China has again warned Nepal that a lake formed in the upper reaches of the Lhende river system could breach its banks at any time, pointing to a change in the colour of the water as a possible sign of increasing danger. However, Beijing said that even if the lake were to burst, the maximum flow entering the river system would be around 500 cubic metres per second.
In a message sent to Nepal's Ministry of Foreign Affairs, Chinese authorities said the colour of the lake, which began forming after the deadly flash floods that struck parts of Nepal and Tibet earlier this week, had been gradually becoming darker. According to China, this could suggest that the lake is at risk of bursting.
"The colour of the lake that began forming the day before yesterday is continuously becoming darker. This means that it could burst," the message stated. It added that the lake did not contain a particularly large volume of water, meaning downstream rivers could see a slight increase in flow, but a major rise was considered unlikely.
Chinese authorities advised people living in downstream areas to stay alert. The temporary lake was created following a glacial collapse believed to have triggered the devastating flash floods in Nepal and Tibet.
Debris from the collapse formed a natural dam, resulting in the creation of the lake and raising concerns that it could eventually breach. The lake has formed near the meeting point of the Chochen River on the Chinese side and the Purepu River on the Nepali side.
China's Ministry of Water Resources said the lake's water level was continuing to rise. By Friday, around 2.5 million cubic metres of water had accumulated.
FLOOD MODELLING TO ASSESS THE RISK
China has conducted flood modelling to determine the potential impact of a breach. According to Beijing's assessment, the maximum flow into the river system could reach 500 cubic metres per second if the lake were to burst.
The Chinese message said, "If part of the dam breaks, the maximum water flow could be 500 cubic meters per second. It will remain confined within the river's banks."
China had previously estimated that another 3 million cubic metres of water could collect in the lake over the following three days. Authorities are using drones and satellites to continuously monitor the area.
The lake began overflowing into the Lhende Khola and Trishuli rivers on Friday. By midday, China's state broadcaster CCTV reported that the situation was considered manageable.
The possibility of the temporary lake breaching and triggering another round of flooding has nevertheless kept Nepalese authorities on alert as the country deals with the aftermath of Wednesday's devastating flash floods. At least 587 people have died so far, while at least seven deaths have been confirmed in Tibet.
