Toddbrook Reservoir is to be rebuilt, it was confirmed at a meeting with evacuated residents last night.
While water levels had now been reduced to a level safe enough to allow engineers to inspect the damage, the emergency phase is still ongoing, the meeting held at Chapel High School heard.
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Once the emergency phase is over, the reservoir will be rebuilt in the long-term, though this may take as long as three years, residents were told.
The meeting heard: "We will rebuild the reservoir.
"We are still in the emergency phase at the moment, but it will be rebuilt over the long-term. It may be as long as three years, but we don’t know at the moment.
"Once we move from the emergency phase, we will move to the reconstruction phase."
People living in 55 homes in the Horwich End area, who were evacuated on Saturday night, have been allowed to return home.
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Other residents, who were evacuated from their homes on Thursday, are hoping to hear later on today if they can also go home, after a meeting at 12noon.
The incident began last Thursday after damage to the dam wall caused by heavy rain.
Since then, over 1,000 people have been involved in the incident, working around the clock to try and shore up the dam.
As well as police, the fire service, the Canal and River Trust, Environment Agency and other agencies, the army and RAF have also been involved in the operation, with an RAF Chinook helicopter being used to drop bags of aggregate to reinforce the damaged spillway and stop water from entering the reservoir.