Low water triggers at an aquifer critical to the Pilbara’s development have been breached, according to Traditional Owners, due to water abstraction and low rainfall.
Low water triggers at an aquifer critical to the Pilbara’s development have been breached, according to Traditional Owners, due to excessive water abstraction and years of low rainfall.
The fresh water fears follow Yindjibarndi Aboriginal Corporation’s submission to the Environmental Protection Authority arguing the case for a reduction in abstraction rates to 4 gigalitres per year, instead of Water Corporation’s requested 9-gigalitre take – 3 gigalitres above what has for the past decade been accepted as sustainable.
Business News understands low water level triggers have been breached at as many as half of the Millstream aquifer’s monitoring points this year.
That is backed up by data from Yindjibarndi Water which showed five of nine bores in the aquifer with triggers set have consistently breach low water indicators since 2022.
A Water Corporation spokesperson said no licence conditions had been breached.
“Water Corporation respects the position of Yindjibarndi Aboriginal Corporation regarding groundwater abstraction from the Millstream aquifer and recognise the area’s cultural significance to Yindjibarndi people,” they said.
“While license conditions governing groundwater abstraction have not been breached, we remain committed to responsibly managing this important resource alongside representatives from DWER, DBCA and the Yindjibarndi and Ngarluma nations.”
YAC wants Water Corporation to spread out its bores to reduce pressure on ecosystems dependent on the Millstream aquifer in the interim and build a desalination plant as a long-term solution.
“YAC has raised these and other alternate options and possible strategies to alleviate pressure on Millstream in its objection to the grant of the proposal by DWER and brought these matters directly to the attention of the Minister for Water and the Premier,” YAC said in its EPA submission.
“YAC’s concerns have not been adequately addressed to date.”
Harding Dam concerns
The trigger breaches were coupled with concern about the ability of the Harding Dam to meet the demands of the West Pilbara Water Supply Scheme.
YAC’s submission to the Environmental Protection Authority shows use of water from the Harding Dam has been slowly declining since it was built.
Abstraction from the Millstream aquifer, however, has been increasing in recent years due to a lack of rainfall in the catchment.
The Harding Dam was built against Yindjibarndi’s wishes in 1985 and was supposed to be the main source for the West Pilbara Water Supply Scheme, which supplies water for residential and industrial use in and around Karratha.
At 22 per cent capacity the dam is close to unusable, with a little under 14.5 gigalitres left in storage currently.
Water from Harding Dam becomes problematic to use if the level drops below 14 gigalitres due to quality issues.
“We strive to maximise the output from Harding Dam whilst providing safe water, so it may be possible to take levels below 14GL under appropriate water quality conditions,” a Water Corporation spokesperson said.
“Planning is underway to upgrade the Harding treatment plant during 2025-26, following works to replace treatment membranes in 2023-24.
“These upgrades will allow us to process and treat a higher volume of water more efficiently.
“Rainfall permitting, we expect these works will increase daily supply from Harding Dam which will allow us to reduce groundwater abstraction.”
Broader issue
The EPA submission comes amid a backdrop of rising angst about industrial water abstraction in the Pilbara, and a plethora of planned water-guzzling projects for the region.
YAC is not the only traditional owner group raising the alarm about the impact of water use to ngurra (country) in a drying climate.
Robe River Kuruma Aboriginal Corporation (RRKAC), whose lands are south of the Yindjibarndi, is pressing the case to cease water abstraction from the Bungaroo borefield.
That borefield was opened in 2014 to supply water for Rio Tinto’s Dampier port operations and was supposed to ease pressure on the Millstream aquifer.
RRKAC has described the impact of abstraction from Bungaroo as a “real emergency” and is urging all industrial water use from the site to be stopped to prevent further damage to ngurra.
Former premier Colin Barnett and former water minister Mia Davies hailed the 10-gigalitre/year borefield in 2014 as one which saved taxpayers from having to fund a desalination plant.
That is the same desalination plant YAC is now arguing needs to be built.
Rio Tinto is building a $400 million, 4 gigalitre desalination plant in Dampier to reduce dependence on groundwater at its ports.
When the project was announced in June last year Rio Tinto flagged the potential to double its capacity.
Plans were revealed this year for a Traditional Owner-backed 150 gigalitre desalination plant between Karratha and Port Hedland to supply industrial customers.
A Water Corporation spokesperson said work to reduce demand and increase water efficiency was underway for the West Pilbara scheme.
That includes through a program which saved about 1.5 million litres of water in Karratha last year.
A study for a new water source – likely desalination – is likely to wrap up next year.
