Colo. Rev. Stat. § 37-43-211
An irrigation district proposing to become a contracting district shall submit the question of whether to become a contracting district at a special election called for that purpose. Copies of the contract proposed to be entered into shall be maintained at the office of the district from the date of notice of such election until the election is held, and such copies shall be available for inspection by landowners of the district during business hours. Each landowner who owns property within the district which is assessed for district taxes shall be entitled to cast one vote for each acre, or fraction thereof, of land owned by such landowners in the district. If a majority of the votes cast at such election are in favor of the irrigation district becoming a contracting district, such district shall be deemed to be subject to the provisions of this part 2, and the board of directors thereof shall be authorized to enter into a salinity control contract and to execute such modifications, extensions, and supplements thereto from time to time as the board shall deem appropriate.
C.R.S. § 37-43-211