Watford pond is due to be emptied and refilled because its water has turned an unsightly shade of green just days after it was officially reopened.
The borough council attributed the problem to "teething problem" with the water features new filtration system.
The pond was refilled last week after work on its revamp was completed as part of The Parade’s £4.3 million regeneration.
Before work started on the refurbishment, the council promised to improve the pond’s stagnant water with a new filtration system and beefed-up cleaning regime.
However days after the pond was refilled the water has turned a vomit green hue, prompting complaints from people on social media site Twitter that it looks a "cesspit".
Contractors were seen pumping the ponds waters today as work to improve the colour started.
Today Peter Nelson, a Watford Borough Council spokesman, said: "In commissioning the works a fault was identified affecting the pond's filtration system which keeps the water clean.
"This is a short-term teething problem and we are currently working hard with our contractors to rectify the issue.
"In the meantime, we are emptying and refilling the pond and hope to have it looking as we intended as soon as possible.
"There are currently no fish in the pond. They will only be returned once the filtration system is fully operational and the water is ready for them."