Dozens in Indiana
While the Mullenbach Ditch is one of only a few 2-stage ditches in Minnesota, more can be found in Indiana, Ohio and Michigan. "I became interested in the practice after talking to colleagues in Indiana. I found researchers at the U of M with a similar interest in 2-stage ditches." Biske says.
"They won't work everywhere," Biske says. "You need stable soils and the right hydrology. But they have dozens of them in Indiana -- it's an EQIP practice of NRCS there. The environmental benefits haven't been fully assessed in Minnesota yet, but when they're better proven, I expect the 2-stage ditch to be an NRCS practice in more states."
An ideal candidate for a 2-stage makeover would be a drainage ditch with high nitrate loading and stable soils that requires cleanout, in a watershed of a priority stream. Landowners should consult with a qualified drainage engineer, Biske says.
Conservation innovation grant funds
TNC secured funds from Cargill and General Mills to match funds from a USDA Natural Resources Conservation Service Conservation Innovation Grant for the $200,000 project. The grants are intended to demonstrate and promote wider use of proven conservation practices. Partners in the project include TNC, the Mower County Soil and Water Conservation District, Minnesota Pollution Control Agency, and the Minnesota Board of Soil and Water Resources.