Engineer says deep aquifers in Port Lincoln area look promising as second water supply

OPTIONS: Darryl Bothe of AquaterreX has raised several alternative possibilities for supplementing the region's water supply. Photo: Jarrad Delaney
OPTIONS: Darryl Bothe of AquaterreX has raised several alternative possibilities for supplementing the region's water supply. Photo: Jarrad Delaney

A former local has raised several alternative possibilities for supplementing the region's water supply, after hearing about industry and public outcry over the proposed desalination location at Billy Lights Point.

Following the announcement of the new desalination site, Darryl Bothe of AquaterreX, a water-sourcing company, has suggested SA Water look at more alternatives.

"We specialise in finding Deep Seated Water," he said.

"DSW is high-quality groundwater, typically sourced from deeper aquifers that are located below shallow aquifers.

"Since taking over as managing director of AquaterreX in April 2020, I have asked our technical team to put some attention on the Eyre Peninsula and see if there is any Deep Seated Water there.

"While our investigation is a preliminary one, there are some very good indicators for being able to tap into some deep aquifers to supplement the Port Lincoln supply."

Mr Bothe said the technology to locate deep aquifers has not been available until now, but he believes their could be "significant quantities" of good quality groundwater "that has not been explored or tapped previously in all of Port Lincoln history".

"Port Lincoln is my hometown," he said.

"In 2003 to 2006, I ran my own business in Port Lincoln as a pump engineer and was engaged by Port Lincoln Council to service the stormwater pumps in Liverpool Street and Le Brun Street...through my industry contacts, I was made aware at the time of a concern that there was a predicted drinking-quality water shortage by around 2025.

"While I am currently Adelaide based, I still have a passion for Port Lincoln and want to see her flourish in all her beauty."

Mr Bothe said two sites drilled on Buckleboo station had produced two supplies - one of high quantity and good for stock water as it is still slightly saline, but the other of high quality and can be used immediately for human consumption.

"The significant point of this is that the generally accepted view is that there is no good quality groundwater in that area - however, we have proven otherwise," he said.

However searching for Deep Seated Water is not the only option Mr Bothe has proposed, and also suggests that cleaning the Tod Reservoir of high salinity and other chemicals present with a specialised agent could restore the reservoir.

"It is my personal opinion that to leave the Tod River Reservoir in this state of chemical and high saline content is a crime against the environment and should be cleaned up irrespective of whether it can be reused as a potable water supply for Port Lincoln," he said.

"I concede that the salinity would likely still need to have a desalination process used, but I expect there would be less hypersaline waste because the salinity levels are significantly lower than sea water.

"If a full wetlands soakage system was implemented upstream from the reservoir, I believe the future salt and chemical ingress should be kept to a minimum."

Mr Bothe said while all investigation were preliminary, and no estimation of cost had been made, he believed it would be "money well spent".

"I feel that even if it did cost similar to the $90 to $100 million estimate that SA Water are prepared to spend on the desalination plant for Port Lincoln, then it would be money well spent to achieve so much more and still solve the initial problem of four gigalitres to eight gigalitres per year of potable water needed by 2025."

Regional Development Australia Eyre Peninsula chief executive officer Dion Dorward said he had been in contact with Mr Bothe, and has called for a "birds eye view" of the EP's water system and to investigate more options.

"Water can be used as an economic tool and so we have industries like hydrogen, mining, agriculture that all require a lot of water in the future and SA Water isn't best placed to have that birds eye view of that bigger picture," he said.

"It's not necessarily their role...perhaps that's a role for the government.

"But we've also asked that the current distribution system, pipes and pumps, should be looked at...because that will change as we learn to rely less on climate-fed water sources.

SA Water general manager of sustainable infrastructure Amanda Lewry said it was not considering the Tod Reservoir as an option for long-term water usage on the Eyre Peninsula due to factors such as its salinity.

"Unlike the planned desalination plant, Tod River Reservoir is not a climate-independent water source, relying instead on natural inflows to fill the storage," she said.

"As the water within the reservoir is quite saline, we would also need to build additional treatment infrastructure to ensure the water is suitable for drinking, which would be an added and unnecessary cost."

Ms Lewry said the planned desalination plant would initially be designed to a four gigalitre per year capacity to meet current drinking water demands but there would be room for expansion should needs emerge.

"Marine and underground pipework will however be designed to provide for an additional four gigalitres per year, should it be required to support future drinking water demand," she said.

"This enables us to effectively meet forecast population growth opportunities and manage existing groundwater sources in the long-term."