SUMMARY
One of the efforts to prevent water pollution is done by mapping of potential pollution vulnerability to support water quality control policy making. The research location is in Panas Sub-watershed, a part of the Saba Watershed which originates on the northwest slope of the Bratan Volcano Complex and upstream is Lake Tamblingan, Buleleng Regency. The objectives of the study include: 1) mapping the parameters of potential surface water pollution vulnerability, 2) mapping land cover changes in 2000 and 2016, 3) mapping the potential surface water pollution vulnerability and its dynamics in 2000 and 2016, and 4) formulating a management recommendation to control surface water pollution. Mapping the potential surface water pollution vulnerability was conducted by GIS and Point Count System Model (PCSM) method using parameters of slope, land cover, and annual average rainfall. The results showed that some of the upstream and middle areas of the Panas Sub-watershed were categorized as high potential vulnerability caused by steep slopes, plantation cover, and annual average rainfall of 2,251 - 2,500 mm/year. Various recommendations to control surface water pollution are conducting integrated waste management individually or in groups, such as collectively septic tank construction, waste disposal organization, and waste water management installation; providing directions for appropriate land cultivation for farmers so that the pollutant load due to the use of pesticides could be controlled; as well as controlling and supervising the tourist area around Tamblingan Lake.