ABSTRACT
The aim of the paper was to present the works and results of investigations connected with the control of water quality for the inhabitants of Krakow city. The investigations started in 1898 and were performed by K. Olszewski, being advised by O. Bujwid. The water - works started to operate in 1901, and ground water comming from several digged wells created the water intake system. The increase of potable water demands of growing Krakow, and unacceptable pollution level of Vistula water decided to base the water intake for Krakow on rivers: Rudawa, Sanka and Dłubnia, but since 1986 also on Raba river.