Analysis of The Total Maximum Daily Load of The Buntung River in Ngaglik District, Sleman Regency

The Buntung Sub-watershed is part of the Winongo Watershed, and the water quality of the Buntung River is influenced by surrounding land use. Data from the Sleman Regency Central Bureau of Statistics indicate significant changes in land use from agricultural land to built-up areas, potentially increasing the pollutant load entering the river. This study aimed to calculate the pollutant load capacity of the Buntung River using the Water Quality Analysis Simulation Program (WASP). Sampling was conducted by dividing the river flow into eight segments. Water quality testing focused on the parameters of Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Additionally, river morphometry and flow discharge measurements were inputted for water quality modeling using the WASP software. The results indicate that the total BOD pollutant load is 44.206 kg/day, while the total COD pollutant load is 657.291 kg/day. The carrying capacity for the total BOD pollutant load is 0.177 kg/day, and for the total COD is 17.457 kg/day. Nearly all segments are unable to accommodate the pollutant load. For BOD, only segments 3 and 5 are able to accommodate the BOD pollutant load, while for COD, only segments 1 and 6 can accommodate the COD pollutant load. © 2025 Institute of Physics Publishing. All rights reserved.