Dordt University Saturated Buffer

Sioux County, IA | Water


An industry leader in Edge of Field (EOF) conservation practices, ISG collaborated with the Iowa Department of Agriculture and Land Stewardship (IDALS) and Dordt University to provide technical support on the design and installation of a saturated buffer at the University’s research farm to study and improve nitrate reduction in agricultural drainage.


Dordt University is nestled in the West Branch of the Floyd River watershed, a region in Iowa with a high concentration of livestock that is known to impact water quality contaminant levels. ISG assisted in plan production and construction administration for a saturated buffer installed at the research farm.


Designed to accommodate topography with a split weir height, this unique application of a 3-chamber water control structure provides the opportunity for dual head elevations to optimize available buffer length.

Following a controlled burn of existing vegetation, much of the saturated buffer was planted in spring 2018 and treats approximately 35-acres. Once vegetation was reestablished, the saturated buffer functions at a premium as soil carbon is regularly replenished and nitrates in the water are removed via denitrification or taken up by the vegetation in the buffer before entering other surface water. Currently, Dordt University is studying nitrate removal in the buffer with shallow monitoring wells.

Requiring minimal maintenance or management, the saturated buffer significantly reduces nitrates in subsurface drainage water proving to be an innovative, cost-effective solution in conservation and land stewardship practices.

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