the study<\/a>, published in the journal Geophysical Research Letters, shows an alarming rate of withdrawal of a vital water source for a region that could also see its supply of Colorado River water shrink.\n <\/p>\n\n \u201cWe\u2019re using it faster and faster,\u201d said Jay Famiglietti, an Arizona State University professor and the study\u2019s senior author.\n <\/p>\n
\n In the past two decades, groundwater basins \u2013 or large, underground aquifers \u2013 lost more than twice the amount of water that was taken out of major surface reservoirs, Famiglietti\u2019s team found, like Mead and Lake Powell, which themselves have seen water levels crash.\n <\/p>\n
\n The Arizona State University research team measured more than two decades of NASA satellite observations and used land modeling to trace how groundwater tables in the Colorado River basin were dwindling. The team focused mostly on Arizona, a state that is particularly vulnerable to future cutbacks on the Colorado River.\n <\/p>\n
\n Groundwater makes up about 35% of the total water supply for Arizona, said Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, who was not directly involved in the study.\n <\/p>\n
\n The study found groundwater tables in the Lower Colorado River basin, and Arizona in particular, have declined significantly in the last decade. The problem is especially pronounced in Arizona\u2019s rural areas, many of which don\u2019t have groundwater regulations, and little backup supply from rivers. With wells in rural Arizona increasingly running dry, farmers and homeowners now drill thousands of feet into the ground to access water.\n <\/p>\n
\n Scientists don\u2019t know exactly how much groundwater is left in Arizona, Famiglietti added, but the signs are troubling.\n <\/p>\n
\n \u201cWe have seen dry stream beds for decades,\u201d he said. \u201cThat\u2019s an indication that the connection between groundwater and rivers has been lost.\u201d\n <\/p>\n
\n Some land has also begun to cave in, with deep fissures forming in parts of the state as ground water has been pumped out. This is not unique to Arizona, Famiglietti said, with similar signs of disappearing groundwater happening in the agriculture-heavy Central Valley in California.\n <\/p>\n
\n Porter said the results illuminate the magnitude of the groundwater crisis in the Southwest, which is particularly helpful for state officials and lawmakers.\n <\/p>\n
\n \u201cThere are a lot of people who aren\u2019t sure if we have a serious situation with respect to groundwater, because groundwater is hidden,\u201d Porter said. \u201cThe value of the study is that it really adds a lot of information to the picture.\u201d\n <\/p>\n
\n Groundwater may be hidden, but scientists know with relative certainty that once it is pumped out, it won\u2019t be able to recharge within our lifetimes. Much of it was deposited tens or hundreds of thousands of years ago.\n <\/p>\n
\n \u201cIt takes geologic time\u201d to refill these deep aquifers \u2014 meaning thousands of years \u2014 \u201cand we as humans have more or less been burning through it in the last over the last century,\u201d Famiglietti said.\n <\/p>\n
\n Famiglietti warned the groundwater situation could worsen if the state\u2019s allocation of Colorado River water is further decreased, a decision that could be made in the next two years.\n <\/p>\n
\n If Arizona\u2019s Colorado River water allocation was cut to zero, \u201cwe could burn through the available groundwater in 50 years,\u201d Famiglietti said. \u201cWe\u2019re talking about decades. That\u2019s scary. No one wants that to happen.\u201d\n <\/p>\n
\n But Porter pushed back on that characterization, pointing out that Arizona cities have another stable water supply\u2014the Salt River. Porter added cities like Phoenix and Tucson are storing groundwater and have regulations designed to keep it from running out. Arizona has had a groundwater management law in place since 1980.\n <\/p>\n
\n \u201cWe\u2019re not expecting that the whole state would turn to groundwater,\u201d Porter said.\n <\/p>\n
\n Famiglietti said he hopes the study will prompt discussions over how to more effectively manage groundwater use in the region, especially from agriculture, which uses the lion\u2019s share of water. Much <\/strong>of Arizona\u2019s crops are exported, either to other states or, as is the case with alfalfa, internationally.\n <\/p>\n\n Famiglietti called it the \u201cabsolutely biggest\u201d choice that policymakers will have to decide.\n <\/p>\n
\n \u201cAgriculture just uses so much water,\u201d Famiglietti said. \u201cAre we going to plan to continue to grow as much food? Are we losing food that\u2019s important for the state, that\u2019s important for the country, or is it alfalfa that\u2019s being shipped to Saudi Arabia?\u201d\n <\/p>\n","protected":false},"excerpt":{"rendered":"Facebook Tweet Email Link Deep below the surface of the ground in one of the driest parts of…\n","protected":false},"author":2,"featured_media":147411,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3843],"tags":[728,70,16,15],"class_list":{"0":"post-147410","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-science","10":"tag-uk","11":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114603755110115931","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/147410","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=147410"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/147410\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/147411"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=147410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=147410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=147410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}