| Abstract | The Herbert River Catchment is situated in the Wet Tropics Region of Far North Queensland and covers approximately 10,000 square kilometers and unlike many other coastal streams in the wet tropics, the Herbert River has a significant inland component dominated by areas of relatively low rainfall (< 1000mm per annum) This program aimed to provide scientifically robust water quality (WQ) data to be used in association with previously collected WQ data to estimate loads on a catchment scale for the validation of models, as well as to provide insight into relative concentrations of reef pollutants on a sub-catchment and paddock scale for use by extension staff and catchment managers to improve sustainable land management practices which will lead to improved WQ to the Great Barrier Reef (GBR). This program aims to address knowledge gaps on water quality issues in the region identified in the Herbert Healthy Waters Management Plan (draft) such as land use specific contributions and pollution hot spots within the catchment. The HWQMP also provided the necessary catalyst for managers and industry to engage and assist landholders in the Herbert in future decision making by identifying specific issues that contribute to WQ degradation within the catchment. Further, the data collected has been a significant contribution to the assessment of actions and priorities identified as part of the new Wet Tropics Water Quality Improvement Plan improved land management practices (BMPs) which will deliver the greatest gains in improved Water Quality flowing to the Great Barrier Reef Lagoon. Results obtained demonstrate that there are clear differences in the impact of land use on local water quality within the upper and lower catchments. The upper catchment does not contribute significantly to contaminant levels in the water quality observed within the lower catchment. Within the lower catchment sugarcane and urban land use have considerable influence on local water quality that is comparable to that observed in other north QLD catchments. Sediment concentrations measured within the Herbert catchment were low compared to concentrations reported in neighbouring catchments (Burdekin and Tully). Nutrient concentrations were highest in waters draining from sugarcane sites, with urban land use also contributing significantly to the levels of dissolved bioavailable phosphorus within the Herbert River. Overall, the range and average concentrations of nutrients and suspended solids measured in samples discharging from sugarcane sites during event conditions are comparable with those reported in waters sampled in other Australian sugarcane growing regions. The HWQMP was integrated into a number of other P2R programs, including paddock scale; Rainfall Simulation trials and demonstration sites within the Herbert Catchment. The results from these programs have all been integrated into extension programs to better facilitate the transfer of the knowledge obtained among the local industry representatives. The project was supported by two Regional Councils (HSC, TRC); Sugar Research Development Corporation (SRDC); and the Queensland Government (DEEDI & DNRM) and was funded to undertake monitoring for a period of three (3) years between July, 2011 and July, 2014. Work has commenced to continue monitoring on a reduced scale within the lower catchment under the direction of the Herbert Cane Productivity Services Ltd. |
