Heat network warming 750 homes with water from a flooded coal mine wins national Gamechanger Award

A scheme that uses warm water from a flooded coal mine to heat hundreds of affordable homes has won a national award, showing how Britain's mining heritage can help power a low-carbon future.

The Seaham Garden Village mine water heat network in County Durham won the Gamechanger Award at the 2026 Accelerate to Zero Awards, the Mining Remediation Authority announced on 10 November. Judges chose it from projects across the UK, and it was recognised at a ceremony on 5 November held as part of BE-ST Fest in Glasgow. The award celebrates innovative ways to support a just transition in the built environment.

Heat from a closed colliery

Dawdon Colliery began producing coal in 1904 and operated for 85 years. After it closed, the old mine workings gradually filled with groundwater, rainwater and seawater. The Mining Remediation Authority's Dawdon treatment scheme already pumps and treats this water to protect the local aquifer.

That water comes to the surface at a naturally warm 18C to 20C. A 733kW water source heat pump raises the temperature further, and a heat network carries the warmth to 750 affordable homes at Seaham Garden Village. The scheme is expected to save 505 tonnes of carbon emissions a year.

"Putting a former coalfield's mining legacy to work"

Andrew Simpson, head of innovation, by-products and service delivery at the Mining Remediation Authority, said: "We're delighted that Seaham Garden Village has won the Gamechanger Award."

"The scheme shows what's possible when we put a former coalfield's mining legacy to work for the community. It uses warm water from our Dawdon mine water treatment scheme to provide clean, affordable and secure heat for hundreds of homes."

Kieran Walsh, regional manager for Vital Energi, which designed and built the energy centre and will run it, said: "This is a really special project because it continues the story of the north-east's mining heritage. It gives the infrastructure at Dawdon Colliery a new purpose, providing low-carbon heat for the surrounding area."

A partnership

The heat network was developed by Durham County Council, the Mining Remediation Authority, Karbon Homes and Vital Energi. Seaham Garden Village is part of a wider masterplan for 1,500 homes.

Could it work closer to home?

The Mining Remediation Authority operates more than 80 mine water treatment schemes across Great Britain, and says Seaham shows how existing infrastructure could also provide low-carbon heat. Coal mining once shaped large parts of the Black Country and Warwickshire, and the warm water left in old workings is an energy source many former coalfield communities could one day tap.

For residents at Seaham, the result is affordable, low-carbon heating for homes built on the doorstep of a pit that once powered the region, and a national award to show for it.