Water Quality Status and Water Quality Index of Selulu Reservoir, East Kalimantan, Indonesia

Selulu Reservoir is located in Waru District, North Panajam Paser Regency. It is one of the tourist destinations in supporting the tourism sector. Land use changes and urbanization have potential impacts on the environment. This study aimed to determine Water Quality Status and Water Quality Index (WQI) in Selulu Reservoir. Hopefully, the result will become the basis for future reservoir management to keep the water quality well. The method in this study used the survey method. These research steps include surveys, water samples, laboratory analysis, and data analysis. Parameters analyzed include temperature, pH, BOD, COD, and DO. The results showed that the reservoir’s water quality in all samples still met the standard, except for pH at point 3. The difference fluctuating value found in COD at point 3, although it still meets the standard. This location is close to residential areas that dump their waste into the reservoir. The Water Quality Status of the reservoir still meets the standards, and WQI is in the excellent category. This is due to the dominant land use of forest and plantations with few settlements around the reservoir, domestic waste is small, and the reservoir capacity is still supportive. Management is needed to maintain reservoir water quality in the future.