Developing strategies for real-time control of stormwater systems: A review

• Case study applications of real-time control are not typically transferable. • Review focuses on how strategies are developed rather than what the strategies are. • A strong reliance on intuitive design choices is identified. • More systematic and adaptable methods are needed to facilitate wider implementation. • Remaining challenges related to strategy development are explored. Stormwater systems have traditionally been operated passively; however, interest in real-time control (RTC) as a low-cost means of improving performance is growing. Whilst many model-based studies have now demonstrated potential of RTC, real-world implementations remain limited. Publications typically focus on a case study application and are not easily transferable, and decision-making related to the development of control algorithms has been identified as a barrier to the transition to smarter stormwater management. To address this knowledge gap, this paper provides a comprehensive review of approaches to developing RTC strategies for stormwater systems, focusing particularly on how the strategies are developed rather than what the detailed strategies are. This includes identification of strategy objectives, selection of system component(s) for control, scale of implementation, and choice of observed (real-time) and forecast data inputs, followed by discussion on the different types of control strategy that have been implemented, their key characteristics, and how each is designed. A review of implementation and evaluation approaches is also provided, followed by exploration of remaining challenges. The review reveals a strong reliance on intuitive design choices, with limited methodological transparency and transferability. Research to date typically focuses on description of the strategy (or strategies) being evaluated and their performance, without elaborating on the process by which the strategy was selected and designed. Moving beyond case-specific solutions towards more systematic and adaptable methods is identified as a key need, with development of guidelines for RTC strategy development for stormwater systems a priority for future research.