They are part of a £730,000 investment by North Somerset Council in its leisure centres which will also see work carried out at Strode in Clevedon and Hutton Moor in Weston-super-Mare.
"Leisure centres play a vital role in our local communities by improving residents' physical and mental wellbeing," said Cllr Mike Solomon, the council's executive member for communities, tourism and leisure.
"The council is committed to supporting leisure provision across the district at a time when maintaining a good level of physical and mental health is more important than ever for our residents."
At Backwell, which has been closed since March due to the coronavirus pandemic, the boilers responsible for heating the building and pool will be replaced and extensive repairs carried out to the leaking roof.
"During the period of the first lockdown it became apparent that significant maintenance work was needed at Backwell," said Cllr Solomon. "Work to establish what was required to enable the centre to operate again has been completed and I now look forward to this being done and the centre re-opening as soon as possible in the new year."
In addition to the work at Backwell, repairs will also be carried out at Strode and Hutton Moor leisure centres to ensure the buildings remain as efficient as possible. Both of these centres, along with Scotch Horn in Nailsea and Parish Wharf at Portishead, are currently closed due to the latest lockdown restrictions.
At Strode tiling in the pool changing rooms will be replaced and work to strengthen internal columns carried out.
Building cladding in poor condition will be replaced at Hutton Moor where fire safety works and repairs to leaks in the pipes servicing the swimming pool have already been completed.