---

An analysis of the state of Iran's water resources shows that hydro-political challenges have shifted from the national scale to the sub-national scale (at the catchment level) and the conflict of interests of users has led to a contradiction in the approach of agents, especially in times of drought. Meanwhile, Karkheh catchment in Khuzestan feeds by Kashkan river in Lorestan province. On the other hand, climate change and Kashkan floods have often been associated with losses. The basic agricultural livelihood of Delfan city and the prevention of floods have made the construction of Gaushmar dam on Kashkan inevitable. The construction of this dam has reduced the volume of water entering the downstream cities of the dam and the Karkheh catchment in Khuzestan, especially during dry seasons. The construction of this dam has led to the conflict of interests of the actors and the emergence of hydro-political challenges on a subsidence scale. The present article is applied and the methodology of the text is explanatory-analytic. The data and information required for the research were collected by library and field methods (interview). The result of the research showed that with the construction of Gaushmar Dam, hydro-political relations within the province (Lorestan) and extra-provincial relations between Khuzestan and Lorestan provinces have been brought hydro-political tension. The adaptation of these conflict of interests eventually led to a reduction in the height of the dam and the volume of water stored behind the dam due to the authorities’ policies.