Most Wellington beaches were off-limits for swimmers on Thursday after the sewage treatment plant was forced to release wastewater due to heavy rainfall the night before.
It is the second time this week the Moa Point plant has discharged wastewater from its long outfall, off the coast of Lyall Bay.
Wellington Water said the screened wastewater, which has had solid debris removed, would appear murky and urged swimmers to check the Land Air Water Aoteaora (LAWA) website.
Wellington Water recommended all recreational water users follow LAWA's advice, which suggested staying out of the water for two to three days after heavy rain.
The country continues to clean up after the heavy rainfall and damage caused by Cyclone Hale over the last few days.
South Wairarapa communities cut off
Meanwhile, South Wairarapa has been hit hard by the tail of Cyclone Hale, isolating about 100 households.
The local council said the White Rock community was cut off by flooding at the Tuturumuri School area.
Tora and Te Awaiti areas are also blocked by a slip on Tora Rd.
The council said crews were working to clear slips and assess the state of the roads, but they were hampered by flooding and ongoing land movement. It said it could be several days before they were fully cleared.
Further north, Te Wharau Rd is closed between Gladstone and the east coast.
Several rural roads between Masterton and the coast are also closed.