Sunderland City Council is taking legal action after revealing a £20m aquatic centre will have to close for up to nine months because of leaks.
The city's Olympic-sized facility was opened by the Princess Royal in January 2009 and is the largest of its kind between Yorkshire and Scotland.
The council has now "issued legal proceedings" against Balfour Beatty who built the complex.
Balfour Beatty said it would be "inappropriate to comment".
A council spokeswoman said the centre, which was used as a training venue for the London 2012 Olympics and adjoins Sunderland Football Club's Stadium of Light, would close in 2018 to allow "substantial repairs" to be carried out.
A statement added: "These works are required to remedy problems with condensation and leaks.
"To allow for the necessary arrangements to be put in place, the works will be carried out next year and it is estimated they will take six-nine months to complete.
"During the period of the works it is anticipated some dry-side facilities will remain in use such as the gym and changing areas.
"In parallel, the council has issued legal proceedings in respect of the remedial works that are now required to be undertaken."
The council's cabinet secretary Mel Speding, said: "Much as we don't want to close the pool at the aquatic centre for any length of time it is essential that this happens at some point in 2018 to allow the structural repairs that are needed to go ahead.
"There's never going to be a good time to carry out this kind of work, but we will be working with our partners Everyone Active, who manage the city's sports and leisure facilities on our behalf, to minimise the impact on users as much as much as we possibly can."
The pool's design incorporates a moveable floor so the water depth can be adjusted and a roof made of curved timber beams, aluminium and glass.