Lowering of Imja Tsho in Khumbu

Imja lake in the eastern part of Sagarmatha National Park is a glacier lake fed by Lhotse Shar, Imja and Amphu glaciers. HRE is currently carrying out the project of lowering Imja Tsho in Khumbu of Sagarmatha National Park. This project was funded by UNDP and through Department of Hydrology and Meterology, HRE is currently managing the work.           

                                         

          Photo: Imja Lake by Alton C. Byers. Institute of Arctic and Alpine Research, University of Colorado at Boulder.     

At an extreme geographical and climatic condition of Imja Lake which is located at an elevation of 5100m, our team of technician, construction workers and management staffs along with Nepal Army are currently carrying out this herculean task of lowering the depth of Imja Lake by 3m.  

 

                                                        

                                                                 Photo: Camp of Imja construction work at the base of Mt. Lhotse 

Glacier Lake Outbrust Flood (GLOF) are deemed as one of the most hazardous and dangerous impact of climate change. There is no denying in the fact that a small meltwater pond of four decades back is now a 1km long, 0.5 km wide and 150m deep; holding over 75 cubic millions. This huge amount of water is hold back by unconsolidated rubble mass of lateral and terminal moraines, which when triggered by any factors that would cause imbalance of the loosely places moraines, would result in devastating flood capable of washing away the settlements downstream. Because of which, the Imja Lake was placed among 21 most dangerous glacier lakes of Nepal. 

 

 

 

                                                         

                                                                  Photo: M25 RCC work in Main open Channel of the Lake.  

Realizing this fact, the work of lowering the Imja Lake commenced in April, 2015. And the work is running in the full pace now. Till date, the work of mobilization the work force, surveying the construction areas, setting up, excavating the diversion channel, constructing of cofferdam and excavation of main open channel has been completed. 

 

                                                        

                                                           Photo: Construction details at outlet channel of Imja Lake. Credit: Ghana Shyam Basnet 

 We expect that the work of opening the neck and coffer dam to drain out the water would be completed by the next two months of time. After draining out the water, the diversion channel would be closed and thus the depth of the lake would be reduced to a safer level.