Efficient integration of IoT-based micro storages to improve urban drainage performance through advanced control strategies
Abstract The smart rain barrel (SRB) consists of a conventional rain barrel with storage volumes between 200 and 500 L, which is extended by a remotely (and centrally) controllable discharge valve. The SRB is capable to release stormwater prior precipitation events by using high-resolution weather forecasts to increase detention capacity. However, as shown in the previous work, a large-scale implementation combined with a simultaneously opening of discharge valves clearly reduce effectiveness. The aim of this work is to systematically investigate different control strategies for wet weather by evaluating their impact on sewer performance. For case study, an Alpine municipality is hypothetically retrofitted with SRBs (total additional storage volume of 181 m3). The results show that combined sewer overflow (CSO) volume and subsequently pollution mass can be reduced between 7 and 67% depending on rain characteristics (e.g., rain pattern, amount of precipitation) and applied control strategy. Effectiveness of the SRBs increases with lower CSO volume, whereas more advanced control strategies based on sewer conditions can clearly improve system's performance compared to simpler control strategies. For higher CSO volume, the SRBs can postpone start of an CSO event which is important for first-flush phenomenon.