MRC: Rapid Increase in Water Levels Caused by Extremely High Rainfall from Tropical Storm Son-Tinh

AKP Phnom Penh, July 25, 2018 —

The Mekong River’s water levels have increased rapidly during the period of July 15-24, with a rise of over three metres in some stations along the mainstream. But they are not at the alarm level yet, according to a press release from Mekong River Commission (MRC)’s Secretariat.

For example, in the upstream part of Lao PDR in Luang Prabang, water levels had risen from 8.97 metres on July 18 to 13.32 on July 23, a rise of slightly over four metres. A sudden increase was detected at this motoring station, with a jump from 10.85 to 13.28 metres during July 21-22.

Water levels in Vientiane monitoring station also had increased from 4.64 metres on July 18 to 9.40 metres on July 23, representing an almost 5-metre rise in five days. Further downstream of Lao PDR in Pakse, water levels increased by three metres, moving from 7.95 to 10.95 metres over the same period.

In Nong Khai of Thailand, there was an increase of almost five metres, with water levels at the stations climbing from 5.58 to 10.30 metres over this monitoring period. Slightly down the mainstream in Thailand, water levels in Nakhon Phanom station had plunged from six metres on July 15 to 9.88 metres on July 24, indicating an almost 4-metre rise over 10 days. At 10.30 AM on July 24, the water levels in this station was recorded at 9.949 metres, which is 1.5 metres lower than the alarm level of 11.5 metres and two metres below the flood level.

With this continued increase in water levels, Nakhon Phanom and Pakse water monitoring stations may expect to reach their alarm level, set at 12 metres, on July 27 and 29, respectively.

In Cambodia, three water monitoring stations in Stung Treng, Kratie and Kampong Cham all indicated an increase. Water levels in Stung Treng had risen from 7.68 metres on July 18 to 9.25 metres on July 25, while in Kratie, the water levels had jumped from 7.68 metres to 9.25 metres over the same period. In Kampong Cham, there was an increase of slightly over two metres (10.51 metres – 12.56 metres). These stations may reach their flood warning levels next week, when water levels in Stung Treng reach 12 metres, in Kratie 23 metres and in Kampong Cham 16.2 metres.

The water monitoring stations in Viet Nam did not show any increase or worrying trend yet.

Analysis of the Mekong River Commission’s data reveals that the rapid rises of water levels are the results of extremely high level of rainfall from the upper part of Luang Prabang to Vientiane due to the tropical storm Son-Tinh. This caused a rapid rise in many tributaries of the Mekong and resulted in a rapid peak in the mainstream.

During the dry season the MRC’s Regional Flood Management and Mitigation Centre (RFMMC) provides a weekly update on water levels monitoring for same key stations along the Mekong mainstream. Each member country of the MRC monitors water levels in the tributaries of the Mekong River in its own nation and has set different flood warning levels.

The Commission also conducts daily flood forecasting for key stations along the Mekong mainstream from Chiang Sean of Thailand to Tan Chau and Chua Doc of Viet Nam. It detects accumulated rainfall based on a flash flood guidance system to see which parts of the basin will experience possible flooding.

The MRC is an intergovernmental organisation for regional dialogue and cooperation in the lower Mekong river basin, established in 1995 based on the Mekong Agreement between Cambodia, Lao PDR, Thailand, and Viet Nam. The organisation serves as a regional platform for water diplomacy as well as a knowledge hub of water resources management for the sustainable development of the region.

By Khan Sophirom