Koncepcja sanitarnego wykorzystania wody deszczowej w zlewni potoku Straconka w Bielsku-Białej

The article presents the conceptual research on the management of rainwater in the Straconka stream catchment, most of which is located within the territory of the city Bielsko-Biała (Poland). The study was focused on the possibility of using rainwater for flushing toilets in order to reduce the consumption of treated tap water (intended for consumption). Sanitary use of rainwater requires its collection in a tank of appropriate capacity. The selection of the tank depends on the roof area, the number of residents generating water consumption and the technical possibilities of the installation. To conduct the simulation, all buildings were inventoried, the roof area was determined. Data on the number of residents were also included. In turn, data on the amount of atmospheric precipitation in the study area enabled determining the degree of coverage of the demand for rainwater for flushing toilets. The analyses were conducted for single-family housing, multi-family multi-level housing (blocks), terraced multi-family housing as well. In the first and third cases, it was proposed to implement individual closed tanks, while in the case of blocks of flats, open tanks were used. It was demonstrated that the use of rainwater tanks allows for a significant reduction in the consumption of treated water. In the case of single-family housing, the use of a domestic tank with a capacity of 250 dm3·person-1 would reduce the consumption of treated water in the toilet by 95.8%. For multi-family multi-level housing, the construction of one open retention tank with a capacity of 300 m3 would reduce the consumption of water in toilets by 51.6%. In the case of terraced multi-family housing, the use of a domestic tank with a capacity of 350 dm3·person-1 would reduce the consumption of water in toilets by 90.8%. For the purpose of selecting the individual tank capacity, a nomogram was formed that takes into account the roof area per resident.