Asem River is one of the three main rivers in the Subang Regency.[4] There are a total of 21 rivers and 61 tributaries in the watershed area of (Daerah Aliran Sungai/DAS) Ciasem of 745 km2. Compared to the other two main rivers - Ci Punegara and Ci Lamaya - Asem River and its many tributaries all flow only within the Subang Regency. The river has a total length of 60 kilometer until the northern coast.[4]
Geography
The river flows in the northwest area of Java with a predominantly tropical monsoon climate (designated as Am in the Köppen-Geiger climate classification).[5] The annual average temperature in the area is 25 °C. The warmest month is September when the average temperature is around 28 °C, and the coldest is July, at 24 °C.[6] The average annual rainfall is 2810 mm. The wettest month is January, with an average of 454 mm of rainfall, and the driest is September, with 14 mm of rainfall.[7]