A Model of Optimal Best Management Practices Placement

The nonpoint source pollution control is in the beginning stage in Taiwan. The techniques of nonpoint source pollution control with Best Management Practices (BMPs) have also been under limited research. The soil and water conservation and environmental laws provide regulations that require the land developer to detain excessive stormwater runoff and sediment resulted from any significant development in the watershed. Most of stormwater quantity and quality controls have been designed at the local or on-site level, but not at the regional or watershed level in a comprehensive and systematic manner. The purpose of this study is to establish an optimization model for the optimal placement of structural Best Management Practices (BMPs) on the watershed scale. The complete model consists of two interacting components; i.e. a reservoir water quality model and an optimization model with genetic algorithms (GAs). This research chooses Fei-Tsui Reservoir and its watershed in northern Taiwan for case study. In the optimization model, the objective function is to minimize the total cost of BMPs and its constraints considering water quality standards for pollutant concentrations in rivers and reservoir. The model developed in the present study can be used as an efficient approach to the implementation of BMPs in the entire watershed to mitigate the impact of stormwater pollution on the receiving water bodies.