Managing Storm Water Runoff of a Housing Scheme Employing Low Impact Development Techniques

Abstract

Development practices have directly impacted natural hydrological cycle and resulting in storm water flooding scenario as it is happening in southern Lahore. Low Impact Development Techniques (LIDs) such as Bioretention Cells, Rain Gardens, Rain Barrels, Porous Pavements, Infiltration Trenches and Green Roofs etc are the mitigation measures to compensate such disturbance in hydrological cycle. This research broadly encompasses utilization and significance of LIDs in efficient control of storm water runoff and reducing flooding problems in one of the rapidly developing area of Lahore. Land use and rainfall data of study area was collected and analyzed for preparation of IDF curves in order to analyze and predict rainfall distribution pattern in the study area. After that EPA's Storm Water Management Model SWMM 5.1 was used to carry out storm water management studies by designing a storm water drainage network of the study area and for assessing significance of LIDs. Model results exhibited that there is about 54.68% reduction in quantity of storm water runoff along with 51.29% increase in soil infiltration rate. Similarly, LIDs (chiefly rain barrels) provided water storage of about 1.455 acres feet. This depicted that LIDs are not only fruitful in efficient management of storm water runoff but also contribute towards groundwater recharge and water conservation.