Spalding’s Castle Swimming Pool remains closed to the public.
The facility on Pinchbeck Road was shut after flooding damaged the pool’s plant room on August 17.
It had been hoped the pool would re-open in time for the remainder of the summer holidays.
But the schools have gone back this week and there is no sign of the pool being open.
“The damage was much more serious and we need to make sure we prevent water getting in again,” said Coun Gary Taylor, portfolio holder for facilities.
New parts had to be sourced after the flooding and tests carried out on water quality.
Initially, South Holland District Council was hoping to re-open once the new parts were fitted.
“We still have to have further electrical inspections and we need to ensure it doesn’t happen again.
“There were similar floods ten or 12 years ago and we don’t want to open it and have to close it again after a downpour,” said Coun Taylor.
He said the closure couldn’t have happened at a worse time because the number of people using the pool had been steadily increasing post-Covid.
“It’s been a real dig in the ribs,” he said.
“The numbers were looking good, but it’s better to be safe than sorry and we want to be sure things are right,” he said.
Coun Taylor couldn’t give a date that was being aimed at, but said there would be plenty of publicity once all the inspections had been successfully passed.