Colo. Rev. Stat. § 37-23-112
In case the board of directors adopts the alternative method of assessment of benefits provided by sections 37-23-109 to 37-23-111, and after a tax has been levied upon the benefits so assessed for the purpose of paying the costs of completion of the proposed plan for the drainage system and carrying out the objects of the district, thereafter taxes may be levied for the purposes of meeting the maintenance, operating, and ordinary expenses of the district for the coming year and any deficiency in the payment of such expenses already incurred, and such taxes shall be levied in the manner provided by sections 37-23-107 and 37-23-108, with the exception that the amounts of money to be raised shall be apportioned among the several tracts assessed in proportion to the benefits assessed thereon under section 37-23-111 and with the further exception that the amount to be raised for the purposes of meeting the interest upon and the principal of the bonds of the district as the same accrue, together with any deficiencies in the payment of the same, shall be determined in the manner provided by sections 37-23-109 to 37-23-111, and shall so appear in the assessment roll provided by section 37-23-107.
C.R.S. § 37-23-112