In order to create a proper and effective flood control and water management program related to the Mekong river, it is necessary to fully understand the phenomena that occurs in the Lower Mekong area, since between the dry season and the rain season the water flow on the river changes direction, thus any related project has to take in consideration this phenomenon.

CTI efforts were focus in the understanding of the Lower Mekong water flow phenomena through technical studies and analysis. Also CTI was in charge of Institutional strengthening and capacity building of the Mekong River Commission (MRC).

With this project the following facts were understood.:

• Flood attenuation effects occur in combination with flow into the bypass channels and over-bank flooding along the floodplains, and the peak discharge of 51,000?m³/s at Kompong Cham was reduced to 38,000?m³/s at Phnom Penh in the 2002 floods;
• After the flood attenuation, floodwater conveyed to Phnom Penh was diverged into three channels at the Chak Tomuk junction and, in the 2002 floods, the flood peak of 38,000?m³/s was distributed to the Mekong downstream at 25,500?m³/s, to the Tonle Sap at 7,300?m³/s as reverse flow, and to the Bassac River at 5,200?m³/s;
• In the latter half of the flood season, the flow direction of the Tonle Sap changes towards the Mekong, discharging the water detained in the Great Lake through the Tonle Sap. Flow contribution rate of the Tonle Sap for the Mekong downstream was estimated at 40 to 60% from November to March, and 40 to 20% in April in the 2002/2003 dry season.