Coordinated Operation of Urban Storm Detention Ponds with Optimal Control of Gates Using Harmony Search Algorithm (Case Study: Drainage Network in East Watershed of Tehran)

Today, with population growth, urbanization and expanding demands of societies, water resources management has received more attention than the past decades. Urban water management is mostly conducted by controlling and directing surface runoff through reducing the peak discharge and flood volume. The construction of storm detention ponds in urban drainage systems delays the time of peak flow and reduces the peak discharge. The performance of these ponds depends on not only their dimensions and their inlet/outlet structures, but also the procedure of operating these structures. In this study, coordinated operation of detention ponds is taken into consideration at Tehran’s East stormwater urban drainage system, through the gates optimal maneuver. To achieve this, harmony search algorithm (HS) was linked to the SWMM hydrological-hydraulic model to find optimal gate openings of inlet/outlet structures of ponds in order to minimize the volume of stormwater exceeding the hydraulic capacity of drainage network. The results for five extreme rainfall events at the studied catchment showed that the optimal coordinated operation of these ponds has improved the level of ponds performance in terms of network flooding compared to the current method of operation and flooding in the drainage network was reduced by 62% in average for the considered extreme rainfall events.