New tree rules change rural power-line maintenance

Expanded clearance requirements now apply above rural power lines, with planting restrictions and new treefall hazard notices to follow. For arborists and landscape contractors, the changes affect maintenance planning, species selection and advice to clients

Arborists and landscape maintenance contractors working near rural power lines need to account for expanded overhead clearance requirements under changes to the Electricity (Hazards from Trees) Regulations 2003.

Since 17 October 2026, the 'clear to the sky' growth limit zone has been extended to lines at 11kV or below outside urban areas. MBIE’s guidance explains that this prevents 'tunnel trimming', where vegetation is cleared around a line but allowed to remain above it.

The June 2026 amendments also introduce restrictions on new planting from July 2027 and formal treefall hazard notices from July 2028, creating separate requirements for maintaining existing trees and planning new landscapes.

Look above the line

The growth limit zone is the space around a power line that vegetation must not enter. Its dimensions depend on the line’s voltage and span length.

The expanded requirement means maintenance assessments must consider branches overhanging affected rural lines, alongside vegetation growing towards them from below or beside them.

Trees entering the growth limit zone must generally be trimmed back to the cut-back zone, which extends another 1m, unless a dispensation applies. A separate hazard warning notice zone extends 2m beyond the growth limit zone, allowing lines owners to alert owners before vegetation reaches the clearance boundary.

Mature height will shape planting

From 23 July 2027, a low-height planting zone will restrict new trees within 24m horizontally of rural power lines.

Within the zone, owners or occupiers must have reasonable grounds to believe a tree’s mature height will not exceed its distance from the line. The closer the planting position, the shorter the tree must remain at maturity.

For landscape projects, the practical implication is to consider mature height when selecting and positioning trees, including planting undertaken by a contractor on a client’s behalf.

Exceptions apply to existing forest land, urban areas, trees planted as part of a shelterbelt, and land administered under the Conservation Act 1987. These exceptions depend on the definitions in the Regulations.

Owners who breach the planting restriction can be liable for resulting damage and the removal of hazardous trees. They cannot avoid responsibility for unlawfully planted trees through a no-interest notice. MBIE’s guidance also identifies restrictions on using that process for unmanaged self-sown trees within the zone.

Arborist assessments underpin new notices

From 23 July 2028, lines owners can issue treefall hazard notices for trees assessed as posing a moderate or high hazard.

The assessment zone extends horizontally 24m from the edge of the growth limit zone. Unlike the planting zone, its starting point therefore varies with the line’s clearance requirements.

Being within this zone does not automatically require removal. Lines owners must consider both the likelihood and impact of a fall, taking written advice from a suitably qualified and experienced arborist on fall likelihood. Each tree must be individually assessed, even where one notice covers several trees.

Moderate-hazard trees must be removed within 45 working days; high-hazard trees within 25.

Lines owners generally meet reasonable removal and debris costs. However, MBIE warns that refusing consent for a lines owner to enter and remove the tree ends its obligation to meet those costs. Owners have 10 working days to apply to the Tree Arbitrator to dispute a moderate- or high-hazard assessment.

Coordinate before cutting

Landscape maintenance crews should contact the network before proceeding if people, trees, tools or equipment could come within 4m of a power line. Specialist contractors or line isolation may be required.

Network Waitaki warns that branches can fall or swing unexpectedly and electricity can arc without direct contact – making early coordination essential when planning clearance work.

Changes at a glance

• 17 October 2026: expanded 'clear to the sky' requirements apply to rural lines at 11kV or below.

• 23 July 2027: low-height planting restrictions begin.

• 23 July 2028: formal treefall hazard notices can be issued.