Breaking the flood-drought cycle

Cambodian scholar Mak Sithirith argues that Cambodia can get beyond the endless cycle of having either too much or too little water, if governments would take a broader view of water resources beyond irrigation management.

He bases his argument on research on the local community impacts of three different water management structures:

• the Stung Chreybak irrigation scheme in the Tonle Sap region;
• the Lower Sesan hydropower dam in ‘3S’ river basin of the Sesan, Sekong and Srepok rivers; and
• flood control structures on the Vietnam side of the Mekong Delta, which regulate seasonal river flows.

He finds that each type of water infrastructure presents its own issues for local populations in Cambodia.

The Stung Chreybak irrigation scheme, which dates from Khmer Rouge time, was rehabilitated by a foreign NGO in the 1980s to provide supplementary irrigation to farmers. The research found that smallholder famers still rely on rainfall for irrigation, so as to avoid incurring fuel costs for pumping water out of Stung Chreybak.

The Lower Sesan 2 hydropower dam, operating since 2017, has brought far-reaching changes to the traditional lifestyles of indigenous peoples and local communities resettled as part of the dam development process. While people were compensated for the loss of their ancestral lands, they have lost access to the diversity of fish species that were an important part of their diet and livelihoods. They have access to electricity and modern appliances, but are spending some of their compensation money on buying food that they previously were able to get from the environment.

Flood control structures on the Bassac River at the border area between Vietnam and Cambodia have blocked fish migration from Cambodia to Vietnam and affected fish productivity in the Mekong Delta system. Rubber dams (flexible membrane structures), dikes and other water control structures in the Vietnam part of the Mekong Delta have exacerbated flood and drought events on the Cambodia side. Some structures are thought to have caused flooding in Takeo province in Cambodia.

Sithirith states that water resource management in Cambodia should aim to balance the problems of too much water in the wet season and too little water in the dry season. He suggests that Lower Mekong countries are potentially in breach of the 1995 Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin (the Mekong Agreement), specifically Article 3 on protection of the environment and ecological balance, because water resource infrastructure built by the Lower Mekong countries themselves have had adverse impacts on the environment and ecosystems.

To remedy this, he calls for protecting natural river systems and lakes, and building reservoirs that would increase dry-season water availability. He also calls for community-based water management at the local level, which will address the needs of local people. Finally, he flags the prospect of strengthening transboundary water governance, through a review of the 1995 Mekong Agreement and the institutional arrangements embodied in the Mekong River Commission.

Sithirith, M. (2021). Downstream state and water security in the Mekong region: A case of Cambodia between too much and too little water. Water, 13(6), 802.