Farm owner James Adam said flooding on the Taieri during the first few days of January left many of his paddocks under water.
Then, as the water receded and dropped to about 10cm deep, the hot sunny weather arrived and started boiling the grass.
"When you get a hot day, it cooks it. It’s all dead and pretty smelly now. It’s all rotten.
He said if the grass was only under water for about six days, it would have survived and regrown, but these paddocks were under water for much longer.
While it was devastating to look at, he was used to working under Mother Nature’s whim, and said he was well prepared for such events.
"Its hard to make a sad story out of something that we’ve always dealt with. It’s where we live.
"You can get a flood here any month of the year, and occasionally this happens."
Mr Adam said he was about to start resowing the grass on about 98ha.