Murky water seen flooding into Wellington's Lyall Bay is likely the product of a burst water main, the council says.
Swimmers and locals enjoying a rare sunny day were disappointed after the dirty brown water started coming out of the bay's stormwater pipe about 5pm.
Some speculated that the fluid could be sewage, leading Wellington City Council to warn people against entering the water until it was confirmed safe.
However, the council also tweeted that a major water main had burst earlier today in the suburb Kingston, which could have caused the dirty water.
Water would be off for some households in Kingston for a few more hours, particularly in the area of Quebec Street.