Lake Macdonald is a rural locality in the Shire of Noosa, Queensland, Australia. In the 2021 census, Lake Macdonald had a population of 1,352 people. Located adjacent to the suburb is the Six Mile Creek Dam, a rock and earth-fill embankment dam across the Six Mile Creek that impounds the reservoir, called Lake Macdonald. The main purpose of the reser…Lake Macdonald is a rural locality in the Shire of Noosa, Queensland, Australia. In the 2021 census, Lake Macdonald had a population of 1,352 people. Located adjacent to the suburb is the Six Mile Creek Dam, a rock and earth-fill embankment dam across the Six Mile Creek that impounds the reservoir, called Lake Macdonald. The main purpose of the reservoir is for potable water supply of the Sunshine Coast region and for recreation.