| Happy Jacks Dam | |
| Location Map: | New South Wales |
| Location Map Caption: | Location of the Happy Jacks Dam in New South Wales |
| Coordinates: | -36.0167°N 174°W |
| Country: | Australia |
| Location: | Snowy Mountains, New South Wales |
| Status: | O |
| Opening: | 1959 |
| Owner: | Snowy Hydro |
| Dam Type: | G |
| Dam Crosses: | Tumut River |
| Spillway Count: | 1 |
| Spillway Type: | Uncontrolled |
| Res Name: | Happy Jacks Pondage |
Happy Jacks Dam is a major ungated concrete gravity dam across the Tumut River in the Snowy Mountains region of New South Wales, Australia. The dam's main purpose is for the generation of hydro-power 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 and now run by Snowy Hydro.
The impounded reservoir is called the Happy Jacks Pondage. The dam wall is immediately downstream of the confluence of Happy Jacks Creek and the Tumut River.
Completed in 1959, Happy Jacks Dam is a major dam, located within the Snowy Valleys local government area. The dam was constructed by a consortium comprising Kaiser-Walsh-Perini-Raymond based on engineering plans developed by the United States Bureau of Reclamation under contract from the Snowy Mountains Hydroelectric Authority.
The dam wall comprising of concrete is high and long. At 100% capacity the dam wall holds back of water. The surface area of Happy Jacks Pondage is . The uncontrolled spillway is capable of discharging .[1] [2]