The diesel contamination of the Makotuku Stream near Raetihi would have been a disaster in summer, says Federated Farmers Ruapehu provincial president Lyn Neeson.
Farmers reliant upon Raetihi's water supply were as frustrated as the urban residents, she said, but remained hopeful alternative water supplies would be secured by the end of this week.
But buying extra equipment to water stock is an expense they don't need, she said, and if it had happened in summer it would have been a crisis.
"With livestock understandably refusing to drink from contaminated troughs, it had been a difficult week for the affected farms and especially those who draw water from Raetihi's water supply.
"What we need now is some heavy rain and it looks like some is on the cards.
"Farmers are coping quite well by moving stock to alternative sources either on or off-farm. This includes on-farm water supplies like dams through to sending stock off-farm.
"I know farmers are also installing tanks and pumps and we thank Ruapehu District Council for filling tanks for farm use if they can access them. But this comes at a cost which sheep and beef farmers didn't need."
"As farmers are just getting through calving and with lambing and docking under way, the timing isn't ideal but at least it isn't summer. If it had happened in several months time we would have been looking at a full-scale farming emergency," she said.
"The one dairy farm in the catchment has been thankfully unaffected.
Mrs Neeson said both the Ruapehu District Council and Horizons Regional Council had been "putting in hard graft to fix things and that is appreciated by us".
"As for how it happened, there will be questions that need to be answered but the first focus is rightly on getting water supplies running again.
"Like homeowners, farmers will then have to flush out our lines, tanks and troughs that have been turned off since the crisis started. The water should be fit for stock drinking water. We are also monitoring farms below Raetihi and will be closely check the impact any alternative supply may have on river levels.
"This shows how our livestock need clean drinking water and will reject contaminated water."