Western Snowpack Improving, But Odds Of Lower Colorado Basin Shortage Still North Of Two-Thirds

Winter storms have blanketed the mountains with snow across the Colorado River basin. But even this year’s above-average snowpack won’t be nearly enough to make up for the river’s chronic overallocation, compounded by 19 years of drought and the worsening effects of climate change.

Lake Powell and Lake Mead, the country’s two largest reservoirs, are now at just 40 percent of full capacity. The reservoirs have together been at their lowest levels since Glen Canyon Dam was built and Lake Powell was filled in the 1960s.

A shortage could be declared at Lake Mead starting next year, leading to water cutbacks in parts of the Southwest. And while it’s not yet clear whether Mead will sit below the trigger point for a shortage at the end of the year, federal water managers say chances are the reservoir will cross that critical threshold for the first time.

The latest projections from the federal Bureau of Reclamation this month show a 69 percent chance of a shortage in the river’s Lower Basin in 2020.

“Although this year's precipitation levels and snowpack are currently above average and trending in the right direction throughout much of the basin, it would take multiple above-average years for the storage conditions to recover from the drought,” Bureau of Reclamation spokeswoman Patti Aaron said in an email. She pointed out that the drought, which started in 2000, has been the driest 19-year period in more than a century of record-keeping.

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https://www.azcentral.com/story/news/local/arizona-environment/2019/02/27/colorado-river-shortage-arizona-snowy-winter-lake-mead-water-cutback-drought-contingency-plan/2994490002/