Researchers from OzFish and UNSW have been studying Tuckean Swamp in a bid to improve its water quality.
Researchers from OzFish and UNSW have been studying Tuckean Swamp in a bid to improve its water quality.

'Fatal to fish': Most acidic waterway found in NSW

A DRAIN where the water's about as acidic as lemon juice has been found on the North Coast.

Researchers attached to OzFish and the University of NSW Water Research Lab have been involved with an ongoing Options Study into Tuckean Swamp.

During this mostly DPI-funded study, researchers - who are about halfway through a 12-month investigation - found water with a pH of 2.08.

OzFish director of habitat programs Cassie Price said while it wasn't the only acidic location found in that area, it was a standout.

"We think in fish terms," Ms Price said.

"Anything lower than (a pH of) five becomes dangerous for fish.

She said acidic water erodes the protective layers of fish, and anything below a pH of four was "fatal to fish".

"A pH of 2... it's like washing your hands in lemon juice," she said.

She said many of the issues with the swamp were the result of historic human intervention.

"A lot of the problem with the Tuckean Swamp is the historic draining that's happened out there has meant that the water quality is quite poor," she said.

Through new hydrological modelling, she said researchers would model the swamp's water movement and make a plan to improve its quality in this system, which affects everything downstream.

It's the first study of its scale in 20 years.

Ms Price said they had been consulting landowners and UNSW researchers had just completed modelling, which they will now trial in the lab.

"We're probably about six months away from some really clear results," she said.

UNSW's water research lab researchers have been looking at NSW waterways for the past seven years, but the pH of 2.08 is the most acidic they've found.

"It's an Options Study. We are at this stage, not doing or proposing any works.

She said the community in that area would be consulted before anything happens.

Ballina Shire councillor and Rous County Council chair Keith Williams said it was a major problem.

"The drain feeds directly into Tuckean Nature Reserve," he said.

"We know that the Tuckean Swamp is a source of really bad water, of large amounts of acid ... and generally just poor water quality.

"It's running through farmland and enters into the Tuckean Nature Reserve.

"Clearly the drain goes through some areas of acid sulphate soils.

"That's a big source of the acid in that area.

"They found this area where the pH is the lowest that the University of NSW researchers have seen.

"That kind of pH is flowing then into the rest of the system."

He has meanwhile praised Ballina Shire Council's Healthy Waterways Program for attracting almost $1.1 million in funding, almost matching the council's contribution.

He said the program was going some way toward improving the shire's waterways.

One project will see 2.6km of Emigrant Creek's bank revegetated.

"Compared to what the river needs it's probably just a drop in the bucket," he said.

"We need to put vegetation on probably thousands of kilometres of stream bank if we're going to improve the health of the Richmond River.

"But it's a really good start."

The Tuckean Swamp Options Study also involves a steering committee of about 11 groups.

Ms Price encouraged any landholders wanting to have their say on the study to contact her on 0402408791.