Serei Sophorn River (Khmer: ស្ទឹងសិរីសោភ័ណ) is a river that flows through Banteay Meanchey province in Cambodia. It is a major tributary of the Tonlé Sap.[1] References [1]State of Water: Cambodia. Water Environment Partnership in Asia. This article related to a river in Cambodia is a stub. You can help Wikipedia by expanding it.vteWikiwand - on Seamless Wikipedia browsing. On steroids.