Thornton, CO Property Maintenance: Property Blight (2026)

Section 38-400, most recently amended by Ordinance No. 3745 on August 26, 2025, declares that blighted property impairs taxable values and threatens the health, safety and general welfare of Thornton residents, and it sets out specific causes of blight that are unlawful to maintain on any residential or commercial lot. These include outdoor, uncovered storage of building materials without an active permit; outdoor storage of dilapidated, damaged or unusable merchandise; accumulation of trash, rubbish, garbage or refuse in yards or common areas; landscaping that is not mowed, trimmed, or cleared of noxious weeds exceeding the height limits in Section 38-444; inoperable, unsafe, unlawful or abandoned motor vehicles, motor homes, or recreational vehicles in residential zones; unpermitted materials tied to a required temporary use permit; and dangerous major surface distress (potholes) on off-street parking or private drives.

A code compliance officer who finds a violation must give notice, and if the owner or occupant does not remove the blighting condition, the officer issues a written notice to show cause, setting a hearing before the city manager or a designee. At that administrative hearing the city bears the burden of proving blight by a preponderance of the evidence; hearsay is admissible but cannot be the sole basis for a finding. The city manager or designee then either clears the property or orders the owner to remove the blighting condition within a reasonable time, and in weed-height cases may issue a continuing order that stays in effect for one year.

A property owner who does not appeal within the applicable period waives the right to contest the order in district court under Colorado Rule of Civil Procedure 106(a)(4).