Johnstone Basin

The Johnstone Basin population is 15,000 and largely concentrated within the towns of Innisfail, Malanda, Millaa Millaa and South Johnstone.

The two key tributaries of the Johnstone River include the North Johnstone and South Johnstone Rivers. The North Johnstone River Basin can loosely be divided into three sections.

The upper river is a ‘mixed land use’ area consisting of dairy, beef grazing, sugar cane, horticulture (potatoes) and the townships of Millaa Millaa and Malanda.

The middle section contains steep forested areas, much of which is in the Wet Tropics World Heritage Area.

The lower reaches are characterised by low sloping hills and coastal floodplains, which contain a majority of the agricultural areas including the larger townships of Innisfail and South Johnstone.

The Johnstone Basin has an area of 2,326 km² and has a relatively high proportion of natural/minimal use lands (55%). The remaining area contains 16% grazing, 12% sugarcane, 6% dairy (in the upper catchment), 3% bananas, 1% other crops, 2% urban and 4% other land uses.

The Johnstone Basin grade has remained ‘good’ in 2023-24 and the score of 66 decreased from 68 the previous year.

Key results

• The water quality grade for the Johnstone Basin remained ‘good’ and the score of 75 was unchanged.
  The grades for sediment (‘very good’) and pesticides (‘good’) were the same as the previous year, whilst nutrients improved from ‘moderate’ to ‘good’.
  The flow indicator declined from ‘good’ the previous year to ‘moderate’ and this was due to higher-than-average rainfall events in July and December compared to years with more typical rainfall patterns.

The diagram below shows the detailed results for each indicator by year. Click on the timeslider to see data from previous years.