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New York City Closes Tunnel Supplying Half of Its Water for Big $2B Fix

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Monday, September 30, 2024

A stretch of aqueduct that supplies about half of New York City's water is being shut down through the winter as part of a $2 billion project to address massive leaks beneath the Hudson River.The temporary shutdown of the Delaware Aqueduct in upstate New York has been in the works for years, with officials steadily boosting capacity from other parts of the city's sprawling 19-reservoir system. Water will flow uninterrupted from city faucets after the shutdown begins this week, officials said, though its famously crisp taste might be affected as other sources are tapped into more heavily.“The water will alway be there,” Paul Rush, deputy commissioner for the city’s Department of Environmental Protection. “We’re going to be changing the mix of water that consumers get.”The Delaware Aqueduct is the longest tunnel in the world and carries water for 85 miles (137 kilometers) from four reservoirs in the Catskill region to other reservoirs in the city's northern suburbs. Operating since 1944, it provides roughly half of the 1.1 billion gallons (4.2 billion liters) a day used by more than 8 million New York City residents. The system also serves some upstate municipalities.But the aqueduct leaks up to 35 million gallons (132 million liters) of water a day, nearly all of it from a section far below the Hudson River.The profuse leakage has been known about for decades, but city officials faced a quandary: they could not take the critical aqueduct offline for years to repair the tunnel. So instead, they began constructing a parallel 2.5-mile (4-kilometer) bypass tunnel under the river about a decade ago.The new tunnel will be connected during the shut down, which is expected to last up to eight months. More than 40 miles (64 kilometers) of the aqueduct running down from the four upstate reservoirs will be out of service during that time, though a section closer to the city will remain in use. Other leaks farther north in the aqueduct also will be repaired in the coming months. Rush said the work was timed to avoid summer months, when demand is higher. The city also has spent years making improvements to other parts of the system, some of which are more than 100 years old.“There’s a lot of work done thinking about where the alternate supply would come from,” Rush said. Capacity has been increased for the complementary Catskill Aqueduct and more drinking water will come from the dozen reservoirs and three lakes of the Croton Watershed in the city's northern suburbs. The heavier reliance on those suburban reservoirs could affect the taste of water due to a higher presence of minerals and algae in the Croton system, according to city officials.“While some residents may notice a temporary, subtle difference in taste or aroma during the repairs, changes in taste don’t mean something is wrong with the water," DEP Commissioner Rohit Aggarwala said in a prepared statement. "Just like different brands of bottled water taste a bit different, so do our different reservoirs.” Copyright 2024 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.Photos You Should See - Sept. 2024

A stretch aqueduct that supplies more than half of New York City’s water is being shut down through the winter as part of a $2 billion project to address massive leaks beneath the Hudson River

A stretch of aqueduct that supplies about half of New York City's water is being shut down through the winter as part of a $2 billion project to address massive leaks beneath the Hudson River.

The temporary shutdown of the Delaware Aqueduct in upstate New York has been in the works for years, with officials steadily boosting capacity from other parts of the city's sprawling 19-reservoir system. Water will flow uninterrupted from city faucets after the shutdown begins this week, officials said, though its famously crisp taste might be affected as other sources are tapped into more heavily.

“The water will alway be there,” Paul Rush, deputy commissioner for the city’s Department of Environmental Protection. “We’re going to be changing the mix of water that consumers get.”

The Delaware Aqueduct is the longest tunnel in the world and carries water for 85 miles (137 kilometers) from four reservoirs in the Catskill region to other reservoirs in the city's northern suburbs. Operating since 1944, it provides roughly half of the 1.1 billion gallons (4.2 billion liters) a day used by more than 8 million New York City residents. The system also serves some upstate municipalities.

But the aqueduct leaks up to 35 million gallons (132 million liters) of water a day, nearly all of it from a section far below the Hudson River.

The profuse leakage has been known about for decades, but city officials faced a quandary: they could not take the critical aqueduct offline for years to repair the tunnel. So instead, they began constructing a parallel 2.5-mile (4-kilometer) bypass tunnel under the river about a decade ago.

The new tunnel will be connected during the shut down, which is expected to last up to eight months. More than 40 miles (64 kilometers) of the aqueduct running down from the four upstate reservoirs will be out of service during that time, though a section closer to the city will remain in use.

Other leaks farther north in the aqueduct also will be repaired in the coming months.

Rush said the work was timed to avoid summer months, when demand is higher. The city also has spent years making improvements to other parts of the system, some of which are more than 100 years old.

“There’s a lot of work done thinking about where the alternate supply would come from,” Rush said.

Capacity has been increased for the complementary Catskill Aqueduct and more drinking water will come from the dozen reservoirs and three lakes of the Croton Watershed in the city's northern suburbs.

The heavier reliance on those suburban reservoirs could affect the taste of water due to a higher presence of minerals and algae in the Croton system, according to city officials.

“While some residents may notice a temporary, subtle difference in taste or aroma during the repairs, changes in taste don’t mean something is wrong with the water," DEP Commissioner Rohit Aggarwala said in a prepared statement. "Just like different brands of bottled water taste a bit different, so do our different reservoirs.”

Copyright 2024 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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South Africa’s Coast Is Rising—And Scientists Have a New Explanation Why

Human water management contributes to sinking land across the globe, and it may also be responsible for an unexpected rise

October 7, 20254 min readSouth Africa’s Coast Is Rising—And Scientists Have a New Explanation WhyHuman water management contributes to sinking land across the globe, and it may also be responsible for an unexpected riseBy Avery Schuyler Nunn edited by Sarah Lewin FrasierLand rising along South Africa’s coast may be closely tied to humans’ use of water. For decades geologists thought the slow rise of South Africa’s southern coast was driven by forces deep below—buoyant plumes of molten rock ascending through Earth’s mantle and heaving the crust upward over millions of years. But now satellite data and precise GPS measurements are tilting such assumptions off their axis. A study in the Journal of Geophysical Research: Solid Earth suggests this land rise may have less to do with deep tectonic forces and more to do with missing groundwater just under our feet.Human activity has long been depleting South Africa’s groundwater. In 2018, after grappling with severe droughts for years, the country came close to a full-blown water emergency when Cape Town was nearly the world’s first major city to literally run out of water—a scenario dubbed “Day Zero.” For several months that year the city’s residents faced the very real prospect of having to regularly queue for critically limited water supplies, an outcome staved off only by timely rainfall and intensive water-saving campaigns. The extreme shortage resulted from a combination of climate change and unsustainable water use, which drained surface reservoirs and placed mounting pressure on aquifers across the region.The recent study hypothesizes that the ground, once compressed by the sheer weight of the surface water and groundwater above it, is now expanding like a foam mattress relieved of pressure. Using GPS and satellite gravity data from between 2000 and 2021, the researchers detected a roughly six-millimeter rise in the land surface—a shift that coincides with humans’ depletion of South Africa’s water reserves and periods of drought.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.“Sometimes the first explanation isn’t necessarily the right one,” says University of Bonn geodesist Christian Mielke, the study’s lead author. “Perhaps it isn’t plate tectonics after all.”That misunderstanding, not necessarily the rising land itself, may be the most striking thing about South Africa’s situation. What was once chalked up to the slow churning of Earth’s mysterious and inaccessible interior may instead reflect human activity, especially our management—or mismanagement—of water.“The presence of water, either as ice and snow on the land surface or as groundwater below, and the removal of that water are intimately tied to the deformation of the ground’s surface,” says Stanford University geophysicist Rosemary Knight. In most places around the globe, this process usually leads to sinking, called land subsidence, to fill the gap.But in South Africa, the new study suggests, that tie between water and land movement shows up in a surprising way. During the rainy season, rivers and reservoirs fill, adding weight that presses the crust down. In the dry months, much of that water either evaporates or gets pumped away, and the land rebounds upward. Over time the long-term loss of groundwater tips the balance toward uplift rather than sinking.This “seasonal breathing” is the giveaway that the cause is probably not solely a mantle plume. If molten rock were pushing upward, the motion would be steady, not tied to rainfall cycles. The expansion, if verified, could be yet another example of the ways human water use is reshaping the planet.From 1945 to 1970 more than 13,000 square kilometers of California’s San Joaquin Valley, once hailed as a “land of milk and honey” for Dust Bowl migrants, sank by at least 30 centimeters—and in some places by nearly nine meters. The San Joaquin sinking has only sped up since then, and parts of the valley drop more than 30 centimeters a year during severe droughts. On average, the pace has accelerated by 70 percent from the mid-20th century.Something similar is happening to the Chesapeake Bay, which, with its sweeping estuaries and lush tidal wetlands, is one of the U.S. East Coast’s most ecologically significant regions. Here land subsidence—driven by both groundwater extraction from aquifers and the lingering effects of ancient glacial shifts—is accelerating flood risk and relative sea-level rise. Satellite data, tide gauge records and projections from the Intergovernmental Panel on Climate Change suggest that by 2100 the combination of subsidence and sea-level rise could inundate up to 1,100 square kilometers of the Chesapeake Bay’s coastline.Mielke notes that such findings highlight the complexity of the planet’s response to human-induced environmental change. The consequences are still gradually being uncovered, and the implications may be profound. As climate change accelerates, land movements could exacerbate other challenges, especially in coastal areas with rising seas.To monitor such hidden shifts on a global scale, scientists use the GRACE satellite mission (Gravity Recovery and Climate Experiment) to detect changes in Earth’s mass by measuring minuscule variations in gravity. Because water has weight, depleting or replenishing groundwater subtly alters the planet’s gravitational field, which GRACE can detect from orbit.Knight and other researchers are looking for ways to keep land from shifting on such a vast scale by maintaining a careful balance. “Basically you get subsidence when water out exceeds water in,” Knight says. “And for water in, the term that’s used is ‘recharge.’”Some recharge happens naturally as rain or snowmelt soaks into the soil, but this precipitation isn’t enough to offset decades of groundwater extraction and current demand. That’s why places such as California are now turning to managed aquifer recharge: strategically spreading excess surface water (such as winter floodwaters) across land where it can percolate into the ground and rebuild depleted reserves, or injecting water directly into aquifers. Estimates suggest there is space underground for a total amount of water 30 times the volume of California’s Shasta Lake, enough to begin reversing the land’s descent.As Knight puts it, the solution can’t be about just cutting back on groundwater pumping. It must involve replenishment: restoring water to the ground from which it was drawn.It’s Time to Stand Up for ScienceIf you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Cold-Water Immersion May Offer Health Benefits -- and Also Presents Risks

Claims about the benefits of cold-water immersion date back centuries

Dr. Mark Harper recalls his first cold-water swim in the south of England 20 years ago. It was August, but the initial jolt from the plunge took his breath away. The shock to his system lasted a minute or two until he was “recombobulated and able to think about something other than the cold," Harper says. A surprise sensation soon replaced his discomfort. “I remember getting out of the water the first time and feeling so good," Harper, an anesthesiologist who has since researched the potential risks and rewards of taking a nippy dunk. "I wasn't expecting that.”Claims about the benefits of cold-water immersion date back centuries. Thomas Jefferson, the principal author of the Declaration of Independence and the third American president, wrote toward the end of his life about using a cold foot bath daily for 60 years. He also owned a book published in 1706 on the history of cold-water bathing. But Harper, who became a regular cold-water swimmer after his initiation, said there are strong signs that people can derive mental health benefits from the activity. He mentioned a positive effect on depression and general well-being.“For now, we have a very strong base, but not hard evidence, that cold-water immersion is effective for mental health," Harper told The Associated Press. Harper said his own early experiences with cold-water swimming piqued his professional curiosity. As a physician, he wondered if the brief bodily shock had clinical uses for treating depression. He cited the biological phenomenon of hormesis, in which a stressor introduced at a low dose creates a positive response.Muscles and bones put under stress —for example, with weight-bearing exercise — also respond and grow.Harper acknowledged that the positive effects he's observed may be the result of the placebo effect, a phenomenon in which people who are given a medicine they think will help them report responding to the treatment even if it had no active ingredients. In the case of cold-water immersion, the benefits may come from meeting people, the exercise itself, or simply accepting a challenge and accomplishing it, which improves self-confidence, he said.“Personally, I think it’s all of those things, and the cold has an additive effect,” Harper said. “I think we have a good physiological basis for that. The basic science tells us the cold has a very strong effect on the body.“What we’re talking about is an intervention, when it's used clinically, that produces beneficial effects on mental health. So in a way it doesn’t matter which aspect is generating the positive effects.”Harper cited what he said was a common reaction among first-timers who have taken the plunge.They often say “the fact that I’ve done this means I can do anything,” he said. “It’s quite a confidence builder and it’s something people stick to because they enjoy it so much.” Know the risks when you start Dr. Mike Tipton, a physiologist at the University of Portsmouth in England who has studied extreme environments, authored a paper along with Harper and two more researchers several years ago. The title highlighted the potential advantages and dangers of stimulating the body with a sudden drop in temperature: “Cold Water Immersion: Kill or Cure.” “Like other environmental constituents such as pressure, heat and oxygen, cold water can be either good or bad, threat or treatment depending on circumstance,” they wrote after reviewing the research then available on the topic. One of their findings: The activity presents dangers. Deaths from cold-water immersion are not uncommon. The shock of frigid water can cause people to hyperventilate and drown. But Tipton told The AP the risks can be managed with common sense and precautions.You do not need to go to extremes to get a potential payoff. Entering water at a temperature of 20-15 degrees Celsius (68-59F) and staying for only a few minutes is sufficient.Tipton explained if the water is colder than that, you may get more benefit — but limit your exposure.“If you ask me what protocol you would follow if you thought this was going to be doing you good, I wouldn't go in water much below 12C (54F), and I wouldn’t stay in for much more than two minutes,” Tipton said.Tipton and Harper both said that any benefits from cold-water immersion come from the body's cold-shock response: the sudden fall of skin temperature, the release of the stress hormones, the release of endorphins, and the anti-inflammatory effect. Tipton cautioned against long spells in an ice bath.“Sitting in water for as long as I can fills me with horror,” Tipton said. "This could destroy small nerves, blood vessels in extremities and could result in amputation the same way frostbite can."Harper, who has swum as long as four-hour stretches in open water, advised vigilance.“People think it’s got to be super cold, super long and the longer the better,” Harper said, "and that’s wrong.” Be safe. You're a tropical animal Tipton said he's not trying to be the “fun police” but suggested caution and a medical screening if you take the plunge. He said humans are considered “tropical animals” who need to adapt to the cold and are better suited to warm conditions. A human’s resting body temperature is about 36.5 to 37.5 degrees Celsius (97.7 to 99.5F). Because of that, cold-water immersion is stressful and carries risks for the cardiovascular and respiratory systems. Not to mention the risk of drowning.“We don’t want to stop people doing it, but we want to make sure they do it in a way that maximizes the benefits and minimizes the risks,” Tipton said.He suggested swimming in a life-guarded area, or going with experienced outdoor swimmers. He also suggested knowing the body of water you're swimming in. Hazards, among others, include tides, temperature, depth and pollution.“Understand that taking a tropical animal and putting it in cold water is probably the greatest stress that most people will experience in their life,” Tipton said.He suggested entering the water in a controlled fashion instead of jumping in. "Be sensible about it,” he said. “Incremental is the key.”Copyright 2025 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.Photos You Should See – Sept. 2025

Millions rely on dwindling Colorado River — but are kept 'in the dark' about fixes, critics say

Negotiations aimed at solving the Colorado River's water shortage are at an impasse. Environmentalists are criticizing a lack of public information about the closed-door talks.

The Colorado River, which provides water across the Southwest, has lost about 20% of its flow in the last quarter-century, and its depleted reservoirs continue to decline. But negotiations aimed at addressing the water shortage are at an impasse, and leaders of environmental groups say the secrecy surrounding the talks is depriving the public of an opportunity to weigh in.Representatives of the seven states that depend on the river have been meeting regularly over the last two years trying to hash out a plan to address critical shortages after 2026, when the current rules expire. They meet in-person at offices and hotels in different states, never divulging the locations.The talks have been mired in persistent disagreement over who should have to cut back on water and by how much.“We need more transparency, and we need more accountability,” said Kyle Roerink, executive director of the Great Basin Water Network. “I think if we had more of those things, we wouldn’t be in the situation that we are currently in.”Roerink and leaders of five other environmental groups criticized the lack of information about the stalled negotiations, as well as the Trump administration’s handling of the situation during a news conference Wednesday as they released a report with recommendations for solving the river’s problems.Roerink said there is “a failure of leadership” among state and federal officials, and “everybody else is being left in the dark.”Disagreements over how mandatory water cuts should be allotted have created a rift between two camps: the three downstream or lower basin states — California, Arizona and Nevada — and the four states in the river’s upper basin — Colorado, Utah, Wyoming and New Mexico. State officials have talked publicly about the spat, but much of the debate is happening out of the public eye.“This process is a backroom negotiation,” said Zachary Frankel, executive director of the Utah Rivers Council. “We need to shift the governance of the Colorado River Basin ... back into the halls of democracy so that people can get engaged.” Frankel said the limited details that have filtered out of the negotiators’ “secret backrooms” indicate officials are still debating water cuts far smaller than what’s really needed to deal with the current shortage. He said the Southwest could face “serious water crashes” soon if the region’s officials don’t act faster to take less from the river.The Colorado River provides water for cities from Denver to Los Angeles, 30 Native tribes and farming communities from the Rocky Mountains to northern Mexico.It has long been overused, and its reservoirs have declined dramatically amid unrelenting dry conditions since 2000. Research has shown that the warming climate, driven largely by the use of fossil fuels, has intensified the long stretch of mostly dry years. Water overflows Lake Mead into spillways at Hoover Dam in 1983 near Boulder City, Nev. (Bob Riha Jr. / Getty Images) Near Las Vegas, Lake Mead, the nation’s largest reservoir, is now just 32% full.Upstream from the Grand Canyon, Lake Powell, the country’s second-largest reservoir, is at 29% of capacity.“We’re using a third too much water. There’s no accountability for the fact that the reservoirs are disappearing,” Frankel said. “And we’re not even looking at what the drop in future flows is going to be from climate change.”California uses more Colorado River water than any other state, and has been reducing water use under a three-year agreement adopted in 2023. As part of the water-saving efforts, Imperial Valley farmers are temporarily leaving some fields dry in exchange for cash payments.A large portion of the water is used for agriculture, with much of it going to grow hay for cattle, as well as other crops including cotton, lettuce and broccoli. The main sticking point in the negotiations is how much and when the upper basin states are willing to share in the cuts, said J.B. Hamby, California’s Colorado River commissioner. “The river is getting smaller. We need to figure out how to live with less, and the upper basin absolutely must be part of that,” Hamby said in an interview. “We are running out of time.”The new rules for dealing with shortages must be adopted before the end of 2026, and federal officials have given the states “several milestones” in developing a consensus in the coming months, Hamby said. “The clock is ticking,” he said. “And we’re still essentially at square one.” Morning sunlight hits Lone Rock on Lake Powell in Glen Canyon National Recreation Area. (Rebecca Noble/Getty Images) Federal officials have not said what they will do if the states fail to reach consensus. The impasse has raised the possibility that the states could sue each other, a path riddled with uncertainty that water managers in both camps have said they hope to avoid. Hamby said he believes solutions lie in a compromise between the upper and lower states, but that will require all of them to stop clinging to “their most aggressive and rigid dreamland legal positions.”Experts have called for urgent measures to prevent reservoirs from dropping to critically low levels.In a study published this week in the journal Nature Communications, scientists found that if current policies remain unchanged, in the coming decades, both Lake Powell and Lake Mead will be at risk of reaching “dead pool” levels — water so low it doesn’t reach the intakes and no longer gets through the dams, meaning it doesn’t flow downstream to Nevada, Arizona, California and Mexico. The researchers said a more “sustainable policy” will require larger water cutbacks throughout the region. Federal officials have said they recognize the need to move quickly in coming up with solutions. In August, Scott Cameron, the Interior Department’s acting assistant secretary for water and science, said “the urgency for the seven Colorado River Basin states to reach a consensus agreement has never been clearer. We cannot afford to delay.”But the coalition of environmental groups raised concerns that federal and state officials are flouting the normal procedures required when making new water rules. The environmental review began under the Biden administration, which announced several options for long-term river management. Roerink and other advocates noted the last time the public received any information about that process was in January, as Biden was leaving office. They said the Interior Department was expected to have released an initial draft plan by now, but that has not happened.“The Trump administration is absolutely missing an opportunity here to get everybody at the table and to get something meaningful done under the time frame that they are obliged to get it done,” Roerink said. “The fact that we’ve heard nothing from the Trump administration is troubling.”

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