A recent study has identified Las Vegas as one of 25 cities in the United States that is sinking into the ground at alarming rates, although it is not sinking as rapidly as it did in the 1960s and 70s.
Once, in the early days of the city, residents faced a significant water crisis long before Lake Mead became the primary drinking water source.
During the 1960s, the use of groundwater exceeded replenishment by nearly double, leading to a crisis situation.
Reports indicated that the groundwater levels dropped dramatically, causing parts of Las Vegas to sink as much as 3 centimeters each year.
This phenomenon was particularly severe in specific neighborhoods, such as a historically segregated area in North Las Vegas, where homes suffered structural damage from subsidence, including cracked ceilings and sinking backyards.
The study released by Columbia University in early May provides a current look at this ongoing issue, attributing the continued sinking of Las Vegas primarily to groundwater pumping.
James Prieur, a licensed geologist and Southern Nevada Water Authority hydrology supervisor, noted that historical subsidence raised concerns about Las Vegas’s long-term sustainability as a habitable area.
He stated, “In the late ’60s, the springs stopped flowing, and they had to put pumps in the wells, which caused water levels in some areas to drop over 100 feet.
The underlying clay and silt layers, which were previously under pressure, became deflated as a result of this groundwater depletion.”
Leonard Ohenhen, the study’s lead author and postdoctoral researcher at the Lamont-Doherty Earth Observatory, emphasized the need to make the issue of land subsidence visible to lawmakers and residents.
He explained that people often overlook the hazards of land subsidence due to its invisibility compared to other hazards.
As a result, the study aimed to raise awareness of an issue that could affect community decision-making.
Among U.S. cities, Houston was noted as the fastest sinking, with 40 percent of its area subsiding more than 5 millimeters annually.
Comparatively, only small areas in the Las Vegas region approached that degree of sinking.
Fortunately, the mighty Colorado River has played a crucial role in mitigating Las Vegas’s subsidence challenges.
In 1987, the Southern Nevada Water Authority embarked on an aquifer recharge program that successfully banked over 100 billion gallons of river water underground.
This initiative aimed to prevent neighborhoods from sinking too drastically.
The results have been promising: a 2008 study indicated that the sinking rate in the northwest valley’s highest-risk area dropped from over 3 centimeters per year to less than 1 centimeter.
While the problem is not entirely resolved, there has been significant improvement.
John Bell, a retired lead author of previous subsidence studies, praised the aquifer recharge program for its essential role in reducing the rate of sinking in these areas.
Bell reported that regions in the northwest valley had previously sunk as much as 6 feet, according to his earlier analysis.
He stated, “That was a very effective program. It reduces the net groundwater reservoir withdrawal, and that has reduced much of the subsidence.”
The stored water provides a sort of emergency reserve if Las Vegas requires additional freshwater due to unforeseen circumstances like a broken water main or power outage.
Prieur noted that while it may not cover all needs during emergencies, it would assist in mitigating crisis situations.
Concerns surrounding subsidence have particularly impacted residents of Windsor Park, a historically significant neighborhood in North Las Vegas.
Established in the 1960s, Windsor Park is notable as one of the first all-Black housing communities in the area, shaped by segregationist policies that dictated residential options for Black families.
According to law professor Frank Fritz in a 2021 UNLV documentary, groundwater extraction has exacerbated geological faults beneath the neighborhood.
Fritz explained, “When the groundwater is drawn out, the ground sinks.
But near the faults, parts of the ground sink more.
If your house is on top or near one of those cracks, your house cracks, pipes crack, roads crack.”
In response to the challenges faced by Windsor Park residents, Nevada Senator Dina Neal, D-North Las Vegas, championed the Windsor Park Environmental Justice Act.
This piece of legislation aims to provide financial assistance, including $37 million, to relocate residents from the affected neighborhood.
Neal’s efforts were designed to ease the community’s long-standing struggle and allow residents a path to better living conditions.
A new bill, Senate Bill 393, has emerged to amend the 2023 law, enhancing relocation support by allowing funds to cover existing mortgages and ensure that all neighborhood residents can benefit from the program.
Absent this legislation, Neal warned that residents would remain in a “state of suspension.”
A spokesperson for Governor Joe Lombardo did not specify whether he would sign the bill if presented to him, only stating that he would evaluate it fairly.
While Windsor Park’s issues represent a particular case, Neal warns that the ongoing problem of subsidence due to groundwater depletion poses risks for low-income and marginalized communities overall.
“Subsidence is real, and it costs if you don’t take care of it at the time that it’s ongoing,” Neal remarked, emphasizing the importance of education and awareness surrounding this pressing issue.
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