Controlling rainwater storage as a system: An opportunity to reduce urban flood peaks for rare, long duration storms

Real-Time, Smart Rainwater Storage Systems: Potential Solution to Mitigate Urban Flooding

“…Consequently, the optimal control strategies for each tank are identified using a formal optimization approach, based on knowledge of the hyetograph of an incoming rainfall event. It should be noted that these hyetographs are assumed to be known as part of the experiments conducted in this study, as was the case in Di Matteo et al [29], thereby providing a theoretical upper bound on the effectiveness of the real-time smart systems approach.…”

“…The effectiveness of the real-time smart systems approach is tested for a theoretical residential two-allotment catchment adapted from Di Matteo et al [29], as illustrated in Figure 1. Details of the configuration of the case study system are given in Table 1.…”

“…DEAP (v1.3.0) is an evolutionary computation framework developed for solving real-world problems by applying evolutionary algorithms to simulation modules and is used to select the decision variable values i.e., the degree and timing of the opening of the tank outlets (see Sections 2.2 and 2.3) [34]. The NSGA-II genetic algorithm (Non dominated sorting genetic algorithm) was chosen in the DEAP package, as its variants have already been used successfully for the optimization of urban stormwater systems [29,35,36]. For each optimization run, a population size of 500 was used and the optimization process was continued for 1000 generations to ensure the convergence of the optimization process [29].…”

“…In order to address this shortcoming, Di Matteo et al [29] introduced an approach for controlling the outflow from systems of rainwater tanks in real time during a storm event so as to minimize system peak flow rate based on knowledge of future rainfall patterns. They showed that by using a real-time systems control strategy during the storm, this approach is able to reduce peak flows by up to 48% under conditions that result in large runoff volumes (i.e., 1 in 100 year rainfall event of 24 h duration), compared with no reduction in peak flow when tanks are emptied prior to the rainfall event, but not operated as systems during the rainfall event.…”

“…However, Di Matteo et al [29] only considered a single return period, a single rainfall duration and a single location (Adelaide, SA, Australia). While this provides a proof-of-concept of the approach, it does not provide a comprehensive assessment of the effectiveness of the approach under the range of conditions likely to be experienced for different urban catchments.…”