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Kolnbrein Background

dam type: thin double curvature concrete arch buttress

purpose: hydroelectric power, flood control, and water supply

height: 656 ft (200 m)

width at foundation: 121.4 ft (37 m)

length of crest: 2054 ft (626 m)

storage capacity: 162,000 acre-ft.

photo courtesy of Erich Wagner

Kolnbrein is part of the Malta hydro power complex, the most powerful in Austria.
location: Carinthia, Austria, in the Hohe Tauern Mountain range

river: Malta river

foundation & abutments: granitic gneiss on one side, schistose gneiss on the other, and highly schistose gneiss at the bottom of the valley

  • While most arch dams are built in V-shaped valleys, Kolnbrein was built in a U-shaped valley and has a longer crest than most.
  • As is done for many dams, grout curtain was constructed in the foundation near the upstream side. A grout curtain is a thin wall of a strong cement-like material. The curtain sits as a wall in the foundation under the dam, keeping water from seeping under the dam and creating uplift pressure.
owned by: Osterreichische Draukraftwerke AG

construction start date: 1973

construction end date: 1979

volume of concrete in the dam: 2,094,941 yd3 (1,600,000 m3) (this is considerably less than a )

first partial reservoir filling: 1978

second partial reservoir filling: 1979

Empty reservoir
photo courtesy of Erich Wagner

Filling had to be stopped 39.4 ft (12 m) below top reservoir level because uplift and seepage occurred.

Kolnbrein dam Kolnbrein problem