Minimizing the Ecological Impact of Dam Removal

Abstract

Dam removal managers have struggled with the challenge of determining the magnitude, timing, and scale of physical and biological responses of a river following dam removal. This information is critical in deciding if and how dam removals should be performed. The river restoration community has a keen interest in identifying the best methodologies that project managers can use to minimize ecological impacts from a removal. We analyzed the results of studies assessing the ecological recovery of dam removal sites, along with the respective dam removal design plans to discern what methodologies, if any, could be identified as least impactful to river ecosystems. We found that all best management practices relate to managing the mobilization and erosion of sediments that have accumulated behind dam structures. Our findings also support that more systematic monitoring is needed to conduct a robust meta-analysis of the impacts of dam removal on stream ecology.