Salient Features of The project
| 1. Project Location: | |
| Province | Koshi Province |
| District | Taplejung |
| Intake Site | Mikhawa Gaupalika |
| Powerhouse Site | Mikhawa Gaunpalika |
| Geographical Coordinates | |
| Latitude | 27° 32′ 38″ N to 27° 33′ 55″ N |
| Longitude | 87° 37′ 16″ E to 87° 38′ 38″ E. |
| 2. General: | |
| Name of River | Palun Khola |
| Nearest Town | Taplejung Bazar |
| Type of Scheme | Run-of-River |
| Gross Head | 299.50 m |
| Net rated Head | 290.55 m |
| Installed Capacity | 21 MW |
| Dry Season energy (saleable) | 39.18 GWh |
| Wet Season Energy (saleable) | 86.06 GWh |
| Average Annual Energy after Outage (saleable) | 125.25 GWh |
| 3. Hydrology: | |
| Catchment Area | 187.48 km2 |
| Catchment Area Below 3000 masl | 15.23 km2 |
| Catchment Area above 3000 and below 5000 masl | 158.26 km2 |
| Catchment Area above 5000 masl | 14.00 km2 |
| Design Discharge @43% | 8.69 m3/s |
| Riparian Release | 0.29 m3/s |
| Annual flood | 127.37 m3/s |
| Design flood at intake (1 in 100 Years) | 391.26 m3/s |
| Design flood at tailrace (1 in 100 Years) | 419.03 m3/s |
| Average Annual Precipitation | 2316.33 mm |
| 4. Power and Energy: | |
| Rated net head | 290.55 m |
| Maximum rated net head | 298.68 m |
| Installed Capacity | 21 MW |
| Dry Season energy (saleable) | 39.18 GWh |
| Wet Season Energy (saleable) | 86.06 GWh |
| Average Annual Energy after Outage (saleable) | 125.25 GWh |
Outage and Losses (Dry and Wet season outages along with self-consumption and Flushing, repair and maintenance losses) | 4% of Monthly Energy Generation |
| 5. Weir and Stilling basin: | |
| Type of Weir | Sloping glacis free overflow concrete weir |
| Length of Weir (excluding under sluice) | 23.95 m |
| Crest Elevation | EL 2099.50 masl |
| Weir Height (from U/S river bed) | 6.00 m |
| U/S High Flood level (100 years return period) | EL 2103.72 masl |
| Operation Platform Elevation | EL 2104.70 masl |
| Stilling Basin Length | 35.00 m |
| D/S High Flood level (100 years return period) | EL 2093.45 masl |
| 6. Undersluice: | |
| No. of Gates | 2 |
| Under-sluice Opening (W X H) | 2.10 m x 2.10 m |
| Under-sluice Crest Level | EL 2093.0 masl |
| 7.Intake Structure: | |
| Type of Intake | Side Intake (Orifice type) |
| No. of Opening | 2 |
| Size of Orifice (W x H) | 4.10 m x 2.00 m |
| Intake Sill Level | EL 2096.50 masl |
| 8. Gravel Trap: | |
| Type | Hopper shaped |
| No. of Chamber | 1 |
| Length | 7.50 m |
| Width of hopper at top | 9.40 m |
| Width of hopper at base | 2.20 m |
| Particle size to be trapped | 5 mm and greater |
| Gravel Flushing Culvert (W x H) | 1.20 m x 1.70 m |
| Length of Flushing Culvert | 38.23 m |
| 9. Approach Culvert: | |
| Type | Rectangular |
| No | 2 |
| Length | 31.40m Each |
| Internal Dimension (W x H) | 2.00 m x 1.80 m |
| Longitudinal Slope | 1:500 |
| Culvert invert level at start | EL 2098.05 masl |
| Culvert invert level at end | EL 2095.25 masl |
| 10. Approach Tunnel: | |
| Type | Inverted D shaped |
| No | 2 |
| Length | 61.60 m Each |
| Internal Dimension (W x H) | 2.50 m x 3.20 m |
| Longitudinal Slope | 1:500 |
| 11. Desanding Basin: | |
| Type | Underground Double Chamber with Reverse S4 Flushing |
| No. of Chambers | 2 |
| Dimension (L) | 60.00 m (Effective Length) |
| Dimension (B) | 7.00 m of each bay |
| Dimension (H) (Average) | 12.10 m |
| Inlet Transition Length | 25.75 m |
| Normal Water Level | EL 2099.13 masl |
| Particle Size to be settled | 0.20 mm |
| Trapping Efficiency | 90% |
| Flushing Tunnel (W x H) | Inverted D Type 2.0 m x 2.0 m (60.25m in Length) |
| Sediment Flushing Culvert (W x H) | 1.00 m x 1.70 m (106.20m in Length) |
| Length of Sediment Flushing Culvert | 105.90 m |
| Slope of Flushing | 1:100 |
| 12. Headpond: | |
| Type | Rectangular |
| Length | 8.00 m |
| Number | 2 nos. |
| Size (W x H) | 8.00 m x 14.80 m |
| Normal Water Level | EL 2099.09 masl |
| 13. Construction Tunnel: | |
| a. Main Construction Tunnel | |
| Type | Inverted D Shaped |
| Number | 1 |
| Internal Dimension (W x H) | 3.20 m x 3.50 m |
| Length | 215.45 m |
| Support types | S3, S4, S5 |
| b. Adit Branch Tunnel 2 | |
| Type | Inverted D Shaped |
| Number | 1 |
| Internal Dimension (W x H) | 3.20 m x 3.50 m |
| Length | 99.50 m |
| Support types | S3, S4 |
| c. Adit Branch Tunnel 3 | |
| Type | Inverted D Shaped |
| Number | 1 |
| Internal Dimension (W x H) | 3.20 m x 3.50 m |
| Length | 126.55 m |
| Support types | S3, S4, S5 |
| 14. Headrace Tunnel: | |
| a. Link Tunnel | |
| Type | Inverted D Shaped |
| Number | 2 |
| Internal Dimension (W x H) | 3.20 m x 3.50 m |
| Length | 24.55 m each |
| Longitudinal Slope | 1:500 |
| Support types | S3 |
| b. Headrace Tunnel | |
| Type | Inverted D Shaped |
| Number | 1 |
| Internal Dimension (W x H) | 3.20 m x 3.50 m |
| Length | 2899.90 m |
| Longitudinal Slope | 1:500 and 1:400 |
| Support types | S1, S2, S3, S4, S5, S6 |
| c. Offset Tunnel | |
| Type | Inverted D Shaped |
| Number | 1 |
| Internal Dimension (W x H) | 3.20 m x 3.50 m |
| Length | 13.40 m |
| 15. Surge Shaft: | |
| Type | Circular Shaft with Simple Orifice |
| Total internal depth | 24.60 m |
| Diameter (Main Shaft) | 8.00 m |
| Orifice dimensions | Inverted D shaped 2.70 m X 3.25 m |
| Up Surge Level | EL 2105.45 masl |
| Down Surge Level | EL 2092.60 masl |
| Static Condition Level | EL 2099.50 masl |
| Normal Operational Level | EL 2099.50 masl |
| 18. Generator: | |
| Type | Synchronous with horizontal shaft |
| Number of Units | 2 Nos. |
| Efficiency | 97% |
| Voltage | 11 kV |
| Power Factor | 0.85 |
| Rated Output per unit | 12.88 MVA (+10% COL) |
| 19. Transmission Line: | |
| Voltage Level | 132 kV |
| Length upto the Powerhouse of Mewa Khola HPP | 9 Km, Single circuit |
| Length from Powerhouse of Mewa Khola HPP to substation | 12 Km, Double circuit |
| 20. Financial Indicators (Based on dry season price NRs. 8.40/KWh and wet season price NRs. 4.80/KWh) | |
| Project life | 30 years from the day of operation |
| B/C ratio on Project | 1.41 |
| IRR on Project | 14.29% |
| B/C ratio on Equity | 2.17 |
| IRR on Equity | 16.18% |
| Total cost of the project (Inclusive of VAT and Tax) | NRs. 4,106,685,586.37 |
| 21. Construction Period: | 36 months |
**Note:
- These salient features are based on the DPR report of Palun Khola Small Hydropower Project Prepared by HCE.
- Salient features of all alternatives are presented in Chapter 15 of this report.