Letchworth Lido remains closed due to "flooding" since yesterday afternoon.
With just under a week left of the swimming pool's season, the pool has been forced to shut.
The heated outdoor facility is run by Sport and Fitness group Everyone Active in partnership with North Herts County Council.
Everyone Active took to Facebook and said: "Due to flooding, Letchworth Lido will remain closed on Wednesday, September 4.
"We are closely monitoring the situation and plan to reopen on Thursday, September 5 for the remaining few days of the season.
"We apologise for any inconvenience this may cause and thank you for your patience and support."
Paul Dunstan, general manager for Everyone Active, Letchworth said: "We are pleased to confirm that Letchworth Lido will reopen at 7am tomorrow (Thursday, September 5) following a brief closure.
“Tuesday's heavy downpour caused rainwater and debris to flow into the pool area. We've thoroughly re-filtered the pool water and deep cleaned the entire area to ensure customer safety. We apologise for any inconvenience and look forward to welcoming swimmers back."
The Hitchin outdoor pool remains open to the public between 6am and 10pm.
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