Thornton, CO Landscaping Rules: Tree Trimming (2026)

Section 38-523 lists the city's local additions and modifications to the 2020 Edition of the Model Traffic Code for Colorado Municipalities, and item H repeals and reenacts MTC Section 114, Removal of Traffic Hazards, as Thornton's own rule. Subsection (1) puts the duty on the owner of real property abutting or on the right-of-way of a highway, sidewalk, or other public way: trim or remove, at that owner's expense, any tree limb, shrub, vine, hedge, or other plant that projects beyond the property line onto or over the public right-of-way and obstructs the view of traffic, obscures a traffic control device, or otherwise creates a hazard.

Subsection (2) extends the duty to dead, overhanging boughs that endanger life or property on the right-of-way once the city gives notice. If an owner fails to act within 10 days of written notice under subsection (3), the city may do the trimming or removal itself and bill the owner for the cost. A related nuisance provision, Section 38-396(11), lists dangerous surface distress and blight items separately, and Chapter 46, Article III, Division II governs tree trimming and removal within city parks rather than along streets, a distinct topic from this roadway-visibility rule.