At its greatest extent, which is roughly along a north-south axis, the lake is 35 kilometres long. It lies in a glacial valley formed during the last ice age, and is fed by the Hunter River. Nearby Lake Wanaka lies in a parallel glacial valley eight kilometres to the west. At their closest point (a rocky ridge called The Neck), the lakes are only 1000 metres apart.
The only flat land around the lake is at its southern end, surrounding its outflow into the Hawea River, a short tributary of the Clutha, which it joins near Albert Town. The settlement of Hawea is found at the lake's southern shore.
The lake is a popular resort, and is well used in the summer for fishing, boating and swimming. The nearby mountains and fast-flowing rivers allow for adventure tourism year-round, with jetboating and skiing facilities located nearby.
In pre-European history, Hawea had an important role, when, in the 1830s the Maori residents of Hawea brought warning to the residents of the South Island east coast of a planned attack over alpine passes by a war party of the warrior Te Puoho.
- Wise's New Zealand Guide (4th ed.). (1969). Dunedin, NZ: H.Wise & Co. (N.Z.) Ltd.