A man rides his machine boat along the Tonle Sap Lake in Kampong Khleang, passing floating houses on silts. (Photo: Mekong River Commission)

The MRC’s Situation Report, which explores hydrological conditions in the LMB during January-July 2020, preliminarily identifies multiple possible causes of the low flows and drought this year. Among these are abnormal low rainfall affected by the El Nino weather phenomenon, prolonged low flow conditions carried over from 2019, and lower water flow contributions from the Mekong tributaries.

The low flows have caused Cambodia’s Tonle Sap Lake to experience “extremely dry conditions”, with reverse flows at their lowest on record since 1997.

Using available monitoring, rainfall and weather data from the MRC and other global sources, the report adds that operations of the mainstream dams in the Upper Mekong Basin and the tributary dams in the LMB may have affected the present low flow conditions. However, the MRC Secretariat has been unable to obtain official data and information to verify the potential impacts of storage operations in the upper basin.

“We call on the six Mekong countries to increase data and information sharing on their dam and water infrastructure operations in a transparent and speedy manner with the MRC. It is time to walk the talk and to act in the common interest of the entire Mekong River Basin and the affected communities,” said An Pich Hatda, the MRC Secretariat’s Chief Executive Officer.

The 32-page long report points out that the current low flows could have severe impacts on Cambodia due to a loss of fisheries and irrigation potential. Vietnam may experience reduced productivity in the Delta rice bowl, and agricultural productivity in Lao and Thailand may also be affected.

The report suggests that the MRC member countries, including Cambodia, Laos, Thailand and Vietnam, should request hydropower operators and irrigation operators to adjust their near-term operations and monitor potential bank erosion.

If the low flows persist, according to the report, the four countries should consider requesting China to discharge a “water supplement”, as they did in 2016, to relieve the situation in the LMB, especially during the upcoming dry season./.VNA