Reed Maxwell @reedh2o.bsky.social · 16/01/2026For all we know about the planet, we still don't really know how much freshwater we have. Surface water? About 1% of the total. The rest is groundwater — varying wildly over short distances, poorly observed, hard to model. 130
Reed Maxwell @reedh2o.bsky.social · 16/01/2026New work from our team: we mapped water table depth at 30-meter resolution across the entire continental US. That's ~8 billion grid cells, trained on over 1 million well observations. Highest-resolution estimate to date. 1214
Reed Maxwell @reedh2o.bsky.social · 16/01/2026We estimate ~306,500 km³ of groundwater beneath North America. That's 13× the volume of all the Great Lakes — hidden beneath our feet. ~40% of the country has water within 10 meters; shallow groundwater sustains streams and farms during drought; existing maps systematically undercount it. 130
