The North and South Johnstone Rivers rise in the tablelands of the north tropical coast and flow through steep narrow gorges to their junction on the coastal plain at Innisfail. The head waters of the catchments are located in high rainfall areas and the rivers are capable of producing severe flooding, especially in the Innisfail area. The North and South Johnstone Rivers have a combined catchment area of about at Innisfail; with the North Johnstone being the larger of the two with a catchment of about . Major
tributaries of the river system include the North Beatrice River and the Ithaca River that both flow into the North Johnstone River. This branch is the longest and its catchment is drawn from the
Malanda Falls Conservation Park, and the following national parks:
Ella Bay,
Eubenangee Swamp,
Herberton Range,
Japoon,
Malaan,
Palmerston Rocks,
Topaz Road,
Tully Falls,
Tully Gorge and
Wooroonooran. Malanda Falls is located in the upper reaches of the North Johnstone River. Downey Creek is the only major tributary on the South Johnstone River. There are no
dams or
reservoirs in the catchment area. However water is taken from the river for town water supply,
dairy farming and
sugar cane production. The river is subject to periodic flooding (On the 8th of March 2018 the Johnstone burst its banks cutting off Innisfail from Cairns) popular for white-water rafting, and other tourist activities. ==History==