26 Jan Scientists Finally Figured Out How Much Groundwater There Is Under the US and It Is Enough to Fill the Great Lakes 13 Times Over
ZME Science (1/26/2026)
It’s not easy to determine how much water there is across a landscape. A measly 1% of Earth’s freshwater is on the surface, where it can be seen and measured with relative ease. But beneath that, measurements vary massively depending on water table depth and ground porosity we can’t directly see.
Reed Maxwell, a hydrologist at Princeton University, likes to think of rainfall, snow, and surface water as a checking account used for short-term water management needs and groundwater as a savings account, where a larger sum should, ideally, be building up over time.
“We’re operating in a situation where we don’t know how much is going into the savings account every month, and we don’t know how much is in our savings account,” he said.