This report presents the conclusions of a detailed review of the best options for rainwater harvesting to provide a reliable source of freshwater for valuable wildlife on the islands of Lake Urmia in the Islamic Republic of Iran. Rainwater harvesting (RWH) is a modern solution for collecting, conducting and storing rainfallinduced runoff from natural and artificial impermeable surfaces. This method is particularly useful for remote areas where usual water supply systems may not be applicable. The report was prepared by Iranian Rainwater Catchment Systems Association (IRCSA) for the Conservation of Iranian Wetlands Project. The conclusions are based on a review of international best practices, as well as field investigations at the site. The results are of specific value for addressing current biodiversity conservation challenges at Lake Urmia, as well as of general interest for applying similar approaches in other regions.