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 RB with storage volumes between 200 and 500 L, which is extended by a remotely (and centrally) controllable discharge valve. The SRB is capable of releasing stormwater prior to precipitation events by using high-resolution weather forecasts to increase detention capacity. However, as shown in a previous work, a large-scale implementation combined with a simultaneous opening of discharge valves clearly reduced the effectiveness. The aim of this work was to systematically investigate different control strategies for wet weather by evaluating their impact on sewer performance. For the case study, an alpine municipality was hypothetically retrofitted with SRBs (total additional storage volume of 181 m3). The results showed that combined sewer overflow (CSO) volume and subsequently pollution mass can be reduced by between 7 and 67% depending on rain characteristics (e.g., rain pattern, amount of precipitation) and an applied control strategy. Effectiveness of the SRBs increases with lower CSO volume, whereas more advanced control strategies based on sewer conditions can clearly improve the system's performance compared to simpler control strategies. For higher CSO volume, the SRBs can postpone the start of an CSO event, which is important for a first-flush phenomenon. HIGHLIGHTS An alpine municipality is hypothetically retrofitted with 384 smart rain barrels (SRBs) as an IoT-based solution for micro storages utilised for smart rainwater harvesting.; Control strategies based on sewer conditions show a clear improvement in the system's performance compared with without considering sewer states.; Efficiency is particularly high if overflow volume is in relation to storage volume of the SRBs implemented.;

Keywords

• iot-based solution
• real-time control
• smartin toolbox
• smart rainwater harvesting
• weather forecasts
• wet weather