Low impact development implementation: Investigation on the hydrologic performance of bioretention via experimental models

Abstract

Efficient use of water is vital for economic. social and environmental sustainability of water resources. Especially, urbanization and thus high imperviousness results in a decrease in infiltration and percolation. Consequently, surface runoff generated over the surface increases tremendously and results in floods. Surface runoff also washes off the pollutants that are built up on the surface during dry days which results in poor water quality. Therefore, new methods in hydrology are necessary for environmental sustainability, protection of water resources, and mitigation of impacts of urbanization on environment and water resources. In this study, Low Impact Development (LID) Best Management Practices (BMP) are investigated in order to prevent high surface runoff and water pollution due to land use change caused by urbanization. Bioretention, which is a LID type of storm water management practice, is investigated to mitigate impacts of high surface runoff and non point source pollution. For this purpose, an experimental set-up is developed to observe the hydrologic efficiency and performance of bioretention. Performance of bioretention on peak flow decrease is observed by evaluating experimental results. The mechanical properties of materials used in bioretention columns are investigated. It is observed that the material type and properties are effective in retaining water in bioretention. As the sand content increases, the outflow at the exit of the column also increases and if the fine grained material increases, the outflow at the exit of the column decreases.