Assessing national water resource development plans from a basin-wide perspective

The Council Study

Sustainable development within the Lower Mekong Basin (LMB) requires mitigating the risks and seizing the opportunities that the Mekong River creates for the people of the LMB in a manner that conserves the river’s functions for future generations. Achieving this goal is essential and urgent. Basin-wide cooperation is needed to ensure long-term water, energy and food security, address environmental needs, and realize opportunities for collaborative development that shares benefits across borders. Countries acting alone cannot achieve this goal.

The Study on Sustainable Management and Development of the Mekong River including Impacts of Mainstream Hydropower Projects, known as the Council Study, assesses current and potential future development plans of the Mekong countries in six water-related sectors – hydropower, land use, irrigation, navigation, flood protection and industry – and predicts both positive and negative impacts across economic, social and environment spheres.

To achieve this, the Council Study considers three main water resource development scenarios:

the 2007 early development scenario (baseline),

the 2020 definite future scenario (medium-term plan), and

the 2040 planned development scenario (long-term plan).

Developments include existing and planned mainstream and tributary hydropower projects, expanded agriculture and irrigation schemes, waterway navigation, flood protection, and domestic and industrial water use. The three main scenarios aggregate combinations of water resource developments according to the sectors so that cumulative impacts on the environment, social issues, and the economy can be assessed.

The 2007 scenario (including existing mainstream dams – Manwan and Dachaoshan – in Upper Mekong Basin, or Lancang in Chinese) represents the baseline conditions in the LMB and is the scenario against which the others are compared. The 2020 definite future scenario – called ‘2020 plans’ – includes all existing, under-construction, and firmly-committed developments in the six sectors, including the Xayaburi and Don Sahong hydropower projects on the Mekong mainstream. The 2040 planned development scenario – called ‘2040 plans’ – includes 2020 developments plus developments in the six sectors planned for implementation by 2040.

To isolate sector-specific contributions to the outcomes of the main 2040 scenario, the Council Study considers sub-scenarios. The sub-scenarios assume either increased or decreased investments in the six sectors in comparison to the 2040 main scenario. All the 2040 sub-scenarios contain the condition of climate change. The main climate change scenario assumes climate will become more seasonal with slightly wetter and drier conditions and sea level rise – referred to as the ‘2040 plans with climate change’. Two further climate change sub-scenarios assume either a wetter or drier climate and sea level rise for the 2040 plans.


This publication is based on the Council Study reports. The Council Study reports are considered final drafts prepared by specialists of the Mekong River Commission (MRC) and international experts through an extensive process of consultation with representatives of the Member Countries and interested stakeholders. The contents, findings and recommendations serve as knowledge base and reference for the work of the MRC and its Member Countries in their ongoing technical and policy dialogues to ensure sustainable development of the Mekong River Basin, as declared in the Siem Reap Declaration of the Prime Ministers in the 3rd MRC Summit 2018.

This snapshot of the MRC Council Study findings and recommendations highlights the main potential benefits and impacts of water resource developments in different sectors, and underlines some of the key recommendations that reflect basin-wide needs and opportunities in the Lower Mekong Basin (LMB). The figures presented here should be interpreted considering the assumptions, methodologies and data sources of the Council Study. The Council Study framework is designed to be flexible, transparent, and replicable to accommodate new or improved data and continued refinements of the assessment tools.

The MRC Council Study is the first study of this scale for the LMB. It is open for review and has been commented on by various stakeholders during its development. Recent studies conducted by other organisations and stakeholders have verified the key trends the Council Study has brought to light.

The MRC is funded by contributions from its Member Countries and Development Partners: Australia, Belgium, the European Union, Finland, France, Germany, Japan, Luxembourg, the Netherlands, Sweden, Switzerland, the United States of America, and the World Bank.