Colo. Rev. Stat. § 31-25-537
When any improvement authorized by this part 5 is petitioned for by the owners of property to be assessed for more than one-half of the entire costs estimated by the governing body to be assessed, it is the duty of the municipal officials whose duty it is to act to authorize said improvement, and an order in the nature of mandamus may issue out of any court of competent jurisdiction requiring said officials to take such action as is required by this part 5; but, if the material petitioned for is known to be worthless or of poor quality or would not make a good, substantial, and reasonable permanent improvement, the governing body may refuse to grant a petition for that reason. If a material petitioned for or designated in the specifications is a patented or proprietary article on which there can be but one bid, the governing body may refuse to award a contract if the entire bid is excessive as compared with improvements of equal value or may reject the bid or readvertise.
C.R.S. § 31-25-537
(1) This section is similar to former § 31-25-538 as it existed prior to 1975.
(2) This section was originally numbered as § 31-25-536 in House Bill 75-1089 but was renumbered on revision in 1977 for ease of location.