Colorado River depleted due to dry cycle and climate change
Climate change caused the Colorado River to experience 10 of its lowest flow years in more than a century and is depleted due to a dry cycle, Bureau of Reclamation Commissioner Mike Connor said at a Senate Energy and Natural Resources subcommittee on water and power July 16 hearing.
Evidence of increasing temperatures in the basin, accompanied by diminished snowpack caused the low flow from the river, Connor said.
The findings come from the Colorado River Basin Water Supply and Demand Study, a basin-wide study from the Interior Department's Reclamation Bureau that will be finalized in December.
The study, 3 years in the making, looked at Colorado River water use in Utah, Colorado, Wyoming, New Mexico, Arizona, Nevada and California. The study projected how population growth and climate change might shape demand in the next 50 years.
Upper Colorado River Commission Director Don Ostler said the study's findings were not surprising.
The study highlighted the differences between the upper basin states and the lower basin states.
The upper basin states have additional water to develop and "climate assumptions are the most significant factor to our vulnerability in the upper basin," Ostler said.
The lower basin states have already developed their full allotment of Colorado River water, he said, so their problem is facing system shortages.
Water conservation and reuse could help quell the problem and shore up shortfalls, but they aren't the complete solution.
"It is very tempting to look at conservation and reuse as the sliver bullet for Colorado River imbalances, but Arizonans have also learned we have to augment our water supplies," Arizona Municipal Water Users Association Director Kathleen Ferris said.
- go to the hearing page (webcast and prepared testimony available)