Flow framework for planning

The flow framework for planning is to be used to periodically assess future basin-wide development policies and scenarios to inform national and transboundary planning, decision-making and governance processes.  It is intended to provide the opportunity for the Member Countries to utilize considerable quantities of water of the Mekong River without compromising its natural flow regime.  The potential impacts of development plans or a large project will be assessed using the simulation models of the Decision Support Framework (DSF) and evaluated with respect to the agreed flows framework for planning purposes.

Development plans or proposed projects are usually grouped within “scenarios” and added to the existing infrastructure.  For each scenario the models of the DSF provide simulated hydrological time-series at each of the selected hydrological stations.  Subsequently, the scenarios will be compared with respect to the agreed flows framework for planning purposes.  Scenarios that are outside the agreed thresholds would be deemed unacceptable.


Summary of flow framework for planning purposes

 Article referenceFlow framework for planning purposes
Article 6A Acceptable minimum monthly natural flow during each month of the dry season (December - May)

Applied at all stations except Kampong Luong (in the Tonle Sap Lake) and Prek Kdam (in the Tonle Sap River)
The following flow framework and associated thresholds will be tested:
  • Option 1: a range of the 1:4-1:5 Annual Recurrence Interval (ARI)
  • Option 2: a range of the 80-90% time exceedance of Flow Duration Curve (FDC)
Article 6B Acceptable natural reverse flow of the Tonle Sap taking place during the wet season (June - November)

Applied at Kratie (in the Mekong River) and Prek Kdam (in the Tonle Sap River) as shown, but also using data from Kampong Luong (in the Tonle Sap Lake)

Probability of exceedance of total wet season flow volumes (June - November) at Kratie within the upper and lower 90% confidence interval of the Baseline scenario

Article 6C Preventing average daily peak flows greater than what naturally occur on the average during the flood season (July - October)

Applied at all stations except Kampong Luong (in the Tonle Sap Lake) and Prek Kdam (in the Tonle Sap River)

Average daily peak flow during the flood season (July-October)