GLOF risks in High Mountains
GLOFs occur relatively infrequently, but are the most hazardous flood risk in the High Mountains, due to the impacts of Climate Change.
Imja Lake is located in Solukhumbu district, Khumbu region – a popular tourist destination in the country, is considered as one of the rapidly growing lakes in the Hindu Kush Himalayan region, which poses a high risk to the local inhabitants and thousands of tourists visiting the area every year.
In 2000, Department of Hydrology and Meteorology has successfully mitigated Tsho Rolpa Glacial Lake by lowering the lake level by 3 meter through the construction of drainage channel for controlled discharge of water, the first of its kind in Nepal.
The project aims to replicate the knowledge and experiences gained from Tsho Rolpa to mitigate GLOF risk arising from Imja Lake by reducing the lake volume through an artificial controlled drainage system combined with a community-based early warning system.
Flooding in Terai & Churia
The magnitude and frequency of flash floods have increased in recent years, particularly in the Terai and Churia range, as a result of increasing trends in extreme rainfall events. Various studies conducted in the Churia range show that the bed levels of Churia originating rivers are rising by about 10-15 cm every year. The river bed rise may cause the change of river course leading to the bank erosion and sedimentation in the fertile land. Many poor communities in the Terai are vulnerable due to the flash flood hazards because of their proximity to the hazards. The situation in the area is so severe that their awareness level is very low.
Among the flood prone districts in the country, the project is being implemented in the Mahottari, Siraha, Saptari and Udayapur districts. The project aims to increase the adaptive capacity of the vulnerable communities living in these four districts, especially in the eight VDCs of five river systems. Implementation of locally-appropriate structural measures including plantation is expected to work as sediment control measures for flood risk reduction. Various capacity building programs in different level and establishment of Community Based Early Warning System (CBEWS) are expected to enhance the adaptive capacity of different stakeholders including vulnerable communities.
Project Implementing Areas
The two main components of the project are being implemented in two discrete geographic areas of the country. The activities under first component are being implemented in and around Imja Lake in Solukhumbu district. Four Village Development Committees (VDCs) Chaurikharka, Khumjung, Namche and Juving along 50 Km downstream from Imja Dudh Koshi River corridor are the project working areas for first component.
Under second component, the project is being implemented in four flood prone districts; Mahottari, in Central Region and Saptari, Siraha and Udaypur in Eastern Region. Project is being focused in eight VDCs: Sarpallo and Nainhi – Mahottari; Tulsipur and Pipra Pra Pi – Siraha; Dighawa and Pakari – Saptari and Hadiya and Jogidaha – Udaypur, respectively in Ratu, Gagan, Khando and Triyuga (two tributaries i.e. Hadiya and Kong) River Basins.