Dynamic Distributed Storage of Stormwater in Sponge-Like Porous Bodies: Modelling Water Uptake

• Main Authors: T. Staffan Lundström, Hans O. Åkerstedt, I. A. Sofia Larsson, Jiri Marsalek, Maria Viklander
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Water
• Subjects: stormwater; storage; sponge-like; porous media; wetting; modelling
• Online Access: https://www.mdpi.com/2073-4441/12/8/2080

An innovative concept of dynamic stormwater storage in sponge-like porous bodies (SPBs) is presented and modelled using first principles, for down-flow and up-flow variants of SPBs. The rate of inflow driven by absorption and/or capillary action into various porous material structures was computed as a function of time and found to be critically dependent on the type of structure and the porous material used. In a case study, the rates of inflow and storage filling were modelled for various conditions and found to match, or exceed, the rates of rainwater inflow and volume accumulation associated with two types of Swedish rainfalls, of 60-min duration and a return period of 10 years. Hence, the mathematical models indicated that the SPB devices studied could capture relevant amounts of water. The theoretical study also showed that the SPB concepts could be further optimized. Such findings confirmed the potential of dynamic SPB storage to control stormwater runoff and serve as one of numerous elements contributing to restoration of pre-urban hydrology in urban catchments. Finally, the issues to be considered in bringing this theoretical concept to a higher Technological Readiness Level were discussed briefly, including operational challenges. However, it should be noted that a proper analysis of such issues requires a separate study building on the current presentation of theoretical concepts.