The river rises at the slopes of Mount Buanmangge, within the district of Batukliang in
Central Lombok Regency, at an elevation of 2600 meters. It follows a
dendritic drainage pattern as it descends, following a generally southwesterly direction until it approaches Mataram, when its course turns closer to the west. It has several tributaries, the longest of which is 23 km in length. Jangkok's main course has a length of just under 49 km.
Watershed Jangkok has a watershed area of 170.29 km2. Most of Jangkok's watershed is still forested in 2011, with an average annual precipitation of around 800 mm. Due to the pollution, the river water is contaminated with heavy metals and
E. coli bacteria. ==Use==