Wellingtonians are being urged to stay out of the water after sewage leaked into the harbour.
A water main burst near the central police station on Victoria Street this morning.
Wellington City Council spokesman Richard MacLean says unfortunately, they've had to let quite a bit of diluted sewage flow into the harbour through the storm water system, to ease pressure.
He says Frank Kitts Lagoon is the main area affected.
MacLean says anyone entertaining the idea of a mid-winter swim is urged to reconsider, until the water is given the all clear.