Summary:

The work analyses the eight-year (1997–2004) period of research on water consumption by a selected household in a housing estate in Krakow. Water consumption was referred to the number of persons using water in the investigated household, a unit consumption was determined and daily irregularities in the uptake of water. The household numbered four permanent dwellers. The basis for analysis were daily indications of water meter registered in the observation journal, temporary changes of the number of inhabitants and water use outside the flat, e.g. for garden watering or car washing, etc. The investigated building is fully furnished with running water and sewer system, i.e. running water is supplied to the flat furnished with kitchen sink, flushed toilets and two fully equipped bathrooms. In the initial period of investigations, wastewater from the building was directed into a cesspool but since November 1997 it has been drained by common sewer system. Obtained research results revealed that daily unit water use in 1997–2004 ranged between 5.9 and 693.3 dm³∙M^-1∙d^-1, whereas average unit daily water consumption fell within the 135.5 and 177.5 dm³∙M^-1∙d^-1 depending on year. The biggest difference between average daily unit water uptakes in individual months was registered in 2000 and reached 132.8 dm³ ∙M^-1∙d^-1, while the smallest was noted in 1997 (44.6 dm³∙d^-1). Maximum daily unit water use was noted in the summer period, which has been found in six out of eight analysed years. Water intake in individual years was characterised by daily irregularity coefficient ranging between 2.4 and 4.5, therefore much higher than stated by the respective guidelines (1.6). Indexes of unitary water consumption and their irregularity are to a greater extend shaped by the frequency of occurrence and kind of additional purposes of water use, which appear mainly in summer, so unit water consumption in the summer season 171.1 dm³∙M^-1∙d^-1 was much higher than in the other seasons (149.3 dm³∙M^-1∙d^-1).