Búðarháls hydropower plant

The Búðarháls hydroelectric project is located in the river Tungnaá downstream of existing Hrauneyjafoss station in South Iceland.

The river originates in Vatnajökull and Hofsjökull glaciers and has been harnessed by several hydro power schemes upstream, including the Þórisvatn reservoir.

The project will harness the Tungnaá river from the tailwater of the existing Hrauneyjafoss power plant and the Kaldakvísl river, to the Sultartangi reservoir located downstream of the Búðarháls ridge. A rockfill dam, Sporðalda dam, with a central impervious core will retain the Sporðöldukvísl reservoir. The dam is separated into two parts by the existing ridge between the Kaldakvísl and Sporðöldukvísl rivers. An overflow spillway located at the dam left abutment will be constructed to secure the dam during flood situations. A headrace tunnel will be excavated through the Búðarháls ridge. A tunnel intake, equipped with gates for filling control and maintenance, will be made together with a short approach canal.
A surge basin excavated downstream of the headrace tunnel, is foreseen. The power intake will be located adjacent to the surge basin, made of concrete with two waterways, trashracks, bulkhead gates and wheel gates with hydraulic control. Two steel penstocks connect the intake to the powerhouse. The penstock pipes will be installed in a trench on concrete bedding and buried in concrete and fill. The powerhouse will be an open air structure with two Kaplan turbines and generators on a vertical axis.
The powerhouse and intake will be equipped with all necessary systems such as control and protection system, drainage and dewatering system, cranes, oil filtering system, station service transformers, MV and LV distributions, DC systems, ventilation and security systems. The main transformer units will be located outside downstream of the machine hall. High voltage cables are foreseen for connection to the grid.
A 0,4 km long tailrace canal will be excavated from the powerhouse draft tubes, leading to the Sultartangi reservoir.
Verkís services was review of project planning design and design criteria, review of civil work design, tender design of mechanical and electrical equipment, tender documents, evaluation of bids and contracting, design review for electromechanical equipment and detail design for mechanical and electrical systems in buildings.

Technical information


Tungnaá river, Iceland


95 megawatts

Project period:

2007 – 2014


World goals