Water Quality Index for Assessing Water Purification Ecosystem Services in Jakarta Urban Lake

This article aims to assess the ecosystem services related to water purification by analyzing the water quality conditions of three lakes in Jakarta, each with distinct characteristics. The analysis utilizes both national quality standards and the Water Quality Index (WQI). Water samples collected during the rainy and dry seasons were evaluated using the WQI, which combines various physical, chemical, and biological parameters into a single standardized score, comprehensively representing overall water quality. The study found that several water quality data points did not meet national standards for recreational use due to high levels of water pollutants. The fluctuating WQI values across the seasons indicated that seasonal variability significantly impacts water quality. The WQI scores for the lakes were categorized as medium to poor, with scores of 51.40 for Situ Babakan Lake, 45.20 for Srengseng Urban Forest Lake, and 46.20 for South Sunter Lake. Additionally, the results highlighted that water purification ecosystem services are influenced by the surrounding landscape conditions, human activities, and the presence of wastewater treatment plant (WWTP) facilities. This information is expected to provide valuable insights for local government agencies to enhance lake water quality within environmental policy frameworks.