Principal of Reasonable water use in Iran and international water law

The rule of reasonable or optimum usage of water resources is a key aspect of water resource management in Iran as well as international water law. According to rules and regulation of water allocation in agricultural sector of Iran, optimum and economic amount of water should be determined and considered to issue any surface or groundwater withdrawal licenses. Illegal and overuse of water would lead to termination of licenses. According to the study, determination of optimum water use in agricultural sector of Iran violate the rule of reasonable use of water and isn’t adequate to water availability and sustainable management of water resources. Despite some revision of law and regulation of water allocation for agricultural purpose have been made so far, wasteful usage of water is being seen mainly due to non-volumetric delivery of water, lack of water user participation, lack of guarantees and little cooperation of related public organizations. Revising water document base on climate change circumstances, volumetric delivery of water, reviewing water tariffs, diminishing water licenses time validity and considering tradable water rights are some suggestions to facilitate rational use of water resources in agriculture of iran.