Mekong river

Planned outflows from Jinghong dam continue to disrupt river communities downstream

The fate of Mekong river communities downstream is hanging in the balance as China has alerted the Mekong countries downstream that it would postpone its plan to cut down outflows from the Jinghong dam upstream_without a specific deadline given

China’s Ministry of Water Resources has freshly notified the Mekong downstream countries as well as the Mekong River Commission (MRC) that it would postpone the plan to reduce the outflows from its Jinghong dam upstream. According to the MRC, the notification sent to it late last week did not specify the new deadline, only simply noting that it would be the end of August. This was due to “technical preparation”, according to the ministry.

China earlier informed the countries and the MRC that it would cut down the outflows of the dam from July 31 to August 20. This would see a reduction of the outflows alternating between 900-1,300 cubic metres per second (m³/s) and 700 m³/s, or a drop of as much as 50% for 20 days. The available recorded outflow at the Jinghong dam on July 28 was 1,569 m3/s. All these could mean a drop in the river levels immediately downstream, the MRC earlier projected.

The Mekong Dam Monitor, an online platform run by the US-based Stimson Center, has posted that the brief abruption of China’s plan was temporary good news for the Mekong downstream as a major upstream restriction would deliver significant impacts to the Mekong mainstream and the Tonle Sap Lake floodplain expansion following the river’s natural cycle. The platform noted that the reason given for the outflow reduction plan for Jinghong seemed too “convenient”.

“Looking back through the data, the first three weeks in August are typically when China’s major dams at Xiaowan and Nuozhadu fill the most. They are turning off the tap at a time when the Mekong downstream needs water,” the platform noted.

As noted by the platform, the week before the Mekong mainstream already experienced below-average wetness throughout the headwaters.

The Mekong river section in Sang Khom district in Nong Khai province, where it turned to crystal clear with algae booming, disrupting local fishing there. Credit: Ormbun Thipsuna/ Rak Mekong Group

River disruptions

This is not the first time that the Mekong mainstream is subject to disruptions by the dams upstream.

In late May, the Office of National Water Resources (ONWR) issued a warning to provinces by the Mekong River that China would reduce the outflows from the same dam from 2,525 m³/s to 1,854 m³/s or the reduction of 671 m³/s for a few days. The office projected that the reduction of the outflows from the dam could result in a drop in river levels above the Xayaburi dam around 80 to 100 centimetres, while whether further downstream could see the water levels in the river drop depended on the operation of the Xayaburi dam.

Early this year, in early January, China’s Ministry of Water Resources notified the Mekong downstream countries that the outflows from Jinghong would be restricted to 1,000 m³/s from Jan 5 to 24 due to “the maintenance of power grid transmission lines”.

The Ministry, however, did not specify the river water level before the outflow restriction nor the volume to be restored on Jan 25 onwards, according to the MRC. It just said the amount of water flow would be gradually restored to its normal operation.

China had already agreed last year to share year-round water level and rainfall data with the MRC. By agreement with the MRC, China pledged to notify the MRC and its member countries of any abnormal rise or fall in water levels or discharge, and provide relevant information on factors that might lead to sudden flooding, according to the Mekong’s governing body.

Based on the MRC’s observed water level data at Jinghong, as available until January 4, the outflow level started decreasing from 1,410 m³/s on 31 December 31, 2020, to 768 m³/s on  Jan 1, representing an almost 50% drop. The flow slightly rose slightly to 786 m³/s over Jan 1 to 4, according to the MRC.

The MRC had projected based on its observed and forecasting water level data that the water levels along the Mekong River would likely drop by about 1.20 metres as such.

In Chiang Saen, which is the first river monitoring station in Thailand and located approximately 300 km away from Jinghong, for instance, the water was recorded as having dropped by about two metres during Jan  2 to 4.

Since the initial fall on Jan 1, the MRC’s data showed that the outflow levels at Jinghong from Jan 1 to 7 were stable at around 785 m³/s. They then fluctuated, gradually rising to 1,400 m³/s again on Jan 15, and then dropping to 740 m³/s over the next week, or during Jan 15 to 23. The outflow levels then rose to 990 m³/s on Jan 29 before falling gradually through to February 11, which recorded the level at 800 m³/s. 

The MRC at the same time had recorded, based on its monthly rainfall observations, that since November last year, rainfall had been consistently lower than average, falling by 25%.

It noted that the water levels in the river between Jinghong and the Mekong Delta in Viet Nam had fallen to worrying levels, citing various factors from lower rainfall to dam operation in tributaries. The outflow restrictions from the Jinghong dam were also included. 

“There have been sudden rises and falls in water levels immediately downstream of Jinghong and further down to Vientiane, which has been challenging for authorities and communities to prepare for and respond to possible impacts,” Dr. Winai Wangpimool, Director of the MRC Secretariat’s Technical Support Division, had said of the situation early this year. 

“Continuing this flow pattern could have an impact on river transport, fish migration, agriculture and river weed collection,” he said, while calling on China and the Lower Mekong countries themselves to share their water release plans with the MRC in order to help the countries downstream manage risks more effectively.

By mid-February, the situation did not improve. The ONWR decided to contact China through the Lancang-Mekong Cooperation Framework (LMC) to notify China about the worrying levels of the Mekong River.

Dr. Somkiat Prajamwong, the ONWR’s Secretary-General, had said by mid-February, the outflow levels from the Jinghong dam had not returned normal. The office had found that it was still around 1,000 m3/s and over 500 m3/s was needed to maintain the monthly average level for March measured at Thailand’s Chiang Saen (1,540 m3/s).

The office called on China to release the water from the dam immediately to help lessen impacts downstream. It also called on China to share its quarterly dam operational plans to the downstream countries, while urging it to notify the countries two weeks before if its dams would cause abrupt changes in operations, which would result in a change of outflow discharge 400 m3/s and over. This is because at this rate it would suddenly disrupt the water level at Chiang Saen, or within a day.

Chiang Khong is next to Chiang Saen and also feels the impacts from the Jinghong dam. Credit: Thai Mekong People’s Network from Eight Provinces

A new approach on the upstream dam operations

Niwat Roykaew, Chair of Raksa Chiang Khong Group, which has been campaigning for sustainable development for the Mekong mainstream, has voiced his views on the current cooperation framework following its latest meeting held in mid-June that the framework still focuses on data sharing, which is not capable of dealing with the growing challenge.

Data sharing to manage risks, he said, is not enough. The issue needs to be tackled from the start, which is about dam operations in contrast to the natural cycle of the river.

“This is not equal cooperation among the countries. It’s just a plea after a plea, and it does not lead to a true solution that helps address the issue and challenges that we have. The LMC needs to understand and realise this first, it needs to realise the problem at its root. Without realization, we would never acquire room to develop solutions that we need,” said Mr. Niwat.

In late June, the MRC launched the Situation Report, encouraging the member countries and its Dialogue Partners, China included, to share and exchange operational data more widely to garner a deeper understanding of recent changes in Mekong mainstream flow patterns and to address any potential impacts on the riverine communities.  

“For the sake of better management of the basin and of good faith cooperation, both Member Countries and China should notify any planned major changes in the operation of hydropower projects and share that information with the MRC Secretariat. This is important where such operations may result in abnormal rises and falls in water levels,” Dr. An Pich Hatda, MRC Secretariat Chief Executive Office had said.

According to the MRC Procedures for Maintenance of Flows on the Mainstream, the member countries are obligated to “enable the acceptable natural reverse flow of the Tonle Sap River to take place during the wet season” and prevent human-made peak flows that what would not naturally occur during the flood season.

The organization also invited other platforms monitoring the river levels to coordinate and verify data with the MRC Secretariat.

The report, which has evaluated hydro-meteorological conditions during the 2020–2021 dry season spanning November 2020 to May 2021, shows fluctuations in water levels in the upper reaches of the Mekong mainstream in Lao PDR and Thailand, as well as low water volume stored in the Tonle Sap Lake.

Rainfall in April to May was the highest on record for these months for the last 18 years in places. “This was particularly striking over the middle part of the Lower Mekong Basin areas of Thailand and northern Cambodia. But overall, river flows did not increase significantly”, the report notes.

The report notes that rapid changes in water levels in the flows due to hydropower operations in the Upper Mekong continued in 2021.

The lower flows in the Mekong in the 2019 and 2020 wet seasons decreased return flows and seasonally flooded area of the Tonle Sap Lake, on which much of Cambodia’s population rely for their livelihoods. This triggered adverse impacts on agricultural production, the ecological balance, reduced nutrient-rich sediment mobilisation, and transportation as well as decreased household fish catch in the Tonle Sap Lake area, according to the report.

The report recommends a more detailed study on the pattern of water level changes as well as further studies into active management of water storage in the whole basin as this could lead to improved operations by the riparian countries, thus reducing the potential adverse impacts on the communities.

The ONWR, meanwhile, has prepared to issue a warning for provinces by the Mekong River once it has received confirmation from China for the latest reduction of the outflows from the Jinghong dam.