Stormwater management: methods for measuring near-surface infiltration capacity in clayey till

Glacial till forms a major proportion of the surface deposits in Northern Europe, and in Denmark more than 40% of the land surface is covered by clayey till. At the same time the majority of densely populated areas are situated on this fertile sediment type. In urban areas, one of the major tools in adaptation to climate change are sustainable drainage systems (SuDS). Their function is to manage the increasing amounts of stormwater on site, often by direct infiltration into the sediment. Accordingly, a realistic estimate of nearsurface hydraulic properties is required when dimensioning SuDS for infiltration. Clayey tills are generally believed to have a low-bulk hydraulic conductivity and thus a low infiltration capacity. However, clayey tills can be very heterogeneous and especially their bulk hydraulic properties can vary significantly