Hvammsvirkjun HEP

The Hvammur Hydroelectric Power Project (“HEP”) is located at the Þjórsá river in southern Iceland, 120 km East of the capital of Reykjavik. Hvammur HEP is the uppermost of three planned hydropower plants in the lower region of the river. Mannvit is a lead engineer in the design on behalf of Landsvirkjun.

Technical info:

Installed capacity: 93 MW
Turbines: 2 Kaplan units, vertical shaft
Gross head: 32 m
Harnessed discharge: 352 m3/s
Annual energy production: 720 GWh
Dam: Total length main dam 900 m
Water reservoir: Hagalón reservoir 116 m.a.s.l, storage capacity of 13,2 Gl.
Headrace canal: Width/height: 6,6/7 m; length 140 m
Penstocks: 2 penstocks, ø6,8 m; length 191 m
Tailrace canal: 2000 m

Hvammsvirkjun jarðgrunnsrannsókn

Mannvit has been the main engineering consultant, doing research, engineering, tender documents, HSE planning and cost estimates in cooperation with Verkis. 

Mannvit also did 3D graphic and managed the setup of an online EIA report for Hvammsvirkjun Hydropower Plant. The report includes information on the effects on tourism and effects on the landscape and visual changes in the area.



  • Geology
  • Hydraulic design
  • Civil design
  • Design memorandum
  • Tender design and tender documents
  • Final design (remaining)
352 m3/s 
Harnessed discharge
720 GWh 
Power production
93 MW 
Installed power

Hvammsvirkjun - Hydropower plant