Dam-lake Operation to Optimize Fish Habitat

Abstract

The existence of dams cannot be ignored. The dam-lake formed due to the construction of a dam can be considered an integrated part of the natural watershed. A question which must be answered is how to operate a dam-lake so that the negative impacts of the dam on the natural flow system are reduced and at the same time the intended purposes of the dam are efficiently met. Among many aquatic species, the fish species are probably the most highly impacted species by the construction of a dam. As a result of the dam, fish habitat can decrease resulting in low productivity to no productivity at all for some fish species. This paper presents a methodology to develop a dam-lake operation model to maximize fish habitat. This study considered the physical habitat of smallmouth bass in its adult life. The operation model is developed by linking one-dimensional hydraulics model HEC-2 and dam-lake simulation model HEC-5 with a meta-heuristic optimization algorithm, the Shuffled Frog Leaping Algorithm (SFLA). The computation of physical habitat, which is a function of habitat suitability index and some hydraulic parameters, is coded within the optimization algorithm. The model has been successfully applied to an unnamed dam-lake in the northeast of the U.S. The fish habitat for smallmouth bass in its adult life stage increases as the water surface in the dam-lake increases. Some recommendations to improve the model are discussed in the conclusions section.