"The reason we do this is because the roads that lead to school eventually become flooded. The school is always above the flood level.
"We have sent home students a number of times before. Last time was during the 2015 flood."
Bieleski said he could monitor the river level online from a gauge at Riminui Station 3km downriver.
The river level peaked this afternoon at 16.5 metres higher than usual, and has now receded slightly to 16.44 metres above normal.
"It's covering the road outside the schoolhouse by about half a metre," he said.
"If that's all we get, we have dodged the bullet. But with more rain to come, who knows what will happen tonight?"
The school was closed for three weeks in 2015, but Bieleski said the community accepted that the road would be closed sporadically.
"There's nothing you can do about it," he said. "You could shift the road but it would be hugely expensive."
Two parents rang him to discuss closing the school before he made the decision to close.
Despite its remoteness, the school has wireless internet and students can access resources online from their homes.
"We have wireless through Inspire Net so it's pretty fast, and most people in the valley now have got it, thanks to Inspire," he said.
"But of course if the power goes off you can't use it. If it keeps raining we'll get slips as well, they take out power poles."
