A new multi-criteria framework to identify optimal detention ponds in urban drainage systems

Urban development and the increase of impervious surfaces have a broad impact on the hydrological cycle, leading to increased peak flow and flooding, especially in downstream areas. Surface water detention ponds are among the most efficient measures for attenuating peak flow and returning it from development to pre-development conditions. However, the major challenge is to identify optimal locations and cost-effective designs for these ponds that lead to the reduction of urban flooding. This paper presents a new framework for identifying the best strategies for using detention ponds to control floods in Urban Drainage Systems (UDS). The framework comprises a portfolio of simulation tools coupled with evolutionary optimisation and multi-criteria decision analysis models. Hydraulic simulation of UDS is first modelled using SWMM and GIS tools. A multi-objective optimisation model was used to find the optimal location and design for detention ponds. The Compromise Programming (CP) multi-criteria decision-making method was then used to prioritise potential best management solutions for detention ponds based on several sustainability criteria, comprising economic, environmental, physiographic, and social factors. The results identified the key features of potential detention ponds appearing in all multi-objective optimal solutions that is useful for decision-makers/designers when planning/designing for new detention ponds. The results also show that the selected optimal pond strategies can significantly improve the UDS performance by decreasing flood damage between 66% and 90% at a cost of between $50,000 and $160,000