is equal to what one might expect from bioreactors or wetlands.

Schilling and Jones agree that oxbows provide a multitude of benefits. “Oxbows can provide a triple benefit of habitat, flood storage, and stream water-quality enhancement,” Jones said, “And all for not much money.”

To read IIHR’s full report on the project, click here.

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