The Russell Basin has a population of approximately 1,700 people, largely in Babinda and Miriwinni.
The Russell River is among the least variable rivers in terms of annual flows in Australia, and the basin receives the highest rainfall in the region. The Russell River and Babinda Creek are the two key tributaries of the Russell Basin.
The upper catchment is in the relatively undisturbed rainforest environments of the Bellenden Ker Range.
The river floodplains and the lower river valley are dominated by sugarcane where the environment has been significantly modified with the loss of much of the original lowland rainforest.
The Russell Basin grade has remained ‘good’ with a score of 70 that was unchanged from the previous year.
The diagram below shows the detailed results for each indicator by year. Click on the timeslider to see data from previous years.
The water quality grade in 2018-19 for the Russell Basin remained ‘good’ with the score increasing slightly from 68 in 2017-18 to 75.
The dissolved inorganic nitrogen (DIN) indicator scored the lowest (58) and remained ‘moderate’, with some monthly median concentrations not meeting guideline values.
Filterable reactive phosphorus (FRP) scored 90 and increased from ‘good’ in 2017-19 to ‘very good’, with monthly median concentrations mostly meeting guideline values.
TSS (the indicator for sediment) scored 76 and the grade declined from ‘very good’ in 2017-18 to ‘good’, with monthly median concentrations often meeting guideline values.
Pesticides for the Russell Basin were improved from “moderate” in 2017-18 to ‘good’ and scored 75, equating to over 97 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 catchment monitoring site at East Russell, capturing 78% of the basin.
Habitat and hydrology
The habitat and hydrology index is comprised of the flow indicator category (updated annually) and four longer-term indicator categories that are updated every four years: wetland extent, (updated for 2017-18), riparian extent (to be updated for 2019-20), instream habitat modification consisting of impoundment length (updated for 2018-19) and fish barrier indicators (in development), and invasive weeds (to be updated for 2019-20).
The annual scores for habitat and hydrology index for 2015-16 and 2016-17 represented changes due to the addition of the invasive weeds and flow indicators, respectively, and not changes in the indicator scores themselves. The index score for 2018-19 includes the third year of reporting for the flow indicator. The Russell Basin habitat and hydrology index scored 63 for 2018-19 and the grade remained ‘good’.
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 are impounded by artificial structures. There was no change in impoundment length score for the 2018-19 assessment.
The fish barrier indicator method is still being developed and will be available in future report cards.
Riparian extent for the Russell Basin scored 79 (‘good’) with 5.7% from pre-clear extent to 2013. It is expected that the majority of loss is in the lowlands due to development and land use.
Wetland extent scored 33 (‘poor’) with 37.4% loss of palustrine (freshwater) wetlands from pre-clear to 2017.
The invasive weeds indicator scored 41 (‘moderate’) and represents some impacts of aquatic weeds within the Russell freshwater system including hymenachne (Hymenachne amplexicaulis), salvinia (Salvinia molesta), and pond apple (Annona glabra).
The Russell Basin grade for flows declined from ‘very good’ in 2017-18 to ‘good’. Flows in the Russell Basin retained similar characteristics to modelled pre-development flows in their capacity to support the key ecological assets of water holes, low flow spawning fish, riffle habitats and fisheries production.
The flow indicator provides scores for each flow assessment site and this can be used to assess flows at more local scales.
The fish index for basins was introduced for the first time in 2017-18 and included both the Russell and Mulgrave basins. For the Russell Basin the fish index was graded ‘very good’ and scored 86. The native species richness indicator scored 82 and the pest fish indicator scored 91. A total of 39 native fish species and 3 pest fish species were sampled in the Russell Basin. Of the 14 sites used to calculate the fish index for the Russell Basin one was ‘moderate’ and the remainder were ‘good’ or ‘very good’.