Port waterways

The Port waterways was suffering from extensive nutrient pollution.

This pollution led to phytoplankton blooms and the abundant growth of nuisance algae such as Ulva (sea lettuce). Phytoplankton blooms cause noticeable discoloration of the water column, reduce water clarity and sometimes consist of species that are toxic and have led to the prohibition of the collection of shellfish throughout some areas of the Port River. Ulva and other macroalgae form floating rafts that block cooling water intakes, smother mangrove pneumatophores and accumulate along the shoreline in large drifts that decompose, producing unpleasant odours.

The major sources of nutrients entering the waterways for many decades have been from the Bolivar wastewater treatment plant and the Penrice soda ash plant (discharges ceased in July 2013) at Osborne. Stormwater is also a source of nutrients for the Port waterways and Adelaide’s coastal waters.

The EPA began a study of the water quality of Port waterways in 2004 with the assistance of funding from the federal government. The study has led to the development of the Port River Water Quality Improvement Plan (WQIP) and Appendices. This plan worked with a range of stakeholders to reduce the quantity of nutrients discharged into the waterway. The targets for water quality improvement for the Port Waterways have been included into the Adelaide Coastal Water Quality Improvement Plan.

Prior to 2008 the EPA monitored and reported on water quality in the Port waterways across 9 sites in the Port River and Barker Inlet. In 2009–10 the EPA shifted its monitoring to focus on the condition of habitats, which are a better indication of the condition of the waterway than water chemistry (see rationale report). Now several sites within the Port waterways are included in the Aquatic Ecosystem Condition Reports for the Adelaide metropolitan waters.

Over the last 20 years, significant nutrient pollution has been reduced through the closure of Penrice Holdings and the SA Government funded improvement of processes at the Bolivar Waste Water Treatment Plant.

The EPA are currently undertaking further scientific assessment of the current state of the Port waterways to understand how decreases in pollution discharges have changed the condition of the system. As of 2019, 83% of the Water Quality Objectives set out in the Port River Water Quality Improvement Plan (WQIP) have been met, as have the majority of community values (environmental values).

Prior to 2008 the EPA monitored and reported on water quality in the Port waterways for the following sites:

• Port River: Site 1 – Hindmarsh Reach, adjacent Snowdens Beach
• Port River: Site 2 – Lipson Reach adjacent quarantine station
• Port River: Site 3 – Outer Harbor
• Port River: Site 4 – North Arm adjacent causeway bridge
• Port River: Site 5 – North Arm adjacent Magazine Creek
• Port River: Site 6 – Torrens Reach adjacent mouth of Angas Inlet
• Port River: Site 7 – Torrens Reach
• Port River: Site 8 – Barker Inlet north of Section Bank
• Port River: Site 9 – Inner harbour

Historical data for Port River sites

Adelaide Metropolitan Nearshore Marine BiounitA geographic (marine) area usually between 30–100 km long which contains similar marine habitats.

Clinton BiounitA geographic (marine) area usually between 30–100 km long which contains similar marine habitats.

• Port River Water Quality Report No. 1 (1997)
• Port River Water Quality Report No. 2 (2002)
• Port River Sediment Quality Report (1997)
• Port River: Heavy metals and PCBs in dolphins, fish and sediment (2000)
• City of Port Adelaide Enfield
• City of Salisbury
• Adelaide and Mount Lofty Ranges Natural Resources Management Board
• Marine Discovery Centre