Columbine CDP (part), Arapahoe County, Colorado Property Maintenance: Vacant Lot Maintenance Rules (2026)

Vacant lots in unincorporated Arapahoe County are subject to the same nuisance and weed-control standards as occupied properties under County Code Section 7 and the Colorado Noxious Weed Act (CRS Title 35, Article 5.5). Grass and weeds must be maintained under 12 inches. Colorado List A (eradication required) and List B (containment) noxious weeds must be controlled regardless of property occupancy — Canada thistle, leafy spurge, musk thistle, purple loosestrife, and Russian knapweed are common in the Front Range. Trash, debris, and illegal dumping must be removed. Abandoned structures on vacant lots must be secured (windows and doors boarded or locked) to prevent unauthorized entry. The county does not require vacant lot registration in unincorporated areas. Code Enforcement conducts complaint-driven inspections plus an annual aerial photography review in summer to identify weed violations. Abatement mowing is performed at owner expense with costs ($300-$800 per acre typical) plus a 25% administrative fee liened against the property.