Kier delivered new stormwater storage infrastructure for Severn Trent Water across the Finham catchment in Coventry. The scheme included construction of a rectangular stormwater storage tank at Finham Wastewater Treatment Works and a storm storage shaft at Unicorn Lane. Together the assets provide around 4,880m³ of additional storm storage, helping reduce storm overflow spills and improve river health as part of Severn Trent’s Bathing Rivers Programme.
Stormwater storage capacity
4,880m³
Finham Tank
60m x 37m
Operational from
March 2025
Improving river health
The new stormwater storage infrastructure captures excess flows during heavy rainfall, reducing the likelihood of storm overflow discharges to the river. Delivered as part of Severn Trent’s Green Recovery and Bathing Rivers programmes, the scheme supports improved river health and water quality across the catchment while strengthening the resilience of the wastewater network serving Finham Wastewater Treatment Works.
Severn Trent Water representativeThis project demonstrates how collaboration and practical engineering solutions can deliver meaningful environmental improvements while maintaining programme certainty. The additional stormwater storage will help reduce overflow events and support better outcomes for our rivers and local communities.
Delivering complex infrastructure
The primary asset delivered at Finham STW is a new rectangular reinforced concrete storm storage tank measuring 60 metres by 37 metres and providing 4,880m³ of additional storage capacity. Constructed on 77 piles to ensure structural stability, the tank integrates with the existing storm storage system through new gravity pipework, pumps and return infrastructure that manage flows safely during heavy rainfall.
Working within constraints
Part of the scheme was delivered at Unicorn Lane, where a storm storage shaft was constructed within a pub car park and connected into the network serving Finham STW. The works were carefully coordinated with the landlord and local stakeholders to minimise disruption and maintain access for customers and nearby residents while maintaining programme certainty.
Foundation piles installed:
77
The project demonstrates Kier’s capability in delivering complex water infrastructure within live operational environments and constrained urban locations. Delivered safely with zero RIDDOR incidents, zero lost time injuries and no environmental impacts, the scheme provides long-term benefits for Severn Trent and the communities it serves. The new tank at Finham integrates with the existing storm storage system, intercepting flows downstream of existing tanks and providing additional capacity before discharge to the river. Gravity pipework manages the majority of storm flows, with pumps returning the final stored water to the treatment process. Together with the Unicorn Lane storage asset, the infrastructure increases storm resilience across the catchment and supports improved river health.