One of the biggest water mains in Auckland's CBD bursts

One of the biggest water mains in Auckland's CBD has burst, sending a torrent of water flooding through a park.

Watercare says it broke in Arch Hill Scenic Reserve, Grey Lynn early this morning.

"The 550mm diameter water main is one of the bigger water pipes in the CBD and we anticipate repairs could take up to 24 hours," a spokesperson says.

Contractors are on-site and the broken section of pipe has now been isolated.

"Water has stopped flowing through the park and repairs will begin shortly," a spokesperson says.

Traffic management is in place along nearby roads while the pipe is being fixed.

A map of the affected area.
A map of the affected area. Photo credit: Watercare / Supplied

"No water outages are expected but residents over a wide area of central-west Auckland may notice reduced water pressure, whilst the repairs are underway," Watercare says.

"We ask residents to please reduce water consumption whilst this emergency work takes place."

Updates are available on the Watercare website.