Question Time

Livestock Industry

The Hon. N.J. CENTOFANTI (Leader of the Opposition) (14:22): I seek leave to make a brief explanation before addressing a question to the Minister for Primary Industries regarding livestock health risks.

Leave granted.

The Hon. N.J. CENTOFANTI: Blue-green algae sludge, which poses health risks to both humans and livestock, has begun trickling down the Murray River from New South Wales after the Minister for Climate, Environment and Water, the Hon. Susan Close, agreed to accept the flushing into South Australia without warning communities. A press release from the New South Wales government states that, and I quote:

We know residents are worried and we have heard their concerns loud and clear, which is why NSW is taking strong action to send up to 45-50 GL downstream…

The algal blooms have not budged in weeks, even as the weather has cooled down and we don't want to wait any longer because communities are suffering…

The advice from New South Wales Health to the community is not to drink water direct from the river, or to swim, bathe or eat fish in locations where there is a red alert in place…

Not only is the foul smell and colour of the water extremely distressing for the local community, blue-green algae can also pose potential health risks to humans and livestock.

In this press release, the New South Wales government announced it will flush 50 gigalitres of blue-green algae-infested water through the Lower Darling and, I quote, 'appreciates the understanding and support provided by South Australia'. My questions to the minister are:

1. Was the minister aware of her government's support of the 50 gigalitres flush of blue-green algae-infested water downstream?

2. What effect is the water expected to have on irrigators' water needs and farmers' water needs for livestock in South Australia?

3. What action is the minister taking to protect river communities from these risks in South Australia?

4. Did the government assess the risks of releasing this water, and what were the findings?

The Hon. C.M. SCRIVEN (Minister for Primary Industries and Regional Development, Minister for Forest Industries) (14:24): I thank the honourable member for her question. I have been provided with some accurate information from the Minister for Environment and Water in the other place as follows—

The Hon. N.J. Centofanti: Are you saying the New South Wales government aren't accurate?

The Hon. C.M. SCRIVEN: No, I am saying you are not accurate. I am advised that low flow and poor water quality in the Lower Darling River and Medindee Lakes has been a significant issue for western New South Wales communities in recent years, largely driven by a number of mass fish deaths linked to low or stagnant river flow, algal blooms and low dissolved oxygen levels in the water. In recent months, the Lower Darling River, including upstream of Weir 32 and the Menindee Lakes, has been affected by a widespread bloom of predominantly non-toxic blue-green algae. To date, the bloom has posed no immediate threat to potable water supplies or fish health.

On 22 May 2024, the Murray-Darling Basin Authority (MDBA) wrote to Basin Officials Committee members (BOC members) requesting their support of a trial to enable environmental water from the Northern Basin to be released or passed through Menindee Lakes to improve water quality in the Lower Darling River and at Menindee, as well as support connectivity across the basin. At a meeting of BOC on 28 May, senior government officials agreed to a trial release of 50 gigalitres prior to 30 June, and incorporating several strategies to assist in mitigating downstream water quality impacts.

Since 30 May, Weir 32 releases have steadily increased from the base flow rate of 400 megalitres per day towards a planned maximum of 4,000 megalitres per day. DEW provided initial information about the water quality of upstream flows in its River Murray Flow Report, issued on 31 May, and will continue to update this information each week.

The event will result in some poorer quality water from the Darling River entering the River Murray at Wentworth over a period of about six weeks, from around 8 June 2024. It is expected that water entering the Murray from the Darling River may have a higher than usual algal load and turbidity, with actual values dependent on a number of factors, including the effectiveness of mitigation measures.

Department for Environment and Water (DEW) and SA Water officers are working with the MDBA and environmental water holders on mitigation strategies to minimise water quality impacts in South Australia. The following mitigation measures are being worked on by river operators:

coordination with an upstream environmental watering event;

management of weir and weir pools to encourage dilution and mixing; and

diversion of a portion of the flow into Lake Victoria.

While the Darling River algal bloom, according to my advice, is predominantly a non-toxic species, possible impacts from the movement of high volumes of blue-green algae into the Murray include the potential increased treatment load and associated costs for SA Water treatment. Algae could also cause odour issues in reticulated systems that provide non-potable water, potentially affecting households.

Water discharge from the Darling in the first weeks will contain the highest volume of algae as it is pushed down the river ahead of the environmental water pulse, then algae levels are expected to reduce as progressively more mixing occurs. SA Water has already mobilised staff to commence sampling of the Lower Darling River to gain as much information as early as possible to inform water treatment processes and river operations. Water quality will continue to be monitored throughout the event.

I note the allegation that it was kept quiet. I refer back to what I have said earlier in this answer, which was in regard to when it was made publicly available through the River Murray Flow Report issued on 31 May.