Some Colorado River scholars say that a plan by the lower-basin states to leave more water in Lake Mead embodies a principle they explore in a recently published article: Dropping reservoir levels have opened a window of opportunity for water-management policies that move the river system toward sustainability.

In December, water managers from California, Nevada and Arizona signed a memorandum of understanding, or MOU, to spend up to $200 million to add 500,000 acre-feet of water in both 2022 and 2023 to Lake Mead, the nation’s largest reservoir, which has dropped precipitously low due to climate change and drought.