Assessing Alternatives for Sustainable Management of A Flood Control Dam

Dam decay provides opportunity to restore degraded ecosystems. When choose an alternative to manage a dangerous dam to ensure dam safety and satisfy other human needs, ecological needs should be considered. In this paper, based on sustainable management goal, alternatives for managing a small flood control dam were assessed from improving dam safety, controlling flood and restoring riparian vegetation. Impacts on dam safety were quantified by an index integrating social influences from dam break flood inundation. Capability to control flood was assessed based on reservoir routing and hydrologic modeling. Opportunity to recover riparian vegetation was quantified by an index representing hydrologic alterations to natural flow regime. Final priority of each alternative was then obtained by multiplicative synthesis. Synthesization results indicated the decreasing dam height alternative had the highest priority to achieve the sustainable goal, because it flexibly regulated inflows for ecological considerations within the limits of flood control standard.