“Right now inflows across the basin are well below average. In fact we are setting records for what is in the stream today” (Dave Kanzer) — The #Colorado Sun #ColoradoRiver #COriver #aridification

Gunnison River Basin snowpack January 25, 2021 via the NRCS Colorado Snow Survey.

From The Colorado Sun (Jason Blevins):

The Bureau of Reclamation’s dire projections for Colorado River Basin reservoirs for the first time triggers drought contingency planning across seven basin states.

The dry 2020 and the lack of snow this season has water managers in seven states preparing for the first time for cutbacks outlined in drought contingency plans drafted two years ago.

A sobering forecast released this week by the Bureau of Reclamation shows the federally owned Lake Mead and Lake Powell — the nation’s two largest reservoirs and critical storage for Colorado River water and its 40 million users — dipping near-record-low levels. If those levels continue dropping as expected, long-negotiated agreements reached by the seven Colorado River Basin states in 2019 will go into effect, with water deliveries curtailed to prevent the federal government from stepping in and making hard water cuts.

The Bureau of Reclamation’s quarterly report was dire, showing Lake Powell at 42% of capacity and downriver’s Lake Mead at 40% capacity. And there’s not much water coming.

“Right now inflows across the basin are well below average. In fact we are setting records for what is in the stream today,” said Dave Kanzer, deputy chief engineer with the Colorado River Water Conservation District, presenting the bureau’s latest forecasts to the district’s board last week.

The bureau’s January report showed the impacts of a warming, drying climate peaking last year. The period from April to December was among the driest stretches ever recorded in the Southwest, with current conditions mirroring 2002, 2012, 2013 and 2018, four of the five driest years recorded in the Colorado River Basin. The bureau forecasts three scenarios for the next 24 months. Those three projections detail a most probable result, a best-case scenario and a worst-case situation.

Snowpack conditions right now in the mountains that feed the Colorado River and eventually fill Lake Powell are perilously close to the worst-case scenario. The bureau report shows the 2021 inflow into Lake Powell most likely will land around 53% of normal, but could end up as bad as 33% of normal.

The bureau expects the Utah reservoir will finish 2021 at 35% of capacity. If things get worse and follow that worst-case projection, the water level at Lake Powell could drop below a critical level — 3,525 feet above sea level — in early 2022 and that would threaten the ability of Glen Canyon Dam to generate electricity…

The “bathtub ring” at Lake Powell evidences lower flows coming into the reservoir. According to preliminary data from the Bureau of Reclamation, the total inflow into Lake Powell for the 2020 water year was about 6 million acre-feet, just 55% of average. Photo credit: Brent Gardner-Smith/Aspen Journalism

If the reservoir falls below that 3,525-foot elevation level, the Glen Canyon Dam will be unable to deliver hydro-electricity to more than 3 million customers and the federal government could lose as much as $150 million a year in revenue from selling that electricity. Any projection that the reservoir is headed toward that critical threshold gets water managers in all seven basin states ready for drought-response operations that spread the pain of water cuts across every region of the Colorado River Basin.

Jim Lochhead has helmed Denver Water for half of this prolonged drought. He’s seen good years like 2011 — really the last decent year for water in Colorado — and bad years, like 2013…

But with the lack of snow this season and snowpack in all but one of the state’s seven major river basins below median levels, Lochhead said he is “certainly very concerned about the supply outlook.”

[…]

Kanzer, in his report to the Colorado River district board last week, said soil conditions are very dry across Western Colorado. So the state can’t blizzard itself out of this drought hole.

“Even if we did get a good spring we would not get much benefit because all of the moisture would go into the soil and not run off,” Kanzer said.

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