The Colorado River Compact of 1922 allocated both the upper and lower basins each 7.5 million acre-feet per year, but States are recognizing that they cannot plan on that amount of water being available.
The lower basin, made up of Arizona, California and Nevada, are estimated to have consumed less than 7 million acre-feet in 2016, the lowest rate of consumption since 1992.
New Mexico and Wyoming (upper basin states) base their planning on 5.8 million acre-feet of water being available to the upper basin.
While conservation programs are being pursued in both basins, there are also new proposed diversions. For example, a nuclear plant's right to withdraw water from the Green River in Utah was recently upheld by a state appeals courts.
As the population grows, demands on the basin increase and climatic changes alter when and how much water is available at any given time, the stress will only increase.
- "Colorado River’s Tale of Two Basins, " 2 August 2016 accessible at http://www.circleofblue.org/2016/world/colorado-rivers-tale-two-basins/.
- "Big CAP cuts coming as 3-state water agreement nears," 23 April 2016 accessible at http://tucson.com/news/local/big-cap-cuts-coming-as--state-water-agreement-nears/article_876e3aa6-6cf0-53ec-bd0c-95be8c6468ae.html.