07-10-2075 (B.S.); 21-01-2019 (A.D.)
24-06-2080 (B.S.); 11-10-2023 (A.D.)
14-04-2075 (B.S.); 30-07-2018 (A.D.)
09-10-2079 (B.S.); 23-01-2023 (A.D.)
Machhapuchchhre Bank Limited (Lead), Lumbini Bikas Bank Limited
Clean Energy Consultants (P) Ltd.
Technoquarry Consults Pvt. Ltd.
Mr. Narayan Poudel, CA
S Subedi & Associates
Mr. Ramsharan Giri, CA
Located in Falelung Rural Municipality, Panchthar district, Province no. 1, Eastern Nepal, Hewa A Small Hydropower Project is a run-of-river (RoR) type with a capacity of 7.5 MW. The project’s design discharge and gross head are 4.95 m3/sec and 204.8 m respectively. Situated on the left bank of Hewa Khola, a tributary of Tamor River, the project area’s coordinates are between Longitudes 87º51’00” E and 87º53’15” E, Latitudes 27010’40” N and 27011’38” N. Its major components include river diversion, headworks, gravel trap, desander, forebay, headrace, penstock, powerhouse, and tailrace canal. The project is accessible via Kathmandu-Phidim-Yagnam road, with a total distance of approximately 770km, and the nearest airports are Suketar and Bhadrapur Airport.The transmission line is connected to the national grid through a 33KV transmission line, which passes through the HKSHP Switchyard area and extends for 10km to reach the 33kv/132KV NEA Substation at Thapatar, Phidim Panchthar.
Additionally, the excavation works at the Powerhouse, which were 70% complete at the time, were also washed away. Infrastructure such as a 150KVA transformer, construction power equipment, and access roads suffered damage and required full repair and maintenance due to heavy rainfall, landslides, and soil erosion. Significant losses included the civil contractor camp, an excavator, a 30KVA DG, and transformers (100KVA and 150KVA), along with partial damage to two excavators and one bike. Thankfully, there were no human casualties.
| 1 | Project Location |
|---|---|
| Province | Koshi |
| District | Panchthar |
| Intake Site | Papundin |
| Powerhouse Site | Yanyeppa |
| Geographical Co-ordinates | |
| Latitude | 27˚ 10’ 40’’ N to 27˚ 11’ 38’’ N |
| Longitude | 87˚ 51’ 00’’ E to 87˚ 53’ 26’’ E |
| Conservation Area | n/a |
| 2 | General |
| Name of River | Hewa Khola and Niwa Khola |
| Nearest Settlement | Phidim Bazaar |
| Type of Scheme | Run-of-river |
| Gross Head | 204.8 m |
| Net rated Head | 175.31 |
| Installed Capacity | 7.5 MW |
| Peak Hour (if P-RoR) | N/A |
| Average Annual Energy after Outage | 48.42 GWh |
| Deemed Wet Energy | 30.91 GWh |
| Deemed Dry Energy | 17.51 GWh |
| 3 | Hydrology |
| Catchment Area | 162.08 km2 |
| Hewa Intake= 139.88 km2 | |
| Niwa Intake= 22.20 km2 | |
| Average Annual Discharge | 10.33 |
| Minimum Monthly Discharge | 2.02 |
| Maximum Monthly Discharge | 27.68 |
| Design Discharge (at 40% PoE) | 4.95m3/s |
| Hewa Intake= 4.10 m3 /s | |
| Niwa Intake= 0.85 m3 /s | |
| Design Flood Discharge | For Hewa Intakes: 495 m3/s |
| For powerhouse: 637 m3/s | |
| Average Annual Precipitation | 2255.05 mm |
| 4 | Hewa Headworks |
| Type of Weir | Free Flow Gravty Weir |
| Length of Weir | 20.05 m |
| Crest Elevation | 1138.00 masl |
| No. of Undersluice Opening | 1 no. |
| Size (W x H)/td> | 3.00 m x 3.00 m |
| Type of Intake | Side Intake |
| No. of Intake Opening | 3 nos. |
| Size of Intake Orifice (W x H) | 2.00 m x 1.00 m |
| Intake Invert Level | 1137.00 masl |
| 5 | Niwa Headworks |
| Type of Weir | Free Flow Gravty Weir |
| Length of Weir | 16.06 m |
| Crest Elevation | 1142.80 masl |
| No. of Undersluice Opening | 1 no. |
| Size (W x H)/td> | 2.00 m x 1.85 m |
| Type of Intake | Side Intake |
| Size of Intake Orifice (W x H) | 1.50 m x 0.85 m |
| Intake Invert Level | 1141.64 masl |
| 6 | Gravel Trap |
| Length | 25.00 m |
| Width and Depth | 7.20 m x 3.7 m avg. |
| Slope | 1:6 in transition and 1:10 in main section |
| 7 | Connecting Canal |
| Length | 162.56 m |
| Size (W x H) | 2.40 m x 2.30 m |
| Invert Level at Exit | 1135.88 masl |
| 8 | Desanding Basin |
| Type | 3-bay, Dufour Single Chamber Type |
| Dimension (L x B x H) | 50.02 m x 5.00 m x 4.5 m avg |
| Length of Inlet Transition | 9.98 m |
| Particle Size to be Settled | 0.20 mm |
| Settling Criteria | 5000 ppm |
| Settling Efficiency | 92% |
| 9 | Headrace Pipe |
| Type | IS 2062-BO, E350 MPa |
| Internal Diameter | 1.55 m, 1.45 m & 1.35 m |
| Length | 3888.23 m upto Surge Junction |
| Thickness | 7mm |
| 10 | Surge Pipe |
| Type | Inclined Pipe buried on ground |
| Internal Diameter | 1.55 m, 1.45 m & 1.35 m |
| Length | 3.00 m |
| Thickness | 10 mm |
| Upsurge Level | 1158.20 masl |
| Downsurge Level | 1107.40 masl |
| Static Level | 1137.73 masl |
| 11 | Steel Penstock Pipe |
| Type | Steel Lined Penstock, open/buried (Confirming to IS 2062 BO, E350) |
| Internal Diameter | 1.30 m |
| Length | 413.43 m e |
| Minimum Steel Thickness | 14 mm |
| No. of Anchor Blocks | 9 nos. |
| 12 | Powerhouse |
| Type | Sub-surface |
| Size (L x W) | 38.30 m x 11.40 m |
| Height | 18.88 m from Machine floor level to the roof |
| Switchyard | Outdoor |
| 10 | Tailrace Canal |
| Type | RCC, Box Culvert Free flow type |
| Length of Tailrace | 3.55 m |
| Tail Water Level | 930.00 masl |
| 11 | Turbine |
| Type | Horizontal axis Pelton |
| Number | 3 nos. |
| Rated Output Capacity per unit | 2600 KW |
| Center line of turbine | 933.2 masl |
| Efficiency | 92% |
| 15 | Governor |
| Type | Electronic PID Control |
| Adjustment for Speed Drop | Between 0-5% |
| 16 | Generator |
| Type | 3-phase AC synchronous |
| Rated Output Capacity per Unit | 2941 KVA |
| Power Factor | 0.85 pf generation |
| Voltage | 6.6 kV |
| Frequency | 50 Hz |
| No of Units | 3 nos. |
| Excitation System | Brushless excitation |
| Efficiency | 97% |
| 17 | Transformer |
| Type | Outdoor step-up power transformer, Three Phase |
| Rated Capacity | 9000 kVA |
| Voltage Levels | 6.6/33 (Secondary/Primary) |
| No of Units | 1 no. |
| Vector Group | YNd11 |
| Efficiency | 99% |
| 18 | Transmission Line |
| Voltage Level | 33 kV Length |
| 10 Km Conductor | |
| ACSR” DOG” | |
| From | Power plant switchyard |
| To | 33/132 kV Thapatar Substation |
| Delivery Point | 33 kV Busbarn |
