[1/3] An aerial view of Lake Powell is seen, where water levels have declined dramatically as growing demand for water and climate change shrink the Colorado River in Page, Arizona, U.S., November 19, 2022.
"Six of the seven basin states are playing catch-up to reduce water use from the Colorado River, which is absolutely critically needed after 20 years of drought and the impacts of climate change," Moran told Reuters.
When the states struck their agreement 100 years ago, it envisaged the river could provide 20 million acre-feet of water a year.
Although California was deluged for weeks from late in December by seven atmospheric rivers that dumped up to 30 inches (76 cm) of rain over some areas, little of that reached the Colorado River basin.
A letter signed by the six states showed they all recognised the need for a change in operating procedures for the Colorado River and deliveries from it, she added.