The paper discusses the 13.5 year flight operation experience of the orbiting space station Mir's water supply system (WSS) comprising a regenerative system and a water storage system. The basic water recovery system operational data are analyzed. It is shown that stage-by-stage introduction of additional recovery systems and updated units during its operation allows the system performance to be improved considerably and its functions to be expanded. Data on the quantity and quality of the water processed are presented including the economic efficiency of water recovery aboard the OSS. The experience in international cooperation of water management is described. It is shown that an updated water supply system of the Russian segment of the International Space Station fully accounts for the experience gained in development and operation of Mir's WSS.