PMFM - Technical Guidelines

The Technical Guidelines on implementation of the PMFM have been developed after extensive consultation between representatives of the Member Countries within the Technical Review Group (TRG), established by the MRC Joint Committee for this purpose in 2003.

In 2006, the MRC Council approved the Procedures for Maintenance of Flows on the Mainstream (PMFM) and assigned the MRC Joint Committee to prepare the Technical Guidelines for the implementation of the PMFM. The MRC Joint Committee delegated the responsibility for preparation of the Technical Guidelines to TRG. The TRG comprises experts assigned by the National Mekong Committees (NMCs), as well as staff from the Mekong River Commission Secretariat (MRCS). The TRG has met ten times in the intervening period.

At the 10th Meeting of the TRG held in October 2011, agreement was reached on most aspects of the Technical Guidelines except for three pending issues. Nevertheless, the TRG resolved that the next steps are to implement the PMFM Technical Guidelines on an interim basis using a “learning-by-doing” approach and by testing the agreed flow frameworks for Article 6A for monitoring purposes and the flow frameworks for Articles 6B and 6C for both planning and monitoring purposes, and making further assessments related to the considered alternative flow frameworks for Article 6A for planning purposes. The 35th MRC Joint Committee Meeting acknowledged that the PMFM Technical Guidelines could be tested using a learning by doing approach.

Objectives of the PMFM Technical Guidelines

The main objective the PMFM Technical Guidelines is to provide guidance on the implementation of the PMFM by the MRC and its Member Countries by providing flow frameworks, considered as (working) guidelines for planning and monitoring purposes.

Flow frameworks in the context of the PMFM Technical Guidelines are established thresholds for flows at each of the selected hydrological stations defining flow conditions at those sites which are considered acceptable by the member Countries in relation to Article 6 of the 1995 Mekong Agreement, and/or which cause certain actions to be taken if transgressed.


Flow framework for planning purposesFlow framework for monitoring purposes

The flow framework for planning is to be used to periodically assess future basin-wide development policies and scenarios to inform national and trans-boundary 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 the 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.

The monitoring of flows will raise awareness of daily flow conditions that are not within the agreed flow framework for monitoring and prompt coordinated action by the Member Countries when needed. Daily monitoring will provide confidence that the PMFM is being implemented and natural flows are being maintained at the selected hydrological stations for meeting important economic, social and environmental needs.

Given the inherent uncertainties associated with the accuracy of information and analytical tools employed, errors inherent in flow determinations and future impacts of climate change, the PMFM Technical Guidelines are to be reviewed every five years, based on past implementation experiences and new data and information.


Selection of Hydrological Stations

Nine hydrological stations have been selected, based on an analysis of hydro-geographic reaches, to provide the basis for implementing the PMFM in the mainstream. A further two, Prek Kdam and Kampong Luong stations, have been selected for monitoring the natural reverse flow of the Tonle Sap.

Hydrological Stations
Chiang Saen Thailand
Vientiane Lao PDR
Khong Chiam Thailand
Pakse Lao PDR
Stung Treng Cambodia
Kratie Cambodia
Phnom Penh
(Chrouy Changvar)
Prek Kdam Cambodia
Kampong Luong Cambodia
Tan Chau Viet Nam
Chau Doc Viet Nam


Applicability of the PMFM under conditions of severe droughts and/or floods

The PMFM make clear that the PMFM Technical Guidelines apply “except in the cases of historically severe droughts and/or floods”. If historically severe droughts or floods occur, other relevant provisions of the 1995 Mekong Agreement shall apply.

Historically severe droughts are deemed to occur when the daily updated observed level or derived discharge during the dry season are less than the 1: 20 year (ARI) of historically observed daily flows at the selected hydrological stations. Historically severe floods on the other hand are deemed to occur when the daily observed water level and derived discharge during the flood season are higher than the 1: 20 year (ARI) of historical annual daily peak flows or water levels.

These thresholds of the severe droughts and/or floods are noted as being applicable for the time being, until such time as more experience or new knowledge is gained.