A weather warning for rain, storms and floods has been issued as emergency teams work to stop a dam from bursting in Derbyshire.

Residents have been allowed to briefly visit their homes on Saturday to collect essential items, such as medication that cannot be collected from elsewhere, and stranded pets.

Water levels at the Toddbrook Reservoir have been reduced by half a metre since Thursday but the damage to the 180-year-old structure remains at a "critical level".

Image: An officer comforts a resident during a 15-minute window when people could return home

Image: Residents rescue their mail from the post office

Kem Mehmet, assistant chief constable of Derbyshire Police, warned that there is still a "substantial threat to life".

"We would ask people only to return to their properties if absolutely necessary."


Image: A resident rushes to remove items from his home

The Met Office has issued its lowest yellow warning for much of northern England and the Midlands on Sunday, saying there could be damage and disruption from floodwater and lightning strikes - potentially hampering the race to stop the dam in Whaley Bridge from bursting.

The response to the damaged dam wall continued throughout the night.

Prime Minister Boris Johnson visited the damaged dam on Friday, describing it as "dodgy but stable" and a "substantial risk".

'Dodgy' dam needs to be rebuilt - Johnson

Image: Boris Johnson meets local residents and rescue crews near Whaley Bridge

If the dam collapses, destruction could be wreaked on "the whole of the village below, on livelihoods, on families, on homes", the prime minister said.

In a news conference not long before Mr Johnson arrived, police said the risk to life nearby "remains high".

Image: The prime minister at the site where sandbags are dropped by the RAF to help repair the dam

Mr Mehmet said the decision to allow people to collect pets and belongings had been "difficult", and it would happen in a "controlled" fashion.

He said one person per household will go at "their own risk".

"I would like to remind people that this still remains a critical incident. The structural integrity of the dam wall is still at a critical level and there is still a substantial threat to life," he said.

Police reassured residents with concerns for the security of their properties that a staffed cordon around Whaley Bridge is in place where officers are monitoring who goes in and out of town.

RAF Chinook drops sandbags to try to stop dam collapsing

The water level needs to drop by "several more" metres, the Canal and River Trust said, with further high-volume water pumps being brought in.

An RAF Chinook has been dropping one-tonne sandbags to bolster the damaged reservoir wall.

Asked to give his impressions, Boris Johnson said: "It's looking dodgy but stable is how I would describe it.

"The water all needs to come out, there needs to be a proper repair, a rebuild of that dam, and that's obviously what we're going to do," he told reporters.

Speaking separately at Chapel-en-le-Frith High School, he said: "I flew over the dam and it looks pretty scary. I can see the problem."

Residents would "all be properly housed" if the dam burst, he said.

Mr Johnson added to a group of police officers: "Let's hope it doesn't happen."

Image: Boris Johnson meets police at Whaley Bridge Football Club

Image: Boris Johnson meeting local people and rescue crews near Whaley Bridge

Environment Secretary Theresa Villiers, who chaired a meeting of the government's emergency Cobra committee on Friday aftermoon, said the dam had not been stabilised.

Ms Villiers urged people in Whaley Bridge to be "patient" and to continue to listen to advice from the emergency services.

She added that engineers were working "at pace to do everything we can to ensure that we stabilise the situation" but admitted it is "not stabilised as yet".

Image: The dam has been badly damaged

Image: Local people have been evacuated

Image: Water is pumped out of the reservoir

The reservoir, on the northwest edge of the Peak District National Park, was built in 1831, according to experts, although the Environment Agency records it as being built in 1840-41.

It "has a history of leakage", according to a 2011 Environment Agency report on national dam incidents.

A local resident who ignored calls to evacuate said the atmosphere was "eerie".

Hanna Sillitoe said: "The weather is beautiful, the sun is shining, and then a great big Chinook flies over the house and the stark reality of what's happening upstream hits us again."

Brian Stanway, who has a fireplace and woodburner business in Whaley Bridge, said he had "no time frame whatsoever" about when he would be able to return.

"We just hope that everyone's safe, that's the main thing, and that people have their homes to go back to," he said.

"It's a lovely town with a great local community and local spirit."