The Mekong River is an important resource for about 65 million people living in the Lower Mekong River Basin (LMB). Flowing for 4,900 km through six countries – China, Myanmar, Thailand, Lao PDR, Cambodia and Viet Nam – the river holds great potential for the region’s economic development. However, intensive investments in water infrastructure, rapid population growth, and climate change represent challenges to the Mekong countries as they bid to ensure that the people in the region benefit from the river’s rich and diverse ecosystems.  

Since the 1950s, the four LMB countries – Cambodia, Lao PDR, Thailand, and Viet Nam – have been working together to address these challenges. In 1995, they signed an agreement (1995 Mekong Agreement) for regional water cooperation and created the Mekong River Commission (MRC) to jointly manage the river’s shared water resources in a more sustainable and equitable manner.

The MRC has since provided a platform for water diplomacy, enabling the four Member Countries to collaborate closely on better use of water resources, despite differences in national interests and development priorities. Serving as a knowledge hub, the MRC has also accumulated and shared a wealth of scientific knowledge and technical expertise on various water-related sectors, such as fisheries, flood and drought management, hydropower, and navigation to support better basin development planning.

The Mekong Agreement and MRC Procedures

The 1995 Mekong Agreement provides a legal framework for the four Member Countries to cooperate for better development and management of water resources. It defines the mission and goals of the organisation and sets out the roles and responsibilities of its three bodies – the Council, the Joint Committee and the Secretariat – and the strategic objectives of cooperation. Ultimately, the agreement tasks the MRC to promote the optimal use of water and well-balanced development of the basin, and enable the Mekong to reach its full potential through the formulation of a basin development plan.

Over the years, the MRC and its Member Countries have developed five sets of procedural rules and associated technical guidelines on data sharing, water use monitoring, water use cooperation, flow maintenance, and water quality. The first three establish the process of water cooperation, while the remainders set the criteria to assess water conditions. These rules, known as the MRC Procedures, provide a systematic and unified instrument for implementation of the Mekong Agreement.

1. Procedures for Data and Information Exchange and Sharing (PDIES)

Transboundary water resources management in the Mekong River largely depends on the availability of reliable data and information on various sectors. From fisheries to hydrology to water quality, basin-wide field data are crucial for a better understanding of the basin’s conditions. However, it is difficult to obtain data on transboundary phenomena, as due to national security and other reasons, countries usually place restrictions on how domestic data are shared with other countries. 

The Procedures for Data and Information Exchange and Sharing (PDIES) provide a framework for the Mekong countries to share regional data for better water resources management. Adopted in November 2001, the PDIES became the first set of rules to support cooperation among the four governments.

For more information on PDIES, click here. 

2. Procedures for Water-Use Monitoring (PWUM)

In the Mekong River Basin, millions of rural people rely on the river and its vast natural resources for their food security and livelihoods. Governments and investors look for opportunities to capitalise on its potential for economic development and broader poverty reduction through water infrastructure projects such as hydropower irrigation, and flood control. It is therefore important to monitor how the Mekong countries use water resources to ensure sustainable development of the basin, as data on water use can provide valuable information to support basin planning and management. 

Adapted in November 2003, the Procedures for Water Use Monitoring (PWUM) support effective monitoring systems for the use of water resources that might impact the Mekong’s mainstream. Under the PWUM scheme, any use of water resources within the Mekong River Basin (intra-basin use) and between the Mekong and another basin (inter-basin diversion) with potential significant impacts must be monitored.

For more information on PWUM, click here. 

3. Procedures for Notification, Prior Consultation and Agreement (PNPCA)

To harness the Mekong River Basin’s full potential for development, the Mekong countries have begun building bridges, large-scale irrigation and flood control structures, and hydropower along the mainstream and tributaries. These projects will bring economic benefits to many, but may also cause adverse transboundary impacts on the ecosystems and livelihoods of people relying on the Mekong. 

The Procedures for Notification, Prior Consultation and Agreement (PNPCA) establish a regional cooperation mechanism over planned water development aimed at optimising the use of water resources for development while minimising potential adverse transboundary impacts on the environment and livelihoods of riverine communities. Adopted in November 2003, the PNPCA requires any Member Country planning a water development project that may significantly alter water flow or quality of the Mekong mainstream to undergo one of the three processes: Notification, Prior Consultation, or Specific Agreement.

For more information on PNPCA, click here.

4. Procedures for the Maintenance of Flows on the Mainstream (PMFM)

The Mekong River’s seasonal flow fluctuations are vital to the basin’s ecosystems and the livelihoods of riparian communities. Without its annual flood pulse, fish would not migrate from deep pools to floodplains for spawning. Stored floodwaters support irrigation in the dry season while flood-deposited sediments improve soil fertility. Floods also flush out stagnant and polluted waters. It is essential for the Mekong ecosystems to maintain these natural flow patterns, particularly against pressures from intensive water investments and climate change. 

The Procedures for the Maintenance of Flows on the Mainstream (PMFM) set out a framework on how to maintain minimum or maximum levels of river flow in the Mekong mainstream and reverse flow of Cambodia’s Tonle Sap River, which connects the mainstream and the Tonle Sap Lake. The reverse flow is a unique phenomenon that happens during the flood season where the Tonle Sap River flows backwards and pushes its excess water into the lake, causing the lake to expand to six times its normal size. Adopted in June 2006, the PMFM defines technical criteria to assess adequate levels of water flow in order to safeguard the unique seasonal river flow against water diversions, storage releases from reservoirs, and other actions that may significantly affect the mainstream.

For more information on PMFM, click here:

5. Procedures for Water Quality (PWQ)

Preserving the Mekong River’s water quality is essential to secure the health of riverine communities and the future of the river’s aquatic life. Recognising that water quality issues are transboundary by nature, the Member Countries established the Procedures for Water Quality (PWQ) with the aim of ensuring the maintenance of acceptable water quality in the Mekong River and its main tributaries. Adopted in January 2011, the PWQ and associated technical guidelines establish assessment criteria to manage water quality. 

The PWQ defines two types of action to maintain water quality at acceptable levels for humans, flora, and fauna: (1) water quality monitoring; and (2) emergency response. Technical guidelines for the establishment of an emergency response and management system were developed in 2017. The guidelines recognise existing mechanisms for emergency responses to natural disasters developed by the Association of Southeast Asian Nations (ASEAN). To avoid establishing two parallel emergency responses in the basin, the MRC is seeking to collaborate with ASEAN to develop standardised regional emergency response mechanisms that meet national, transboundary and regional needs for water quality disaster control.

For more information on PWQ, click here.