The National Centre for Hydrology and Metereology (NCHM) called off the manual observation of water level of Thorthormi Lake from yesterday.

The monitoring of the lakes, according to a NCHM notification, would be continued from glacial lake outburst flood (GLOF) control room in Wangduephodrang and national weather and flood warning centre at head office in Thimphu.

This comes after the NCHM officials, teachers of Lhedi Primary School and health staff of Lunana basic health unit relocated the automatic water level station (AWLS) damaged by the June 20 flood from subsidiary lake II to subsidiary I on June 24.

Both the subsidiary lakes breached on June 20.

The four-member technical team, comprising of a glacier expert, two engineers and a technician, who were airlifted to Lunana on June 23, two NCHM officials stationed in Lunana, health and education officials repaired and maintained the AWLS in Thanza yesterday.

The Thorthormi Lake was manually or visually monitored by the staff deployed at the lake site after the AWLS in subsidiary lake II was damaged. It was learnt that NCHM official in Lunana had to monitor the water level by marking the boulders.

NCHM officials said the water level is decreasing, but the stability of the moraine dam of the main Thorthormi Lake is likely to remain uncertain because of the breaching of subsidiary lake II.

NCHM cautioned people living along the Phochhu and downstream to be vigilant.

NCHM director, Karma Dupchu, said the technical team is still assessing the stability of the moraine dams. “Our priority was to install the AWLS first.”

He said they would be able to provide a complete analysis once the officials return from Lunana.

Tashi Dema