Nepal, Oct. 27 -- In February 2023, all three deep borewells at Tribhuvan University Teaching Hospital in Maharajgunj ran dry. More than 300 feet deep, one had supplied the hospital for nearly 40 years. Today, despite treating thousands of patients daily, the hospital relies on water tankers and a pilot rainwater-harvesting initiative to meet its needs.

When a well runs dry, we often blame over-extraction. But a more fundamental question remains unanswered: What lies beneath the Valley? Where are the water-bearing sand and gravel layers? Where does clay restrict groundwater flow? And where does rainwater seep back in? Without understanding this underground landscape, every new borewell is a gamble, and groundwater policy is built on inco...