As the #ColoradoRiver shrinks, can the basin find an equitable solution in sharing the river’s waters? — @WaterEdFdn #COriver #aridification #crwua2021

From The Water Education Foundation (Douglas E. Beeman):

Drought and Climate Change are raising concerns that a century-old compact that divided the river’s waters could force unwelcome cuts in use for the upper watershed

Climate scientist Brad Udall calls himself the skunk in the room when it comes to the Colorado River. Armed with a deck of PowerPoint slides and charts that highlight the Colorado River’s worsening math, the Colorado State University scientist offers a grim assessment of the river’s future: Runoff from the river’s headwaters is declining, less water is flowing into Lake Powell – the key reservoir near the Arizona-Utah border – and at the same time, more water is being released from the reservoir than it can sustainably provide.

Udall’s slides and charts suggest that unless something changes soon, water levels behind Lake Powell’s Glen Canyon Dam on the Arizona-Utah border may fall so low by 2025 or 2026 that no water can get past the dam. That could ultimately leave downstream states like California, Nevada and Arizona short of water promised under the century-old Colorado River Compact that divided the river’s waters between the upper and lower watersheds.

And that has the potential to set up something that many water interests on the river say they want to avoid – a so-called “Compact call.” Such a scenario could force the Upper Basin states – Colorado, New Mexico, Utah and Wyoming – to curtail their own water use to fulfill their Compact obligation to send a certain amount of water to the Lower Basin states of California, Arizona and Nevada.

There has never been a Compact call on the river. But as evidence grows that the river isn’t yielding the water assumed by the framers of the 1922 Colorado River Compact, questions arise about whether a Compact call may be coming, or whether the states and water interests, drawing on decades of sometimes difficult collaboration, can avert a river war that ends up in court. It’s no small matter for a river that serves water to 40 million people from Denver to Los Angeles and irrigates more than 4 million acres of crops. The growing risk and the difficult actions that might be necessary to avoid a Compact call have been hot topics of discussion at several recent Colorado River conferences.

“The temperature, metaphorically, seems to be rising,” Anne Castle, a former assistant secretary of the Interior for Water and Science and a Colorado River veteran, said in an interview. “There is a need for speed in reaching some sort of agreement to share the reduced flows of the river.”

A River in Trouble

Without question, the Colorado is a river in trouble. After more than two decades of drought, both of the river’s anchor reservoirs – Lake Powell, upstream of Lee Ferry (the dividing point between the Upper and Lower Basins), and Lake Mead, the nation’s largest reservoir located downstream of Lee Ferry near Las Vegas – are only about 30 percent full. The river’s Rocky Mountain watershed has begun to see snow this winter, but many more rich winters of storms would likely be needed to undo 22 years of drought.