Amendments to the Electricity (Hazards from Trees) Regulations 2003 by the government would create a 'clear to the sky' zone to prevent vegetation hanging over lines, which regulations currently allowed, Energy Minister Simeon Brown said.
There would also be a 'notice zone' of one metre around the existing limit. If vegetation entered this zone, lines owners would be able to alert tree owners about the risk of the encroaching vegetation.
"Trees or parts of trees falling on power lines is one of our most common causes of electricity outages - particularly in high winds," Brown said.
During Cyclone Gabrielle, branches falling from trees too close to power lines interrupted electricity supply to 68,000 households, he said.
The changes would come into effect in September.
Electrifying large parts of the economy would require large investments in transmission and local lines, he said.
"Strengthening the protection of our electricity lines by proactively removing risks is a strategic solution that will save New Zealand significant future investment in network repairs after weather events.
"Consultation will also begin shortly on further possible changes."