The Daintree Basin has an area of 2,107km2 with a high proportion of protected areas (56% natural/minimal use lands and 32% forestry). The remaining area consists of 7% grazing, 2% sugarcane, 1% urban and 2% other.

Steep mountains and hills dominate this basin, with a narrow coastal plain. The coastal lowland fringe is characterised by mangrove wetlands, sandy beaches and inshore fringing reefs.

The majority of public and private land in the highlands is included in the Wet Tropics World Heritage Area, and there is a high level of tourism associated with the basins natural values.

The Daintree Basin grade  remained ‘very good’ in 2021-22. The score was unchanged at 83. 

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

WATER QUALITY

Water quality reporting for the Daintree Basin commenced in 2017-18 with monitoring conducted at the Lower Daintree end-of-catchment site. The site is located within the mid-estuary water type and is tidally influenced during base-flows. Consequently, freshwater basin condition assessment was restricted to high flow water quality data. In 2019-20, water quality monitoring commenced at the lowland freshwater site further upstream on the Daintree River operated by Douglas Shire Council during base-flows and allows reporting for the whole year. Water quality scores are based on aquatic ecosystem guidelines for protection of freshwater systems and are not based on load reduction targets for the marine environment.

Water quality in the Daintree Basin in 2021-22 remained ‘very good’ with a score of 87.

The score for sediment, comprised of the total suspended solids (TSS) indicator, was 90 (‘very good’) with monthly median concentrations of TSS mostly meeting the guideline values. The grade and score was unchanged since 2020-21.

Nutrients were graded ‘good’ with a score of 80. Dissolved inorganic nitrogen (DIN) was graded ‘very good’ with monthly median concentrations mostly meeting guideline values, and filterable reactive phosphorus (FRP) was graded ‘good’ with monthly median concentrations often meeting guideline values.

Pesticides were graded ‘very good’ and scored 93, equating to over 99 percent of species protected for the risk assessment metric.

Water quality grades are based on aquatic ecosystem guidelines for protection of freshwater systems and are not based on load reduction targets for the marine environment. The results are derived from the end of system monitoring site at Lower Daintree on the Daintree River, capturing 93% of the basin and at the Douglas Shire Council monitoring site just upstream of the mid-estuary.

HABITAT AND HYDROLOGY

The habitat and hydrology index is comprised of four longer-term indicator categories that are updated every four years: wetland extent, (updated for 2017-18), riparian extent (date of update to be determined), instream habitat modification consisting of impoundment length (updated for 2018-19) and fish barrier indicators (in development), and invasive weeds (updated for 2019-20).

The annual scores for the habitat and hydrology index from 2014-15 to 2016-17 represent changes resulting from the addition of indicators and not changes in the indicator scores themselves, whilst the index scores for 2017-18 to 2019-20 included updates to the wetland extent indicator, impoundment length and invasive weeds indicators. There were no indicators updated for 2021-22. The Daintree Basin habitat and hydrology index remained ‘good’ with a score of 78.

The habitat modification score of 100 (‘very good’) is comprised of an impoundment length score of 100 (‘very good’) indicating that less than 1% of the total length of the waterways with a stream order of 3 or higher was impounded by artificial structures.

Riparian extent for the Daintree Basin scored 99 (‘very good’) with 0.01% loss from pre-clear extent to 2013, due to the basin predominantly being in the World Heritage Area.

Wetland extent scored 60 (‘moderate’) with 15.8% loss of palustrine (freshwater) wetlands from pre-clear to 2017. There was no recorded loss of wetland area since the last assessment in 2013. These results reflect a historic loss, with the Daintree wetlands largely intact in the upper catchment.

The invasive weeds indicator scored 54 (‘moderate’) in the Daintree Basin and was the third highest scoring basin in the Wet Tropics region.

The flow indicator category could not be assessed for the Daintree Basin due to the lack of modelled pre-development flow, which is required for the analysis.

The fish barrier indicator method is still being developed and will be available in future report cards.

FISH

The fish index is currently being rolled out for the basins in the Wet Tropics and will be available for the Daintree Basin in upcoming report cards.

See the detailed reports for further information on the methods used to produce the scores and grades and detailed results