An Auckland sinkhole will be repaired almost a year after it first opened up

The hole opened up in a carpark on Parnell's St George's Bay Road in September last year.

It caused millions of litres of raw sewage to spill into the Waitemata Harbour before a temporary bypass was installed.

Months later, local businesses are reporting a noticeable decline in foot traffic, with some having to close their doors entirely.

Watercare asset and upgrades renewals manager Suzanne Lucas says they'll have the carpark back up and running by September.

She says they'll start reinstating the carpark and removing the bypass pump in the coming months.