This paper aims to assess the pollution status of Umur Creek Catchment Area, a region with rapid industrialization in Istanbul. It also evaluates the impact of domestic and industrial discharges into this creek. The scope of this research is the evaluation of a developed procedure for the determination and characterization of domestic and industrial wastewater sources. All domestic and industrial sources, 4 and 16, respectively, are subjected to assessment of pollution profiles in terms of meaningful pollutant parameters as indicated in the literature. The distribution and intensity of domestic wastewater discharge canals together with industrial mills located along the Umur Creek are also assessed and the time-based changes determined via satellite images of various dates. The comparative evaluation of 1993 and 2000 satellite images indicated significant changes and land use patterns that effectively correlate with the deterioration of water quality. These observations suggest the use of higher resolution satellite images and, consequently, more detailed controls around the catchment areas.