Urban drainage systems are under significant pressures as a combined consequence of increased urbanisation structures, population growth and ageing infrastructure. In addition, climate change projections indicate the likelihood of more frequent and intense urban flooding events as the natural precipitation patterns deviate from the norm. 

Urban flooding poses numerous risks. In particular, urban flood water carries elevated concentrations of bacterias and viruses originating from the sewer network, exchanging from the sewer network to surface during flood events through interaction structures such as manholes, with sediments serving as carriers for contaminants during surcharged flows from manholes during urban floods. However, not much is known about this. 

Therefore, the aim of this research is to experimentally investigate the flow exchanges and hydraulic energy losses within manholes during sewer-to-surface flood conditions. This will further include the quantification and analysis of sediment transportation and deposition during sewer surcharged flood conditions, to later evaluate the potential risks associated with urban floods from surcharging manholes.