Anglian Water, working with Cambridge Water, is progressing plans for a new reservoir in the Cambridge Fens to secure future water supplies for Cambridge, nearby communities and West Norfolk. The area is one of the driest in the UK, with increasing pressure from housing growth and expanding technology industries.
The proposed reservoir would cover around six square miles north of Chatteris, bordered by the navigable 40 Foot River to the south and the 16 Foot River to the east. These waterways are expected to play a key role in how the reservoir integrates with the surrounding landscape and water supply network.
Inland Waterways Association (IWA) has been involved from an early stage as part of the project’s consultation group. In October 2025, Anglian Water published its Phase Three proposals, to which IWA submitted formal feedback in December.
Further consultation will take place ahead of a Development Consent Order application planned for early 2027, with a government decision expected in 2028. If approved, construction would start in 2030 and the reservoir would become operational in 2036.
IWA experts have raised concerns about the impact on navigation, waterway channels, air draft and moorings, particularly on the River Nene, River Great Ouse and the Middle Level navigation system, which will be used to move water during and after construction.
Plans include a visitor and watersports “lagoon” in the reservoir’s northwest corner. IWA has welcomed this, recommending early inclusion of infrastructure and suggesting that proposed paths and nature areas should also incorporate moorings to improve access for boaters and the public.
Around 2 million tonnes of aggregates and rock will be needed for construction. While nearby rivers are navigable, materials are currently expected to be delivered by rail and then by HGV, which could affect local roads. IWA has proposed using barges instead to reduce road traffic.
The Phase Three plans also favour transferring water by pipeline rather than restoring the Horseway Channel, closed to navigation since 2006. IWA has urged reconsideration, arguing that reopening the channel would benefit navigation, walking and cycling access, and public enjoyment of the Ouse Washes.
