[1][2] The river is known for its unusual seasonal reversal, which plays a crucial role in supporting biodiversity, sustaining local livelihoods, enhancing agricultural productivity, and contributing to the ecological, economic, and cultural vitality of the region.

[8] From the lake, the Tonlé Sap flows 147 kilometres (91 mi) southeast to its confluence with the Mekong river near Phnom Penh, the capital of Cambodia.

[2] The reversal carries water, along with fish eggs and larvae, into the Tonle Sap Lake, where they find a nutrient-rich environment that supports their feeding and growth.

[11] The Bon Om Touk, or Water Festival, is one of Cambodia's most prominent cultural events, celebrated annually on the Tonlé Sap River.

These dams, particularly those in China and Laos, disrupt critical seasonal flooding patterns, leading to delays or failures in the river's annual reversal.