Freshwater found beneath Great Salt Lake

March 21, 2026

A groundbreaking scientific study has revealed compelling evidence of a vast underground freshwater reservoir hidden beneath the Great Salt Lake. Using advanced airborne electromagnetic (AEM) technology, researchers have gained unprecedented insight into the geological structures below Farmington Bay and Antelope Island along the lake’s southeastern edge.

Advanced technology uncovers hidden water resources

Scientists from the University of Utah conducted a helicopter-based AEM survey to map subsurface formations. This cutting-edge method allowed researchers to “see” beneath the lake’s salty surface and identify freshwater deposits buried deep underground.

The findings show that freshwater saturates sediment layers at depths ranging from 3 to 4 kilometers (10,000–13,000 feet) beneath the lake. This discovery followed earlier observations of pressurized freshwater emerging through the lakebed in Farmington Bay, forming unusual reed-covered mounds.

Breakthrough in freshwater detection beneath saltwater

According to lead researcher Michael Zhdanov, the study marks the first successful use of AEM technology to detect freshwater beneath a conductive saltwater layer like that of the Great Salt Lake.

By analyzing the collected data, the research team was able to:

• Map the extent of the underground freshwater reservoir

• Estimate the depth of water-bearing sediments

• Identify key geological structures influencing water distribution

Understanding these factors is crucial for estimating the total volume of freshwater stored beneath the lake.

A larger research initiative on groundwater systems

Published in Scientific Reports, this study is part of a broader research effort aimed at understanding groundwater systems beneath the Great Salt Lake—the largest terminal lake in the Western Hemisphere.

Researchers suggest that freshwater may be flowing toward the lake’s interior rather than entering from its edges, which challenges traditional hydrological assumptions.

Hydrologist Bill Johnson noted that, typically, denser saltwater would dominate beneath the lake, while freshwater would remain near the margins. However, the new data indicates that freshwater may extend deep beneath much of the lake, potentially covering a far larger area than previously believed.

Environmental implications: a potential solution to dust pollution

The discovery could have important environmental benefits. As water levels in the Great Salt Lake continue to decline, large sections of the lakebed—known as playa—have become exposed. These dry areas are a growing source of toxic dust pollution affecting nearby communities.

Researchers are exploring whether this underground freshwater could be used to:

• Moisturize dry lakebed areas

• Reduce airborne dust containing harmful metals

• Improve regional air quality

However, scientists emphasize the need for careful study before any extraction to avoid disrupting the natural groundwater system.

Mapping the subsurface: how the study qorked

To differentiate between freshwater and brine, researchers measured electrical resistivity, as saltwater conducts electricity more efficiently than freshwater.

During the 2025 survey:

• A helicopter carried electromagnetic instruments across 154 miles of flight paths

• Data was collected across Farmington Bay and northern Antelope Island

• Scientists created detailed maps of the boundary between saltwater and freshwater layers

The results showed a thin saline layer near the surface, with freshwater located just 10 meters below in some areas, extending much deeper underground.

Geological insights and future exploration

The study also revealed key structural features beneath the lake. While the bedrock beneath Farmington Bay is relatively shallow in some areas, it drops dramatically to depths of several kilometers in others. These variations may influence how freshwater is stored and flows beneath the lake.

Researchers believe expanding the survey across the entire 1,500-square-mile lake could:

• Improve regional water resource management

• Support environmental protection efforts

• Guide similar freshwater exploration projects worldwide

Conclusion

The discovery of a deep freshwater reservoir beneath the Great Salt Lake represents a major scientific breakthrough. Not only does it reshape our understanding of groundwater systems in saline environments, but it also opens the door to potential solutions for environmental challenges like dust pollution.

Further research will be essential to determine how this hidden resource can be responsibly managed and utilized.