The short answer
Gauge height measures water-surface height relative to the gauge reference. Discharge measures water volume passing per unit time. Use a verified local threshold to interpret flood stage.
Read the measurement label
Gauge height, also called stage, is water-surface height relative to a station reference. Discharge describes flow volume per unit time. Our river pages currently show gauge height in feet.
A station-specific relationship
USGS relates measured water level to flow using information specific to the site. Channel changes can affect this relationship. A stage value alone is not a portable conversion to cubic feet per second.
Use a same-station trend
Compare observations from the same station and reference. The available daily history may be daily mean stage, while the latest observation is an instantaneous reading. Keep these different time summaries visible when describing a change.
Flood interpretation needs another source
A gauge height does not itself establish flood status. A flood-stage threshold must be matched to the same forecast point and reference. Our pages link to official station information and do not assign a flood category from an unverified threshold.
Your next steps
- Height question → gauge height in feet.
- Flow question → discharge, if the source provides it.
- Flood question → matched official forecast and thresholds.
- Comparison question → same station, reference and time basis.
Common questions
Is gauge height the depth of the river?
No. It is stage relative to a station reference, not the depth everywhere across the channel.
Can gauge height be converted directly to discharge?
A conversion needs a site-specific relationship. Changes in the channel can change that relationship.
Sources and editorial record
Prepared with AI assistance from the linked sources. Independent human review pending. “Public Atlas Editorial” is a publication label. First edition: 2026-09-28. Scheduled source review: 2026-10-28. Data examples update with their source snapshots; the guide text is versioned separately.
Changes to this guide
- 2026-09-28 — First AI-assisted edition published with source links and review status disclosed.
- 2026-09-28 — Added Harrisburg–Marietta station comparison with dated USGS readings and distinct-datum caveat.
- 2026-09-29 — Added focused reader questions and concise answers with source links; checked primary-source guidance and retained pending human review.