State Highway 2 will be deliberately closed this morning so police can retrieve a truck that was washed away in floodwaters at Katikati.
The floodwaters have already affected a 100m stretch of SH2 north of the township.
NZTA communications manager Natalie Dixon said the highway would be closed from at least 9am to 10am to allow for the salvage.
There were concerns that high tide could make the retrieval difficult and it was possible the road closure would take longer.
Cars and other light vehicles were advised to avoid the area. Trucks and 4WDs would be managed through the area by police, she said.
Katikati residents were bracing for high tide this morning with fears flooding will worsen and the township will be cut off.
Authorities are on high alert as concern grows about the impact high tide will have on saturated roads and properties.
A swollen creek at the southern end of the town had breached its banks and spilling on to State Highway 2.
A reporter in Katikati said the flood waters had washed a small truck off the road near Lindemann Rd, north of the township.
However, some traffic was being allowed through one lane at Lindemann Rd.
SH2 north of Katikati is CLOSED due to severe flooding. Please delay ur travel if possible or take an alt route ^LC pic.twitter.com/khAtRqVERR— NZTA Waikato/BoP (@NZTAWaiBoP) July 7, 2016
"Katikati is sited on the Uretera Stream tidal inlet so there is concern that as the high tide rises at 9 am the flooding will worsen," said Sergeant Tristan Murray.
"There is also reports coming in of a small creek 100m east of Hot Springs Road breaching the road at the moment.
"This may well mean Katikati will get cut off at both ends."
Earlier floodwaters had closed off the highway to both lanes, with motorists asked to delay their journey or take an alternative route such as SH29 over the Kaimai Range.
It was understood flooding was also affecting the highway south of Katikati.
Police said the flooding has affected the road between Philip Walter Drive and Lindemann Rd.
Water levels from the rising tide on Uretara Stream are going over the bridge and will continue to rise as high tide is at 9am.
Motorists are advised to avoid the area as there are currently no available diversions and there will be delays into the late morning.
Police ask people to please drive carefully and patiently in these weather conditions.
The NZTA warns the road will be closed for some time.
SH2 north of Katikati will remain CLOSED due to flooding for some time. Tauranga Traffic consider using SH29 Kaimai. ^LC— NZTA Waikato/BoP (@NZTAWaiBoP) July 7, 2016
Last month heavy downpour contributed to flooding in Papamoa, affecting several houses.