Latest news with #GeophysicalResearchLetters
Washington Post
2 days ago
- Science
- Washington Post
Satellite measures river flow waves for the first time
Long river waves, known as flow waves, have been measured by satellite for the first time, researchers announced May 14, a breakthrough that could expand understanding of river dynamics, floods and the other hazards sometimes present when the waves form. In a study in Geophysical Research Letters, the researchers found that the long waves can be spotted and studied using data from a NASA-French space agency satellite designed to study Earth's water.
Yahoo
3 days ago
- Business
- Yahoo
The Colorado River Basin has lost as much groundwater as the entire volume of Lake Mead
Deep below the surface of the ground in one of the driest parts of the country, there is a looming problem: The water is running out — but not the kind that fills lakes, streams and reservoirs. The amount of groundwater that has been pumped out of the Colorado River Basin since 2003 is enough to fill Lake Mead, researchers report in a study published earlier this week. Most of that water was used to irrigate fields of alfalfa and vegetables grown in the desert Southwest. No one knows exactly how much is left, but the study, 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. 'We're using it faster and faster,' said Jay Famiglietti, an Arizona State University professor and the study's senior author. In the past two decades, groundwater basins – or large, underground aquifers – lost more than twice the amount of water that was taken out of major surface reservoirs, Famiglietti's team found, like Mead and Lake Powell, which themselves have seen water levels crash. 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. 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. 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's rural areas, many of which don't 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. Scientists don't know exactly how much groundwater is left in Arizona, Famiglietti added, but the signs are troubling. 'We have seen dry stream beds for decades,' he said. 'That's an indication that the connection between groundwater and rivers has been lost.' 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. Porter said the results illuminate the magnitude of the groundwater crisis in the Southwest, which is particularly helpful for state officials and lawmakers. 'There are a lot of people who aren't sure if we have a serious situation with respect to groundwater, because groundwater is hidden,' Porter said. 'The value of the study is that it really adds a lot of information to the picture.' Groundwater may be hidden, but scientists know with relative certainty that once it is pumped out, it won't be able to recharge within our lifetimes. Much of it was deposited tens or hundreds of thousands of years ago. 'It takes geologic time' to refill these deep aquifers — meaning thousands of years — 'and we as humans have more or less been burning through it in the last over the last century,' Famiglietti said. Famiglietti warned the groundwater situation could worsen if the state's allocation of Colorado River water is further decreased, a decision that could be made in the next two years. If Arizona's Colorado River water allocation was cut to zero, 'we could burn through the available groundwater in 50 years,' Famiglietti said. 'We're talking about decades. That's scary. No one wants that to happen.' But Porter pushed back on that characterization, pointing out that Arizona cities have another stable water supply—the 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. 'We're not expecting that the whole state would turn to groundwater,' Porter said. 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's share of water. Much of Arizona's crops are exported, either to other states or, as is the case with alfalfa, internationally. Famiglietti called it the 'absolutely biggest' choice that policymakers will have to decide. 'Agriculture just uses so much water,' Famiglietti said. 'Are we going to plan to continue to grow as much food? Are we losing food that's important for the state, that's important for the country, or is it alfalfa that's being shipped to Saudi Arabia?'
CNN
3 days ago
- Business
- CNN
The Colorado River Basin has lost as much groundwater as the entire volume of Lake Mead
Deep below the surface of the ground in one of the driest parts of the country, there is a looming problem: The water is running out — but not the kind that fills lakes, streams and reservoirs. The amount of groundwater that has been pumped out of the Colorado River Basin since 2003 is enough to fill Lake Mead, researchers report in a study published earlier this week. Most of that water was used to irrigate fields of alfalfa and vegetables grown in the desert Southwest. No one knows exactly how much is left, but the study, 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. 'We're using it faster and faster,' said Jay Famiglietti, an Arizona State University professor and the study's senior author. In the past two decades, groundwater basins – or large, underground aquifers – lost more than twice the amount of water that was taken out of major surface reservoirs, Famiglietti's team found, like Mead and Lake Powell, which themselves have seen water levels crash. 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. 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. 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's rural areas, many of which don't 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. Scientists don't know exactly how much groundwater is left in Arizona, Famiglietti added, but the signs are troubling. 'We have seen dry stream beds for decades,' he said. 'That's an indication that the connection between groundwater and rivers has been lost.' 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. Porter said the results illuminate the magnitude of the groundwater crisis in the Southwest, which is particularly helpful for state officials and lawmakers. 'There are a lot of people who aren't sure if we have a serious situation with respect to groundwater, because groundwater is hidden,' Porter said. 'The value of the study is that it really adds a lot of information to the picture.' Groundwater may be hidden, but scientists know with relative certainty that once it is pumped out, it won't be able to recharge within our lifetimes. Much of it was deposited tens or hundreds of thousands of years ago. 'It takes geologic time' to refill these deep aquifers — meaning thousands of years — 'and we as humans have more or less been burning through it in the last over the last century,' Famiglietti said. Famiglietti warned the groundwater situation could worsen if the state's allocation of Colorado River water is further decreased, a decision that could be made in the next two years. If Arizona's Colorado River water allocation was cut to zero, 'we could burn through the available groundwater in 50 years,' Famiglietti said. 'We're talking about decades. That's scary. No one wants that to happen.' But Porter pushed back on that characterization, pointing out that Arizona cities have another stable water supply—the 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. 'We're not expecting that the whole state would turn to groundwater,' Porter said. 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's share of water. Much of Arizona's crops are exported, either to other states or, as is the case with alfalfa, internationally. Famiglietti called it the 'absolutely biggest' choice that policymakers will have to decide. 'Agriculture just uses so much water,' Famiglietti said. 'Are we going to plan to continue to grow as much food? Are we losing food that's important for the state, that's important for the country, or is it alfalfa that's being shipped to Saudi Arabia?'
Yahoo
7 days ago
- Business
- Yahoo
Groundwater supplies are plunging across the Colorado River Basin: Study
The Colorado River Basin's groundwater supplies are dwindling, thanks to a combination of both natural events and human pumping activities, a new study has found. The critical Western system has lost about 42 million acre-feet of water storage since 2003 — with 65 percent of those declines, or 28 million acre-feet, attributable to groundwater depletion, according to the study, published on Tuesday in Geophysical Research Letters. Over the past century alone, the authors noted, the Colorado River's flow has plunged by about 20 percent, with climate models predicting additional reductions of up to 30 percent by mid-century, due to escalating temperatures and diminishing Rocky Mountain snowpack. 'The decline of the river poses a severe threat to both agricultural and municipal water supplies, which are heavily reliant on the river,' the researchers warned. The Colorado River system, which serves about 40 million people in the U.S. and Mexico, is divided on this side of the border into a Lower Basin and an Upper Basin, which respectively include California, Arizona and Nevada, and Wyoming, Colorado, Utah and New Mexico. The actual amount of water available in the Colorado River Basin varies every year, based on snowpack, other environmental conditions and usage. But historic treaties allotted annual allocations of 7.5 million acre-feet to each domestic basin, as well as 1.5 million acre-feet to Mexico. For context, Western U.S. households tend to consume about half an acre-foot of water every year. Harnessing satellite observations of the region's water storage, the scientists found that groundwater depletion accounted for about 53 percent of the total water supply loss in the Upper Basin and 71 percent in the Lower Basin — far greater than the amounts lost by the system's two largest reservoirs, Lake Powell and Lake Mead. With much less surface water available, the demand for groundwater is expected to climb — and in the Lower Basin, this resource already accounts for 40 perent of the water supply, the researchers explained. Yet although groundwater is seen as 'a crucial buffer' in arid environments, it is also 'rapidly disappearing due to excessive extraction one one hand and insufficient recharge and management on the other,' the authors added. About 80 percent of the basin's water is devoted to irrigation, which bolsters a $1.4 billion agricultural industry in Arizona alone, according to the study. 'This situation places immense pressure on the region's groundwater resources,' the scientists stressed. Looking forward, the scientists emphasized a need to identify factors that contribute to the system's groundwater loss — with the goal of creating 'sustainable water management strategies that can help secure water resources for the region's future.' These considerations may prove particularly important in the current moment, as the region's states negotiate long-term operational and conservation guidelines for the 1,450-mile artery. The current interim rules, set in 2007, will expire at the end of 2026. 'As climate change intensifies and demands on the Colorado River continue to grow, the inclusion of groundwater in interstate [Colorado River Basin] water discussions has become a national imperative,' the researchers concluded. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
The Hill
7 days ago
- Science
- The Hill
Groundwater supplies are plunging across the Colorado River Basin: Study
The Colorado River Basin's groundwater supplies are dwindling, thanks to a combination of both natural events and human pumping activities, a new study has found. The critical Western system has lost about 42 million acre-feet of water storage since 2003 — with 65 percent of those declines, or 28 million acre-feet, attributable to groundwater depletion, according to the study, published on Tuesday in Geophysical Research Letters. Over the past century alone, the authors noted, the Colorado River's flow has plunged by about 20 percent, with climate models predicting additional reductions of up to 30 percent by mid-century, due to escalating temperatures and diminishing Rocky Mountain snowpack. 'The decline of the river poses a severe threat to both agricultural and municipal water supplies, which are heavily reliant on the river,' the researchers warned. The Colorado River system, which serves about 40 million people in the U.S. and Mexico, is divided on this side of the border into a Lower Basin and an Upper Basin, which respectively include California, Arizona and Nevada, and Wyoming, Colorado, Utah and New Mexico. The actual amount of water available in the Colorado River Basin varies every year, based on snowpack, other environmental conditions and usage. But historic treaties allotted annual allocations of 7.5 million acre-feet to each domestic basin, as well as 1.5 million acre-feet to Mexico. For context, Western U.S. households tend to consume about half an acre-foot of water every year. Harnessing satellite observations of the region's water storage, the scientists found that groundwater depletion accounted for about 53 percent of the total water supply loss in the Upper Basin and 71 percent in the Lower Basin — far greater than the amounts lost by the system's two largest reservoirs, Lake Powell and Lake Mead. With much less surface water available, the demand for groundwater is expected to climb — and in the Lower Basin, this resource already accounts for 40 perent of the water supply, the researchers explained. Yet although groundwater is seen as 'a crucial buffer' in arid environments, it is also 'rapidly disappearing due to excessive extraction one one hand and insufficient recharge and management on the other,' the authors added. About 80 percent of the basin's water is devoted to irrigation, which bolsters a $1.4 billion agricultural industry in Arizona alone, according to the study. 'This situation places immense pressure on the region's groundwater resources,' the scientists stressed. Looking forward, the scientists emphasized a need to identify factors that contribute to the system's groundwater loss — with the goal of creating 'sustainable water management strategies that can help secure water resources for the region's future.' These considerations may prove particularly important in the current moment, as the region's states negotiate long-term operational and conservation guidelines for the 1,450-mile artery. The current interim rules, set in 2007, will expire at the end of 2026. 'As climate change intensifies and demands on the Colorado River continue to grow, the inclusion of groundwater in interstate [Colorado River Basin] water discussions has become a national imperative,' the researchers concluded.
