Prime Minister Boris Johnson has met families affected by the Whaley Bridge dam evacuation.
Mr Johnson met a number of the families affected by the evacuation, telling them he had flown over the dam twice and it was "dodgy but stable".
Julie Odams, the assistant director of communications at Derbyshire County Council, said around 1,000 people had been evacuated from Whaley Bridge.
The Prime Minister said at the Chapel-en-le-Frith High School: "I flew over the dam and it looks pretty scary. I can see the problem."
He assured residents "you will all be properly housed" if the dam burst.
Mr Johnson told a group of police officers: "Let's hope it doesn't happen."
During a multi-agency press conference, Assistant Chief Constable Kem Mehmet of Derbyshire Police urged residents to continue to stay away from the area.
He said there was still "a substantial threat to life" if the dam wall fails.
"We would ask residents to continue to heed police advice and stay away from Whaley Bridge," he told the press conference.
Due to concerns raised by residents over pets being left behind, he said officials had made the "difficult" decision to allow people to return to their homes in a "controlled" way.
"We will be putting plans in place for residents to return to their home to pick up very vital things they need along with their animal welfare.
"This is very controlled, I must stress that, because this is still life at risk."
Mr Mehmet said they had lowered the water level by half a metre by using pumps but the structural integrity of the dam wall is still at a "critical level".
He added that more pumps were being drafted in to help reduce the flow of water.
Julie Sharman, chief operating officer for Canal and River Trust, told the press conference the water level needs to be reduced by "several more" metres.
Residents will be restricted on how long they would be able to spend at their homes after returning to collect essentials, police said.
"Plans are being put together at the minute, you'll know we have a physical presence around that area where we don't want people to enter," Mr Mehmet told reporters.
"It'll be very controlled. We'll be recording who enters, we'll be restricting that to one person per household and we'll be giving clear instructions on how long residents have got before they report back to us."
He added that it was "difficult" to say when people would be allowed to return to their homes.