USA has rampant consumption of groundwater – 09/12/2023 – Environment

With global warming, concerns have turned to the soil and air, as rising temperatures intensify hurricanes, droughts and wildfires. But another climate crisis is unfolding invisibly, right beneath the feet of U.S. residents.

Many of the aquifers that supply 90% of the nation’s water systems, and that have transformed vast swaths of America into some of the world’s most abundant farmland, are being severely depleted. This decline threatens to cause irreversible damage to the American economy and society as a whole.

A comprehensive assessment by The New York Times of groundwater depletion in the United States reveals that this vital resource is running out across much of the country and, in many cases, will not renew itself. Huge industrial farms and sprawling cities are draining aquifers that may take centuries or millennia to replenish, if they ever recover. States and communities are already suffering the results of this.

The loss of groundwater is harming states like Kansas, where the main aquifer, lying beneath an area of ​​10,500 square kilometers of land, can no longer support industrial-scale agriculture. Corn production has plummeted, and if the decline spreads, it could threaten the United States’ position as a food superpower.

In New York state, 1,500 miles east of the Kansas aquifer, overpumping is threatening drinking water wells on Long Island, where modern American suburbia originated, home to working-class towns as well as the Hamptons and its mansions by the sea.

In Phoenix, one of the fastest-growing cities in the United States, the crisis is so severe that the state has said there is not enough groundwater in parts of the county to build new aquifer-dependent homes.

In other areas, including parts of Utah, California and Texas, the amount of water being pumped is so great that it is causing roads to give way, foundations to crack and fissures to open in the earth. And across the country, rivers that relied on groundwater have become streams, trickles or just a distant memory. “It’s a no-return situation. It’s almost impossible to explain the importance of this,” Don Cline, associate director of water resources at the U.S. Geological Survey, said of the disappearing groundwater.

This analysis is based on data collected from tens of thousands of groundwater monitoring wells, widely dispersed across the country, and often without adequate monitoring, from dozens of federal, state and local jurisdictions.

This database reveals the magnitude of the crisis in several ways. For example, in every year since 1940, more wells have been recorded with falling than rising water levels.

One of the biggest obstacles is the fact that the depletion of this invisible but essential natural resource is almost unregulated. The federal government has an almost non-existent role, and each state has implemented a huge variety of rules, often not very effective.

There is also a lack of dedication to analyzing the problem on a national scale. Hydrologists and other researchers often focus on specific aquifers or regional changes.

All of these issues contribute to enabling and reinforcing practices that are depleting aquifers, such as the cultivation of water-intensive crops such as alfalfa or cotton in arid areas, as well as excessive dependence on groundwater in fast-growing urban areas. .

Oklahoma is working to determine how much water remains in its aquifers, information that state lawmakers could use to set pumping limits. However, Christopher Neel, director of water rights at the Oklahoma Water Resources Board, noted that people may not appreciate the government telling them that their land is running out of groundwater: “If we start releasing this kind of data, it it will be reflected in the value of the properties. If we show that the groundwater in a certain area could be exhausted in two years, for example, it will be impossible to sell that property.”

To get the clearest picture possible of the state of groundwater in the United States, The New York Times interviewed more than 100 scientists, policymakers and hydrology experts. Additionally, it concatenated a national database of millions of well measurements used to determine groundwater depth.

Analysis of this data, including information from wells monitored a century ago, allowed the Times to cross-reference water levels with crop cover and population patterns over time. The results were also compared with readings from sophisticated satellites that can estimate changes in groundwater from space by measuring subtle changes in gravity.

Climate change is worsening the problem. By depleting aquifers that took thousands or even millions of years to form, regions risk losing access to this water in the future, just when they may need it even more, as climate change makes rainfall less predictable or droughts less predictable. , more intense. “From an objective standpoint, this is a crisis because parts of the U.S. could run out of clean drinking water,” said Warigia Bowman, a law professor who specializes in water resources at the University of Tulsa.

The most visible symbol of America’s agricultural bounty is the “center pivot” irrigation system, a metal structure on wheels that is connected to a pump and rotates around a central point. A single arm equipped with sprinklers can be up to 800 meters long, distributing hundreds of liters of water from a well per minute, 24 hours a day, for weeks or months on end.

Although much of the High Plains landscape is dominated by these pivots, anyone visiting Wichita County in western Kansas will notice that their presence is sparse. This is because there is little water to be distributed, since the wells have started to dry up.

Corn production can increase by more than five times per hectare with the help of irrigation. As local farms consume groundwater, corn production declines, reversing decades of progress.

The situation in the region provides a glimpse into the future of the US agricultural sector if groundwater continues to be exploited. “We abused the aquifer because we didn’t know it would run out,” lamented Farrin Watt, a Wichita County farmer with 23 years of experience.

American agriculture hasn’t always been so dependent on extracting large volumes of water from the ground. Until the middle of the last century, farmers relied on rain or river water, and smaller wells were mainly used as supplements.

But advances in pumping technology after World War II turned the United States into an agricultural powerhouse, converting vast regions of the West and High Plains into fertile land for crops such as corn and alfalfa. This transformation provided yields unattainable with surface water alone.

The basis of this success consisted of pumping a quantity of water much greater than nature’s capacity to replace it.

In the late 1990s, Wichita County farmers produced 11,250 to 11,750 pounds of corn per acre, well above the national average. However, this feat came at a cost, requiring farmers to drain the aquifer to irrigate their crops. The region receives, on average, less than 508 millimeters of rain per year, about a third less than the entire continental US — not nearly enough to replace the water being pumped from the ground.

As they ran out of water, farmers began to gradually adopt so-called rainfed agriculture, which depends exclusively on rainfall.

This change is reflected in corn yields over time: Last year, corn farmers across the country harvested an average of 11,600 pounds per acre, but in Wichita County yields were just 4,700 pounds per acre, the lowest in more than six decades.

It’s not just Kansas that is rapidly depleting its aquifers; The situation is the same in different parts of the country.

A little more than a third of the U.S.’s total drinking water supply comes from groundwater, according to data from the United States Geological Survey (USGS). But small rural communities are disproportionately dependent on wells, because of their low cost compared to treating and transporting water from rivers and lakes. Of the nation’s 143,070 water systems, 128,362 rely primarily on groundwater, according to the Environmental Protection Agency.

The impacts of the country’s dwindling groundwater resources are visible in another way: the soil itself is disintegrating.

In southwestern Utah, on the outskirts of a fast-growing city called Enoch, are the outlines of a neighborhood that appears to have disappeared. Streets and sidewalks wind through lots that were once designated for homes but are now littered with waist-high debris and weeds.

The Arizona Department of Geological Survey, associated with the University of Arizona, has mapped 270 kilometers of ground fissures across the state. In 2007, a horse died after falling and getting stuck in one of them.

Local officials in the Houston region reported that excessive groundwater extraction and oil drilling have caused some land to sink more than 10 feet over the decades. In Florida, excessive pumping sometimes creates sinkholes.

But Enoch, with about 8,000 inhabitants, is a glaring example of subsidence. During the enormous real estate boom of the mid-2000s, a developer began planning a subdivision of 800 homes, which ended up going bankrupt, a victim of the housing crisis. It was then that city officials noticed a peculiar crack in the road, which prevented other developers from trying again. It was found that the subdivision was sitting on a fissure in the ground.
Pumping water can cause the land above an aquifer to sink, leading to the collapse of the space left by the removed water. When this space disappears, the earth loses its ability to retain water.

This phenomenon, called subsidence, is occurring across the country, and more than 80 percent of it is the result of groundwater use, according to the USGS. The agency reports that subsidence has affected more than 120,000 square kilometers of land and waterways in the United States.

As the earth sinks, house foundations, sewer systems and other structures suffer damage. But among the most dramatic consequences of subsidence is the appearance of fissures. As the more pliable soil shifts, sometimes an adjacent patch remains still, and the resulting movement causes the earth to crack. “We’re extracting the water and it’s compressing the soil,” explained Rob Dotson, an Enoch city official.

Cracks are difficult to detect before they open, but once they open, they cannot be easily filled or closed. On the contrary, the tendency is for them to become wider and longer.

The new neighborhood of Enoch had to be abandoned, and a fissure was detected in a nearby neighborhood, where there are already residents.

However, despite knowing the consequences, Enoch was unable to suspend groundwater extraction, a decision that is being repeated across the country, in both urban and rural areas. After all, there are plantations to support and communities like Enoch that continue to grow. “People just keep coming,” Dotson said. And these people need water.