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 dam wall is immediately downstream of the confluence of Happy Jacks Creek and the Tumut River.

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.

At 100% capacity the dam wall holds back 271 megalitres (9.6×10^6 cu ft) of water.

The surface area of Happy Jacks Pondage is 5 hectares (12 acres).