This is Eileen Wray-McCann for Circle of Blue. And this is What’s Up with Water, your “need-to-know news” of the world’s water, made possible by support from people like you.
In Australia, Day Zero could arrive in New South Wales as early as November. The state’s water utility has warned that without significant rain or human intervention, several towns there will begin to lose their water supply as the Macquarie River runs dry. Melinda Pavey, the New South Wales water minister, called the situation “critical” and pledged every effort, with $130 million to drill for water and move it to those in need.
Australia’s rivers and lakes have become starved for water. The country’s longest river, the Murray, has received less than a fifth of its usual inflow. The Menindee Lakes, the source of water for the Lower Darling River, usually get about 14 hundred gigalitres of water a year. In the last year, they have gotten only six gigalitres. With river systems receiving only small fractions of their normal inflows, officials are calculating worst-case scenarios in which rivers, and taps, will run dry in the next year or two.
The Guardian reported that while Pavey declined to address whether global warming is causing a “climate emergency,” she agreed that climate change could be a factor in Australia’s drought.
In Brazil, the mining company whose two waste retaining dam collapses killed over 200 people has been accused of misrepresenting its efforts to prevent further such disasters. Vale SA is the world’s largest iron ore exporter, and has faced public pressure after two deadly dam failures in the past four years. In 2015, 19 people died in the collapse of a dam storing waste called “tailings.” Last January, at least 240 were killed when a similar structure gave way.
After that tragedy, Vale’s chief executive said the company had already shut down nine similar dams as a response to the first dam collapse. He said that it intended to eliminate ten more in the next few years. Reuters pursued the claims, which were repeated on the firm’s web site. The news service asked Vale for a list of the nine dams that it had closed. A director of Brazil’s mining regulator reviewed the list and said that these were all smaller structures and not the dangerous kind that collapsed in 2015 and 2019. Reuters said that a review of Vale’s statements show the company “misrepresented what it had done to shut down its riskiest dams.”  It noted that Brazilian prosecutors are said to be looking into the company’s claims as part of a broader criminal investigation into the company’s actions. Vale said that the statements made by its CEO, who has since been removed, were based on the best information available at the time. But regulators are conducting at least two inquiries into Vale’s response to the disaster, and other legal and investigative actions are concurrent.
Brazilian prosecutors say they want to determine if senior Vale executives knew about stability issues at the dams that collapsed, and if they failed to take proper measures to address them. Brazil’s mining regulator is investigating the causes of this year’s disaster, and also whether any rules had been broken.
Reuters said that Vale uses a number of types of dams to store its mining waste. It described the two dams that collapsed as using “an upstream technique in which the dam is gradually built upon a reservoir of sludge.” Vale is not the only major mining firm using upstream dams. This construction is cheaper, but is more vulnerable to water seeping under the dam and weakening it. For this reason, Chile and Peru have long prohibited this type of dam. Last February, Brazil’s national mining agency banned further upstream tailings dams and set a deadline for decommissioning the existing ones.
This May, Vale said that it plans to spend close to 2 billion dollars to decommission the 10 upstream dams on its closure list. It said it had closed smaller structures first because they were easier to handle right away. But Reuters reported that the existing dams continue to be a risk. This spring, one of the dams on the closure list came close to collapse, threatening some 10,000 residents in three historic towns downstream.
In the United States, scientists with the Environmental Working Group are drawing attention to the cancer risks of contaminants in tap water. The non-profit research and advocacy group has released a new study which says that, over a lifetime, some 100,000 cases of cancer in the US are caused by substances in tap water. Most of the risk, it says, is from naturally occurring arsenic, from radioactive contaminants, or the byproducts of chemicals used to disinfect water.
The percentage of cancer cases connected to contaminated tap water is small in terms of the total cases in the U.S., but an official at the Environmental Working Group offered another perspective. In terms of cancers with environmental causes, she said, water contamination is responsible for a high percentage.
The United States gets high marks for the quality of its water, which is largely free of biological contaminants such as E. coli bacteria, which tends to afflict nations with less developed infrastructure. However, the study notes that communities large and small, urban and rural, are vulnerable to other contaminants. The researchers analyzed water profiles for over 28,000 systems. In Washington, D.C, for example, regulators found ten contaminants at levels which exceeded health guidelines, and most of those are associated with cancer.
Sydney Evans is the lead author of the water study. He told the Guardian, “We want people to realize that water that meets legal specifications may still cause health risks based on the latest science.” He advises people to check on their local water through the Environmental Working Group’s drinking water database, and, if necessary, get a water filter that meets their needs.
Contaminated water is an immediate concern in southeastern Texas, which was pummeled by Tropical Depression Imelda. Sections of Jefferson and Liberty counties, which are east of Houston, received more than 20 inches of rain in four days. Estimated rainfall peaked in Jefferson County, near the city of Beaumont, at nearly 44 inches.
Floodwaters shut down highways over the weekend, and thousands of people who were stranded in their homes or on roads had to be rescued. Five deaths have been attributed to the storm.
A host of chemicals and bacteria are potentially swept up with the floods. Household wells that are flooded should be considered a safety hazard, according to water experts at Texas A&M extension service. They are advising residents to test flooded wells before using the water for drinking, cooking, and washing.
Frequent flooding is beginning to weigh on residents. Just two years ago Hurricane Harvey inundated the Houston area with up to 60 inches of rain. The region has experienced at least four severe floods in the last five years. The increase in flooding has several causes. Heavier rainfall is a consequence of climate change, while an expansion of paved surfaces prevents water from soaking into soils.
Residents told the Houston Chronicle they are debating the merits of moving away. Most will choose to stay, but that choice does not sit easy when the rains threaten. “There’s nothing you can do,” one Houston resident told the Chronicle. “You’re powerless. You have no control over where the storm will go.”
Circle of Blue tells a story of water in the west: There’s not enough water to go around in the Snake Valley, and experts are weighing options as humans compete with habitat.
The Snake Valley lies in a semi-arid desert ecosystem straddling the Nevada-Utah border. The U.S. Geological Survey has made a study of the area, and has determined that if all permitted and proposed groundwater rights are exercised, there will not be enough water left to support important wetlands and springs.
There also may not be enough groundwater to satisfy the desires of the Las Vegas area, whose water agencies have eyed the valley for decades as a potential supply source. The Snake Valley is some 250 miles north of the city. It’s threaded with groundwater-fed springs and wetlands. Those waterways are habitat for threatened and endangered fish species and they support the rural area’s ranching and farm operations. The water beneath the valley has also been targeted by the Southern Nevada Water Authority, a regional wholesaler that serves Las Vegas. As the region becomes drier, climate change is putting pressure on water availability for humans and nature.
What happens to this ecosystem and to groundwater levels if pumping increases?
The USGS study, the latest of several recent investigations, did scenario modeling on groundwater levels at 47 sites of interest to the Bureau of Land Management and National Park Service, which manage land in the valley. Sites of interest for the two federal agencies include wetlands, creeks, seeps, wells, and springs.
Melissa Masbruch was the lead author of the research, which used a number of scenarios. One of them was a “worst case” that represented the maximum permitted and proposed extraction volumes. Masbruch said the potential drawdown is large. In the worst-case scenario, most sites of interest would suffer declines of 300 to 400 feet.  Such a decline could affect groundwater levels and discharge to springs and wetlands at “almost all” of the sites. At some sites all of the discharge that typically feeds a spring or creek would instead be removed by a well.
The number of sites in which groundwater flows are completely captured depends on how much groundwater is pumped. Masbruch modeled 11 pumping scenarios. Those scenarios account for irrigation return flows and increasing groundwater extraction. Springs and wetland sites at which all the groundwater flows are captured because of increased pumping range from four (if all current rights are used) to 13 (under the worst-case scenario).
The drawdown does not happen immediately. The model ran the scenarios out an infinite number of years, but most of the groundwater declines occurred within the first 100 years, Masbruch said.
The study also looked at how pumping would affect water levels at sites of interest to the Southern Nevada Water Authority for potential municipal use. The study says that the actual volume available to the authority might be significantly lower than what it seeks, because the groundwater may recede out of reach of their wells. The model showed water levels in proposed well locations dropping below 2,000 feet. That’s the deepest the wells would presumably be drilled, and so, Masbruch told Circle of Blue, “They aren’t going to be able to pump the full amount out of these wells.”
The water authority was not aware of the study until contacted by Circle of Blue, according to spokesperson Bronson Mack. Mack said the authority would not be able to comment without time to review the study. And, he said, the Snake Valley groundwater applications are “not a high priority for us at this time.”
Even if Southern Nevada is granted groundwater rights, the state governments of Nevada and Utah must reach an agreement on how much pumping will occur. That’s because of a law enacted by Nevada in 2004. Some years later, attempts were made to form an interstate groundwater compact, but the effort was abandoned in 2013.


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