THE Mekong River is the twelfth longest river in the world at 4,173 kilometers. The headwaters originate in the Tibetan region of China and the river then flows through Yunan province in China into five Asean countries: Myanmar, Cambodia, Laos, Thailand and Vietnam.

The Mekong forms the boundary between Laos and Myanmar. It courses through Laos for approximately 500 km before once again becoming the boundary between Laos and Thailand. Then the Mekong passes through the southwest corner of Laos and flows through the heart of Cambodia where a very unique physical feature exists, the Tonle River and the Tonle Sap Lake. Then it flows into Vietnam and empties out through the Mekong Delta of Vietnam into the South China Sea.





The Mekong River basin covers 795 km. (A water basin, also known as a catchment basin, is a geographical and hydrological unit consisting of a main river and all the territories between the water source, the spring and the mouth of the river).

The tremendous natural resources of the Mekong Basin have long been recognized. The tropical climate of the region along with the abundance of water during the wet season supports an extremely productive and diverse aquatic ecosystem with numerous ecologically important wetlands. In addition, the basin states rely upon the natural productivity of the basin’s fisheries to help meet the subsistence needs of many of the approximately 60 million residents of the Mekong basin.

Common ground

While the interest of each country is different and there are diverse upstream and downstream issues, the Lower Mekong countries have found a common ground on which to cooperate in addressing issues from a basin point of view. Cooperation in all fields of sustainable development, utilization, management conservation of water and other resources is somehow evident in irrigation, hydro-power, navigation, flood control, fisheries, timber floating, recreation and tourism initiatives and projects.

It was the United Nations which drew attention to the potential for integrated development in the lower Mekong basin as early as the 1950s. A Mekong Committee was set up by Cambodia, Laos, Thailand and the then Republic of South Vietnam in 1957 “to promote, coordinate, supervise and control the planning and investigations of water resource development projects.”

Political events, however, transpired to dampen the committee’s prospects and the change of government in Laos, Cambodia and Vietnam during the mid-1970s cast doubt on the committee’s future. By 1991, reactivation of the Mekong Committee began.

Circumstances, however, had changed considerably since the mid-1970s in many ways: a) although the region seemed to be entering a new era of peace in the 1990s, the governments were no longer as closely allied to each other as they were before the mid-1970s; b) the viability of large mainstream dams, the quest for joint developments under the original Mekong Committee was under question due to the potential environmental and social impacts; c) China was in the process of implementing a large-scale hydropower development program in the upper reaches of the Mekong River which could significantly alter the downstream flow regimes and hence, there was a need to bring China into a more active cooperation framework (Far Eastern Economic Review, 1992).

Basin nations’ agreement

In 1995, the Agreement on Cooperation for the Sustainable Development of the Mekong River Basin was signed by Cambodia, Laos, Thailand and Vietnam and established the Mekong River Commission. The philosophy of the agreement is “to improve the livelihood of 60 million people living in the Lower Mekong River Basin. China and Myanmar which are part of the Mekong River Basin have not signed the agreement but were designated Asean “dialogue partners” in 1996 and have participated in various Mekong River-related activities.

A close look at the 1995 agreement reveals that while signatory countries agreed to “cooperate in maintaining minimum flow levels of no less than the acceptable monthly minimum flow rates during each month of the dry season,” the same agreement does not require consent/consensus/agreement of the riparians for national projects which may affect the river flow levels. The prior legal agreement in place required the consent/concurrence of all riparian countries for any national project that involved the Mekong River. Moreover, the agreement is silent about distribution of water to the member states although basic principles to be applied in developing rules for water distribution are set forth in the agreement.

After sixty 60 years of Asean riparian country cooperation in the utilization of the Great Mekong River, some questions surfaced that needed to be attended to: a) What types of activities are or should be forbidden within the shared Mekong River Basin?; b) Is it possible to harmonize national laws of the riparian countries to regulate the use of the shared basin?; c) What does it really mean to manage the Mekong River Basin in an integrated manner?; d) What rights and obligations do upstream and downstream states have?; e) How can environmental flows be effectively regulated within the shared Mekong River basin?

Above all, what approach should be taken if and when the water flow from the Mekong River’s source markedly lessened or diminished because of the gigantic dam projects of China to divert the flow for its own use to open up agricultural areas to attain food security for its overgrown population?

The author contributed to the evolution and progressive realization of environmental law.