“Motorists should expect longer travel times using the detour route,” Waka Kotahi said.
Tauranga will be hit by increasingly heavy rain today as the city heads to a top temperature of 21C before having possibly heavy falls again on Saturday with a top of 23C.
An orange heavy rain warning is also in place for areas west of Whakatāne until 7pm Saturday and the Coromandel today and into Saturday.
MetService says 70-100mm of rain could fall near the Coromandel coast, while the ranges could expect a dumping of 100mm to 140mm of rain.
In the Bay of Plenty west of Whakatāne, MetService expects between 130 and 180mm to fall.
Heavy rain watches are also in place for the Wairarapa, Tongariro National Park and Bay of Plenty from Whakatāne, east towards Gisborne.
The effects of the weather are already being felt with an outage at Waiomu, north of Thames, which knocked out power to about 347 homes around 9am.
Powerco expects to restore electricity by 1pm.
Several events for the holiday weekend are planned for the region including the One Love festival where up to 22,000 people are expected to descend on the Tauranga Domain over two days.