Later, Mr Monds said he had been spraying for porina and had made several runs without incident.
About halfway through the job, he had been making a short, half-run working his way up a slope when the plane struck the line.
An air tractor's capacity means the pilot is able to make four long runs and one short run for each load.
Mr Monds said he "knew what it was" when he hit the power line. "It was an old wire, not visible in the light."
Mr Monds said, when spraying, pilots can be flying fairly close to the ground at speeds up to 120 knots.
A pilot of 35 years, Mr Monds said he had only once before hit a power line and that "was about 20 years ago".
He hoped this would be "the last call" for hitting power lines.
Mr Monds described the air tractor as being a solid aircraft. "They are very strong and capable."
Lines company Powerco arranged for temporary generators to be supplied to the farms that had lost the ability to pump water and called in a helicopter yesterday to help complete repairs, which were expected to be finished by 5pm.
The Civil Aviation Authority confirmed the incident had been reported promptly by the pilot, as required under part 12 of Civil Aviation rules.
Corporate Communications manager Mike Richards said the pilot had 10 days to lodge a formal account of the accident.
"Once this is received, we will review it and it may then be assigned to a CAA investigator."