This document is Deliverable 8.3 of the Co-UDlabs project, funded under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101008626. This deliverable is an output from Task 8.3. of Work Package 8 “Improving resilience and sustainability in urban drainage solutions”. The lead beneficiary of Work Package 8 is University of A Coruña, the University of Sheffield is the responsible partner for this Deliverable. The Deliverable is a report on the main activities and results obtained within Task 8.3. Within this task the main activities have included experimental work to quantify the transport of sediments from urban drainage systems to street surfaces during flooding/sewer surcharge conditions. The influence of different system geometries (lid grate types) and hydraulic conditions have been explored. This work has produced new experimental datasets which will inform future guidance of the performance of urban drainage systems under intense rainfall conditions. Further work in 8.3 has considered the impacts of poor maintenance on BGI’s hydrological performance through a comprehensive experimental campaign under controlled conditions. These works have produced new experimental datasets which will inform future guidance of the performance of urban drainage systems under intense rainfall conditions and the long-term hydrological performance of BGI.