Lower Hunter River Health Monitoring Program

Project summary report

This report summarises the main findings of a monitoring program conducted between 2014 and 2016. The program identified pollutants and their impacts on water quality and ecological condition in the Hunter River estuary.

3 August 2017
Office of Environment and Heritage
  • ISBN 978-1-76039-638-1
  • ID OEH20170191
  • File PDF 2.3MB
  • Pages 26
  • Name lower-hunter-river-health-monitoring-program-project-summary-report-170191.pdf

In 2014, the NSW Land and Environment Court imposed penalties on Orica Australia for a number of polluting incidents that occurred in 2010–11 at their Kooragang and Botany facilities. The monetary penalty was directed to fund projects that aimed to restore and enhance the environment for the benefit of affected neighbouring communities. Part of this environmental service order was issued to the former Office of Environment and Heritage to fund the Lower Hunter River Health Monitoring Program.

The program included:

Main findings

Monitoring of the Hunter River estuary included the tidal sections and tributary rivers and creeks. Water quality in the Hunter River estuary had not been assessed on a broad scale for over a decade. Since 2000, land use and activities in the Port of Newcastle had changed considerably and the population in the region had also increased.

The 2014–16 monitoring program found:

  • Water quality in the Hunter River estuary had improved significantly over the past decade, with concentrations of ammonium, nitrates and phosphates in the South Arm (Newcastle Harbour) 5–10 times lower than before 2000.
  • Improved water quality had been achieved through rehabilitation of portside land formerly used for steelmaking, pollution reduction programs by industry to improve the treatment of wastewater discharges, and remediation of contaminated lands and sediments.
  • Significant improvement of the ecological condition of the estuary had been achieved by restoration of natural tidal flows and rehabilitation of estuarine habitats and riverbank vegetation.
  • Ecological condition in the South Arm (Newcastle Harbour) and Throsby Creek was poor. The lower reaches of the harbour and the Port of Newcastle have been modified extensively by human activity. Decades of land reclamation and dredging for port operations removed intertidal mudflats and sand shoals from the lower estuary, drastically reducing its ecological function. When functioning properly, these habitats improve water quality by removing excess nutrients and sediment from estuary waters, and by filtering nutrients and sediment from stormwater.
  • Despite improved water quality since 2000, the Hunter River estuary receives excess sediment and nutrients, such as ammonium, nitrates and phosphates, from agriculture and urban–industrial runoff. It also receives high concentrations of nutrients and metals from industrial discharges and contaminated groundwater. Levels of dissolved nutrients in estuary waters usually exceeded water quality guidelines. Following rainfall, levels of dissolved copper and zinc in lower estuary waters exceeded the guidelines for the protection of marine ecosystems.

The water quality data collected during this program forms a baseline against which future developments in the lower catchment can be assessed. Water quality monitoring in the estuary should continue into the future to build a long-term dataset. This dataset can then be used by stakeholders to detect changes in condition as a result of management and regulatory actions in the heavily urbanised and industrialised catchment.