Abstract
An inhabitant of Okinawa prefecture had troubled with drought water. Because Okinawa have a subtropical oceanic climate, and there is composed of very small islands in Ryukyu archipelagos. Some water resource developments had be done since Okinawa's reversion to Japan in 1972. A quantity of water demand was increased by increase of population and tourists etc. Firstly, this paper shows water supply systems, water use and drought water. These are arranged by relation with regional societies. .Secondly, quantity of water used for tourism using data of Zamami village is made clear. Possibility of drought water is analyzed by two scenarios; 10% number of tourist, and tourists do not save water.
