Colo. Rev. Stat. § 37-43-141
The board of directors of any irrigation district within the state may annually or otherwise levy and assess such tolls or charges as may be necessary to raise moneys for the maintenance and operation or payment of existing unfunded indebtedness of the district, said tolls or charges to be levied and assessed pro rata upon each acre of land within the district for the use of water for the irrigation thereof. By resolution, the board may refuse to deliver water to any land within such district when the owner thereof, within such time as may be fixed by such resolution, fails or refuses to pay in cash, to the secretary or treasurer of the district, such tolls or charges. Where a district takes over by deed or assignment or otherwise any irrigation system or works, or parts thereof, either upon reorganization or otherwise, the board of directors of any such district in like manner may collect any and all assessments theretofore levied for maintenance and operation by its predecessor in the ownership or operation of such system, whether such predecessor is a district or a mutual company, if such assessments are assigned to and become the property of the district seeking to collect the same.
C.R.S. § 37-43-141