Mossman Basin

The Mossman Basin has an area of 479km² with Mossman (~1,700 people) and Port Douglas (~3,200 people) being the major population centres. The basin consists of 76% natural/minimal use lands, 3% grazing, 10% sugarcane, 4% urban and 6% other land uses.

Steep mountains and hills dominate the Mossman Basin, with a narrow coastal plain which has been cleared and developed with agriculture (predominantly sugarcane) and urban land uses.

Key results for 2024-25

The Mossman Basin grade has remained ‘good’ in 2024-25 and the score increased from 70 to 76. 

• The water quality grade remained ‘good’ with the score increasing from 64 to 79.
• Pesticide risk improved substantially from moderate risk to very low risk.
• Dissolved inorganic nitrogen (DIN) improved from ‘moderate’ to ‘good’, which was the second increase of grade in successive years.
• Filterable reactive phosphorus (FRP) improved from ‘moderate’ to ‘good’.
• The Mossman Basin is currently undergoing a transition in agricultural land use. Primary production has been dominated by sugar cane, which has constituted 10% of land use of the entire basin. The 127-year-old sugar mill was a central component of the industry and has now been permanently closed following final processing for the 2024 sugarcane harvest season. Sugar cane production has since declined by over 50% in 2025. This resulted in substantial reductions in fertiliser rates, which is predominantly nitrogen forms, and pesticide application rates.
• Wetland extent grade remained ‘very poor’ and one hectare of wetland habitat was recorded as lost since 2019.
• The flow indicator improved from ‘moderate’ to ‘good’ due to the return of a more typical rainfall pattern for the region including the timing of the wet season rainfall and flow events. During 2023-24 the influence of Severe Tropical Cyclone Jasper (TC Jasper) with the early onset of the wet season and intense rainfall and flood events from mid-December contributed to poorer scores at flow assessment sites across the region.

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