Water deficit sharing: A new approach to conflict resolution among stakeholders in the watershed

Population growth and socio-economic development make the competition for larger share in water allocation more intense among stakeholders in the watershed, which in turn brings up conflicts over the use and allocation of water. Competition for more shares of water between stakeholders, especially in dry areas, leads to over-exploitation of water resources and large deficits in supplying the downstream demands. Equitable allocation of water reduces conflicts among water allocation stakeholders, since it provides equal opportunity for water usage between them. Equitable sharing of deficits among upstream and downstream stakeholders is a promising approach to equitable water allocation. Karkheh watershed is a good example in which operation of very large dam in downstream is influenced largely by hydro-projects to be constructed by upstream stakeholders. Socio-economic development in dam upstream impairs reservoir operation and its capability in supplying water for downstream demands, which in turn brings up conflicts between upstream and downstream stakeholders about future developments in Karkheh watershed. This paper presents a new method for equitable allocation of water resources between different upstream and downstream stakeholders. It is based on mathematical simulation of catchment's hydro-system and evaluation of stakeholders' water usage on deficits upstream and downstream of the watershed. Deficits are distributed among stakeholders based on their share in deficits. Shared deficits are subtracted from each stakeholder target water demand to obtain equitable water allocation to each stakeholder. This approach is applied to Karkheh hydro-system for equitable water allocation