Resurfacing works were completed earlier this year, according to councillor Chris Burbage, but the target opening date of today, June 21, has now been postponed.
A spokesperson for Peterborough City Council confirmed the new opening date, saying: "Given that lockdown restrictions did not end as planned the water park will now remain closed until the new date in July."
Last week prime minister Boris Johnson delayed the government's roadmap out of lockdown, meaning continued limits on numbers for sports events, theatres and cinemas.
Nightclubs have had to stay shuttered and people have been asked to continue working from home where possible.
The new date for lifting restrictions has been set to July 19, although there is likely to be a review of the data on June 28.