A tunnel could be dug under a town’s historic bridges to house cables to power 5,000 new homes.

Thetford & Brandon Times: The Kingsfleet development in Thetford. Picture: Lauren De Boise.The Kingsfleet development in Thetford. Picture: Lauren De Boise. (Image: Archant)

Plans submitted by Balfour Beatty construction company to build a substation and route power cables through Thetford have been lodged with Breckland Council.

The proposal is set to provide power for the Thetford Urban Extension (SUE), which includes the building of 5,000 new homes as part of the Kingsfleet development.

And as the first phase of the build is well underway, developers have said without this “essential infrastructure” it is “unlikely to be completed”.

The planning documents state: “Balfour Beatty has been commissioned to provide the design and build of a new 21MVA substation and interconnection of a 7.5km 33kV cable, extending the power supply from the existing Primary 132kV substation south of Barnham Camp, RAF Honington, to a newly constructed Substation north of Thetford, located on land east of the A1075 and south of the A11 roundabout junction.

Thetford & Brandon Times: The masterplan for Thetford's 5,000-home Kingsfleet housing estate. Photo: Pigeon Investment ManagementThe masterplan for Thetford's 5,000-home Kingsfleet housing estate. Photo: Pigeon Investment Management (Image: Pigeon Investment Management)

“This will enable power supply to the Thetford and the Sustainable Urban Extension (SUE), also known as Kingsfleet, which aims to build a new housing development of approximately 5,000 homes, on the northern edge of Thetford.”

“The 771 hectare development will also include three primary schools, employment land, open spaces and commercial centres.”

The construction company has put forward two options to route the power to the site, which include going under the grade II listed Three Nunns’ Bridges, at varying depths.

The planning documents added: “Option one relates to the cable route going under the Three Nunns’ Bridge Area, but below the foundations and would track along the centre line of the bridges.

Thetford & Brandon Times: A beautiful row of modern townhouses by Hopkins Homes has set the benchmark for other developers to follow on the Kingsfleet development in Thetford. Picture: Neil DidsburyA beautiful row of modern townhouses by Hopkins Homes has set the benchmark for other developers to follow on the Kingsfleet development in Thetford. Picture: Neil Didsbury (Image: Archant)

“Option two relates to the cable route going under the water, well below water level, but going around the bridges.

“It is important to note that all works will be away from the bridge and are quite simple and would be undertaken by a directional drill.

“We believe that this is a far better approach than trying to attach the cable to the bridge somehow or drilling into the road surface of the bridge.”

The Three Nunns’ Bridge Area is a scheduled monument and requires scheduled consent before any work can take place.

Plans will go before Breckland Council for a decision.