(MEDIA GENERAL) – New data from NASA shows the Earth’s global groundwater system is being depleted at a harmful rate.

Data obtained from a system of satellites shows 21 of the world’s 37 largest aquifers are being drawn to unsustainable levels – meaning more water is being removed than replaced. NASA officials say this problem is likely to get worse as humans continue to rely more on freshwater reserves.

A high human population is considered the primary reason for low aquifer levels. Researchers say water reserves can’t keep up with the amount drawn to fuel agriculture needs and certain industries, such as mining.

“The situation is quite critical,” Jay Famigletti, senior water scientist at NASA’s Jet Propulsion Laboratory in California, told the Washington Post. “The water table is dropping all over the world. There’s not an infinite supply of water.”

According to the study, researchers used satellites to take precise measurements of the Earth’s groundwater reserves and tracked changes from 2003 to 2013. The satellites are able to detect subtle changes in the Earth’s gravitational pull. When satellites fly over water reserves, they feel a pull that correlates with the size of the aquifer.

The study notes the world’s most stressed groundwater reserve is the Arabian Aquifer, which sits below six countries, including Iraq, Jordan, Saudi Arabia, Yemen, Oman and the United Arab Emirates. The Arabian Aquifer serves 60 million people.

California’s Central Valley Aquifer is the most stressed in the United States, and reserves along the southeast coast also reportedly also are under duress, but aquifers in the central U.S. still are in good shape.

Famigletti said he didn’t intend to raise fear levels with the study, but the results should have people worried.

“We need to get out heads together on how we manage groundwater,” Famigletti told the Washington Post, “because we’re running out of it.”