Adapting to future changes using smart stormwater storage systems to preserve flow regimes

Abstract

Worldwide, stormwater systems are increasingly stressed due to increased rainfall and runoff caused by climate change and urbanization. Traditional static strategies for addressing these challenges, including increasing infrastructure capacity, are often inadequate as they are not suited to dealing with large uncertainties. In contrast, adaptive strategies, such as smart real-time control (RTC), are suited to dealing with such uncertainties, as they are able to respond to future changes as they occur. However, existing RTC approaches are not truly adaptive, as they require information on future rainfall. In this paper, we modify an existing RTC approach that does not require such information so that it is able to match desired outflow hydrographs in the face of changing inflow hydrographs. The utility of the proposed Target Flow Control for Hydrographs (TFC-H) approach is demonstrated by simulating its ability to achieve desired target flow hydrographs for multiple future worlds of a simplified lot-scale system, in which peak flows increase from 7 % to 95 % and storm volumes increase from 25 % to 57 %. The results show that use of the TFC-H approach effectively maintains the desired target outflow hydrograph with less than 5 % error for this wide range of “future worlds”. Importantly, unlike other RTC approaches, the TFC-H approach is able to adapt without any knowledge/predictions of future rainfall/inflow hydrographs. This clearly demonstrates the potential of the TFC-H approach to enable existing stormwater systems to adapt to future changes.