Geehi Dam

Geehi Dam is a major ungated rockfill embankment dam across the Geehi River in the Snowy Mountains of New South Wales, Australia. The reservoir impounded by the dam is known as Geehi Reservoir.

History
The structure was completed by Thiess Brothers in 1966, and is one of the sixteen major dams that comprise the Snowy Mountains Scheme, a vast hydroelectricity and irrigation complex constructed in south-east Australia between 1949 and 1974 that is now run by Snowy Hydro.

Location and features
The dam is located within what is now the Snowy Valleys local government area. It was constructed by Thiess Brothers based on engineering plans developed under contract by the Snowy Mountains Hydroelectric Authority.

The dam wall, comprising 1421000 m3 of rockfill with an earth core, is 91 m high and 265 m long. At 100% capacity the dam wall holds back 21093 m3 of water. The surface area of Geehi Reservoir is 700 ha and the catchment area is 149 km2. The uncontrolled bell-mouth spillway has a diameter of 32 m and is capable of discharging up to 1534 m3/s.

Power generation
Geehi Reservoir receives water from Island Bend Pondage through the Snowy-Geehi tunnel. Water from Geehi Reservoir is carried via the Murray 1 pressure tunnel to the Murray 1 power station, which is rated for a hydraulic head of 460.2 m and has a total generating capacity of 950 MW (a net generation of 1413 GWh per annum). The outlet structure for the Snowy-Geehi tunnel is shared with the intake of the Murray 1 pressure tunnel and is accessible by a suspended footbridge.