Opinion ID: 2823844
Heading Depth: 2
Heading Rank: 1

Heading: Colorado Water Law and HCU Analysis

Text: Â¶19Â Â Â Â The touchstone of Coloradoâs prior appropriation law is beneficial use. As such, an appropriator of water perfects a water right âonly by application of a specified quantity of water to an actual beneficial use.â Burlington Ditch, 256 P.3d at 661. The General Assembly has defined âbeneficial useâ as âthat amount of water that is reasonable and appropriate under reasonably efficient practices to accomplish without waste the purpose for which the appropriation is lawfully made.â Â§ 37-92-103(4), C.R.S. (2014). In conformance with this overarching principle, we have recognized that âthe right to change a water right is limited to that amount of water actually used beneficially pursuant to the decree at the appropriatorâs place of use.â Santa Fe Trail Ranches Prop. Owners Assân v. Simpson, 990 P.2d 46, 54 (Colo. 1999) (emphasis added). Â¶20Â Â Â Â This focus on beneficial use in a change proceeding complements Coloradoâs concomitant rule of preventing injury to others with vested water rights. See Burlington Ditch, 256 P.3d at 674 (noting that âthe key principle underlying our system of appropriationâ is âno injury to other water rightsâ). Thus, when the owner of a water right files an application to change its use, the water court âscrutinize[s] proposed alterations to existing decreed rights that may injure other decreed water rights.â Id. at 662. To that end, âThe amount of water available for use under the changed right . . . is subject to a calculation of historical beneficial consumptive use lawfully made under the decreed prior appropriation.â Id. (emphasis added). This HCU analysis âguards against speculation and waste, ensuring optimum use and reliability in the prior appropriation system.â Id. at 661. Â¶21Â Â Â Â Crucially, in practical terms, this HCU analysis does not merely measure the amount of water actually used over a representative period. Rather, a proper HCU analysis measures the amount of water actually and lawfully used. In a change proceeding involving, as here, a decree delineating the specific acreage to be irrigated,the amount of water lawfully used is that water used âover a representative period of time for the appropriation made.â Jones Ditch, 147 P.3d at 14 (emphasis added) (holding that although the original decree did not expressly limit consumptive use of the water to any specific acreage, the applicant could not lawfully enlarge the associated water right beyond the amount of water necessary to irrigate the lands for which the appropriation was made). Therefore, any HCU analysis of such a decreed right may only consider water applied to acreage expressly authorized by the relevant decree, i.e., the water lawfully used for the appropriation made. See Santa Fe, 990 P.2d at 52 (â[Amn undecreed change of use of a water right cannot be the basis for calculating the amount of consumable water that can be decreed for change to another use.â). Â¶22Â Â Â Â With these principles in mind, we now turn to the present case and determine the validity of Applicantsâ proposed HCU analysis.