Westbrook Weir Flood Risk Modelling and Design

The Environment Agency is looking for a contractor to conduct flood risk modelling and outline design work related to the removal of the Westbrook Mill weir on the River Wey. **Project Overview** The Westbrook Mill has been operational for around 300 years, but the mill and its associated factory have been closed for many years, resulting in minimal heritage significance. The weir features six sluice gates, each 1.5 meters wide, and has a height difference of 1.3 meters between the upstream and downstream levels. The upstream water level is maintained at 1.6 meters above the weir sill. The structure includes cast concrete walls and a central pier extending under a road bridge, providing access to a parking area. An access walkway is also present over the weir, which is manually operated. The upstream channel is confined by steel sheet pile walls for about 50 meters, and there are three overspill weirs that direct water into the Hell Ditch, which rejoins the main river approximately 3 kilometers downstream. In 2016, a fish pass was installed at the upstream overspill weir to facilitate fish migration past the Catteshall and Westbrook weirs. This project aims to assess the flood risks associated with the weir and develop designs for its removal, ensuring environmental considerations and community safety are prioritized.