What Is Under a River Made Of? 9.5 Million Well Records, One Schema

What is under a river made of? A water well's log answers it: the driller writes down each layer that comes out of the hole.

Those records sit in public agency systems across forty-eight states: bulk downloads, map services, report pages, and paper scans.

We harvest each one through its public door and harmonize them to one schema: where the well is, every depth interval, the driller's words kept verbatim, and the hydraulics the agency published.

Today that is more than nine million well records and twenty-eight million lithology intervals, and it grows with every state we add.

Each well carries what its agency published: a bare record, or depth, water level or yield, or a screened interval with yield, the kind a groundwater model can use. More than eight hundred thousand are model-ready.

Density follows what each state publishes, not where the wells are. Where the map is blank, no public record was found.

Some logs exist only as paper scans. A vision model can read them. In our published test it agreed with human transcription on about ninety-one percent of materials.

Open any watershed, turn on the groundwater wells, and see what the ground records say there.

The inventory is live at swatgenx.com/groundwater-inventory. The paper is under open review at Earth System Science Data.