Acton Lake is a reservoir in Hueston Woods State Park that was created in 1956 by the damming of Four-Mile Creek. Early on, high levels of erosion and agricultural runoff contributed to high sedimentation rates. In 1992, the USDA began encouraging farmers in the Acton Lake watershed to adopt conservation tillage. The goal of this plan was to lower sedimentation rates by reducing the amount of agricultural runoff from the watershed. Miami faculty Dr. Michael Vanni analyzed sediment nutrients in 2001 and published his findings in a 2011 paper, and Dr. Bill Renwick compiled sedimentation data in a 2005 paper with the most recent survey having been undertaken in 1999. Sedimentation rates have gradually declined since the lake’s creation, but it is unknown if this trend has continued over the past two decades. This project was meant to update the findings of the papers by Dr. Renwick and Dr. Vanni since the sedimentation rate and sediment nutrient concentrations and ratios have not been analyzed since these two studies took place over twenty years ago. We used sonar and a pole survey to measure sediment thickness and quantify sedimentation rate. Sediment cores were also collected to analyze nutrient ratios and concentrations. The upper 16 cm of new sediment showed an increase in organic carbon, nitrogen, and phosphorus concentrations while nutrient ratios remained consistent with the 2001 values. The sedimentation rate was found to have remained low at 0.865 cm/yr, despite increasing since the 1999 survey. The sonar survey and pole survey returned very similar results.
Author(s): Max Striedl, Biology Major
Advisor(s): Michael Vanni, Department of Biology
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