Date of Graduation
Project/Capstone - Global access
Master of Science in Environmental Management (MSEM)
School of Management
There have been almost 1,800 dams removed in the United States in the last 100 years. As of 2021, California has a total of 690 dams and has removed 137 dams. The process of removing a dam first undergoes a process called decommissioning. Decommissioning is an assessment of the functional use of the dam and, based on that, a decision on whether a dam will be retained, retrofitted, or removed. In this paper, dams in the US and Asia are reviewed to determine the prioritization of the factors to consider for dam decommissioning and how the cost-benefit analysis can incorporate marsh habitat restoration. The results identified from both sets are extrapolated to determine the feasibility of pairing marsh restoration with dam decommissioning projects by following a life cycle assessment plan. Upon preliminary analysis, sedimentation accumulation is the primary factor for dam decommissioning and removal. The sedimentation transport that occurs downstream of a dam after dam removals can benefit sediment accumulation in rivers deltas and build up marsh elevation. Pairing marsh habitat restoration with decommissioning reduces the cost of decommissioning projects and provides additional restoration benefits, which can result in negative net cost (i.e., positive net benefits). Studying the effects of removals quantifies the benefits of a dam removal project and the efficiency of marsh restoration. However, further studies on sediment transport models of the selected dams would better quantify those benefits by improving our understanding of the sediment accretion rate in the marshes of the estuary.
Angulo, Carla Lissette, "Evaluation of dam decommissioning as a habitat restoration method: A case study of California" (2022). Master's Projects and Capstones. 1482.