Southern Water has released film and images showing what it’s like to walk inside Hampshire’s expanded Yew Hill underground reservoir for the very last time, before it gets filled with water.

Find out more- click here to watch the video.

The Yew Hill Reservoir project started in November 2025 and is scheduled to be complete in the summer of 2027.

Yew Hill Reservoir is part of the Southampton Link Main, a project the water company is investing more than £100 million into, as part of plans to address water scarcity and strengthen water supplies in the southeast.

The Southampton Link Main will connect the Otterbourne Water Supply Works, Yew Hill reservoir and Rownhams Water Supply Works.

When the project is complete, it will allow water to be moved between the sites as required. .

The Southampton Link Main partnership is being delivered by Southern Water and MGjV - a joint venture between M Group Water and Galliford Try. The reservoir will be crucial for the region’s long-term water resilience, supporting flows of up to 60 million litres per day.

Phil Maunder, Engineering & Construction Project Manager at Southern Water said:

“The reservoir is made up of two cells and will collectively hold nine million litres of water, that’s around the size of four Olympic swimming pools. The structure is supported by more than 170 columns, has used more than 3,500m3 of concrete in its build and holds more than 650 tonnes of steel.”