Colo. Rev. Stat. § 37-43-139
Whenever any irrigation district formed under the laws of this state has issued warrants for any purposes for which said irrigation district could lawfully have issued its bonds, it is lawful for said irrigation district to issue bonds for the purpose of retiring said warrants, submitting the question at a general or special election to the qualified voters of said district and otherwise complying with the provisions of the laws of this state in relation to the issuing of bonds by irrigation districts, and when so issued said bonds may be sold in the same manner as provided by law, at not less than ninety-five percent of the face value thereof, and the proceeds applied to the payment of said warrants and accrued interest, or said bonds may be exchanged for said warrants and accrued interest at not less than the face value of said bonds.
C.R.S. § 37-43-139