River cruise in Cambodia – about the water level on the Tonle Sap

Tonle Sap cruise

Information about the water level on the Tonle Sap

The Phocea Mekong cruises team informs our passengers cruising on the Sat Toung between Phnom Penh and Siem Reap, that the water level on the Tonle Sap this year is very low.
Indeed, after heavy rains during the rainy season, the water level of the Mekong River fell rapidly. Thus, the water level of the Tonle Sap Lake quickly fell very early in the year. Thus, from now on, the Sat Toung makes its last cruise of the year until Siem Reap. Beginning of February, passengers will have to make the second part of the cruise on the lake by speed boat. But do not worry, we take care of everything !

Recall of the hydrodynamic system of Tonle Sap

The flow regime of the Tonle Sap River is unique in the world: depending on the season, water flows from the lake to the Mekong in the dry season from November to May, or the Mekong, then in flood, to the lake during melting of Himalayan snow and monsoon rains from May to November. The lake serves as a spillway for the overflow of water during periods of high water and reservoir during periods of low water. This lake is therefore a natural protection, acting as a safety valve, although sometimes insufficient, against variations in water levels of the Mekong. The term “water reversals” refers to periods when the flow of the Tonle Sap River is reversed, once a year in each direction (May and November). The Water Festival (Bon Om Touk in Khmer) in November is at one of these two annual periods. The area of ​​the lake during the dry season (February to May), is about 2,700 km2 for a depth of about 1 meter, it is almost sixfold when the season of the monsoon rains coincides with its beginning with snowmelt. It is estimated that the surface of the lake can then reach 16 000 km2 and its depth 9 meters, drowning rice fields and forests. In volume, this represents a multiplication by a factor 70.