Huntington SUTW Enabling Works & Utility Diversions
Key Achievements
- Delivered enabling works to support a major water treatment infrastructure upgrade.
- Constructed new site access, haul roads and working platforms.
- Successfully diverted high-voltage electrical services and water infrastructure.
- Undertook extensive trial hole investigations and deep excavations using specialist excavation support systems.
- Designed access solutions to facilitate the movement of a 250-tonne crawler crane.
- Coordinated multiple contractors and utility stakeholders within a live operational environment.
Project Overview
GDB Civils Ltd was appointed as Principal Contractor to deliver the initial site preparation package at Huntington Water Treatment Works (WTW) in Chester.
Focus
As a first phase of a wider infrastructure upgrade, the works prepared the operational site for future construction through utility diversions, new access routes, temporary works and ground investigations.
The works
Delivered within a constrained live environment, the project laid the foundations for the successful delivery of the wider programme.
Key Challenges
- Complex Underground Services
The site contained numerous existing assets requiring investigation and protection, including:- Low voltage cabling, medium voltage cabling and high-voltage electrical cables
- Water mains
- Communication cables
- Existing ducts and utility infrastructure
- Trial hole investigations and service verification were required before works could proceed safely.
- Deep Excavations
Multiple excavations were required to locate and divert services. Given the depth and complexity of the works, specialist excavation support systems and temporary works solutions were implemented. - Access Constraints
- The project required the construction of new access routes through woodland areas adjacent to the River Dee while maintaining safe access for personnel, plant and future construction activities.
- Access to all plant and equipment had to be maintained at all times and the project worked tirelessly to ensure that client, contractor and third party access was not prohibited.
- Heavy Plant Requirements
A bespoke engineering solution was required to facilitate access for a 250-tonne crawler crane across a newly constructed culvert, requiring careful planning and design verification. - Multiple Contractor Interfaces
The project involved ongoing coordination with United Utilities, specialist subcontractors and other contractors operating across the site simultaneously.
Our Delivery Approach
GDB adopted a phased delivery approach, beginning with site establishment, service investigations, and access preparation works.
Key activities included:
- Site establishment and compound construction
- Utility investigations, trial holes and service verification
- Vacuum excavation and open-cut excavations for new installlations
- Installation of pre-cast concrete service diversion channels
- Diversion of high-voltage electrical infrastructure
- Water main diversions
- Construction of haul roads and access routes
- Installation of drainage systems
- Construction of a reinforced concrete hardstanding area for site operations
Close collaboration with United Utilities and other contractors ensured works progressed safely and efficiently while maintaining programme requirements.
Safety & Risk Management
Safety management focused on deep excavations, live utilities and heavy construction activities.
Key control measures included:
- Permit-to-break-ground procedures
- Drone and Topographic Survey completed to support design development and as-built drawing documentation
- CAT and Genny surveys prior to excavation
- Vacuum excavation around sensitive services
- Use of excavation support systems and temporary works
- Permit-controlled working around live utilities
- Segregated plant and pedestrian routes
- Lift plans and controlled lifting operations
- Ongoing contractor coordination and daily briefings
- Compliance with United Utilities Construction Health & Safety Standards
Particular attention was given to protecting live high-voltage electrical services and water infrastructure throughout the diversion works.
Outcome
GDB successfully completed the critical enabling works, delivering utility diversions, new access infrastructure and working areas that enabled the next phase of construction.
The project demonstrates GDB’s ability to:
- Deliver complex enabling works packages
- Manage high-risk utility diversions
- Coordinate multiple stakeholders and contractors
- Operate safely within live infrastructure environments
- Develop practical engineering solutions to overcome site constraints
The project demonstrates GDB’s capability to safely deliver complex early-stage civil engineering works that enable major utility programmes to progress efficiently.