The town was hit by extensive flooding in June last year, which left Hatea-a-Rangi School students out of their classrooms for eight months while repairs were completed.
They had only been back on site for a few weeks before water went through the school for a second time.
Hatea-a-Rangi board chairwoman Lillian Ward said the students were once again "school-less".
"It has really devastated us ... our children especially - they were so proud to move into what they called a 'brand spanking new school'.
"It took eight months to fix the school after 20 June. We wouldn't have a clue what the timeframe will be on this one but ... this time around it is more devastating."
Ward said the whole community mucked in with the clean-up last time around and seeing their hard work washed away was awful.
"It's just so frustrating. Our children are devastated that they can't go back to school."
The school was not alone in being hit twice, she said.
"One of our residents, her little pa ended up next door on her neighbour's back verandah. And another two residents lost their caravan, their car and their campervan that they were staying in, still waiting for their house to be fixed from [the June floods] last year."
Students will be doing distance learning for the next three weeks until the holidays while Hatea-a-Rangi negotiates the use of a temporary site, Ward said.
But this comes with its own set of challenges.
"Getting some Chromebooks would be good [for distance learning], we're still waiting on some from the 2020 lockdown. But a lot of our parents, because they don't have internet coverage, they've requested hard copies of the work.
"The principal is contacting the Ministry [of Education] to actually print those resources down in Wellington and send them up here because our printer is under water."
Farmer and former Gisborne District councillor Bill Busby reckoned the clean up would take a year.
"We can get most of the immediate stuff done in a couple of weeks but it's a big job to tidy up from these floods.
"Getting the roads and slips and culverts and the water supplies sorted - that's what takes a long time. It will take about a year to get everything back to running sweetly again."
Busby has a sheep and beef farm in Tokomaru and is missing about 30 cows.
"Some have been found 4-5km on to the neighbouring property but the rest, we don't know where they are. They've probably gone out to sea."
He said there had been more damage on the farm this week than there was from Cyclone Bola back in 1988.
"It's flooded all the valleys and washed out all the fences. The rivers in the valleys, that's what's caused all the damage."
The landline network was still down but most other things were back on, Busby added.
"We lost our power and phones for about a day ... but cellphone coverage and the internet is working again now and the power's back on so it's not too bad."
He said the town was divided after floodwaters broke Tokomaru Bay's bridge, effectively cutting off an entire chunk of the coast.
"On the southern side where most of the flooding has occurred, it's very sad for those people. The second time in a row, within six or seven months so it's not good for them at all."
Busby believed the bridge would be back in use by the end of next week.