Study on the Impacts of Mainstream Hydropower on the Mekong River - Draft Impact Assessment Report: Impact Assessment Methods and Results – Summary Version

This document is a summary version of the Mekong Delta Study (MDS) Impact Assessment Report (IAR).

There have been constant worries that construction and operation of any or all of proposed hydropower dams projects could potentially have substantial and wide-ranging environmental and socio-economic effects in lower Mekong countries. In particular, there is tremendous concern over the impacts of the planned hydropower cascade on the downstream floodplains of Cambodia and Viet Nam. That led to a strong need that conduction of additional studies and analyses, using the most updated data and best available scientific tools, were a must to improve understanding of how the planned hydropower cascade would impact the natural and human environment and the socio-economic status and livelihood of tens of millions of people in the Mekong Delta.

Therefore, the Government of Viet Nam initiated the Study on the Impacts of Mainstream Hydropower on the Mekong River (also known as the Mekong Delta Study or MDS) to study the overall impact of the proposed LMB mainstream hydropower cascade on the natural, social, and economic systems of Cambodian and Vietnamese floodplains implemented in close cooperation with the Governments of Lao PDR and Cambodia. Accordingly, the primary objectives of the MDS were to evaluate changes projected to occur in the hydrological processes of the LMB resulting from the construction and operation of the planned mainstream hydropower cascade, and assess how these changes could potentially impact the human and natural environment in the Cambodian and Vietnamese floodplains.

Other objectives included developing a comprehensive database of relevant environmental, social, and economic conditions for the Lower Mekong River Basin, and seeking Basin wide consensus on the results of the impact assessment and determining avoidance and mitigation measures through close consultation with stakeholders.