The physicochemical parameters of the water of the Biała River and its tributaries were analysed at 11 test points. Some points represented highly urbanized catchment areas while the remaining ones - mixed catchments (with buildings, forest and agricultural areas). The research was conducted from June 2021 to May 2022. Its aim was to identify the pollution of water flowing in developed foothill areas. Basic water quality parameters were determined: C, TDS, CODMn, Fe, Cl-, SO42-, PO43-, NO3-, TKN. During the research period, the parameter values at individual points were very variable (variation over time). Differences in values between points (spatial variation) were also noted. Water quality was related to the development of the catchment area - overall pollution expressed as C or TDS values was greater in highly urbanized catchments and in the lower part of the studied area, but individual substances in high concentrations were also observed locally. It was found that the water was contaminated mainly with organic and biogenic substances.