Multi-million-pound flagship reservoir scheme marks a key milestone5th Dec 2025

The completion of the first earthworks season has capped a landmark year at the multi-million-pound flagship Havant Thicket Reservoir scheme.

Led by Portsmouth Water in partnership with Southern Water, the project is the UK’s first major water-storage reservoir since the 1980s.

Future Water MJJV Ltd, a joint venture between Jones Bros Civil Engineering UK and Mackley, were appointed principal contractor in 2023.

Progress made on site in 2025 includes:

Reservoir embankment: Foundations for the embankment are 60 per cent complete within the ground improvement zone. Once finished, work will focus on above-ground activity.

Culvert: Close to completion and now more than 230 metres long. The first and second lifts of the valve tower, which will be more than 22 metres high and allow for the abstraction of water at different levels from the reservoir, are finished.

Wetlands: The construction of penstock valves, which will control the flow of water in and out, has been completed, with more to follow in 2026. A second embankment is being built with four compartments along the north shore to hold water and create a wetland habitat even when the reservoir is drawn down.

Deputy project director for Future Water and earthworks construction director Geraint Lloyd is pleased with how things are shaping up.

He said: “It’s an interesting scheme to be involved in and the team has worked exceptionally hard to get it to the point it is at.

“We’ve made strong progress, especially considering some of the weather that has impacted ground conditions.

“Regardless, we’ve kept things on schedule, constructing various vital components, including a 14-metre-deep bentonite cut-off, which is an impermeable wall that forms a watertight barrier to prevent seepage, with the help of an 86-tonne long reach excavator.”

Some other notable milestones have included the formal planning approval of the reservoir’s pipelines. Two will be installed, with one carrying water from Bedhampton to Havant Thicket and the other drawing down to supply the customers in drought and emergency situations.

As well as no breaches of dust, vibration, and noise limits, some key environmental work has been taking place.

Geraint added: “We are constantly growing as a team, and I know the entire group is ready for what 2026 brings at Havant Thicket Reservoir.”

Ground was broken on the site in Hampshire in September 2024, with the project due for completion in the early 2030s.

Established in the 1950s, Jones Bros owns one of the largest plant fleets in the UK and employs approximately 550 people.

The company is currently working on contracts in various sectors including highways, flood and marine defence, reservoirs, waste management, and renewable energy around the UK.

The company runs an award-winning apprenticeship scheme, which has produced a large percentage of its current workforce, with several of its senior managers having started out as apprentices or in a trainee role. It has recruited hundreds of apprentices over the years.