Irrigation & Water Resources

Feasibility Study of Dams in Dang Valley

The Dang valley is one of the largest valleys of the country located in Dang district. The Dang valley with the irrigable area of about 65,950 ha has potential irrigable area of about 60,000 ha including Deukhuri valley and Tulsi-Dang. The proper Dang valley has total irrigable area of about 43,000 ha, part of which is being irrigated from seasonal streams and rivers. The year-round irrigation coverage in the valley is limited to small proportion of the area commanded by several farmers managed irrigation systems and deep tube wells. The main objective of this Project was to carry out feasibility level study to 5 dams to impound water for irrigation purpose. The project also aimed to have a general picture of the impact of this project on the current socio-economic status of the area. Since large dams have been rapidly establishing themselves as a major civil-engineering structure in the sector of water-resource management, the significance of project is more highlighted as the first ever study in the sector of irrigation engineering in Nepal.

Client
Mega Dang Valley Irrigation Project

Associated consultants
CMS Engineering Consult P. Ltd., Nepal

Location 
Tulsipur, Dang District

Start date
October 2017

Completion date
July 2019

Approx. value of the services
NPR 11,300,000.00

Professional Staff Provided by Consultant/Entity
No. of Staff-Months: 120.87
Duration of Assignment: 12 months

Senior staffs involved in the project
Team Leader/Dam Engineer: Buddha Krishna Manandhar,
Geologist: Jayandra Man Tamrakar,
Structural Engineer: Krtishna Prasad Shrestha,
Hydraulic Engineer: Ajaya Lall Shrestha,
Irrigation Engineer: Ram Das Maskey

Scope of works
– Carried out detailed hydrological study of the five rivers; catchment characteristics, drainage system, water-uses, and water availability.
– Conducted geological and geo-technical investigation of the area. This included geo-technical investigations at the dam sites of the proposed diversion projects (220 m of boring).
– Assessed the availability of potential construction materials and seismicity of the area.
– Prepared socio-economic profile of the area to ensure social safeguard, environmental study and prepared agricultural development plan.
– Proposed diversion plan for the irrigation development that included 5 dams of differing heights from 15 m to 125 m.
– Conducted detailed design of 5 dams: 3 of moderate heights as Earthen dams and 2 as Clay Core Rockfill Dam. 

  1. Dam at Vutiya Tal-15 m (Earthen Dam) 
  2. Dam at Ranighat Khola-43 m (Earthen Dam) 
  3. Dam At Balim Khola-70 m (Clay Core Rockfill Dam)  
  4. Dam at Vitri Khola-29 m (Earthen Dam) 
  5. Dam at Gwar Khola-125 m (Clay Core Rockfill Dam)