Three days after it breached its banks, the scale of destruction caused by the flooding of the Rangitata River is being revealed.
Four giant power pylons once standing 55 metres high have been bent and buckled by the force of the river and there's a large amount of farm damage.
Rangitata farmer Simon Johnson estimates a third of his 500-hectare dairy farm is underwater.
"This is the money-making end of the season so unfortunately, it's going to impact on that," he said.
Nearby a milking shed has been surrounded by water, with fences and farm tracks no match for the water's destructive power.
Most of the properties on Rangitata Island are dairy farms and for the last two days with the roads cut off they've been having to dump milk.
However, Fonterra staff have now got through and begun the process of checking tanker tracks so the milk can be collected.
South Canterbury Federated Farmers president Jason Grant told Rural Today that around 12 large farms, mainly dairy-operations, had been the worst affected.
He said there was a big clean-up ahead
"People run on adrenaline for two or three days, then that wears off and that's when it hits home," he said.
Farmers had been heartened by offers of support and help.
"The clean-up is going to be where the assistance from the public will be of real value," he said.
The Government announced on Sunday it was to provide funding of up to $50,000 through the Rural Support Trust to help affected farmers.
Meanwhile, residents are being warned of Rangitata River water levels rising again with Civil Defence urging people to evacuate immediately.
A spokesperson says the south branch of the river is of particular concern.
An existing evacuation notice is in place but anyone who has returned to the area risks being cut off.
"Please do not wait, even if your house has been given clearance by the response team yesterday [Monday]," the Timaru District Council said on Facebook.
"If you feel in immediate danger, call 111."