Fonterra says an estimated 20% of farms in the affected area are still without power.

It's supplying generators for these farmers and arranging for them to use neighbours' milking sheds. It's also provided milk tankers for emergency water deliveries.

Fonterra’s Andrew Ferrier says its Plains milk processing plant at Clandeboye suffered minor damage, but is now running normally, as is the Synlait Dairy Company's milk powder plant near Dunsandel.

“It’s basically Kiwis helping Kiwis," said Mr. Ferrier. "We wanted our first reaction to be to jump in and help out – I mean we’re owned by ten thousand farmers just like them."

"We’ve been helping out communities without power, getting generators, and if they couldn’t get generators, then getting cows milked at nearby farms, and if we can’t help everyone directly, we’ve donated cash, because that’s what the guys on the ground need most.”