Monitoring and Evaluation of Vegetated Stormwater Infrastructure

Flood risk is a significant threat to many residents of urban areas. Vegetated stormwater infrastructure (Sustainable Drainage Systems or SuDS) can provide stormwater management that is resilient to future climate and land use changes. However, quantitative evidence confirming the hydraulic performance of SuDS in practice is limited. Such evidence is urgently needed to inform Government policy making and water industry investment, and to support the development and validation of modelling tools used to plan and design drainage infrastructure. Severn Trent Water's ambitious programme for town wide SuDS retrofitting in Mansfield provides a unique opportunity to collect key evidence on how these systems perform in practice. The project will primarily utilise field data (in-sewer/SuDS flow and void space level data) that is already planned to be collected by Severn Trent Water. In addition, we will intensively instrument at least one individual device (e.g., a bioretention cell, or 'rain garden') to permit detailed data collection and scrutiny of the modelling tools, with the goal to recommend improvements to SuDS modelling and design. In addition to natural rainfall events, we will engineer artificial rainfall/inflow inputs into this device to provide test-case data corresponding to extreme design rainfall events.