The use of low impact development technologies in the attenuation of flood flows in an urban area: Settat city (Morocco) as a case

Abstract

Low Impact Development (LID) is an approach to urban drainage design and planning and it is considered to be an effective technical solution to manage urban runoff. The current work demonstrates how LID can be integrated in the management of urban runoff in order to significantly decrease a large volume of stormwater before it reaches the receiving water bodies. To demonstrate our approach, the Personal Computer Stormwater Management Model (PCSWMM) was constructed to simulate the hydrological process in the urban area of the Settat city. Afterwards, the model was calibrated and validated by using four observed stormwater events. Two LID practices, permeable pavement (PP) and rain barrel (RB), were used to estimate their effectiveness under four scenarios (no LID –PP –RB -PP+RB) and four designed rainfall events (with return periods of 5, 10, 25, and 50 years). Results show that the LID practices significantly contributed to surface runoff mitigation. The combination of Permeable Pavement and Rain Barrel (Scenario 4) offered the best runoff control capacity, with a removal rate of 57%. The flooding and overflowing drainage system issues were also remediated after the LID application. Finally, this study provides additional guidance for decision-making process regarding the implementation of appropriate LID practices in the study area.