Several fences were damaged on the property, but no livestock were injured, he said.
Johnstone was in awe of the work of career and volunteer firefighters to bring the fire under control in such challenging conditions.
The fire was fanned by strong winds on Sunday.
"They did a fantastic job and were an absolute pleasure to deal with," he said.
"They were helpful, respectful — magic, really.
"I take my hat off to them ... we felt safe, and it was a very, very scary fire."
The community came together and supported each other throughout the fire.
"It's been pretty special," he said.
It was expected the clean-up would begin next week once fire crews were finished in the area, he said.
Livingstone resident Murray Smith described the blaze as a "freak of nature" and said it affected at least five farms.
"I feel very bad for the genuine farmers," Smith said.
A Department of Conservation crew also patrolled the perimeter last night and were to return this morning to mop up.