As defined by the 1969 Water Right Determination and Administration Act (C.R.S. 37-92-101 et seq.):
Beneficial use is the use of 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.
Therefore, beneficial use stands as the “basis, measure and limit of a water right,” (WEC, 2015:7). The amount needed for each beneficial use is determined by the amount required to move the water to the location of use, plus the amount needed for consumptive use (see the “Water Uses” section for a more detailed discussion of consumptive use). The portion of the water not consumptively used after put to beneficial use (returning to surface waters or aquifers) is referred to as return flow, and act as an important element in the appropriation system in satisfying downstream rights, providing instream flows and delivering water for interstate compacts and equitable apportionment decrees (see the “Agreements, Compacts & Treaties” section for details on Colorado’s downstream obligations). The use of representative historical time periods is typically how the measure and limit of beneficial consumptive use is determined (WEC, 2015). A caveat to this includes transmountain diversions (water exported from a west slope watershed to an east slope watershed), where the imported water is 100 percent consumptive. This means the water can be used to extinction and is not required to provide returns flows, because the water from the diversion will never flow back to its basin of origin (for a more detailed discussion of transmountain diversions, please see the “Agreements, Compacts & Treaties” section).
The definition of beneficial use is purposively flexible to allow for the incorporation of additional uses as new ways of using and delivering water develop, “so long as the need is real, the outcome is productive, and senior water rights are protected,” (Jones & Cech, 2009: 103). While there are others, the following are some of the most common beneficial uses of water rights:
|Augmentation||Fish & Wildlife Culture||Power Generation|
|Colorado Water Conservation Board Instream Flows & Natural Lake Levels||Flood Control||Recreation on Reservoirs|
|Commercial||Industrial||Recreational In-Channel Diversions|
|Domestic||Irrigation||Release from Storage for Boating & Fishing|
|Dust Suppression||Mined Land Reclamation||Snowmaking|
|Evaporation from a Gravel Pit||Municipal||Stock Watering|
|Fire Protection||Oil & Gas Production||Water Storage|