The department of public safety says an ice jam formed on the Tobique River overnight Thursday, leading to the temporary closure of about 20 kilometres of Route 390 between Arthurette and Plaster Rock.
The province said on Saturday that water levels would continue to rise over the next day.
They say people living along streams and rivers are asked to be on alert for ice movement and rapid water level increases.
Homeowners who have experienced flooding in the past should take all necessary precautions, including clearing snow and ice from drains to allow for effective drainage.
The department is asking residents to stay away from shorelines and the banks of rivers and streams, as water is rapidly flowing.