Rising waters are threatening to cut off Ohura and flood parts of Ohakune, Ruapehu District Council says.
It had sent staff to monitor the situation and council contractors had been put on stand-by.
Residents in affected areas were asked to listen to local radio and check the council website for announcements.
Police said State Highway 4 between Wanganui and Raetihi had been closed until further notice.
Road authorities reported that slips and adverse conditions had made the area unsafe, requiring closure of that stretch of road while they tried to clear debris.
Around half a dozen Ohakune residents living on the Mangawhero River Terrace extension had left the as the river continued to rise.
Ruapehu District Council has established a welfare centre at the Ohakune Primary School hall.
Council chief executive and Civil Defence controller Peter Till advised any residents who feel that they are at risk should self-evacuate.
The council had also received reports that there was flooding across State Highway 4 at Erua.
Raetihi was also experiencing flooding.
Several houses in Grey St and Ballance St were surrounded by water though it hasn't gone into homes yet.
Ruapehu College in Ohakune has closed for the day because buses wouldn't be able to get students home with the Mangawhero River looking dangerous.
The Whanganui River was 12 metres at Pipiriki at midday and rising rapidly. It's the highest it's been in 10 years.
