Monitored waters

6,806 of 7,722 river gauges — 88% — sit on a water body Hydrionis can name, because the organisation that operates the gauge says which one. Every relationship here is a publisher answering a question about its own station. None of them was matched by name, inferred from a station label, or measured by distance.

Hydrionis holds 13,505 further monitoring points that measure something other than a watercourse. They are counted here rather than inside the unresolved total, because they were never candidates: a borehole measures an aquifer, a raingauge measures the sky, and a power station’s cooling intake is a place water leaves a river rather than a place it is gauged. Attaching any of them to the nearest stream would turn a category error into a coverage statistic.

A water body is classified from the evidence that linked it, never from how its name reads. The distinction that matters most is between a channel and an area: a gauge sits on a river, but only within a basin, and a United States subbasin named after its largest river contains that river's tributaries too.

Not every water body Hydrionis can name is worth a page, and not every page is worth offering to a search engine. Five signals are counted from what is actually held — gauges with a real record, years spanned, values, distinct measurements, and publishers measuring the same water. Three signals earn a full profile; two earn a page that is reachable but not indexed; fewer means the record stays in the data and the API, listed here.

Ordered by what each holds. A record marked as not indexed is a real page with real data behind it; it is simply not offered to search.