Water Quality Model of Alibeyköy Watershed and LID Implementation

Abstract

Uncontrolled urbanization causes flood and poor water quality which results in an increase in peak flow rate and in Total Suspended Solid (TSS) concentration. Low Impact Development (LID) is a Best Management Practice (BMP) and land planning method which may be used to manage storm water runoff to reduce flooding as well as simultaneously improve water quality. Preserving and recreating natural landscape features, minimizing effective imperviousness to create functional and appealing site drainage, which treats storm water as a resource rather than as a waste product, are intended by implementing LID. There are several LID type of storm water BMPs such as bioretention, vegetated rooftops, rain barrels, vegetative swales and permeable pavements. In this study, the impact of LID implementation on TSS are investigated by developing a water quality model for Alibeyköy Watershed located in Istanbul, Turkey. For this purpose, the calibrated hydrologic model of Alibeyköy Watershed developed by using Environmental Protection Agency Storm Water Management Model (EPA SWMM) is employed. The water quality model is integrated into the hydrological model using EPA SWMM. Then, several LID types such as retention basins, vegetative swales and permeable pavement are incorporated into the water quality model and their impacts on TSS in Alibeyköy Watershed are observed.