PREDICTION OF WATER QUALITY STATUS IN SURABAYA RIVER WITH DYNAMIC SYSTEM METHOD AT SEPANJANG BRIDGE MONITORING STATION, SURABAYAAHMAD IMADUDDIN, MOHAMMAD RAZIF, SAMSUDIN AFFANDI, MOCHAMAD JUNAIDI HIDAYAT, SATRIA FADIL PERSADA AND PRAWIRA FAJARINDRA BELGIAWANAbstract This study aims to predict the water quality of the Surabaya River and determine its water quality status at the Sepanjang Bridge. Dynamic System (Stella) software was used to predict the water quality of the Surabaya River. The water quality status of the Surabaya River was determined by the Storet method or the Pollution Index method. Data obtained from the Sepanjang Bridge monitoring station in the Surabaya River showed that the average concentration of DO, BOD, TSS, and PO4 parameters exceeded the quality standard, while COD and NO3 parameters were still below the acceptable water quality standards in Indonesia. Based on the Storet score, the status of water quality is moderately polluted from 2017 to 2021 and 2023. In 2022, it is categorized as highly polluted. Meanwhile, based on the Pollution Index, water quality in 2017-2023 is in polluted category. This is shown by these results: the majority of TSS was in the highly polluted category; The majority of BOD, COD, DO, and PO4 are in the lightly polluted category; NO3 majority in either category. |