The National Centre for Hydrology and Meteorology (NCHM) has successfully tested a pilot siphon system at Thorthormi Glacial Lake in Lunana yesterday. The technology is being explored as an alternative way to lower lake water levels without disturbing the surrounding moraine and to reduce the risk of glacial lake outburst floods.
After more than a month of preparations, a seven-member technical team from the Centre installed and tested the pilot system to draw water from the lake.
The system uses high-density polyethylene pipes to carry water out of the lake. During the test, it achieved a stable, self-sustaining flow, showing that the technology could work in the high-altitude conditions of the Bhutanese Himalayas.
Trashi Namgyel, Officiating Director General, NCHM, said the system has two main advantages from a technical point of view.
“It is very economical compared to other interventions. The second thing is that it is environmentally friendly. These are the two advantages from a technical point of view. However, I have to clarify that this is just a pilot test. We have a successful result, and based on this, we will plan a full-scale mitigation project for Thorthormi itself as well as other glacial lakes.”
Initial testing began last year with support from the World Bank. Following technical challenges, the team shifted the pilot to an alternative outlet site for the latest test, which the government funded.
“This will be one of the first of its kind in the Himalayan region. We are now confident that this system can be implemented at such high altitudes and under these environmental conditions. Once we receive all the technical details and recommendations from the technical team, we will start planning the next phase of full-scale projects,” Trashi Namgyel said.
The technical team will now analyse the system’s performance, including water discharge rates, pipe integrity and its ability to withstand low temperatures.
NCHM expects to release the findings next month, which will help determine whether the technology can be implemented on a larger scale.
Thorthormi is one of Bhutan’s 17 potentially dangerous glacial lakes. A glacial lake outburst flood could threaten downstream communities, infrastructure and biodiversity in the Pho Chhu and Punatsangchhu river basins.
Karma Wangdi
Edited by Sangay Chezom
