The dam is a mix of a concrete gravity dam with four earth embankments. The dam wall height is 51 metres (167 ft) and the crest is 1,615 metres (5,299 ft) long with the auxiliary embankments extending a further 1,010 metres (3,310 ft). The maximum water depth is 40 metres (130 ft) and at 100% capacity the dam wall holds back 3,005,157 megalitres (106,126.1×10⁶ cu ft) of water at 192 metres (630 ft) AHD. The surface area of Lake Hume is 20,190 hectares (49,900 acres) and the catchment area is 15,300 square kilometres (5,900 sq mi). The dam wall is constructed of rock covered with clay and other earth and is designed to carry vehicular traffic. A controlled concrete spillway that comprises a gated concrete overflow, with twenty-nine vertical undershot gates, is capable of discharging 7,929 cubic metres per second (280,000 cu ft/s).

The dam wall was extended during the 1950s, and completed in 1961, necessitating the wholesale removal of Tallangatta township and its re-establishment at a new site 8 kilometres (5.0 mi) west of the original, as well as railway and road diversions. Monitoring of the dam in the early 1990s revealed that the water pressure and leakage had caused the dam to move on its foundations slightly, leading to concerns that the dam was heading for collapse, threatening Albury-Wodonga and the entire Murray basin. Authorities denied any short-term threat.

Traffic was banned from the spillway, and remedial work commenced involving, in part, the construction of a secondary earth wall behind the original to take the strain. Further upgrades to the dam at an estimated cost of A$60 million commenced in 2010 and are due for completion in 2015. These works include the installation of an improved filter and drainage system on the junction between the concrete spillway and southern embankment, construction of a concrete buttress on the southern training wall, and possible modifications to improve the ability of the dam to manage extreme floods.