Plain-language labels

Water data glossary

A quick reference for the terms that official water systems use.

Alert hysteresis

A reset buffer that prevents a noisy reading from repeatedly triggering near one threshold.

The reference surface or zero point used for a height or elevation.

The height of the water surface above a reference point at a specific gauge.

A value measured at a specific station, for a specific parameter, at a specific time.

Official near-real-time data that have not completed the source agency’s full review process.

The volume of water moving past a point per unit of time, also called discharge.