Lysimeter Study of Sustainable Drainage Capillary Barrier Systems in support of Climate Adaptation Control Technologies for Urban Spaces (CACTUS)

Urban areas are vulnerable to climate change impacts including flooding, and damage to buried infrastructure assets such as popes and foundations due to shrink-swell behaviour of high-plasticity clay soils. One solution for managing these negative effects of climate change in urban settings is the implementation of Sustainable Drainage Capillary Barrier Systems (SuDS-CBS). SuDS-CBS are two-layer systems of materials (fine-grained water retention material overlying coarse-grained drainage material) of contrasting hydraulic properties and can be used to mitigate the effects of climate change in urban areas, including flooding and shrink-swell deformation. Here, two large-scale, outdoor experiments were set up to test SuDS-CBS geometry and material type. The experiments were fully instrumented with soil moisture and soil suction sensors at multiple depths, and they were planted with native vegetation species. Results were analysed following subjection of the large-scale experiments to a range of natural and simulated rainfall events over a two-year period. Results demonstrate the potential of SuDS-CBS as a solution to climate change adaptation.