Healthy Environment, Healthy Community, Healthy Business

Environment Protection Authority

Update on Hunter ‘blackwater’ event

Media release: 14 January 2016

The EPA has conducted investigations and sampling in the Hunter River following recent significant heavy rain that resulted in a naturally occurring ‘blackwater’ event causing fish deaths and odours.

Investigations and sampling conducted on 12, 13 and 14 January indicate that the impacts of the blackwater event appear to be increasing.  Testing at key sites in the Hunter River yesterday and today showed dissolved oxygen levels as low as 0.1 mg/L. Normally, levels of 6 – 8 mg/L would be expected.

The low dissolved oxygen levels extend for a stretch of the Hunter River over 40 km in length, from Hinton to near Fern Bay. The lower sections of the Williams and Paterson Rivers are also affected.

Gary Davey, EPA’s Director North said “With dissolved oxygen levels so low, and with increasing temperatures, it can be expected that further fish deaths will occur along the Hunter River. With this comes an ongoing odour problem”.

Mr Davey said that EPA staff were on the river again this morning monitoring oxygen levels in the water and the extent of the fish deaths.

EPA staff have advised that the river appears darker in colour and the odours from the river (which can be described as a ‘sewage’ or rotten egg gas odour) are getting stronger.

“There is little that can be done to stop this natural phenomenon, which also occurred in March 2013”, Mr Davey stated.

The EPA is working with other agencies such as Office of Environment and Heritage, Department of Primary Industries and Port Stephens Council to monitor this issue and will continue to communicate the findings to the community.

The EPA has also contacted relevant Councils and requested inspections and clean-ups of dead fish from publicly frequented foreshore/riverbank areas.

The Hunter New England Local Health District advises that all river water in NSW may contain infectious organisms and chemicals, particularly after heavy rain periods.  Entering river water after heavy rain periods increases the risk of injury and infection.  Those who choose to swim in rivers at any time should avoid swallowing water. The Hunter New England Local Health District advises people who may have swallowed river water and become ill, to seek medical advice. 

The Department of Primary Industries recommends that swimmers be SharkSmart and do not swim or surf in murky water. This is particularly important around the entrance of the Hunter River and the Port of Newcastle due to the floodwaters and the presence of dead and dying fish that may attract sharks.

Contact: Public Affairs

Page last updated: 14 January 2016