Katherine Colby Hydrologists Limited was commissioned by Stroud District Council (SDC) to provide a detailed design for a reach of the Painswick Brook, a tributary to the River Frome.

Located at Highgrove, near Painswick in Gloucestershire the scheme was part of SDC’s Stroud Rural SuDS project. The Stroud Rural SuDS project has delivered hundreds of Natural Flood Management interventions through the River Frome catchment in an effort to reduce flood risk in the Stroud Valleys as well as improve biodiversity and water quality.

The project brief was to consider options to re-connect the historically straightened Painswick Brook with its narrow floodplain and create flow attenuation. A dilapidated weir towards the downstream end of the reach was to be retained. The restoration and provision of fish passage through this structure was part of the project.

A particular constraint at the site was the presence of Severn Trent Water infrastructure. The precise location and elevation of Severn Trent Water infrastructure was defined by a specialist survey. Consultation with Severn Trent Water was undertaken which identified the easements necessary to protect their infrastructure and these constraints were then included in the design of the scheme.

Natural flood management interventions, such as leaky dams were included in the design to reconnect Painswick Brook with its floodplain. Localised areas of attenuation were provided as floodplain scrapes to reduce downstream flood peaks. As the weir was to remain, a rocky ramp was included in the design to facilitate fish passage over the weir.