This International Standard gives requirements for the establishment and operation of a gauging station for the measurement of stage, or stage and discharge, of a lake, reservoir, river or canal or other artificial open channel. It also describes how a gauging station utilizing one of the measurement methods listed should be operated and maintained. Requirements are provided for stage only measurement stations, stage–discharge stations and direct-discharge measurement stations in natural channels, as well as for stage–discharge stations with artificial structures. Additionally, some requirements are given for measurements under difficult conditions, such as under ice conditions.