This year saw yet another record-setting dry season for the Mekong basin. The Mekong Environment Forum, an NGO based in Can Tho City, has been working closely with the Mekong Dam Monitor project team to provide translations of weekly updates on the operation of hydropower dams in the upstream Mekong. The updates from the first half of 2024 have been synthesized to map and offer insights into the updated impacts of dam operations on downstream hydro- and eco-systems.
The evidence gathered supports the understanding of the potential for a double water crisis when upstream dam operations intersect with downstream climate change effects. These findings echo recent concerns voiced by experts and the public regarding the transboundary impacts of excessive damming in the Mekong region.
We urge for cross-border collaboration and coordination to advocate for responsible, transparent, and sustainable use of the shared water resources in the Mekong basin. As downstream communities, such as the Mekong Delta in Vietnam and many riverine communities in Cambodia, face increasing threats from accelerating climate change and hydropower impacts.
Mapping the Updated Impacts of Upstream Hydropower Dams
During March to June 2024, the lower Mekong region, including northeast Thailand, Cambodia, Laos, and Vietnam, experienced abnormally high temperatures. Severe dryness was observed in various areas such as the Golden Triangle, Tonle Sap Lake in Cambodia, central Laos, and along Vietnam’s coast. The intrusion of saltwater in Vietnam’s coastal provinces caused hardship for many residents in the Mekong Delta.
The production of hydropower and water flow have significant effects on drought conditions in the Mekong, with variations seen seasonally. Reports from the Stimson Center’s Mekong Dam Monitor indicated that the 2024 dry season had the lowest hydropower releases in three years, primarily due to drought conditions in China during the 2023 wet season. This led to reduced hydropower production and near-full reservoirs in dams like the Tuoba Dam. As a result, river levels along the Thai-Lao border dropped significantly, potentially disrupting the ecological balance in those regions.
Despite the lower dam releases from China, which maintained near-normal river levels in March and April, previous years of high dam releases have had severe environmental impacts in the Mekong. The reduced releases in 2024 provided some relief, allowing flooded forests to dry out from previous inundations, but the overall impacts from upstream activities still pose threats to the forest ecosystem.
Furthermore, the early refilling of dams in China restricted water flow downstream, exacerbating drought conditions in the lower Mekong. Operations like hydropeaking at China’s Jinghong Dam also disrupted the river’s ecology, impacting fish habitats and migration.
These developments highlight the need for better understanding and consideration of the impacts of dam operations on downstream ecosystems and communities.
A Double Water Crisis in Vietnam’s Mekong Delta and Policy Recommendations
Despite preparations for the dry season, parts of Vietnam’s Mekong Delta faced severe dryness due to decreased water supply from upstream and salinity intrusion. The lack of freshwater for irrigation caused major challenges for residents in coastal provinces.
Based on recent policy dialogues, the Mekong Environment Forum suggests several recommendations for Vietnam to address the double water crisis:
1. Partner with neighboring countries and research organizations to assess the challenges posed by hydropower and climate risks.
2. Collaborate with riparian governments and dam operators to maintain minimum flows on transboundary rivers to protect downstream habitats.
3. Support alternative farm systems in water-scarce areas, permit crop rotation, and adjust export policies to promote sustainable farming practices.
4. Invest in early warning systems and disaster response management.
5. Provide guidance and support for farmers to adopt alternative crops through partnerships with research institutes, NGOs, and vocational training organizations.
This article is based on data from the Stimson Center’s Mekong Dam Monitor and the Mekong Environment Forum’s collaboration with Stimson for related events.