As I write, the surface elevation of Lake Mead is 2 1/2 inches away from setting yet another record for its lowest levels since it was filled in the 1930s. Henry Brean, with characteristic flair, writes that the threshold will likely be crossed Sunday: The last time Lake Mead was this low was May 1937, …
Continue reading ‘Lake Mead, always with the record setting lows’ »
The folks at the Central Arizona Project and Arizona Department of Water Resources held a workshop yesterday to discuss the implications of Colorado River shortage. I didn’t have time to get down there, but Summer Pauli covered the basic message for Cronkite News Service: Arizona’s communities, industries, mines and Native American tribes aren’t likely to …
Continue reading ‘In a Colorado River shortage, Central Arizona will be fine for now’ »
At the risk of nickel-and-diming you with bad forecast news, today’s Bureau of Reclamation mid-month report is bad forecast news. April-July flow into Lake Powell is now forecast to be just 3.4 million acre feet, 47 percent of average (pdf). That’s down from 3.75 maf (52 percent) just two weeks ago. Runoff for the full …
Continue reading ‘Lake Powell spring runoff forecast this year now less than half of average’ »
Mike Cohen of the Pacific Institute, in some conversations last week sparked by my post about the risk of what we often call the “first ever” shortage in the Colorado River Basin, points out that shortages in fact are routine in the river’s Upper Basin. This is a result of hydrology. The Lower Basin – …
Continue reading ‘The Upper Basin: the Colorado River shortage that has already happened’ »
Sorry, that was a clickbait headline. Let me walk it back: Odds shifted slightly toward a wetter Southwest monsoon this summer! The usual forecast explainer: this shifts the odds from the climatological one-in-three-years-is-wet statistical binning to a 33-40 percent chance of wet in the light green area, upwards of 40 percent in the dark …
More than a million acre feet of water disappeared from Lake Powell in the latest U.S. Bureau of Reclamation operational forecast for the 2015 water year, translating to a 13 foot drop in the big Colorado River reservoir’s projected end-of-September elevation in this month’s forecast compared to just a month ago. The change in this …
Continue reading ‘Lake Powell takes a big hit in latest Bureau forecast’ »
Vanessa Barchfield: University of Arizona geoscientist Karl Flessa said Tuesday that the eight-week flooding helped to germinate and establish cottonwoods and willows that will live for up to 50 years, demonstrating that even a small amount of water can have long-lasting effects on an ecosystem. But, Flessa said, the impact of the water varied. “In …
Continue reading ‘Karl Flessa on the Colorado River pulse flow, one year on’ »
This cemetery, on the “banks” of the All-American Canal overlooking Bard on the California-Arizona desert, has no grass: Immediately behind me as I stood to take this picture last week was the All-American Canal, an artificial river built in the 1930s to carry Colorado River water to the Imperial Valley. A lot of water. The …
update, June 24, 2015: Since this post was written in April 2015, a wet spring has reduced the chance of a “shortage” in 2016. It now appears 2017 is the earliest this could happen. The situation described in rest of the post, detailing what happens when a “shortage” is declared, remains the same. previously tl;dr …
Continue reading ‘1,075: What a Lake Mead “shortage” would mean in practice’ »
Checked in this evening on the snowpack map, which I haven’t been watching closely. Yow, what I missed! On the left is percent of average for March 1, on the right is this morning’s percent of average: Here’s what that looks like summed up across the Colorado River Basin above Lake Powell: