The Bay of Plenty Regional Council says Opotiki is almost completely cut off following the closure of State Highway 2 due to flooding.
Rising river levels have resulted in slips and road closures after heavy rain in the region.
State Highway 2 is closed between Taneatua To Kutarere, east of Opotiki, blocking traffic from the east. Omaio Rd on State Highway 35 is down to one lane due to a washout.
And on Saturday evening the town's access problems were compunded when the stretch of State Highway 2 that links Opotiki with Gisborne, was closed at Waioeka Gorge due to several large slips.
The Bay of Plenty Regional Council says more heavy rain is expected, particularly in the eastern ranges with the heaviest falls expected in the early hours of Sunday morning. Taupo and northern Gisborne district are also expected to be affected.
A second warning level has been issued for the Otara, Waioeka, Waimana and Whakatane rivers which means a risk of floodwaters over rural, low-level stopbanks.
Regional Council staff are on stand-by monitoring river levels, with high tide expected at 11pm on Saturday. They say people should travel only if absolutely necessary.
Several rivers have reached first warning level, where farmers have been told to move stock from low-lying areas.
Regional Council staff are monitoring pumps and drainage systems and have been working with TrustPower to manage the level of Lake Matahina.
The forecast is for a further 150 to 200mm of rain until 6am on Sunday.