In a statement Derbyshire police has outlined the measures that are to take place to secure the dam wall.
Deputy Chief Constable Rachel Swann who is chair of the Local Resilience Forum said: “Over the course of the day we have been dealing with an unprecedented incident at the Toddbrook Reservoir in Whaley Bridge.
“As you will be aware, a wall of the reservoir has been badly damaged during recent heavy rain.
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“Following an assessment by structural engineers the decision was taken to stop access to Whaley Bridge and evacuate parts of the town – along with further areas downstream."
She added that at the same time as officers began those actions a multi-agency taskforce – involving the Environment Agency, Derbyshire Fire & Rescue Service, the Canal River Trust and many others, was working on a plan to address the damage to the dam wall.
The plan to secure the dam wall is now to:
Use 400 tonnes of aggregate to divert water from entering the reservoir and into other surrounding watercourses designed for this purpose.
Use water pumps to remove water from the reservoir to relieve pressure on the dam wall.
Once the above measures reduce the water to a level that is safe – work will then begin on the dam wall itself.
“The response to this incident has come from far and wide. Emergency services from across Derbyshire, the region and across the country have provided support already and will continue to do so in the forthcoming hours and days," Deputy Chief Constable Swann added.
“Ten specialist high-volume pumping fire appliances along with specially-trained fire and rescue flood advisors have been brought into the area from around the UK, utilising fire service national co-ordination arrangements.
“To move the substantial amount of aggregate into place – a Chinook helicopter will be operating in the area in the coming hours to allow precise placement and divert the flow of the water.
“With all that said, at this time the future of the dam wall remains in the balance and I would remind people of the very real danger posed to them should the wall collapse.
“I understand that being evacuated from your home is a very difficult decision and it is certainly not one that we make lightly.
“The evacuation point at Chapel High School, Long Lane, Chapel-en-le-Frith, High Peak, SK23 0TQ, will remain open through the night and residents will be accommodated if they are unable to make alternative arrangements.
“At this moment we have no time that we can give to residents when they will be able to get back into their homes.
“However, they should rest assured that all the agencies are doing everything humanly possible to bring the incident to a conclusion, however, that timescale is currently unknown.”