Where does the Colorado River water go?

Recently, Northern Arizona University (NAU) published information on Colorado River water usage and where it mainly goes.

More than half of the American West’s river is being redirected for agricultural irrigation.

A study done in 2020 by NAU is being updated to include a comprehensive look at where water is going. That includes evapotranspiration along riverbanks, water used by municipal commercial industrial/ institutional users, agriculture, interbasin and transfers, evaporations from reservoirs and use of water across the U.S. Border and Mexico. looking at the entire Colorado River system from where water is received in Wyoming to Tijuana, Mexico. Really encompassing the whole breadth of the Colorado river and where water is used.

Across the Colorado River basin, it was found that 54% of water is used for agriculture and the majority of that is for cattle feed crops such as alfalfa. It depends on where you are in the basin and how much water is going towards agriculture. The upper basin would have more water going to cattle feed crops whereas the lower basin would have less. The Gila River basin found about 54% of agricultural water goes towards alfalfa and 25% towards cotton.

In order to conduct this analysis, they used a modelling team from Virginia Tech University and a combination of data sets such as satellite data.

According to the research, the river loses 19.3 million acre-feet of water each year to cities, farms and evaporation, and the water cycle can’t keep up. This shortage of water triggered a formal declaration of a Tier 1 water shortage beginning in 2021, resulting in cuts in water deliveries, especially for Arizona farmers.

Research shows cattle-feed crops, including irrigated hay and alfalfa, are the prominent water-consuming crops, accounting for 62% of all Colorado River agricultural water usage consumed.

Richard Rushforth, NAU Assistant Research Professor, joined “Arizona Horizon” to discuss the research.

In their discovery, Rushforth explained, “Across the Colorado River Basin, 54% of water is used for agriculture. The majority of that water used in agriculture is for cattle feed crops, and it really depends on where you are in the basin how much water is going to agriculture.”

Rushforth added, “In the upper basin, you may have more water going to crops than in the lower basin. In Arizona or the Gila River Basin, 25% to cotton, so it depends on where you are in the basin how it’s used for.”