Mekong River in Cambodia
Stretch 16: Phnom Penh Chaktomuk (km 347) to Phnom Penh NCT LM17 (km 322) about 25 km
The Chaktomuk area is a four-river water distribution system. All water comes from the upper Mekong and, during a certain period of the year, from the Tonlé Sap, which is returning the water it had caught (and stored in the Great Lake) a few months before. The river bottom of the Chaktomuk is unstable and sand banks are moving back and forth according to the period of the year and the flow patterns. Nevertheless, this stretch of the Mekong River upstream of the Phnom Penh Autonomous Port (PPAP) keeps its importance due to its accessibility for sea going vessels (3,000 DWT) going up the Mekong until Tonlé Bet.
Stretch 17: Phnom Penh NCT LM17 (km 322) to Cambodia – Viet Nam border (km 251) about 71 km
The river is generally deep, straight and shows only a few shallows in this area. There is heavy erosion of the right bank between km 307.0 and Km 314.0 and many bank protections in front of industrial land and LPG-tank farms have failed. The channel leans close to the right bank, which consists of over-saturated, unconsolidated fine sand to silt with little to no resistance to erosion.
A shoal is quickly growing just upstream the right river arm of the Kaoh Kandal island where a sandbank is emerging, obstructing the navigation channel (Km 316.0). The water used to be deep enough but is now silting up to water depths of merely 0.3 to 0.5 m. A dredging authorization has been issued by the Ministry of Mines and Energy for the PPAP to dredge the Koh Keo channel (estimated volume = 7.4 million m3 sand). There are no other difficulties worth mentioning for shipping, even for sea going vessels with a draught of 7.0 m, between the border and the new Container Terminal of the PPAP.
Source: Design of a Master Plan for Regional Waterborne Transport in the Mekong River Basin, Volume I, Page 34, 35