Chilime Hydropower Company Ltd (CHPCL) has obtained Survey License for the study of a medium scale Rasuwagadi Hydroelectric Project of 100 MW installed capacity on July 15, 2008. It is located in Rasuwa district. Bhote Koshi river (Upper reaches of Trishuli river) is the main source river of the project.
Project Location and Accessibility
The project is accessible by the Kathmandu -Trishuli – Somdang road at a distance of 130 km to the northwest of Kathmandu to Syabrubensi. The construction of road between Syabrubensi to Rasuwagadhi, the headwork site of the project (almost 16 km) is under construction by the Government of Nepal in assistance with Chinese Government. The track road between Syabrubesi to Rasuwagadhi has been opened and can be reached with the vehicles.
Present Status of the Project Study
The Feasibility Study Report (draft) of the project has been prepared and submitted to the Ministry of Energy, Department of Electricity Development and Nepal Electricity Authority for their comments and suggestions.
The report is being studied for the comments and suggestions by the hydropower experts also. The final study report is being prepared with the incorporation of the comments and suggestions obtained from these agencies.
The brief description of the project component as seen from this level of study is as follows:
The headwork of the project is located at Rasuwagadhi of Rasuwa District. It consists of a diversion weir of crest length 60.0 m, 6.5 m wide and 5.0m high three bays undersluices, 6.50 m wide 5.0 m high four bays side intake and the 140 m long, 20 m wide Du-four type surface desanding basin located on the right bank of the river. As an alternative study, the underground option of the desanding basin has been studied. The comparative study and expert’s opinion for the selection among the alternative options is being carried out.
Diversion weir diverts the design discharge through the side intake. The design discharge passing through the intake flows towards inlet of desanding basin through an intake channel of length 61.0 m.
The surface desanding basin comprising of two basins will pass the sand free water towards the headpond located in front of the tunnel inlet portal.
The headwork also consists of a gravel trap at intake zone, 32.0 m long side spillway and flushing facilities etc.
Headrace Tunnel & Penstock
The low pressure power tunnel conveys design discharge 80 m3/sec from headpond towards the powerhouse. The total length of 6.0 m dia. headrace tunnel is about 4375 m. The major part of headrace tunnel, surge tank, penstock and underground powerhouse is located on good geological area.
The length of vertical shaft and horizontal tunnel of penstock with bifurcation is about 313m. The vertical shaft is designed to have an inside diameter of 4.80m and is steel lined and covered with backfill concrete in between the rock and steel pipe. The finished diameter of lower horizontal part of the penstock tunnel is varies from 4.80m to 3.60m and is also steel lined and covered with backfill concrete.
As there is not sufficient space available for the surface option of powerhouse, the underground option has been selected. It is located on the right bank of Bhote Koshi river about 260 m inside from the rock surface.
The dimension of the underground powerhouse cavern is 60.00 m long, 12.50m wide & 27.50 m high. The length of the 6.50m dia. D – shaped main access tunnel is 260 m.
The tailrace tunnel of length of 580.0 m and dia. 6.0 m will discharge the tail water from powerhouse to Bhotekoshi river near suspension bridge located below Dalphedi village.
Environmental Impact Assessment (EIA) Study:
The Scoping Document and Terms of Reference (TOR) of the Environmental Impact Assessment (EIA) study have been approved from the Ministry of Environment.
The Final EIA report has been prepared after completion of ‘ Public Hearing Program ‘ at project area and submitted to the concerned Ministries for its approval.