Balclutha Centennial Swimming Pool reopened last Thursday after annual maintenance, and the highly popular hot spa pool is back in action.

The spa had been closed since November last year because of a leaking supply valve which caused rapid draining so water level and temperature could not be maintained.

‘‘It was a complex problem due to the issue being underground . . . and technicians using specialist equipment worked through a process of elimination to determine the location of the leak,’’ a council spokesman said.

The system is now complete, full of fresh water and completely operational.

The main pool and children’s pool have also been refilled, following a shutdown of five and a-half weeks for draining, checking, cleaning, refilling and reheating the fresh pool water.

Reheating the big pool alone takes five days and regular staff took care of basic cleaning — scrubbing 160,000 tiles by hand.

‘‘It’s mostly just body fat,’’ lifeguard Maia Pryde said.

‘‘Pretty gross but satisfying.

‘‘There are a lot of responsibilities to the job — cleaning and hygiene are a major part.’’

The pool is 51 years old and underwent major refurbishment and recladding 10 years ago at a cost of about $5.1 million.

It was open 315 days of its last operational year and has averaged 39,281 visitors per annum over the last 10 years.

Entry fees are 8.7% of the revenue for the pool and go towards about 20 staff, maintenance capital and all other running costs.

‘‘This is a fantastic facility for the Clutha district, and it is great to have such a supportive and engaged community using it,’’ the council spokesman said.

‘‘We appreciate the hard work our staff have put into cleaning it and the patience of the community during this time.’’

Scheduled annual maintenance allows the pool to operate with fewer disruptions during the year and fulfils hygiene compliance requirements.

The cost of the recent work is not yet known, but it is expected to be less than $10,000.

Lifeguard Olivia Pirie was pleased to be back to business as usual.

‘‘People really look forward to coming to the pools, you can feel that as they come through the doors.

‘‘It’s a pleasure to be part of that.

‘‘Making sure they have a really positive experience is the best part of the job.’’