Colo. Rev. Stat. § 37-84-118
Every person or company owning or controlling any canal or ditch used for the purposes of irrigation and carrying water for pay, when demanded by the users from April 1 until November 1 in each year, shall keep a flow of water therein, so far as may be reasonably practicable for the purpose of irrigation, sufficient to meet the requirements of all such persons as are properly entitled to the use of water therefrom, to the extent, if necessary, to which such person may be entitled to water and no more. Whenever the rivers or public streams or sources from which the water is obtained are not sufficiently free from ice, or the volume of water therein is too low and inadequate for that purpose, then such canal or ditch shall be kept with as full a flow of water therein as may be practicable, subject, however, to the rights of priorities from the streams or other sources, as provided by law, and the necessity of cleaning, repairing, and maintaining the same in good condition.
C.R.S. § 37-84-118