A question arising when considering the changing climate is whether real time control (RTC) can be considered as a ‘No Regret’ measure, i.e. can RTC maintain its proven current added-value to reduce emissions from sewage systems in the future under altered rainfall patterns and often higher extreme rainfall intensities. This study explored four climate scenarios relevant for the lowland area of North-western Europe under two time horizons and proved that RTC’s performance only marginally decreased for a representative Flemish catchment under study. Based on this case study, it was found that effects of climate change will lead to, on average, 30–40% more overflow volume in 2050 and 35–65% more overflow volume in 2085. To restore the current situation, additional measures need to be taken, but RTC preserves its contribution to the reduction of overflows. The elaborated methodology is transposable to other locations provided that the necessary information is available.