Implementing Equitable Water Allocation in Transboundary Catchments: The Case of River Nestos/Mesta

Border areas comprise inevitably problematic fields especially when the countries are bound to share common water resources. The conflict potential is rather high and quite often countries are directed to the negotiation table in order to form tranboundary agreements. These agreements aim to the settlement of tensions and conflicts originating from the management of shared water resources. Often a starting point of the conflict resolution is the water allocation scheme between the interested parts. The definition of entitlements over shared water resources in not an easy task and it requires the use of specific decision tools in order to reach the maximum level of objectivity. According to the Water Framework Directive (WFD) 2000/60, management of transboundary catchments shall be based on existing structures set by international agreements, such as the UN Convention on the Protection and Use of Transboundary Watercourses and International Lakes. The main aim of this paper is the implementation of a water allocation tool based on representative indicators characterizing the involved parties while placing emphasis on environmental protection. The variables used are proposed by the UN Convention on the Law of the Non-navigational Uses of International Watercourses incorporating both natural and socio-economic aspects. These factors are quantified for each country and a weight factor is assigned to each one depending on its importance and suitability for describing the environmental and socio-economic situation in each country. As an illustration example the transboundary river Nestos/Mesta case is presented.