By Catherine DeLong

In July of this year a grant was awarded to a group of Iowa State University researchers to study the long term impact of land management practices on the Black Hawk Lake Watershed. The goal of the research team, which includes Michelle Lynn Soupir, Matt Helmers, Amy Kaleita, Leigh Ann Long and Carl Pederson, is to assess the impact of conservation practices on water quality.

Black Hawk Lake occupies 957 acres in Sac County, and its watershed drains an area of 13,156 acres. The lake has been declared an impaired waterway by the Iowa Department of Natural Resources (IDNR) mainly due to the excess sediment that clouds the water. This excess sediment has transported phosphorus into the lake, which in turn has caused algal blooms to appear and compromise the waterway. A Watershed Management Plan was enacted several years ago in order to combat rising phosphorus levels. The management plan has put into action various conservation practices, such as cover crops, terraces and filter strips. The grant awarded to Iowa State University researchers will be used to monitor the outcomes of these conservation efforts.

Three automated monitors have been placed across the watershed to collect water samples. The monitors will notify the researchers, via cellphone, as soon as a runoff event has occurred. Once the samples have been gathered they will be sampled for phosphorus, nitrogen and suspended solids.

The $461,661 grant, awarded by the IDNR, is for five years. As Assistant Professor Michelle Lynn Soupir explains, “[t]here’s a lag time between when you implement land use practices and when you start to see water quality improvement. We need a better understanding of that lag time, and five years of data will help fill in some of those gaps.” Most studies of this nature are only allotted 1 to 3 years to complete their work.