Delineating Reservoir Protection Areas through Spatial Analyses in Support of Water Quality Protection

Developing water protection strategies to prevent drinking water sources from contamination is a high priority throughout the world. As a significant policy measure, the segmentation of the delineated watershed areas into several zones is implemented by defining areas closest to the intake and more distant areas. Article 8 of the Directive 80/778 relating to the quality of water intended for human consumption in the European Union for example, forces Member States to take measures for securing the quality of water while in some connected policy documents the rationale behind constructing safeguard zones with land-use restrictions are referred to this end. Due to the requirements set out in legislations, authorities responsible for protecting the water quality similarly apply some restrictions on collective settlements, industrial and agricultural developments particularly in the protection zones. Such restrictions have direct impacts on the social and economical activities of the population residing in the basin. Besides, descriptive differences between legislations from different levels or different practices performed by the different authorities lead to disparities between the basins that are subject to quite different protective measures and zoning systems in spite of their analogous basin characteristics. All such challenges and disputes in protection mostly relate to the lack of scientific basis of protection regulations that limits its qualification for being widely acceptable by and easily verifiable to the general public. The spatial approach presented in this study is implemented on a case-study selected from the Tahtali Catchment in the west of Turkey by addressing the above challenges arising from the current practices of reservoir protection while aiming at providing guidance for an alternative strategy to achieve a practical solution.