Colo. Rev. Stat. § 13-25-116
In all civil actions, special proceedings, or other modes of litigation before a water judge or referee having power to receive evidence, all records, reports, tables, and other documents of division engineers and water commissioners of the state of Colorado and all records, streamflow tables, rating curves, automatic water register sheets, and special reports of the state engineer and his deputies, hydrographers, and employees, and of the division engineers of the several divisions, and all records of canal headgate keepers, reservoir outlet keepers, gauge readers, and other systematically compiled records or reports of diversions, storage, and discharge of waters or of the flows of streams on file in or constituting a part of the records and files of the state engineer of the state of Colorado, and all copies duly certified as correct by the state engineer or his deputy shall be admitted as evidence of the facts contained therein.
C.R.S. § 13-25-116