Tree touching power lines in Washington, United States: who is responsible
Seattle City Light, Avista and Snohomish County PUD each publish tree pages for their Washington customers, and they draw the line between the utility's wires and the owner's service wire in different places. This page reports what those three pages say.
This page is for tree owners. It reports what the named sources say and is not advice about your tree: for that, ask a qualified arborist or one of the offices under Who to call.
Checked against the sources at the bottom of this page on October 9, 2026. Rules, fees and pay change: the source has the last word.
This page reports what the official source says. It is not legal advice: ask the office named here. It describes three utilities' own pages. It does not cover Washington's other electric utilities, and no state rule or statute was opened for this page. Other states have their own rules.
Seattle City Light
The City Light page Vegetation Management says the utility maintains clearances to above and below ground electric infrastructure under state and federal mandates. It says its practice follows International Society of Arboriculture and American National Standards Institute standards. It gives clearance objectives:
| Facility | Clearance objective on the page |
|---|---|
| Primary voltage distribution lines | 10 ft for slow-growing species, 14 ft for fast-growing species, and 15 ft overhang clearance. |
| Service lines and system neutral lines | 3 ft for slow-growing species and 5 ft for fast-growing species. The page says City Light prunes away from service lines for the first 10 ft from where they connect to utility poles. |
| Transformers | 10 ft for all tree species. |
| Utility poles | 3 ft. |
| Transmission lines, 115,000 and 240,000 volt | Based on line engineering, species, trim cycle and right-of-way width. |
The page says that before trimming, the utility visits the home to inform the owner and leaves a door hanger if no one is home. In an emergency where a tree has caused an outage or poses a safety hazard, trimming may be done at once with a follow-up notice. For trees that pose a significant safety or outage risk, it says it works with property owners on removal and provides free replacement trees and advice for customers living in Seattle, and certificates for free trees redeemable at partner nurseries for customers outside Seattle.
Avista
The Avista page Tree Pruning has a frequently asked questions list that says:
- Avista prunes around its transmission and distribution lines, and does not trim around telecommunications, cable TV or telephone equipment on its poles.
- It does not prune vegetation around the service wire between a nearby pole and a home or business. The page says this is the homeowner's responsibility, and that a customer who needs to trim for this wire can request a no-cost service drop by calling (800) 227-9187. It describes the service drop as de-energizing and temporarily removing the line, available Monday to Friday between 8 a.m. and 3 p.m. with at least three business days notice.
- Avista says it charges nothing for routine tree maintenance, risk tree mitigation, the service wire drop option or its Cycle Buster Replacement program.
- Risk tree mitigation removes visibly dead, diseased, dying or unstable trees near power lines. Trees encroaching on a 10-foot clearance of distribution and transmission lines are addressed, and owners get a postcard before removal.
- Routine maintenance debris is chipped on site and left for the owner. For risk tree mitigation, trimmings are left as they are. For storm damage, the owner is responsible for all trimming and debris cleanup. For work in or near the service wire, the homeowner coordinates all cleanup.
The page also describes a Safe Tree Program in which the utility works with a landowner to assess trees that could contact its lines for removal and replacement with low growing trees, at no cost to the owner.
Snohomish County PUD
The PUD page Tree Trimming Near Power Lines says it dispatches an ISA Certified Arborist to evaluate lines before tree work, except in emergencies, notifies landowners by door hanger, mail, phone, email or postcard, and asks for a signed authorization form if removal is needed. It says a qualified electrical worker must do tree work within 10 feet of a primary conductor. It says the PUD does not maintain vegetation around service lines or standalone communication lines, and gives 425-783-5579, Monday to Friday, 7 am to 3 pm, for questions.
What the sources leave out
The three utilities set different clearance figures. Seattle City Light refers to state and federal mandates without naming them, and the Avista page lists WAC 296-45 among laws and regulations without explaining it. Puget Sound Energy also publishes a tree page, and the pages read did not set out who maintains service lines there.
Who to call
- Avista, (800) 227-9187: a no-cost service drop so a service wire can be worked on safely
- Snohomish County PUD, 425-783-5579: questions about tree maintenance near lines in the PUD area, weekdays 7 am to 3 pm
- Seattle City Light, report a tree problem: a fallen tree or branches near power lines or equipment