The causes of water pollution in a watershed are attributed to various sources. The sources of such pollutants and their routing mechanism are controlled by several natural and anthropogenic factors. Such natural and human-induced complexities make the protection of pollution and hence water resource management too difficult. Therefore, extensive knowledge and information is required not only about the pollutants in concern but also the controlling factors within the environment at varying spatial and temporal scales. Description of the spatial and temporal variability of processes based on conventional measurements or observations, for example field sampling and analysis of stream water quality, to represent and explain the entire watershed is ineffective, expensive and time consuming increasing the intricacy on effective decision-making process. An integrated spatial approach that combines a watershed scale hydrologic models, remote sensing and GIS led to tremendous progress during the last few decades in alleviating such problems and demonstrated to be useful tool. This work showed the effectiveness of such tool in modelling the Rönne River basin in Sweden.