Abstrack:
Sermo reservoir is the only artificial lake found in Yogyakarta. It is a multipurpose reservoir which control water supply for domestic use, fishery, and agriculture, beside tourism. Tourism in Sermo on one hand could be developed; on the other hand there is an uncertainty about its environmental impact. The purposes of this paper are to identify the potency and problem of developing Sermo reservoir as a tourism area, study the contribution of tourism to the local people, and analyze socio-economic impact of tourism in Sermo. Potency and contribution of tourism is assessed using questionnaire to local people and visitors. Key persons and government agencies were interviewed to get deep understanding and insight about Sermo tourism management. We also observed local people activities around the study area to evaluate some social issues related to tourism. Respondent see Sermo has a high potency to develop tourism ?peaceful and natural atmosphere, beautiful scenery, and friendly people. But, lack of adequate facility such as sanitary and toilet, mosque, tour guide, souvenir shop, restaurant, and local culinary shop might become an obstacle. The need to educate local people and improve supporting facility like website and direction guide is also important to promote Sermo. Tourism development expands local people economic in certain rate. But, as a side effect, people concern about some negative impact such as an increasing number of immoral activities and disappearing of some custom. To develop Sermo reservoir precautionary principle must be employed to ensure the sustainability of the reservoir.