Whaley Bridge dam emergency - live: Reservoir wall at ‘high risk’ of collapse as entire town near Manchester evacuated amid major flood fears

Further damage to the Toddbrook reservoir dam could lead to "massive flooding", an expert has warned.

Dr Mohammed Heidarzadeh, assistant professor and head of coastal engineering and resilience at Brunel University in London, said the aid the damaged spillway of the dam - designed to release water - could become "fully broken" within hours.

He said: Due to heavy rainfall in Whaley Bridge area, the spillway is now broken and a big chunk of its concrete structure is damaged.

"There is a possibility that the spillway could then become fully broken in a few hours.

"If the spillway is fully gone, the embankment dam will be washed away very rapidly, which could cause a massive flood."

He added that a similar situation occurred at the Orovill dam in California in February 2017, leading to the evacuation of 188,000 [ep[;e living nearby. No collapse ultimately occurred on that occasion.

Another expert has said the dam would "should be okay" as long as the core of the reservoir is not damaged.

"Within the last few years new valves have been placed in the dam to expedite rapid drawdown in emergencies: presumably, this is happening now," said Professor Roderick Smith, of Imperial College London.

The former chief scientific adviser for the Department for Transport said the reservoir previously had "issues" with an inadequate valve system which has seen been replaced.

Any failure of the the Whalley Bridge dam would be "catastrophic", the area director of the Environment Agency has warned.

Lee Rawlinson told BBC Radio Manchester: "We as an environment agency are deeply concerned and we need to make sure that the reservoir is safe so we’ve issued a severe flood warning because if there was a catastrophic failure it would have devastating impacts to the River Goyt and the communities around it.

"There are quite a lot of dams around this area of the county and these dams are regularly inspected but with the amount of rainfall we’ve had some of these issues can arise."

Here are at the latest images, courtesy of PA, showing the crumbling wall of the Toddbrook reservoir: 

The Environment Agency's area director for the north west has said he is "humbled by the spirit of the community" in Whaley Bridge, where residents have been bringing cups of tea to emergency services working to evacuate the town and prevent flooding.

BREAKING: Police announce more evacuations

Further evacuations will take place downstream of Toddbrook Reservoir, Derbyshire Constabulary has announced.

The force said residents of a small number of properties within the flood risk area in Furness Vale and New Mills are being told by officers to move.

A number of roads have also been closed in the newly-affected areas.

Assistant chief constable Kem Mehmet, of Derbyshire police, said: “We understand that residents will be concerned about leaving their homes, however, our priority is to ensure people are kept safe and well and are not taking unnecessary risks.

“This is not a decision that has been taken lightly and we appreciate that there is significant impact on this community, however, this is an unprecedented, fast-moving, emergency situation.”

Widespread road closures are in place in Whaley Bridge and the surrounding area, including in the neighbouring towns of New Mills, Furness Vale, and Bridgemont.

You can see the full list of roads affected here.

Another section of the Whaley Bridge dam's spillway - designed to release water - collapsed this evening, according to a resident.

Carolyn Whittle, who lives on the town's hillside, told PA: "I've lived in Whaley for the best part of 45 years, and I've never seen water flood over the dam like that, ever, nor thought that we could possibly be at risk in this way."

Another Whaley Bridge resident, Ash Cox, said police officers told him he faced arrest if he refused to evacuate.

"We were told by the police officer leaving was mandatory... and if we don't leave, he would have to make arrests," he said.

"That would be very sad to do so we decided to follow procedure and leave even though we are well above the danger zone in our eyes."

There's an "eerie feeling" in Whaley Bridge tonight after the evacuation of thousands of the town's residents left the streets deserted, says BBC journalist Annabel Tiffin: