Colo. Rev. Stat. § 37-47-121
All assessments on account of special improvements against appraised benefits and interest thereon and penalties for default of payment thereof, together with the cost of collecting the same, from the date of the filing of the "construction fund assessment" record and the "maintenance fund assessment" record in the office of the treasurer of the county wherein the lands and property are situate, shall constitute a perpetual lien in an amount not in excess of the benefits severally appraised upon the land and other property against which said assessments have been levied and such benefits appraised, to which only the lien of the general, state, county, city, town, or school taxes shall be paramount, but no sale of said property, to enforce any general, state, county, city, town, school tax, or other lien, shall extinguish the perpetual lien of said assessment. At any time any landowner may pay the full amount of said assessment, and thereafter the property of any such landowner shall be clear and free from said lien and shall not be subject to assessment for and on account of benefits appraised against any other land or default in the payment of assessments made against any other land.
C.R.S. § 37-47-121