Summary:

In the elaboration the size and variability of water consumption by the two groups of users connected to the main water supply in Olkusz were presented. The consumption of water has been estimated on the basis of the readings of water me-ters conducted in 2005-2007 within the group of detached houses and in 2004––2007 within the group of residential building block of flats). A detailed analysis of water consumption demonstrated, that the unitary average daily water consump-tion within detached houses amounted to 75,96 dm³•d^-1•M^-1 whereas in residential buildings it amounted to 87,78 dm³•d^-1•M^-1. Both consumptions have been remain-ing on the similar level in comparison to the water consumption of other cities in the Małopolska region. In the analyzed group of detached houses within the stud-ied period there has been a 5,2% decrease in water consumption, while in the residential buildings the 6,6% increase was detected. The unitary daily water con-sumption within the group of detached houses and residential buildings decreases with the increasing of the number of residents. An average real unitary water con-sumption within detached houses has been 24% lower from the standard consump-tion, whereas within residential buildings the result amounted to 45,1% from standard water consumption. The variability of water consumption within de-tached houses has been generally average (73,3% of total detached houses), and within the residential buildings has been small (63,3% of total block of flats).