Meeting with Elizabeth Pierce, Geosciences Department

To learn more about soil erosion and dam management, Zehra and Mackenzie met with Professor Elizabeth Pierce in the Geosciences Department.

Elizabeth emphasized the importance of having the right amount of moisture in your soil to prevent erosion and seconded our top solutions for avoiding soil erosion which are vegetation and terracing. On Wellesley's campus, terracing using wooden stakes and netting/metal mesh is present near Lake Waban, and has been effective in preventing soil erosion. It is key to terrace whole area around the dam, instead of only areas close to the bank, because of the risk of undercutting which affects slope stability. Any instability above or below on the slope can be a problem, so we can't just target the lower half of the slope. 

She also said the first thing that came to mind when we asked about strategies to prevent soil erosion was to introduce clay to the system to retain moisture. This is something we would like to research further. 

We asked some questions regarding check dams and walls or barriers that have been built in other locations to prevent soil erosion, but Elizabeth pointed out that the concrete used to build a wall would prevent sediment replenishment because it introduces a new sediment, so walls are not a good solution. We also could have scouring on the banks of the stream feeding into the dam.

Resources she recommended were the US Geological Survey and the DOD (Department of Defense) case studies. Dams in the Pacific Northwest might also might serve as useful models.