29 July 2014
Rainfall in Pittsburgh is normal this year but out West they’re in their 14th year of drought with no end in sight. This is starkly obvious at Lake Mead near Las Vegas where the water level has dropped 138 feet, leaving a “bathtub ring” of mineral deposits.
Seven western states and Mexico depend on Lake Mead for water; three states depend on its dam for electricity. Since last October 4.2 million acre feet came into the lake but 7.9 million was withdrawn. The lake has dropped 30 feet in the past five months alone. As the water drops so does Hoover Dam’s generating capacity, putting the electric supply at risk too.
You’d think this problem could be fixed by controlling surface water consumption but it goes much deeper than that.
Back in January, I wrote about NASA’s GRACE satellite pair that measures groundwater from outer space (click here to read how it works). Using nine years of GRACE data from the Colorado River Basin, University of California Irvine and NASA scientists made an alarming discovery. From December 2004 to November 2013 the watershed lost 53 million acre-feet of water, an amount almost twice the size of Lake Mead. More than 75% of that loss was from groundwater. No one knows how much water is underground but it’s going fast.
When wells deplete groundwater, there are significant downstream consequences. A 2012 study by Stanford Woods Institute found that overpumping can make the surface run dry. Though surface water is carefully managed in the West, groundwater use is often poorly documented and barely managed — if at all.
Water loss at this scale affects every living thing. Near Las Vegas the wetlands along Lake Mead are gone and so are the birds and animals that depended on them.
If the loss continues at this rate, humans may have to leave Las Vegas, too.
Read more about this study in Science Daily.
(photo of Lake Mead by U.S. Bureau of Reclamation)
Great report, Kate ! One would think this issue would be priority no. 1 in a Congress
which cared. I wonder how long it will be until the Great Lakes will be fought over like
a pork chop in a pack of starving dogs.
Much of the western part of our continent is desert. It should have never been developed to the extent it has been because it was inevitable that the amount of water occurring naturally in that area is not enough to support the human habitation and agriculture that has been developed there. I read an article in National Geographic several years ago that said that the past century has been one of the wettest one in in the western US in thousands of years, and humanity developed that area based on that abnormal level of water.
There are a few stories on the National Geographic web site that are discussing this situation:
http://news.nationalgeographic.com/news/2014/02/140214-drought-california-prehistory-science-climate-san-francisco-2/?rptregcta=reg_free_np&rptregcampaign=20140724_rw_membership_n1p_us_se_c1#
http://newswatch.nationalgeographic.com/2014/07/24/how-the-west-was-lost/
Oh, Yeah, where to begin. Unfortunately one of the benefits of all the irrigation, especially by agriculture, which uses 80% of all the water here in CA growing crops for everyone, is that is replenishes groundwater. When there are cutbacks in irrigation, groundwater suffers. One debate in cities like LA is whether to replace “hardscaping” with open ground as that will absorb whatever water it gets. Of course, then you’ll get weeds and that will lead to spraying… Meanwhile, like everywhere, you get those of us who try to conserve (feeling like a pioneer lugging gray water out to my flowers that are full of hummingbirds), but after years you reach a point where you can only do so much, and then there are those “me” people who do what they want. Meanwhile the development goes on and on. I can’t tell you how many letters in LA Times complain about all of us being told to cut back while houses, condos, apartments go up all around. All with landscaping, of course. And whatever we do in cities, that still only accounts for 20% of use. Then there are the places whose water rights were grandfathered in, some of which are currently growing RICE in rice paddies which ends up shipped to China. Just a big story in Sunday’s LA Times about the fortune well diggers are making as they search for more groundwater. I wonder how high food prices will have to go before people realize the reality of climate change. O.K. I’ll stop now.
Yow, Janet! That’s depressing.
I have been worried for a number of years that at some point in the near future millions of people from the southwest will move to the northeastern US in search of our water. This will put even more pressure on the neotropical migrant birds which spend the nesting season here.
Dick, my other worry is that someone will figure out how to economically ship our water to the West … and then they’ll sell it.
Oh, no, sorry. How about this: one of the rice growers is doing it organically, which has greatly increased the number of tri-colored blackbirds in his area.
We don’t need water from the Northeast, we need it from those farms in the Midwest losing crops to floods.
The perfect solution, Janet. 🙂