This International Standard specifies methods of determining the stage-discharge relation for a gauging station. A sufficient number of discharge measurements complete with corresponding stage measurements is required to permit the stage-discharge relation to be determined to the accuracy required by this International Standard.

Stable and unstable channels are considered, including those subject to ice conditions, but considerable care must be taken if this International Standard is applied to flow conditions which suddenly or rapidly vary.

An analysis is included of the uncertainties involved in the preparation and the use of the stage-discharge relation.