Colo. Rev. Stat. § 37-84-116
All headgates, measuring weirs, flumes, and devices used in connection with canals, flumes, and ditches or reservoirs for the measuring and delivering of waters therefrom and thereto shall be under the supervision and control at all times of the state engineer and the division engineer of the water division wherein such headgates, measuring weirs, flumes, and devices are located. Nothing in sections 37-84-112 to 37-84-117 shall be construed as prohibiting any water user in the state of Colorado or his appointed agent from reading any gauge, gauge rod, or measuring device or from determining the quantity of water diverted by any canal or impounded in or delivered from any reservoir, and it is here declared the intent and purpose of sections 37-84-112 to 37-84-117 to give any water user of Colorado or his appointed agent the right of ascertaining the quantity of water being diverted by any canal or impounded in or delivered from any reservoir without his being required to assign any reason for making such observations. Noncompliance with the provisions of sections 37-84-112 to 37-84-117 shall, during such noncompliance, forfeit the right to divert water into any canal or to impound water in or deliver water from any reservoir.
C.R.S. § 37-84-116