Effectiveness of infiltration galleries in reduction of surface runoff and flooding in urban areas

Abstract

Many times the design of drainage structures for storm water management (SWM) follows the conventional approach of conveying flows downstream as quickly as possible. Consequently, low lying and mostly urban poor areas suffer flooding problems. As a solution, the land upstream can be utilized to its maximum potential by incorporating infiltration practices that allow water to infiltrate before it is released downstream. This paper is based on a case study research project carried out at a plot scale on Makerere hill, Kampala, Uganda focused on investigation of the effectiveness of appropriately designed infiltration galleries on reduction of surface runoff. Results indicated that use of infiltration galleries can result into a 40% percentage reduction in the generated runoff. The results further suggested that this reduction is dependent on the soil permeability, size of available land and the size and number of perforated embedded pipes used for the infiltration structure.