Meandering at Duff Lake by Nate Simons

The Duff Lake Fen restoration project took a bit of a meander over the winter. We had hoped to be able to fill all the man-made ditches excavated within the 76-acres of wetland soil in order to retain groundwater thus improving hydrologic function around Duff Lake. As it turns out, one of the ditches originates on a neighboring property. Filling that ditch within the project limits would stop drainage and back water onto the neighbor’s property.

So, in order to maintain good neighbor relations, we hired an engineer to help us solve the problem. How could we change the ditch so that it did not quickly drain the wetland soil while at the same time not negatively impact the neighbor? Mike Gensic, a civil engineer with whom I have had professional confidence for decades, met with me on-site near the end of winter.

Together we took elevation shots both on the neighbor’s property and the Duff Lake Fen property. We took shots of the ditch bottom, culvert elevations, and ground shots. And we developed a plan in the field that would slow water in the ditch and raise the elevation in the ditch bottom without flooding the neighbor. A series of meanders will wind back and forth across the original ditch essentially slowing the water’s velocity and raising the elevation of the stream bottom. The increased sinuosity of the new stream will replicate a natural stream course and increase retention of groundwater. Point bars or wetland benches within the meanders will create places to increase wetland plant diversity in the new channel.

To make sure our plan was buildable, we invited Kevin Northrup to review our idea on-site. Once we received his blessing and discussed project timing, the next step was to obtain permits from Indiana Department of Environmental Management and US Army Corps of Engineers. The agencies were already aware of our intentions to close the site’s ditches since we involved them in a process of early coordination. Their excitement mounted as they chose to direct us to apply for a little-used Nationwide #27 permit to actually “restore” wetlands instead of the usual permit given to disturb wetlands. Progress report: Orbis Environmental Consulting, already involved in grant- and permit-required vegetation inventory and monitoring, applied for the Nationwide #27 on behalf of the project. The Public Notice has been issued by the permitting agencies, and if all runs smoothly (pending agency approval), Kevin will start earth-moving operations to close ditches and re-create a meandering stream in September or October this year.

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