This is an updated and extended presentation of the results of the IAHS Wor
kshop on Quality Assurance in Hydrologic Measurement, held during the XXI G
eneral Assembly of the International Union of Geodesy and Geophysics (IUGG)
, Boulder, Colorado, USA, in July 1995. The main focus at Boulder was on ex
perience with hydrological applications of the international standard ISO 9
002 and developments in rating curve theory. A case study of a quality assu
rance system is presented. Progress in hydrometric quality assurance since
the workshop and areas for future development are discussed.