Clancy has been selected to deliver a £39m pipeline scheme for Southern Water in Hampshire, with the contractor set to take responsibility for the design and construction of the Andover Link Main.
The project will involve installing a new underground water pipeline between Winchester and Andover, alongside associated pumping infrastructure and upgrades intended to improve the resilience of local water supplies, particularly during periods of drought.
Extending 22.8km, the pipeline will connect Crab Wood service reservoir near Winchester with Micheldever Road service reservoir on the outskirts of Andover. Once operational, the link will provide the ability to transfer up to 15 million litres of water a day in either direction, giving Southern Water greater flexibility in managing supplies across the region.
A key objective is to strengthen water provision to the relatively isolated Andover water resource zone, while reducing demand on the rivers Test and Itchen. The additional transfer capacity is intended to improve the ability to balance supplies between different parts of the network, helping Southern Water respond to changing demand and periods of reduced water availability.
Clancy’s proposed contract covers detailed design, enabling works and the main construction programme. Its responsibilities will also include supporting the discharge of planning conditions and obtaining the environmental permits required to undertake the work.
Initial site preparation, including vegetation clearance, is expected to begin later this year. Full construction is anticipated to start in winter 2027, with the programme expected to run for approximately three and a half years.
Delivering the pipeline will involve a number of engineering challenges, particularly where the route intersects existing infrastructure and environmentally sensitive locations. Southern Water’s earlier engineering proposals identified the need for trenchless crossings beneath the rivers Test and Dever, together with multiple crossings of the A303.
These elements will require careful planning and coordination to minimise disruption to road users, watercourses and surrounding land. Trenchless construction techniques will allow sections of the pipeline to be installed beneath obstacles without the need for conventional open-cut excavation across their full width.
Environmental considerations form another important part of the scheme. The pipeline has been designed around a planned operational life of 100 years, reflecting the long-term investment required to strengthen the regional water network. Southern Water is also targeting at least 10% biodiversity net gain, with measures intended to ensure that the development delivers improvements to the natural environment alongside its infrastructure benefits.
Planning applications for the project were submitted earlier this year to Winchester City Council and Test Valley Borough Council. The proposals set out the route and associated infrastructure required to connect the two service reservoirs and establish the additional water transfer capacity.
Clancy’s appointment is expected to be formally confirmed at the end of the month. The scheme will add to the contractor’s involvement in the delivery of essential water infrastructure, with the project combining pipeline engineering, pumping facilities and complex environmental and transport crossings.
For Southern Water, the Andover Link Main represents a substantial investment in the flexibility and resilience of its distribution network. By creating a new connection between Winchester and Andover, the project will provide an additional means of moving water around the region, helping to protect supplies while easing pressure on important local river systems.
