Browns Lake Bog and Dams Blog

Guest Bloggers: Eddie, Stephen, Nolan.

This Monday, October 26, 2026, the Hydrology team (Figure 1) headed into the field to better understand how groundwater moves through the landscape. The Team stopped at two locations, Shreve Lake and Brown’s Bog. Surveying both gave the team a chance to see how water behaves in a natural wetland, as well as the managed, human-built dam at Shreve Lake. Our first stop was at Shreve Lake, where we got to walk on and investigate the earthen dam that contained Shreve Lake (Figure 2).

Figure 2: Earthen dam that contains Shreve Lake.

An earthen dam is built from compacted soil rather than solid concrete, which makes it very different from the concrete dams most people picture. Soil is a porous medium, meaning water naturally seeps through it, and how professionals control that seepage was a focus of our conversation. The team discussed how large concrete walls were installed beneath the dam to control the flow of water. These walls lengthen the path the groundwater must travel, which reduces the force of the water moving beneath the dam. They can also concentrate that flow into one location, which at Shreve Lake is the culvert. Directing seepage to a single, known point matters because water that moves freely through a dam can carry soil particles with it, a process called piping, which can weaken the structure over time.

Map of the kame and kettle topography at Browns Lake bog. The wells shows below are at the northern end of the central Kame.

Figure 3: Nolan, Stephen, and TA Arjan with a tile probe pushing into the peat in the bog. Looks to be at least four rods of peat.

Our second stop was Brown’s Bog, which offered a sharp contrast to the Shreve Lake dam. Bogs form on thick layers of saturated peat, which trap water like a sponge and then slowly release it back into the environment, keeping the water table at or near the surface. This wetland environment is extremely important for flood mitigation, because the peat absorbs excess rainfall and snowmelt during wet periods and releases it gradually during dry periods. To get a closer look at the peat, the team pushed a probe down into the bog (Figure 3). The probe was almost completely absorbed by the bog, showing how loose and deep the peat was.

Covering the surface of the bog was Sphagnum moss (Figure 4), the plant that helps build the peat. Sphagnum can hold many times its own weight in water, as it dies, it accumulates in the low-oxygen conditions of the bog forming the peat layers we probed.

Figure 4: Photo of Sphagnum moss, the prime ingredient of peat, which is mined throughout the region.

We also stopped at two small wells within Browns bog that had been dug at 2 different depths (figure 5). These two wells were dry, so we got no data from the wells. The data that we were trying to get from the well was the different water levels that would be displayed from the two wells. The wells were installed to show a change in the hydraulic head in the vertical while being so close together. This is because water comparing the two would have shown whether groundwater was moving upward or downward through the bog. The deeper well would have a higher level of water than the well that goes down less.  This is because the deeper well would have a higher head, making the water rise more and more water get sucked in the well to go up in the sediment to the higher elevation/lower head well.

Figure 5: Classmate Leo Measuring the depth of water in 2 separate wells installed to 2 different depths.

Overall, this field trip helped us better understand how groundwater moves through the landscape and how water is stored in different environments. At Shreve Lake, we learned how earthen dams control seepage to prevent erosion and keep the structure stable. At Brown’s Bog, we saw how peat and sphagnum moss absorb and store water and helping reduce flooding and how it is well-preserved with a high water table. Even though we could not collect useful data from the two wells, the activity showed us how wells can help measure groundwater levels and understand groundwater flow. This trip showed us the important role groundwater plays in both natural environments and human-built structures.

On the drive out the dust from the ongoing corn harvest spread across the area which is having a role in fertilizing the nutrient – poor bog at Browns Lake.

Source: https://woostergeologists.scotblogs.wooster.edu/2026/10/29/browns-lake-bog-and-dams-blog/