Allai Khwar, Pakistan

The Allai Khwar Hydropower Project is located on a tributary of the Indus River in North West Frontier Province of Pakistan.

Lahmeyer International, together with a group of local engineering consultants, has been appointed by WAPDA as the Engineer to oversee the design and construction of this high head hydropower scheme.

The scheme exploits an elevation difference of almost 700 m between the Allai Khwar tributary and the Indus River. The 32.5 m high weir on the Allai Khwar will create a reservoir of about 1.85 hm3 total capacity, of which 1.13 hm3 will be used as live storage for four-hour daily peak operation. From the intake structure, a steel lined 2366 m long inclined pressure tunnel (headrace) with an inner diameter of 2.2 m will transfer 21 m3/s discharge to the powerhouse. No surge tank is foreseen in this design. The gross head will vary between 679 m and 687 m. The powerhouse will be of the open air type. It will house two Pelton turbine generators of 61.5 MW each. Tailrace and outlet structure will discharge water into the Indus River. The annual energy production will be 463 GWh of which 160 GWh will be peak energy. An open-air 220 kV switchyard will be built on the right bank of the Indus River and will be connected to the future Mansehra 220 kV grid station at a distance of 81 km.


Water and Power Development Authority (WAPDA), Pakistan

Duration2002 - 2013
Technical Data
  • Dam/weir height / type:
33 m / concrete gravity
  • Inclined pressure shaft, length / diameter:
2366 m / 2.2 m
  • Powerhouse type, D / L / W:
Open-air, 20 m/ 43 m / 34 m
  • Net head: 
687 m
  • Installed capacity:
121 MW
  • Units:
2 x Pelton
  • Evaluation of tenders for civil works and equipment
  • Co-ordination, supervision, approval of construction design
  • Construction / erection supervision
  • Commissioning
  • Training

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