Lake Hawea roughly speaking has two main centers of population - by the lake shore itself and a few minutes drive away at Hawea Flat to the east. The former is the one with a shop and hotel. The township is popular with locals as being a bit less hectic than Wanaka 20 mins. drive away, but the lake [raised artificially many years ago], is not so popular with summer lake users as it lacks Lake Wanaka's sheltered bays. However where Lake Wanaka only has trout fishing Hawea has land-locked salmon as well.
To get to some of the locations below does involves land owner's permission, however one popular camping area, Kidds Bush, towards the head of the lake does have a very nice alpine walk.