Menindee fish deaths follow up: Darling-Barka River water tests

The NSW Environment Protection Authority (EPA) is testing water samples from the Darling-Barka River in response to the major fish deaths at Menindee in mid-March 2023. This testing forms part of the EPA’s investigation into the cause of the fish deaths.

Test results for water and fish samples, with links to laboratory reports are listed below.

Summary reports

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected eight water samples on 27 June 2023 at Menindee along the Darling-Barka River.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Routine sampling for this round was interrupted by road closures due to inclement weather. As a result, the additional twelve samples usually collected from the Great Darling Anabranch and lower Darling-Barka River were not able to be collected.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in three of the samples. The algal toxin Cylindrospermopsin was not detected in any of the samples.

An ‘amber alert’ is in place along at Menindee and further downstream, as of 25 July 2023. See WaterNSW for information about alerts

Metals

Copper was slightly above the level set to protect water life in four samples, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

On 27 June 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

Map - Sample locations for the Menindee Weir Pools region along the Darling-Barka River, taken 27 June 2023.

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

All parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

12.2

11.6

606

8.5

7.3

2 (B2)

Outlet of Lake Pamamaroo into Darling River

11.5

7.9

586

8.1

10.5

3 (E1)

Upper weir pool

11.3

10.0

586

8.3

12.1

4 (E2)

Mid weir pool

11.6

9.7

568

8.2

11.7

5 (E3)

Menindee town

11.7

7.3

470

8.0

19.2

6 (E4)

Downstream Menindee town

11.7

6.2

458

7.9

26.1

7 (E5)

Lower weir pool downstream Lake Menindee inflow

11.5

8.9

422

8.2

32.0

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

10.4

10.8

306

8.4

62.4

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at up to three times higher than the guideline value while total phosphorous was detected at up to eight times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in sample 2, 3 and 6 were considered potentially toxic. The algal toxin Cylindrospermopsin was not detected in any samples from this region.

The algae levels detected fall within the ‘amber’ alert levels. An ‘amber alert’ is in place at Menindee and further downstream, as of 25 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for all samples. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.54

1.1

1.1

1.2

2.1

1.8

3.4

6.6

Arsenic

0.07

0.001

0.002

0.002

0.002

0.003

0.003

0.004

0.007

Chromium

0.5

<0.001

0.001

0.001

0.001

0.002

0.002

0.003

0.006

Cobalt

No value

0.0007

0.0009

0.0010

0.0010

0.0012

0.0011

0.0012

0.0016

Copper

20

0.0016

0.0020

0.0020

0.0020

0.0029

0.0028

0.0037

0.0058

Lead

0.1

0.0004

0.0005

0.0007

0.0006

0.0008

0.0008

0.0009

0.0013

Nickel

0.2

0.0033

0.0036

0.0035

0.0036

0.0044

0.0045

0.0050

0.0061

Zinc

30

0.002

0.002

0.002

0.002

0.005

0.004

0.006

0.010

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.001

0.002

0.001

0.001

0.002

0.003

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0012

0.0012

0.0012

0.0012

0.0017

0.0016

0.0020

0.0029

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0024

0.0026

0.0026

0.0027

0.0032

0.0031

0.0025

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.002

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected nineteen water samples between 20 to 22 June 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

One of the samples usually collected from the lower Darling-Barka region was unable to be sampled on this occasion, due to accessibility issues following heavy rain.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in thirteen of the samples. The algal toxin Cylindrospermopsin was detected in nine samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 31 July 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in most samples across all 3 regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 20 to 22 June 2023 from nineteen locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 20 June 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 21 June 2023, four samples were collected from the Great Darling Anabranch region and four samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)
  • Sample 16 (E11) – Bindara Station reach

On 22 June 2023, three samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 17 (E12) – Karoola Station reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Sample 18 (E13) “Coona Point reach” was unable to be sampled on this occasion, due to accessibility issues following heavy rain.

Map - Figure 1: Sample locations where samples were taken between 20 to 22 June 2023.

Map - Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River.

Map - Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region. 

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

12.9

9.7

586

8.5

9.3

2 (B2)

Outlet of Lake Pamamaroo into Darling River

12.8

9.9

586

8.3

12.2

3 (E1)

Upper weir pool

12.7

9.2

556

8.2

13.2

4 (E2)

Mid weir pool

12.9

9.0

442

8.2

24.2

5 (E3)

Menindee town

13.1

7.9

433

8.1

29.0

6 (E4)

Downstream Menindee town

13.0

5.6

396

7.8

35.4

7 (E5)

Lower weir pool downstream Lake Menindee inflow

12.9

8.7

368

8.1

46.9

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

11.8

10.4

317

8.4

62.5

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

12.3

10.2

347

8.6

19.8

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

10.6

12.6

334

9.0

24.5

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

9.7

13.2

345

9.3

25.0

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

11.3

9.6

343

8.8

37.6

13 (E8)

Kinchega National Park upper

12.2

8.6

365

8.0

44.7

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

11.7

9.1

360

8.1

48.8

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

11.2

9.4

367

8.2

45.0

16 (E11)

Bindara Station reach

11.2

10.0

369

8.2

43.2

17 (E12)

Karoola Station reach

10.9

9.3

368

8.0

42.4

19 (E14)

Mullingar Station reach

10.7

9.7

363

8.0

59.0

20 (E15)

Old wharf at Pooncarie

10.9

8.8

369

7.9

57.2

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at up to four times higher than the guideline value while total phosphorous was detected at up to seven times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 1, 2, 3, 9 to 12, 14 to 17, 19 and 20 were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 10 to 12, 14 to 17, 19 and 20.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 31 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.85

1.1

1.4

2.2

2.9

3.7

3.1

6.1

Arsenic

0.07

0.002

0.002

0.002

0.003

0.003

0.004

0.004

0.006

Chromium

0.5

<0.001

0.001

0.001

0.002

0.003

0.004

0.003

0.005

Cobalt

No value

0.0009

0.0011

0.0012

0.0012

0.0014

0.0016

0.0012

0.0015

Copper

20

0.0017

0.0021

0.0021

0.0032

0.0035

0.0039

0.0047

0.0054

Lead

0.1

0.0005

0.0006

0.0006

0.0008

0.0009

0.0011

0.0010

0.0012

Nickel

0.2

0.0034

0.0036

0.0036

0.0047

0.0050

0.0059

0.0049

0.0058

Zinc

30

0.003

0.003

0.003

0.004

0.005

0.006

0.006

0.018

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region

(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.4

2.5

3.1

4.0

Arsenic

0.07

0.006

0.003

0.007

0.007

Chromium

0.5

0.002

0.002

0.003

0.004

Cobalt

No value

0.0007

0.0011

0.0013

0.0020

Copper

20

0.0041

0.0030

0.0042

0.0042

Lead

0.1

0.0004

0.0006

0.0009

0.0012

Nickel

0.2

0.0039

0.0040

0.0043

0.0052

Zinc

30

0.005

0.004

0.010

0.007

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

16

17

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

4.8

5.3

4.7

4.2

3.9

6.7

7.3

Arsenic

0.07

0.004

0.005

0.005

0.005

0.005

0.005

0.005

Chromium

0.5

0.004

0.005

0.005

0.004

0.004

0.006

0.006

Cobalt

No value

0.0016

0.0019

0.0021

0.0020

0.0019

0.00224

0.0025

Copper

20

0.0048

0.0051

0.0047

0.0046

0.0043

0.0053

0.0056

Lead

0.1

0.0011

0.0013

0.0011

0.0011

0.0010

0.0015

0.0016

Nickel

0.2

0.0059

0.0067

0.0068

0.0064

0.0064

0.0075

0.0079

Zinc

30

0.008

0.009

0.007

0.007

0.007

0.010

0.011

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.001

0.001

0.002

0.003

0.003

0.003

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

<0.0001

Copper

0.0014

0.0010

0.0011

0.0012

0.0019

0.0018

0.0020

0.0024

0.0029

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0024

0.0025

0.0026

0.0032

0.0032

0.0033

0.0030

0.0023

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

ANZG 20183

Samples from the Great Darling Anabranch region

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.003

0.007

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0003

0.0004

0.0004

Copper

0.0014

0.0025

0.0016

0.0020

0.0017

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0023

0.0023

0.0019

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

 

ANZG 20183

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

16

17

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.005

0.005

0.005

0.005

0.004

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0004

0.0004

0.004

0.003

0.003

Copper

0.0014

0.0023

0.0023

0.0022

0.0020

0.0021

0.0019

0.0019

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0031

0.0033

0.0033

0.0034

0.0035

0.0035

0.0037

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

0.001

0.001

<0.001

0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

Download the full test results

20 June results

21 June results

22 June results

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected eighteen water samples between 13 to 15 June 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Two of the samples usually collected from the lower Darling-Barka region were unable to be sampled on this occasion, due to accessibility issues following heavy rain.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in eleven of the samples. The algal toxin Cylindrospermopsin was detected in eight samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 25 July 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in most samples across all 3 regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 13 to 15 June 2023 from eighteen locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 13 June 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 14 June 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

On 15 June 2023, three samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 17 (E12) – Karoola Station reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Sample 16 (E11) “Bindara Station reach” and Sample 18 (E13) “Coona Point reach” were unable to be sampled on this occasion, due to accessibility issues following heavy rain.

Map - Figure 1: Sample locations where samples were taken between 13 to 15 June 2023

Map - Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

 

Map - Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for some samples in the Great Darling Anabranch region. 

Dissolved oxygen in a few samples around Menindee town (samples 5 and 6) has dropped to levels which may begin to stress fish if they remain low for prolonged periods.

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

14.9

9.0

585

8.5

10.3

2 (B2)

Outlet of Lake Pamamaroo into Darling River

14.5

9.7

505

8.3

25.2

3 (E1)

Upper weir pool

14.3

8.3

532

8.1

22.2

4 (E2)

Mid weir pool

14.3

7.6

405

8.1

39.0

5 (E3)

Menindee town

14.9

4.6

418

7.8

41.6

6 (E4)

Downstream Menindee town

14.9

4.0

419

7.7

42.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

14.2

5.1

383

7.9

46.9

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

14.2

9.6

332

8.3

64.1

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

14.6

9.3

369

8.5

23.4

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

15.6

16.3

425

9.2

28.4

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

14.3

15.5

382

9.4

20.3

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

14.7

9.1

385

8.8

34.1

13 (E8)

Kinchega National Park upper

13.7

7.5

378

7.8

53.5

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

13.4

8.0

379

7.9

52.2

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

13.4

8.0

386

8.02

55.6

17 (E12)

Karoola Station reach

12.9

7.7

380

7.8

51.8

19 (E14)

Mullingar Station reach

13.3

7.4

371

7.8

73.8

20 (E15)

Old wharf at Pooncarie

13.1

7.5

374

7.8

61.0

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at up to eight times higher than the guideline value while total phosphorous was detected at up to nine times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 2, 3, 9 to 12, 14, 15, 17, 19 and 20. were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 10, 11, 12, 14, 15, 17, 19 and 20.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 25 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.74

2.6

2.3

4.0

3.0

3.4

2.4

4.8

Arsenic

0.07

0.002

0.003

0.003

0.004

0.004

0.004

0.005

0.006

Chromium

0.5

<0.001

0.002

0.003

0.004

0.003

0.003

0.002

0.004

Cobalt

No value

0.013

0.014

0.014

0.016

0.014

0.015

0.011

0.013

Copper

20

0.0021

0.0032

0.0028

0.0044

0.0037

0.0038

0.0037

0.0051

Lead

0.1

0.0007

0.0007

0.0007

0.0009

0.0009

0.0010

0.0008

0.0010

Nickel

0.2

0.0040

0.0047

0.0047

0.0059

0.0055

0.0059

0.0046

0.0052

Zinc

30

0.003

0.005

0.003

0.006

0.005

0.005

0.004

0.007

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region

(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.2

2.2

3.4

3.7

Arsenic

0.07

0.006

0.005

0.007

0.007

Chromium

0.5

0.002

0.002

0.003

0.003

Cobalt

No value

0.0006

0.0031

0.0016

0.0018

Copper

20

0.0042

0.0026

0.0050

0.0042

Lead

0.1

0.0005

0.0009

0.0011

0.0010

Nickel

0.2

0.0038

0.0049

0.0046

0.0049

Zinc

30

0.008

0.006

0.010

0.006

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in water

NHMRC (2008)2

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

17

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

6.2

6.0

6.9

5.6

8.2

4.6

Arsenic

0.07

0.005

0.005

0.006

0.005

0.005

0.005

Chromium

0.5

0.006

0.006

0.007

0.006

0.008

0.004

Cobalt

No value

0.0021

0.0021

0.0030

0.0023

0.0029

0.0020

Copper

20

0.0054

0.0055

0.0063

0.0053

0.0065

0.0047

Lead

0.1

0.0014

0.0013

0.0018

0.0014

0.0019

0.0014

Nickel

0.2

0.0071

0.0069

0.0081

0.0076

0.0086

0.0066

Zinc

30

0.012

0.009

0.012

0.011

0.013

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.003

0.002

0.004

0.004

0.003

0.005

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0011

0.0017

0.0014

0.0023

0.0022

0.0020

0.0023

0.0028

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0026

0.0029

0.0029

0.0034

0.0035

0.0037

0.0031

0.0023

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

ANZG 20183

Samples from the Great Darling Anabranch region

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.005

0.007

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0016

0.0004

0.0003

Copper

0.0014

0.0027

0.0010

0.0019

0.0016

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

0.002

<0.001

<0.001

Nickel

0.011

0.0024

0.0028

0.0017

0.0021

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.002

<0.001

0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

ANZG 20183

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

17

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.005

0.005

0.005

0.005

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0004

0.0003

0.0002

0.0003

Copper

0.0014

0.0024

0.0023

0.0024

0.0022

0.0020

0.0020

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0031

0.0032

0.0035

0.0036

0.0034

0.0035

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected eight water samples on 6 June 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Routine sampling for this round was interrupted by road closures due to inclement weather. As a result, the additional twelve samples usually collected as part of the round from the Great Darling Anabranch and lower Darling-Barka River were not able to be collected.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in one of the samples. The algal toxin Cylindrospermopsin was not detected in any of the samples.

An ‘amber alert’ is in place along at Menindee and further downstream, as of 25 July 2023. See WaterNSW for information about alerts

Metals

Copper was slightly above the level set to protect water life in most samples, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

On 6 June 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

Map - Sample locations for the Menindee Weir Pools region along the Darling-Barka River, taken 6 June 2023

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

All parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

17.4

8.9

628

8.4

10.0

2 (B2)

Outlet of Lake Pamamaroo into Darling River

15.0

8.5

400

8.3

39.2

3 (E1)

Upper weir pool

15.4

8.3

425

8.3

36.9

4 (E2)

Mid weir pool

16.1

7.3

430

8.1

33.9

5 (E3)

Menindee town

14.8

5.5

412

7.9

36.6

6 (E4)

Downstream Menindee town

15.2

4.8

416

7.9

42.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

16.3

6.9

395

8.1

44.2

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

15.2

9.4

338

8.3

55.6

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at up to three times higher than the guideline value while total phosphorous was detected at up to eight times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in sample 1 were considered potentially toxic. The algal toxin Cylindrospermopsin was not detected in any samples from this region.

The algae levels detected fall within the ‘amber’ alert levels. An ‘amber alert’ is in place at Menindee and further downstream, as of 25 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for all samples. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.82

3.3

4.1

3.6

4.2

4.4

4.7

6.1

Arsenic

0.07

0.002

0.004

0.004

0.004

0.004

0.004

0.004

0.006

Chromium

0.5

<0.001

0.003

0.004

0.003

0.004

0.004

0.004

0.006

Cobalt

No value

0.0011

0.0014

0.0016

0.0015

0.0017

0.0017

0.0015

0.0014

Copper

20

0.0018

0.0042

0.0043

0.0040

0.0044

0.0042

0.0046

0.0055

Lead

0.1

0.0005

0.0007

0.0008

0.0008

0.0009

0.0009

0.0010

0.0010

Nickel

0.2

0.0035

0.0056

0.0061

0.0058

0.0062

0.0062

0.0060

0.0059

Zinc

30

0.002

0.005

0.006

0.005

0.007

0.006

0.007

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.004

0.004

0.004

0.004

0.004

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0011

0.0025

0.0022

0.0021

0.0022

0.0019

0.0022

0.0027

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0025

0.0034

0.0034

0.0035

0.0036

0.0036

0.0032

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected twenty water samples between 30 May to 1 June 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in fifteen of the samples. The algal toxin Cylindrospermopsin was detected in ten samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 25 July 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in most samples across all 3 regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 30 May to 1 June 2023 from twenty locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 30 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 31 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

On 1 June 2023, five samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 16 (E11) – Bindara Station reach
  • Sample 17 (E12) – Karoola Station reach
  • Sample 18 (E13) – Coona Point reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Map - Figure 1: Sample locations where samples were taken between 30 May to 1 June 2023.

Map - Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

Map - Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region, and some samples in the Menindee Weir Pool region.

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

14.1

8.1

566

8.3

8.4

2 (B2)

Outlet of Lake Pamamaroo into Darling River

14.2

9.9

394

8.5

34.9

3 (E1)

Upper weir pool

14.6

9.3

408

8.5

32.3

4 (E2)

Mid weir pool

14.4

8.4

406

8.3

32.0

5 (E3)

Menindee town

14.2

7.9

404

8.2

34.5

6 (E4)

Downstream Menindee town

15.5

8.5

415

8.2

36.2

7 (E5)

Lower weir pool downstream Lake Menindee inflow

14.1

7.6

373

8.1

48.1

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

14.3

9.9

337

8.4

58.0

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

14.7

9.9

369

8.5

22.0

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

15.9

12.2

386

9.1

20.1

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

16.4

13.3

391

9.0

22.5

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

15.3

8.2

393

8.7

43.8

13 (E8)

Kinchega National Park upper

13.6

8.5

370

8.0

52.1

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

13.8

8.3

373

8.0

55.7

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

14.1

7.9

388

8.0

52.8

16 (E11)

Bindara Station reach

14.9

7.9

397

7.9

59.5

17 (E12)

Karoola Station reach

14.0

7.3

391

7.8

60.2

18 (E13)

Coona Point reach

14.2

7.9

391

7.8

59.5

19 (E14)

Mullingar Station reach

14.3

8.6

396

7.9

58.1

20 (E15)

Old wharf at Pooncarie

13.8

8.5

399

7.9

61.5

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at up to four times higher than the guideline value while total phosphorous was detected at up to seven times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 1, 2, 3, 4, 9 to 12 and 14 to 20. were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 1, 10, 11, 12 and 15 to 20.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 25 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2*

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.57

nm

3.4

3.2

3.6

3.8

5.0

6.3

Arsenic

0.07

0.002

nm

0.004

0.004

0.004

0.004

0.005

0.006

Chromium

0.5

<0.001

nm

0.003

0.003

0.004

0.004

0.005

0.006

Cobalt

No value

0.0009

nm

0.0014

0.0014

0.0015

0.0015

0.0016

0.0015

Copper

20

0.0016

nm

0.0046

0.0042

0.0043

00042

0.0051

0.0064

Lead

0.1

0.0008

nm

0.0011

0.0011

0.0012

0.0013

0.0014

0.0015

Nickel

0.2

0.0033

nm

0.0057

0.0057

0.0060

0.0059

0.0062

0.0062

Zinc

30

0.002

nm

0.006

0.005

0.006

0.007

0.008

0.010

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

*Please note, sample 2 was not measured (nm) for metals because of damage to the sample on arrival at the laboratory.

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region

(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.8

1.9

2.7

5.1

Arsenic

0.07

0.007

0.004

0.007

0.007

Chromium

0.5

0.002

0.002

0.003

0.005

Cobalt

No value

0.0005

0.0015

0.0011

0.0016

Copper

20

0.0037

0.0035

0.0040

0.0049

Lead

0.1

0.0007

0.0009

0.0010

0.0015

Nickel

0.2

0.0037

0.0040

0.0040

0.0055

Zinc

30

0.004

0.004

0.005

0.008

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

6.3

6.4

6.1

6.0

6.4

7.3

6.4

5.5

Arsenic

0.07

0.005

0.005

0.005

0.005

0.005

0.006

0.005

0.005

Chromium

0.5

0.006

0.006

0.006

0.006

0.006

0.007

0.006

0.005

Cobalt

No value

0.0020

0.0020

0.0023

0.0023

0.0024

0.0027

0.0024

0.0020

Copper

20

0.0056

0.0056

0.0055

0.0055

0.0055

0.0066

0.0053

0.0051

Lead

0.1

0.0017

0.0017

0.0019

0.0019

0.0020

0.0024

0.0021

0.0019

Nickel

0.2

0.0068

0.0067

0.0072

0.0072

0.0074

0.0082

0.0073

0.0068

Zinc

30

0.010

0.009

0.010

0.010

0.010

0.013

0.010

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2*

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

nm

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

nm

0.004

0.004

0.004

0.004

0.005

0.006

Cadmium

0.0002

<0.0001

nm

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

nm

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0003

nm

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0010

nm

0.0023

0.0022

0.0020

0.0020

0.0023

0.0028

Lead

0.0034

<0.0001

nm

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

nm

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0032

nm

0.0032

0.0036

0.0034

0.0035

0.0029

0.0024

Selenium

0.005

<0.005

nm

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

nm

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

nm

<0.001

<0.001

<0.001

<0.001

<0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

*Please note, sample 2 was not measured (nm) because of damage to the sample on arrival at the laboratory.

Metal in Water

ANZG 20183

Samples from the Great Darling Anabranch region

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.007

0.004

0.007

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0005

0.0003

0.0002

Copper

0.0014

0.0023

0.0018

0.0018

0.0020

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

0.001

<0.001

<0.001

Nickel

0.011

0.0021

0.0024

0.0018

0.0024

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

ANZG 20183

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.005

0.005

0.005

0.005

0.005

0.005

0.005

0.004

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0003

0.0003

0.0003

0.0002

0.0003

0.0003

Copper

0.0014

0.0023

0.0022

0.0022

0.0021

0.0019

0.0022

0.0019

0.0019

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0030

0.0031

0.0032

0.0033

0.0033

0.0034

0.0035

0.0032

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

0.002

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected twenty water samples between 23 and 25 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in 14 of the samples. The algal toxin Cylindrospermopsin was detected in 10 samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River and just downstream of Menindee. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 25 July 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in most samples across all 3 regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 23 and 25 May 2023 from twenty locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 23 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 24 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

On 25 May 2023, five samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 16 (E11) – Bindara Station reach
  • Sample 17 (E12) – Karoola Station reach
  • Sample 18 (E13) – Coona Point reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Map - Figure 1: Sample locations where samples were taken between 23 to 25 May 2023. See Figures 2 and 3 below for more detail.

Map: Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

Map - Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka River between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region. 

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

13.8

6.6

556

8.2

8.1

2 (B2)

Outlet of Lake Pamamaroo into Darling River

13.4

10.1

384

8.5

35.7

3 (E1)

Upper weir pool

13.5

9.4

394

8.2

35.8

4 (E2)

Mid weir pool

13.6

8.2

394

8.3

39.8

5 (E3)

Menindee town

14.6

6.6

410

8.1

38.0

6 (E4)

Downstream Menindee town

13.3

4.8

398

7.9

55.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

13.5

7.6

367

8.1

52.1

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

13.1

10.3

325

8.5

55.1

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

15.1

10.1

370

8.6

19.5

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

15.1

13.0

389

9.1

21.3

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

14.3

13.0

362

9.0

19.6

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

14.3

10.1

372

8.8

38.2

13 (E8)

Kinchega National Park upper

12.8

8.6

362

8.1

49.9

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

12.4

8.7

359

8.1

54.2

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

12.3

8.4

369

8.1

53.1

16 (E11)

Bindara Station reach

12.9

8.7

376

8.0

58.4

17 (E12)

Karoola Station reach

12.7

8.1

378

8.0

54.2

18 (E13)

Coona Point reach

12.4

8.4

383

7.9

48.8

19 (E14)

Mullingar Station reach

12.4

9.2

379

8.0

46.4

20 (E15)

Old wharf at Pooncarie

12.5

9.3

379

8.1

46.5

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at up to three times higher than the guideline value while total phosphorous was detected at up to seven times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 1, 2, 4, 8 to 11 and 14 to 20 were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 1, 10, 11, 14, 15 and 16 to 20.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River and just downstream of Menindee. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 25 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.75

4.3

4.2

4.3

4.3

4.4

5.6

5.8

Arsenic

0.07

0.002

0.004

0.004

0.004

0.004

0.004

0.005

0.006

Chromium

0.5

<0.001

0.004

0.004

0.004

0.004

0.004

0.005

0.006

Cobalt

No value

0.0010

0.0015

0.0016

0.0017

0.0019

0.0017

0.0017

0.0014

Copper

20

0.0020

0.0047

0.0046

0.0048

0.0044

0.0042

0.0051

0.0058

Lead

0.1

0.0005

0.0008

0.0009

0.0009

0.0010

0.0010

0.0011

0.0009

Nickel

0.2

0.0037

0.0060

0.0061

0.0064

0.0062

0.0063

0.0062

0.0060

Zinc

30

0.004

0.006

0.007

0.007

0.009

0.007

0.009

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region

(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.3

2.0

2.1

4.6

Arsenic

0.07

0.007

0.005

0.007

0.007

Chromium

0.5

0.002

0.002

0.002

0.004

Cobalt

No value

0.0005

0.0015

0.0007

0.0014

Copper

20

0.0040

0.0035

0.0040

0.0048

Lead

0.1

0.0004

0.0006

0.0005

0.0011

Nickel

0.2

0.0038

0.0042

0.0038

0.0053

Zinc

30

0.005

0.005

0.006

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

5.7

6.2

6.2

5.9

5.9

5.5

5.5

5.2

Arsenic

0.07

0.005

0.005

0.005

0.004

0.006

0.005

0.005

0.005

Chromium

0.5

0.006

0.006

0.006

0.006

0.006

0.006

0.006

0.005

Cobalt

No value

0.0018

0.0021

0.0024

0.0022

0.0023

0.0023

0.0022

0.0021

Copper

20

0.0055

0.0059

0.0056

0.0053

0.0054

0.0056

0.0050

0.0048

Lead

0.1

0.0012

0.0014

0.0014

0.0014

0.0014

0.0014

0.0014

0.0014

Nickel

0.2

0.0068

0.0073

0.0074

0.0073

0.0074

0.0075

0.0073

0.0070

Zinc

30

0.014

0.011

0.011

0.011

0.010

0.011

0.011

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.004

0.004

0.004

0.004

0.003

0.005

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

0.0001

Copper

0.0014

0.0010

0.0024

0.0025

0.0024

0.0021

0.0020

0.0023

0.0028

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0027

0.0033

0.0034

0.0034

0.0036

0.0035

0.0029

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.002

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. 

Metal in Water

ANZG 20183

Samples from the Great Darling Anabranch region

(dissolved metals)

Water Quality Guideline for aquatic ecosystems
(95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.007

0.005

0.007

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0007

0.0002

0.0002

Copper

0.0014

0.0026

0.0018

0.0024

0.0022

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0023

0.0025

0.0022

0.0023

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.001

0.001

0.002

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

ANZG 20183

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.005

0.005

0.005

0.004

0.005

0.005

0.005

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0001

0.0002

0.0003

0.0003

0.0003

0.0003

0.0003

0.0003

Copper

0.0014

0.0024

0.0023

0.0024

0.0022

0.0021

0.0023

0.0019

0.0020

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0029

0.0030

0.0033

0.0035

0.0033

0.0036

0.0034

0.0038

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.002

<0.001

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected twenty water samples between 16 and 18 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in eleven of the samples. The algal toxin Cylindrospermopsin was detected in nine samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 10 July 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in most samples across all 3 regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 16 and 18 May 2023 from twenty locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 16 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 17 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

On 18 May 2023, five samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 16 (E11) – Bindara Station reach
  • Sample 17 (E12) – Karoola Station reach
  • Sample 18 (E13) – Coona Point reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Figure 1: Sample locations where samples were taken between 16 to 18 May 2023. See Figures 2 and 3 below for more detail.

Map showing sample locations where samples were taken near Menindee between 16 to 18 May 2023.

Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

Map showing sample locations for the Menindee Weir Pools region along the Darling-Barka River

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Menindee Weir Pool and Great Darling Anabranch regions. 

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

15.9

10.3

557

8.6

6.9

2 (B2)

Outlet of Lake Pamamaroo into Darling River

14.7

9.5

400

8.5

36.8

3 (E1)

Upper weir pool

15.1

8.7

411

8.4

34.6

4 (E2)

Mid weir pool

14.5

7.9

401

8.3

40.2

5 (E3)

Menindee town

14.9

7.1

412

8.3

34.7

6 (E4)

Downstream Menindee town

15.0

6.4

430

8.2

32.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

15.0

7.2

391

8.2

46.2

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

15.4

9.5

345

8.5

57.1

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

14.4

9.9

360

8.6

20.9

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

15.3

6.8

382

8.5

39.4

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

15.2

11.1

370

8.7

23.8

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

15.6

9.4

383

8.8

43.6

13 (E8)

Kinchega National Park upper

14.6

8.3

387

8.1

48.7

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

14.6

8.0

390

8.1

50.5

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

14.9

7.8

399

8.1

50.1

16 (E11)

Bindara Station reach

14.2

8.2

396

8.1

49.2

17 (E12)

Karoola Station reach

13.7

7.5

386

7.9

53.8

18 (E13)

Coona Point reach

13.9

8.1

391

8.0

48.5

19 (E14)

Mullingar Station reach

13.8

9.1

406

8.1

45.1

20 (E15)

Old wharf at Pooncarie

13.5

8.4

400

8.0

48.2

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at three times higher than the guideline value while total phosphorous was detected at seven times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 1, 9 and 12 to 20 were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 1, 10 and 14 to 20.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 10 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.64

4.0

4.0

5.0

4.3

3.7

6.2

6.8

Arsenic

0.07

0.002

0.004

0.004

0.004

0.004

0.004

0.005

0.006

Chromium

0.5

<0.001

0.003

0.003

0.004

0.004

0.003

0.005

0.005

Cobalt

No value

0.0008

0.0015

0.0015

0.0017

0.0017

0.0016

0.0017

0.0014

Copper

20

0.0016

0.0065

0.0041

0.0044

0.0040

0.0036

0.0047

0.0054

Lead

0.1

0.0004

0.0008

0.0007

0.0010

0.0010

0.0010

0.0012

0.0010

Nickel

0.2

0.0033

0.0056

0.0058

0.0060

0.0058

0.0053

0.0061

0.0057

Zinc

30

0.002

0.007

0.006

0.008

0.030

0.015

0.008

0.008

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region

(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.7

4.2

3.2

6.1

Arsenic

0.07

0.006

0.006

0.007

0.005

Chromium

0.5

0.002

0.003

0.002

0.006

Cobalt

No value

0.0005

0.0013

0.0007

0.0017

Copper

20

0.0036

0.0044

0.0038

0.0052

Lead

0.1

0.0003

0.0007

0.0004

0.0014

Nickel

0.2

0.0035

0.0049

0.0037

0.0064

Zinc

30

0.006

0.007

0.004

0.0010

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

5.3

5.6

5.7

5.2

5.5

5.5

4.7

4.8

Arsenic

0.07

0.005

0.005

0.005

0.005

0.005

0.005

0.005

0.005

Chromium

0.5

0.004

0.005

0.005

0.005

0.005

0.005

0.004

0.004

Cobalt

No value

0.0016

0.0018

0.0024

0.0020

0.0021

0.0023

0.0020

0.0019

Copper

20

0.0046

0.0048

0.0049

0.0045

0.0046

0.0049

0.0042

0.0042

Lead

0.1

0.0011

0.0012

0.0014

0.0012

0.0012

0.0013

0.0012

0.0012

Nickel

0.2

0.0058

0.0063

0.0087

0.0064

0.0064

0.0066

0.0062

0.0063

Zinc

30

0.011

0.010

0.010

0.008

0.008

0.009

0.007

0.008

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.003

0.004

0.004

0.003

0.003

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

<0.0001

Copper

0.0014

0.0010

0.0023

0.0022

0.0020

0.0019

0.0018

0.0022

0.0027

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0025

0.0033

0.0033

0.0032

0.0032

0.0032

0.0028

0.0023

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

Metal in Water

 

 

 

 

ANZG 20183

Samples from the Great Darling Anabranch region

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.005

0.006

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0002

<0.0001

0.0001

Copper

0.0014

0.0024

0.0020

0.0023

0.0019

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0022

0.0023

0.0022

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

Metal in Water

 

 

 

 

ANZG 20183

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.004

0.004

0.004

0.005

0.004

0.004

0.004

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0003

0.0003

0.0003

0.0002

0.0002

0.0002

Copper

0.0014

0.0022

0.0023

0.0021

0.0020

0.0019

0.0019

0.0016

0.0017

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0028

0.0029

0.0031

0.0032

0.0032

0.0033

0.0030

0.0031

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected fifteen water samples between 12 and 13 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in five of the fifteen samples. The algal toxin Cylindrospermopsin was detected in five samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 3 July 2023. See WaterNSW for information about red alerts

Metals

Copper is slightly above the level set to protect water life in fourteen samples across all regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 12 and 13 May 2023 from fifteen locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On the 12 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On the 13 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

Figure 1: Sample locations where samples were taken between 12 and 13 May 2023.

Map showing sample locations where samples were taken near Menindee between 12 and 13 May 2023

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region. 

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

15.4

9.9

540

8.5

8.7

2 (B2)

Outlet of Lake Pamamaroo into Darling River

14.1

8.4

396

8.4

42.8

3 (E1)

Upper weir pool

14.7

9.1

398

8.5

48.6

4 (E2)

Mid weir pool

15.3

7.9

426

8.3

33.1

5 (E3)

Menindee town

16.1

7.7

445

8.3

29.6

6 (E4)

Downstream Menindee town

16.2

5.8

446

8.1

33.9

7 (E5)

Lower weir pool downstream Lake Menindee inflow

15.0

7.2

385

8.2

48.0

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

14.3

10.0

335

8.6

54.6

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

15.5

9.8

374

8.6

20.9

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

16.3

6.5

388

8.6

29.5

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

16.7

11.3

381

8.7

25.8

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

16.1

10.1

393

8.9

34.5

13 (E8)

Kinchega National Park upper

14.4

8.2

382

8.2

47.8

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

14.1

8.0

379

8.1

54.0

15 (E10)

Kinchega National Park lower (upstream of anabranch offtake)

14.5

7.9

391

8.1

49.7

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at three times higher than the guideline value, while total phosphorous was detected at six times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 1, 10, 12 and 14 and 15 were considered potentially toxic. The algal toxin Cylindrospermopsin was also detected in these five samples.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 3 July 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools in the Darling-Barka River

(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

0.57

4.6

5.3

3.8

2.9

4.1

6.1

6.2

Arsenic

0.07

0.002

0.004

0.004

0.004

0.003

0.003

0.005

0.006

Chromium

0.5

<0.001

0.004

0.005

0.003

0.003

0.004

0.005

0.005

Cobalt

No value

0.0009

0.0016

0.0018

0.0016

0.0014

0.0016

0.0017

0.0012

Copper

20

0.0019

0.0047

0.0048

0.0042

0.0031

0.0038

0.0047

0.0056

Lead

0.1

0.0005

0.0009

0.0010

0.0009

0.0008

0.0012

0.0012

0.0010

Nickel

0.2

0.0036

0.0060

0.0064

0.0057

0.0049

0.0058

0.0061

0.0054

Zinc

30

0.003

0.007

0.008

0.006

0.004

0.006

0.008

0.008

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region

(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.7

3.4

3.0

5.0

Arsenic

0.07

0.006

0.006

0.006

0.007

Chromium

0.5

0.002

0.003

0.003

0.004

Cobalt

No value

0.0005

0.0009

0.0007

0.0014

Copper

20

0.0036

0.0041

0.0043

0.0046

Lead

0.1

0.0004

0.0006

0.0005

0.0011

Nickel

0.2

0.0035

0.0041

0.0039

0.0051

Zinc

30

0.004

0.006

0.005

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

6.4

6.3

6.5

Arsenic

0.07

0.005

0.005

0.005

Chromium

0.5

0.006

0.007

0.006

Cobalt

No value

0.0018

0.0020

0.0024

Copper

20

0.0054

0.0052

0.0052

Lead

0.1

0.0012

0.0014

0.0015

Nickel

0.2

0.0067

0.0069

0.0070

Zinc

30

0.0010

0.009

0.0010

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

 

Metal in Water

 

 

 

 

ANZG 20183

Samples from the Menindee Weir Pools in the Darling-Barka River
(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.004

0.004

0.003

0.003

0.003

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0011

0.0023

0.0024

0.0022

0.0018

0.0017

0.0022

0.0029

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0027

0.0033

0.0033

0.0033

0.0032

0.0032

0.0027

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

0.002

<0.001

<0.001

<0.001

<0.001

<0.001

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

Metal in Water

 

 

 

 

ANZG 20183

Samples from the Great Darling Anabranch region
(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.006

0.006

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0002

0.0001

0.0002

Copper

0.0014

0.0025

0.0022

0.0024

0.0020

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0021

0.0023

0.0023

0.0021

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

0.002

0.002

0.002

0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

Metal in Water

 

 

 

 

ANZG 20183

Samples from the Lower Darling-Barka River between Weir 32 and Pooncarie
(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.005

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0003

Copper

0.0014

0.0022

0.0023

0.0021

Lead

0.0034

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

Nickel

0.011

0.0028

0.0029

0.0031

Selenium

0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected twenty water samples between 9 and 11 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Potentially toxic blue-green algae were detected in nine of the samples. All samples had detections of blue-green algae that are not considered potentially toxic. The algal toxin Cylindrospermopsin was detected in eleven samples.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in most samples across all 3 regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 9 and 11 May 2023 from twenty locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 9 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 10 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

On 11 May 2023, five samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 16 (E11) – Bindara Station reach
  • Sample 17 (E12) – Karoola Station reach
  • Sample 18 (E13) – Coona Point reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Figure 1: Sample locations where samples were taken between 9 to 11 May 2023. See Figures 2 and 3 below for more detail.

Map of sample locations where samples were taken between 9 to 11 May 2023.

Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

Map showing sample locations for the Menindee Weir Pools region along the Darling-Barka River

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region. 

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

14.2

7.1

528

8.3

15.7

2 (B2)

Outlet of Lake Pamamaroo into Darling River

14.5

8.2

516

8.1

34.1

3 (E1)

Upper weir pool

14.2

8.4

426

8.3

33.6

4 (E2)

Mid weir pool

15.2

6.5

436

8.2

37.3

5 (E3)

Menindee town

15.5

5.4

428

8.1

44.7

6 (E4)

Downstream Menindee town

16.1

5.1

440

8.0

40.8

7 (E5)

Lower weir pool downstream Lake Menindee inflow

14.7

6.7

383

8.1

55.8

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

12.9

10.1

321

8.6

71.8

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

15.5

9.9

366

8.6

27.2

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

14.8

6.9

378

8.6

37.7

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

15.6

10.7

372

8.7

24.9

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

15.4

9.4

390

8.8

40.1

13 (E8)

Kinchega National Park upper

14.3

7.9

380

8.1

51.7

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

14.0

7.9

380

8.1

52.3

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

14.4

7.7

410

8.1

47.7

16 (E11)

Bindara Station reach

14.9

8.1

416

8.1

43.5

17 (E12)

Karoola Station reach

14.2

7.4

403

8.0

48.9

18 (E13)

Coona Point reach

14.7

8.3

422

8.0

49.3

19 (E14)

Mullingar Station reach

14.5

8.8

408

8.0

47.9

20 (E15)

Old wharf at Pooncarie

14.2

8.0

405

8.0

48.4

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at three times higher than the guideline value while total phosphorous was detected at eight times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in samples 1, 10, 12 and 14 to 19 were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 1, 2, 10, 12, and 14 to 20.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Samples from the Menindee Weir Pools along the Darling-Barka River
(total acid-extractable metals)

Recreational Water Guidelines

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

1.2

3.6

3.6

4.0

4.3

3.8

5.3

6.6

Arsenic

0.07

0.002

0.003

0.004

0.004

0.004

0.004

0.005

0.006

Chromium

0.5

0.001

0.004

0.004

0.004

0.004

0.004

0.005

0.007

Cobalt

No value

0.0012

0.0021

0.0018

0.0019

0.0019

0.0016

0.0018

0.0016

Copper

20

0.0021

0.0032

0.0042

0.0042

0.0042

0.0038

0.0051

0.0063

Lead

0.1

0.0007

0.0013

0.0010

0.0011

0.0013

0.0011

0.0013

0.0013

Nickel

0.2

0.0041

0.0055

0.0059

0.0062

0.0065

0.0060

0.0064

0.0068

Zinc

30

0.004

0.006

0.007

0.007

0.007

0.008

0.009

0.011

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the Great Darling Anabranch region
(total acid-extractable metals)

Recreational Water Guidelines

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

3.1

4.1

2.5

4.2

Arsenic

0.07

0.006

0.006

0.006

0.007

Chromium

0.5

0.003

0.004

0.003

0.005

Cobalt

No value

0.0008

0.0014

0.0007

0.0017

Copper

20

0.0045

0.0050

0.0040

0.0047

Lead

0.1

0.0006

0.0010

0.0005

0.0012

Nickel

0.2

0.0044

0.0051

0.0050

0.0051

Zinc

30

0.011

0.008

0.006

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

NHMRC (2008)2

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(total acid-extractable metals)

Recreational Water Guidelines

13

14

15

16

17

18

19*

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

5.1

5.0

4.2

5.3

4.8

4.6

14

4.6

Arsenic

0.07

0.005

0.005

0.005

0.005

0.005

0.005

0.006

0.005

Chromium

0.5

0.006

0.006

0.004

0.006

0.005

0.005

0.015

0.005

Cobalt

No value

0.0017

0.0020

0.0019

0.0026

0.0021

0.0020

0.0066

0.021

Copper

20

0.0050

0.0050

0.0043

0.0062

0.0049

0.0046

0.013

0.0048

Lead

0.1

0.0013

0.0014

0.0012

0.0016

0.0014

0.0014

0.0045

0.0015

Nickel

0.2

0.0064

0.0067

0.0060

0.0075

0.0068

0.0066

0.013

0.0070

Zinc

30

0.009

0.010

0.007

0.010

0.009

0.009

0.024

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water

 

 

 

 

ANZG 20183

Samples from the Menindee Weir Pools along the Darling-Barka River
(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.002

0.004

0.003

0.003

0.003

0.005

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0011

0.0010

0.0020

0.0020

0.0019

0.0017

0.0021

0.0029

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0028

0.0029

0.0031

0.0034

0.0033

0.0034

0.0029

0.0023

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

*Sample 19 measured higher than usual levels of some total acid-extractable metals on this sampling occasion. However, the measured values are still below recreational water quality guidelines, and the dissolved metals in this sample remain low.

Metal in Water

 

 

 

 

ANZG 20183

Samples from the Great Darling Anabranch region
(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

11

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.006

0.006

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0002

<0.0001

0.0002

Copper

0.0014

0.0024

0.0021

0.0024

0.0018

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0021

0.0022

0.0022

0.0020

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water

 

 

 

 

ANZG 20183

Samples from the lower Darling-Barka River between Weir 32 and Pooncarie

(dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

15

16

17

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.005

0.005

0.004

0.005

0.005

0.004

0.004

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0003

0.0003

0.0003

0.0002

0.0003

0.0003

Copper

0.0014

0.0022

0.0023

0.0020

0.0021

0.0019

0.0018

0.0022

0.0018

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0027

0.0029

0.0032

0.0030

0.0031

0.0032

0.0036

0.0037

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected fifteen water samples between 6 and 7 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, algae and algal toxins. Due to some logistics challenges, there were not enough sample containers for the full suite of testing in this sampling round. Metals and some pesticides were not tested due to insufficient number of sample containers. These have not been detected previously in this monitoring program at levels that would be toxic to fish.

Summary

Pesticides

Samples were scanned for a range of common pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in nine of the fifteen samples. The algal toxin Cylindrospermopsin was detected in seven samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023. See WaterNSW for information about red alerts

 

Sample locations

Water was sampled between 6 and 7 May 2023 from fifteen locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 6 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 7 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

Figure 1: Sample locations where samples were taken between 6 and 7 May 2023.

Sample locations where samples were taken between 6 and 7 May 2023 near Menindee

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region. 

All other parameters were within the expected ranges.

Sample Location Temp (°C) Dissolved oxygen (mg/L) Electrical conductivity (µS/cm) pH Turbidity (NTU)

1 (B1)

Lake Wetderell upstream of tde Main Weir

17.3

5.5

562

8.2

18.7

2 (B2)

Outlet of Lake Pamamaroo into Darling River

16.9

7.0

469

8.2

38.6

3 (E1)

Upper weir pool

17.1

7.6

456

8.3

41.4

4 (E2)

Mid weir pool

17.2

7.1

442

8.2

50.8

5 (E3)

Menindee town

17.7

6.4

472

8.1

47.0

6 (E4)

Downstream Menindee town

18.1

7.9

510

8.3

38.4

7 (E5)

Lower weir pool downstream Lake Menindee inflow

16.8

6.1

429

8.0

61.4

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

16.3

9.3

348

8.5

83.8

9 (B4)

Lake Cawndilla outlet into tde anabranch of Darling River

16.3

9.7

375

8.6

28.1

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

14.5

10.7

375

9.0

22.9

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

14.8

10.9

364

8.8

38.2

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

16.1

7.9

394

8.6

46.9

13 (E8)

Kinchega National Park upper

16.2

7.4

424

8.0

47.1

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

15.6

7.2

417

8.1

50.6

15 (E10)

Kinchega National Park lower (upstream of anabranch offtake)

15.7

6.9

420

8.1

50.0

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at four times higher than the guideline value, while total phosphorous was detected at eight times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

There were positive detections in all samples for a range of blue-green algae. However, the blue-green algae detections found in samples 1, 2, 3, 7, 8 and 9 from the Menindee and Great Darling Anabranch regions were not considered potentially toxic. The algal toxin Cylindrospermopsin was detected in samples 1, 2, 6, 10, 12, 14 and 15 across all regions.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023.

Pesticides

As noted above, a pesticide screening test that scanned for a range of common pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected twenty water samples between 3 and 5 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, algae and algal toxins. Due to some logistics challenges, there were not enough sample containers for the full suite of testing in this sampling round. Metals and some pesticides were not tested due to insufficient number of sample containers. These have not been detected previously in this monitoring program at levels that would be toxic to fish.

Summary

Pesticides

Samples were scanned for a range of common pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Potentially toxic blue-green algae was detected in thirteen of the samples. All samples had detections of  algae that are not considered potentially toxic. The algal toxin Cylindrospermopsin was detected in all except five samples.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023. See WaterNSW for information about red alerts

Sample locations

Water was sampled between 3 and 5 May 2023 from twenty locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 3 May 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 4 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

On 5 May 2023, five samples were collected from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 16 (E11) – Bindara Station reach
  • Sample 17 (E12) – Karoola Station reach
  • Sample 18 (E13) – Coona Point reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

Figure 1: Sample locations where samples were taken between 3 to 5 May 2023. See Figures 2 and 3 below for more detail.

Map showing sample locations around Menindee where samples were taken between 3 to 5 May 2023.

Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

Map showing sample locations for the Menindee weir pools region along the Darling-Barka River where samples were taken between 3 to 5 May 2023.

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

Map showing sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions where samples were taken between 3 to 5 May 2023.

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

pH was outside the guideline value for all samples in the Great Darling Anabranch region. 

All other parameters were within the expected ranges.

Sample

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

18.0

6.2

568

8.2

17.1

2 (B2)

Outlet of Lake Pamamaroo into Darling River

17.0

8.9

427

8.4

57.1

3 (E1)

Upper weir pool

17.5

6.8

448

8.2

67.2

4 (E2)

Mid weir pool

17.7

5.8

496

8.0

49.5

5 (E3)

Menindee town

18.4

5.2

499

8.0

47.3

6 (E4)

Downstream Menindee town

18.6

4.2

526

7.9

39

7 (E5)

Lower weir pool downstream Lake Menindee inflow

18.1

6.4

398

8.1

57.5

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

16.8

9.4

351

8.5

97.6

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

18.0

9.6

390

8.6

25.1

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

16.8

7.3

393

8.7

27.4

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

18.0

10.6

392

8.7

33.6

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

18.0

7.5

415

8.7

41.9

13 (E8)

Kinchega National Park upper

17.4

7.1

443

8.0

49.9

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

17.2

6.8

441

8.1

49.2

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

17.2

6.5

441

8.0

54.8

16 (E11)

Bindara Station reach

17.0

7.0

439

8.0

52.1

17 (E12)

Karoola Station reach

16.5

6.4

424

7.9

57.0

18 (E13)

Coona Point reach

16.9

7.2

442

7.9

51.3

19 (E14)

Mullingar Station reach

17.1

7.0

434

7.9

49.2

20 (E15)

Old wharf at Pooncarie

16.5

6.3

422

7.9

60.3

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at four times higher than the guideline value while total phosphorous was detected at seven times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae. However, only the algae detections found in samples 1, 4, 6, 10 and 12 to 20 were considered potentially toxic. The algal toxin Cylindrospermopsin was detected in all samples except samples 2, 7, 8, 9 and 11.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023.

Pesticides

As noted above, a pesticide screening test that scanned for a range of common pesticides was completed for samples from all three regions. All samples came back negative for pesticide detection.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

The Department of Planning and Environment (DPE) and the NSW Environment Protection Authority (EPA) collected fifteen water samples between 30 April and 1 May 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Algae, including blue-green algae, was detected in all samples. Potentially toxic blue green algae was detected in all except four samples from the Menindee and Great Darling Anabranch regions. The algal toxin Cylindrospermopsin was detected in all except five samples across all regions.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023. See WaterNSW for information about red alerts

Metals

Copper is slightly above the level set to protect water life in eight samples across all regions, but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 30 April and 1 May 2023 from fifteen locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

On 30 April 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee town
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 1 May 2023, four samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E.6) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake)

Figure 1: Sample locations where samples were taken between 30 April to 1 May 2023.

Map showing sampling sites at Menindee 30 April to 1 May

More sampling

The DPE and EPA are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Sample 10, collected from the Great Darling Anabranch region at Redbank Creek, was saturated with oxygen, had a high pH, and had very high nutrient load. When water holds as much dissolved oxygen as it can at a specific temperature, it is said to be saturated with oxygen. The oxygen saturation and nutrient load is likely due to a cyanobacteria bloom at the time. The sample location is adjacent to a complex wetland system and is prone to high variability in water quality.  All other parameters are within the expected ranges.

Sample Location Temp (°C) Dissolved oxygen (mg/L) Electrical conductivity (µS/cm) pH Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

18.5

4.1

554

8.0

25.1

2 (B2)

Outlet of Lake Pamamaroo into Darling River

17.7

7.9

504

8.2

44.5

3 (E1)

Upper weir pool

18.5

7.3

516

8.2

39.4

4 (E2)

Mid weir pool

18.8

6.9

514

8.2

38.9

5 (E3)

Menindee town

19.9

7.8

494

8.3

32.1

6 (E4)

Downstream Menindee town

19.3

6.6

523

8.1

37.6

7 (E5)

Lower weir pool downstream Lake Menindee inflow

17.9

6.5

431

8.1

75.2

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

16.7

9.5

347

8.6

90.9

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

17.1

9.1

382

8.6

40.1

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

19.5

15.3

434

9.5

25.5

11 (E6.5)

Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)

17.4

9.4

388

8.5

48.9

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

18.2

6.8

416

8.6

58.1

13 (E8)

Kinchega National Park upper

17.4

7.1

433

7.9

73.0

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

17.2

7.0

426

8.0

77.8

15 (E10)

Kinchega National Park lower (upstream of anabranch offtake)

17.3

6.7

431

7.9

78.9

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at typically up to four times higher than the guideline value, with the exception of sample 10 at Redbank Creek upstream of Cawndilla Channel confluence, which was 9 times higher, while total phosphorous was detected at eleven times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae. However, the algae detections found in samples 2, 8, 11 and 13 were not considered potentially toxic. The algal toxin Cylindrospermopsin was detected in all samples except samples 7, 8, 9, 11 and 13.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 29 June 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water NHMRC (2008)2 Samples from the Menindee Weir Pools in the Darling-Barka River (total acid-extractable metals)
Recreational Water Guidelines 1 2 3 4 5 6 7 8
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

1.5

3.4

2.9

2.7

2.1

2.4

5.7

8.4

Arsenic

0.07

0.002

0.003

0.003

0.003

0.003

0.003

0.005

0.006

Chromium

0.5

0.002

0.004

0.003

0.003

0.002

0.002

0.005

0.008

Cobalt

No value

0.0013

0.0017

0.0015

0.0015

0.0014

0.0015

0.0019

0.0020

Copper

20

0.0032

0.0033

0.0029

0.0030

0.0025

0.0026

0.0047

0.0066

Lead

0.1

0.0008

0.0010

0.0009

0.0009

0.0009

0.0010

0.0013

0.0016

Nickel

0.2

0.0040

0.0055

0.0052

0.0051

0.0047

0.0051

0.0064

0.0075

Zinc

30

0.003

0.005

0.005

0.005

0.004

0.005

0.009

0.012

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water NHMRC (2008)2 Samples from the Great Darling Anabranch region (total acid-extractable metals)
Recreational Water Guidelines 9 10 11 12
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

3.6

0.73

4.8

4.6

Arsenic

0.07

0.007

0.005

0.007

0.007

Chromium

0.5

0.003

<0.001

0.004

0.005

Cobalt

No value

0.0008

0.0025

0.0012

0.0018

Copper

20

0.0048

0.0021

0.0049

0.0045

Lead

0.1

0.0006

0.007

0.0009

0.0013

Nickel

0.2

0.0044

0.044

0.0050

0.0053

Zinc

30

0.005

0.004

0.007

0.008

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water NHMRC (2008)2 Samples from the Lower Darling-Barka River between Weir 32 and Pooncarie (total acid-extractable metals)
Recreational Water Guidelines 13 14 15
(mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

6.0

6.2

6.4

Arsenic

0.07

0.005

0.005

0.005

Chromium

0.5

0.006

0.006

0.006

Cobalt

No value

0.0019

0.0021

0.0027

Copper

20

0.0048

0.0050

0.0056

Lead

0.1

0.0015

0.0015

0.0017

Nickel

0.2

00063

0.0067

0.0076

Zinc

30

0.009

0.009

0.010

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water ANZG 20183 Samples from the Menindee Weir Pools in the Darling-Barka River (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection) 1 2 3 4 5 6 7 8
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.002

0.002

0.002

0.002

0.002

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0009

0.0014

0.0013

0.0013

0.0011

0.0012

0.0019 0.0028

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0027

0.0029

0.0029

0.0028

0.0028

0.0030

0.0027

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water ANZG 20183 Samples from the Great Darling Anabranch region (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection) 9 10 11 12
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.005

0.006

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0013

0.0001

0.0002

Copper

0.0014

0.0024

0.0010

0.0023 0.0017

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

0.001

<0.001

<0.001

Nickel

0.011

0.0021

0.0025

0.0022

0.0021

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

Metal in Water ANZG 20183 Samples from the Lower Darling-Barka River between Weir 32 and Pooncarie (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection) 13 14 15
(mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.004

0.004

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0003

Copper

0.0014

0.0019 0.0019 0.0020

Lead

0.0034

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

Nickel

0.011

0.0026

0.0030

0.0031

Selenium

0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The EPA and Department of Planning and Environment (DPE) collected seventeen water samples between 26 and 29 April 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

The concentrations of the bacterial indicator, enterococci, in samples collected on 24 April 2023 were below guideline values for recreational use (NHMRC 2008). The EPA is no longer testing for bacteria due to difficulties meeting laboratory holding times for accurate measurement. The holding time is the time allowed from sample collection until analysis, and varies depending on the test. The holding time for bacteria testing is 24 hours.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Potentially toxic blue-green algae was detected in all but one sample from the Menindee region. The algal toxin Cylindrospermopsin was detected in all but two samples from the Menindee region.

A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 20 June 2023. See WaterNSW for information about red alerts

Metals

Copper was slightly above the level set to protect water life in some samples across all 3 regions (primarily along the lower Darling-Barka), but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled between 26 and 29 April 2023 from seventeen locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River to Pooncarie, and along the Great Darling Anabranch.

On 26 April 2023, eight samples were collected from the Menindee Weir Pools along the Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) – Upper weir pool
  • Sample 4 (E2) – Mid weir pool
  • Sample 5 (E3) – Menindee rail bridge
  • Sample 6 (E4) – Downstream Menindee town
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River

On 27 April 2023, three samples were collected from the Great Darling Anabranch region.

  • Sample 9 (B4) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 12 (E7) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

On 28 April 2023, three samples were collected from the lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • Sample 16 (E11) – Bindara Station reach

On 29 April 2023, three samples were collected from the lower Darling-Barka River between Weir 32 and Pooncarie.

  • Sample 18 (E13) – Coona Point reach
  • Sample 19 (E14) – Mullingar Station reach
  • Sample 20 (E15) – Old wharf at Pooncarie

map of Menindee sampling sites 26 to 29 April

Figure 1: Sample locations where samples were taken between 26 to 29 April 2023. See Figures 2 and 3 below for more detail.

 

Map showing sample locations for the Menindee Weir Pools region along the Darling-Barka River 26 to 29 April

Figure 2: Sample locations for the Menindee Weir Pools region along the Darling-Barka River

 

map-menindee-Sample-locations-Weir-32-Pooncarie26to29-April-Figure-3

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE and EPA are conducting regular water quality monitoring at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Sample 10, collected from the Great Darling Anabranch region at Redbank Creek, was saturated with oxygen and had very high nutrient load. When water holds as much dissolved oxygen as it can at a specific temperature, it is said to be saturated with oxygen. The oxygen saturation and nutrient load is likely due to a cyanobacteria bloom at the time. The sample location is adjacent to a complex wetland system and is prone to high variability in water quality.  All other parameters are within the expected ranges.

Sample Location

Temp (°C)

Dissolved oxygen (mg/L) Electrical conductivity (µS/cm) pH Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

21.2

9.5

564

8.7

15.9

2 (B2)

Outlet of Lake Pamamaroo into Darling River

19.7

7.5

538

8.3

26.4

3 (E1)

Upper weir pool

19.8

7.5

538

8.2

26.3

4 (E2)

Mid weir pool

19.8

9.1

517

8.4

26.6

5 (E3)

Menindee rail bridge

19.4

7.8

502

8.3

27.1

6 (E4)

Downstream Menindee town

18.9

6.4

508

8.0

28.8

7 (E5)

Lower weir pool downstream Lake Menindee inflow

18.9

6.6

446

8.0

57.5

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

18.8

9.3

363

8.3

83.2

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

18.4

9.3

390

8.6

44.8

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

21.3

16.4

463

9.5

40.6

12 (E7)

Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)

19.4

7.1

427

8.6

61.5

13 (E8)

Kinchega National Park upper

18.7

7.1

450

7.9

76.5

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

18.7

6.7

442

8.0

71.9

16 (E11)

Bindara Station reach

19.0

5.9

455

7.8

78.8

18 (E13)

Coona Point reach

18.6

6.2

436

7.8

85.6

19 (E14)

Mullingar Station reach

18.6

6.3

451

7.8

83.3

20 (E15)

Old wharf at Pooncarie

18.3

5.9

445

7.8

94.9

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at typically up to four times higher than the guideline value, except for sample 10 at Redbank Creek, which was 11 times higher. Total phosphorous was detected at eleven times higher than the guideline value.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. Blue-green algae was detected in all samples. The algal toxin Cylindrospermopsin was detected in all samples except sample 8 at the Outlet of Lake Menindee into Darling-Barka River and sample 9 at Lake Cawndilla outlet into the Anabranch of Darling River.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place along parts of the lower Darling-Barka River. An ‘amber alert’ is in place along the Great Darling Anabranch and along the Darling-Barka River, at Menindee and further downstream, as of 20 June 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all seventeen locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water NHMRC (2008)2 Samples from the Menindee Weir Pools along the Darling-Barka River (total acid-extractable metals)
Recreational Water Guidelines 1 2 3 4 5 6 7 8
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

0.52

1.6

1.3

1.3

1.1

1.3

2.8

4.4

Arsenic

0.07

0.002

0.003

0.003

0.003

0.003

0.003

0.004

0.006

Chromium

0.5

<0.001

0.002

0.002

0.002

0.001

0.002

0.003

0.005

Cobalt

No value

0.0012

0.0015

0.0014

0.0014

0.0012

0.0014

0.0016

0.0017

Copper

20

0.0021

0.0026

0.0025

0.0026

0.0025

0.0025

0.0039

0.0091

Lead

0.1

0.0005

0.0009

0.0008

0.0012

0.0007

0.0010

0.0011

0.0015

Nickel

0.2

0.0036

0.0046

0.0044

0.0043

0.0042

0.0044

0.0053

0.0061

Zinc

30

0.003

0.005

0.004

0.004

0.008

0.005

0.007

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water NHMRC (2008)2 Samples from the Great Darling Anabranch region (total acid-extractable metals)
Recreational Water Guidelines 9 10 12
(mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

3.1

1.3

3.0

Arsenic

0.07

0.006

0.005

0.007

Chromium

0.5

0.004

0.002

0.003

Cobalt

No value

0.0012

0.0030

0.0019

Copper

20

0.0054

0.0025

0.0065

Lead

0.1

0.0012

0.0013

0.0014

Nickel

0.2

0.0050

0.0051

0.0050

Zinc

30

0.007

0.006

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water NHMRC (2008)2 Samples from the lower Darling-Barka River between Weir 32 and Pooncarie (total acid-extractable metals)
Recreational Water Guidelines 13 14 16 18 19 20
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

3.0

3.3

3.5

6.8

6.4

7.7

Arsenic

0.07

0.004

0.005

0.005

0.006

0.005

0.005

Chromium

0.5

0.004

0.004

0.004

0.007

0.007

0.008

Cobalt

No value

0.0017

0.0021

0.0023

0.0028

0.0029

0.0032

Copper

20

0.0043

0.0046

0.0047

0.0390

0.0056

0.0060

Lead

0.1

0.0017

0.0015

0.0015

0.0020

0.0022

0.0023

Nickel

0.2

0.0055

0.0059

0.0063

0.0080

0.0079

0.0086

Zinc

30

0.007

0.008

0.008

0.011

0.012

0.013

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water

 

 

 

 

ANZG 20183 Samples from the Menindee Weir Pools along the Darling-Barka River (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection)

1

2

3

4

5

6

7

8

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.002

0.002

0.002

0.002

0.002

0.004

0.006

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0002

0.0001

Copper

0.0014

0.0011

0.0012

0.0013

0.0013

0.0013

0.0011

0.0018 0.0028

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0025

0.0029

0.0028

0.0031

0.0030

0.0030

0.0027

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

Metal in Water

 

 

 

 

ANZG 20183 Samples from the Great Darling Anabranch region (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection)

9

10

12

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

Arsenic

0.013

0.006

0.005

0.007

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0014

0.0003

Copper

0.0014

0.0027

0.0010

0.0017

Lead

0.0034

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

Nickel

0.011

0.0023

0.0027

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

Metal in Water

 

 

 

 

ANZG 20183 Samples from the lower Darling-Barka River between Weir 32 and Pooncarie (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection)

13

14

16

18

19

20

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.004

0.004

0.004

0.004

0.004

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0003

0.0003

0.0003

0.0003

Copper

0.0014

0.0018 0.0019 0.0018 0.0019 0.0018 0.0017

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0029

0.0028

0.0031

0.0033

0.0032

0.0031

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

The NSW Environment Protection Authority (EPA) collected three water samples on 24 April 2023 at Menindee along the Darling-Barka River.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, bacteria, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Algae, including blue-green algae, and the algal toxin Cylindrospermopsin was detected in all three samples collected from the Darling-Barka River at Menindee.

An ‘amber alert’ is in place in the Darling-Barka River at Menindee as of 10 May 2023.

Information about algae alerts is available at https://www.waternsw.com.au/water-services/water-quality/algae-alerts

Metals

All metals in the Darling-Barka River samples were under the levels set to protect water life.

Bacterial

The concentrations of the bacterial indicator, enterococci, are below guideline values for recreational use (NHMRC 2008).

Sample locations

Water was sampled on 24 April 2023 from three locations on the Darling-Barka River at Menindee.

  • Sample 1 – approximately 840m NE of Menindee Golf Club
  • Sample 2 – end of Maiden St
  • Sample 3 – beneath Menindee St bridge
Map of Menindee showing sampling sites 

More sampling

The EPA is conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

All parameters are within the expected ranges.

Sample name Location Temp (°C) Dissolved oxygen (mg/L) Electrical conductivity (µS/cm) pH Turbidity (NTU)

1

approximately 840m NE of Menindee Golf Club

19.0

8.0

504

8.2

158

2

End of Maiden St

19.0

6.6

506

8.1

154

3

Beneath Menindee St bridge

19.0

5.9

510

8.0

167

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at three times higher than the guideline value while total phosphorous was detected at four times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae. The algal toxin Cylindrospermopsin was detected in all samples.

The algae levels detected fall within the ‘amber’ alert levels. An ‘amber alert’ is in place in the Darling Barka River at Menindee as of 10 May 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all three locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water NHMRC (2008)2 Sample (total acid-extractable metals)
Recreational Water Guidelines Sample 1 Sample 2 Sample 3
(mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

2.7

2.6

3.8

Arsenic

0.07

0.003

0.003

0.003

Chromium

0.5

0.003

0.003

0.004

Cobalt

No value

0.0016

0.0017

0.0020

Copper

20

0.0029

0.0029

0.0033

Lead

0.1

0.0010

0.0013

0.0014

Nickel

0.2

0.0048

0.0049

0.0055

Zinc

30

0.005

0.005

0.006

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water ANZG 20183 Sample (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection) Sample 1 Sample 2 Sample 3
(mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

Arsenic

0.013

0.002

0.002

0.002

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0003

0.0002

0.0002

Copper

0.0014

0.0014

0.0013

0.0010

Lead

0.0034

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

Nickel

0.011

0.0031

0.0031

0.0028

Selenium

0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council

NSW Department of Primary Industries (DPI) Fisheries collected 5 samples of golden perch (Macquaria ambigua) from the Darling-Barka River at Pooncarie on 28 March.

The gastrointestinal tract and gills of the fish were analysed for metals and pesticides. The gastrointestinal tract can show what chemicals have been ingested by the fish and the gills give an indication of overall exposure from the surrounding water.

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment.

The only metals found in the gastrointestinal tract of the fish were zinc and mercury. These metals are known to bioaccumulate in fish. No gastrointestinal tract data are available as background in NSW, but these concentrations are below concentrations reported internationally.

Zinc and mercury were also found in the gills of the fish. This indicates some recent exposure to these metals from the water. However, water concentrations were all below water quality guidelines indicating these metals will not have adversely impacted the health of the fish.

Heavy Metal Reported mean concentration (mg/kg) in international literature for gastrointestinal tract Reported mean concentration (mg/kg) in international literature for gills Concentration in the gastrointestinal tract (mg/kg) Concentration in gills (mg/kg)

Mercury

0.02-3.6

(12 fish species with varying food regimes)1

0.007 - 0.03

(perch)2

0.044-0.055

0.023-0.036

Zinc

11-559

(pike and bream)3

12-171

(pike and bream)3

10-15

21-28


1
Regine 2006     2 Luczynska 2016     3 Rajkowska 2013

Download the full test reports: 28 March

The full report (with individual's names and addresses redacted for privacy) are available for download

Sample locations

Fish samples were collected from two locations near Pooncarie on 28 March 2023.

  • Sample 1 – Downstream of Pooncarie Weir
  • Sample 2 – Pooncarie Cafe

map showing two testing sites at Pooncarie 28 March 2023

References

FSANZ. 2001. Generally expected levels (GELs) for Metal Contaminants - Additional guidelines to maximum levels in Standard 1.4..1 - Contaminants and Natural Toxicants. Australian New Zealand Food Standards Code.

1Regine M.B., Gilles D., Yannick D. and Alain B. (2006). Mercury distribution in fish organs and food regimes: Significant relationships from twelve species collected in French Guiana (Amazonian basin). Science of the Total Environment. 368: 262-270

2Luczynska J., Luczynski M. J. and Paszczyk B. (2016). Assessment of mercury in muscles, liver and gills of marine and freshwater fish. Journal of Elementology. 21(1): 113-129

3Rajkowska M. and Protasowicki M. (2013). Distribution of metals (Fe, Mn, Zn, Cu) in fish tissues in two lakes of different trophy in Northwestern Poland. Environmental Monitoring and Assessment. 185(4): 3493-3502

WaterNSW collected six water samples for the EPA on 11 April 2023 downstream of Menindee on the Darling-Barka River,  the Murray River and the Great Darling Anabranch.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, bacteria, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels are high. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Algae, including blue-green algae, were detected in all six samples. A ‘red alert’ is in place in the Murray River at Fort Courage and in the Great Darling Anabranch at Silver City Highway as of 28 April 2023. The algal toxin Cylindrospermopsin was detected in samples collected from the Murray River in these locations.

An ‘amber alert’ is in place in the Murray River at Merbein and in the Darling-Barka River at Merbein, Ellerslie and Burtundy.

Information about algae alerts is available at https://www.waternsw.com.au/water-services/water-quality/algae-alerts

Metals

Copper remains slightly above the level set to protect water life but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Bacterial

The concentration of the bacterial indicator, enterococci, exceeded guideline values for recreational use (NHMRC 2008) at two sites in the Murray River at Fort Courage and in the Darling-Barka River at Ellerslie.

Sample locations

Water was sampled on 11 April 2023 from six locations downstream of Menindee on the Darling-Barka River, the Murray River and the Great Darling Anabranch:

  • Sample 1 – Murray River at Merbein Pump Station
  • Sample 2 – Darling-Barka River at Tapio
  • Sample 3 – Darling-Barka River at Ellerslie
  • Sample 4 – Darling-Barka River at Burtundy
  • Sample 5 – Great Darling Anabranch at Silver City Highway
  • Sample 6 – Murray River at Fort Courage

Map showing the six sampling sites downstream of Menindee on  11 April 2023

More sampling

The EPA is conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie as well as the Great Darling Anabranch. The test results from these samples will also be published on this website.

In-field measurements

At the time of sampling, WaterNSW collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Dissolved oxygen ranged from 5.6mg/L to 10.3mg/L at the six locations. Native fish and other large aquatic organisms require at least 2mg/L of dissolved oxygen to survive but may begin to suffer if levels are below 4 to 5mg/L for prolonged periods.

pH was outside the guideline value in the Murray River at Merbein Pump Station and Fort Courage, and in the Great Darling Anabranch at Silver City Highway. 

All other parameters are within the expected ranges.

Sample name Location Temp (°C) Dissolved oxygen (mg/L) Electrical conductivity (µS/cm) pH Turbidity (NTU)

1

Murray River at Merbein Pump Station

19.0

9.1

292

8.2

14

2

Darling-Barka River at Tapio

19.1

6.0

449

7.9

148

3

Darling-Barka River at Ellerslie

19.2

5.7

458

7.9

183

4

Darling-Barka River at Burtundy

19.3

5.6

468

7.8

163

5

Great Darling Anabranch at Silver City Highway

18.7

10.3

489

8.9

61

6

Murray River at Fort Courage

18.7

8.8

433

8.3

69

 

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at five times higher than the guideline value while total phosphorous was detected at ten times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. The water samples from 11 April show high levels of nitrite and nitrate, and there is a potential for further harm to aquatic organisms.

Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity and as a stressor (i.e. nutrient).  The levels would not be expected to be harmful to fish or promote growth in algae and aquatic plants.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae. The algal toxin Cylindrospermopsin was detected in the samples collected from the Murray River at Fort Courage and the Great Darling Anabranch at Silver City Highway.

The algae levels detected fall within the ‘amber’ to ‘red’ alert levels. A ‘red alert’ is in place in the Murray River at Fort Courage and in the Great Darling Anabranch at Silver City Highway as of 28 April 2023. An  ‘amber alert’ is in place in the Murray River at Merbein and in the Darling Barka River at Merbein, Ellerslie and Burtundy.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all six locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water NHMRC (2008)2 Sample (total acid-extractable metals)
Recreational Water Guidelines Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

0.29

4.7

4.9

4.3

1.7

2.2

Arsenic

0.07

0.001

0.005

0.005

0.005

0.006

0.005

Chromium

0.5

<0.001

0.005

0.005

0.004

0.002

0.002

Cobalt

No value

0.0005

0.0020

0.0024

0.0021

0.0019

0.0020

Copper

20

0.0011

0.0060

0.0055

0.0051

0.0033

0.0032

Lead

0.1

0.0004

0.0017

0.0021

0.0018

0.0010

0.0011

Nickel

0.2

0.0010

0.0068

0.0070

0.0067

0.0043

0.0042

Zinc

30

0.001

0.011

0.010

0.009

0.005

0.005

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water

 

 

 

 

ANZG 20183 Sample (dissolved metals)
Water Quality Guideline for aquatic ecosystems (95% species protection)

Sample 1

Sample 2

Sample 3

Sample 4

Sample 5

Sample 6

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

<0.001

0.005

0.004

0.004

0.006

0.004

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

<0.0001

0.0002

0.0002

0.0002

0.0007

0.0005

Copper

0.0014

0.0006

0.0022 0.0019 0.0018

0.0014

0.0012

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

0.003

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0007

0.0032

0.0033

0.0031

0.0024

0.0022

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

0.002

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

References

ANZG (2018), Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. Available at www.waterquality.gov.au/anz-guidelines.

Basin Plan (2012), Schedule 11, Water Act 2007, Murray-Darling Basin Authority, Commonwealth of Australia.

NHMRC (2008), Guidelines for managing risks in recreational waters, Australian Government National Health and Medical Research Council.

The EPA collected two water samples on 4 April 2023 downstream of Menindee at Pooncarie.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, bacteria, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorus remain at high levels. The water samples were taken after many fish had died so the high levels could be due to rotting fish. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Algae, including blue-green algae, were detected in both samples. An ‘amber alert’ remains in place for the Darling-Barka River at Menindee and Pooncarie as of 24 April 2023. A low concentration of the algal toxin Cylindrospermopsin was detected in the sample collected from Karoola Reach.

Information about algae alerts is available at https://www.waternsw.com.au/water-services/water-quality/algae-alerts

Metals

Copper was slightly above the level set to protect water life but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Bacterial

The concentrations of bacterial indicators, faecal coliforms and enterococci, are below guideline values for recreational use (NHMRC 2008).

Sample locations

Water was sampled on 4 April from two locations on the Darling-Barka River at Pooncarie:

  • Sample 1 – Karoola Reach, approximately 60 kilometres north of Pooncarie
  • Sample 2 – Pooncarie Bilbarka Park
Menindee fish kill sampling sites, Pooncarie 4 April 2023 

More sampling

WaterNSW has collected more water samples for the EPA from the Darling-Barka River on 11 April 2023. The test results for these samples will also be published on the EPA webpage.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Dissolved oxygen at Site 1 was 2.53mg/L and at Site 2 was 3.11mg/L. Native fish and other large aquatic organisms require at least 2mg/L of dissolved oxygen to survive but may begin to suffer if levels are below 4 to 5mg/L for prolonged periods.

All other parameters were within the expected ranges.

Sample name

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1

Karoola Reach, approximately 60km upstream from Pooncarie

20.6

3.11

419

7.72

109.5

2

Pooncarie Bilbarka Park

21.1

2.53

404

7.59

115.9

Nitrogen and phosphorus

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at five times higher than the guideline value while total phosphorous was detected at seven times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. The water samples from 4 April show high levels of nitrite and nitrate, and there is a potential for further harm to aquatic organisms.

Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and aquatic plants. The ammonia is likely to be from river sources including rotting fish and flood detritus rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in both samples for a range of algal species, including blue-green algae, and common toxins produced by blue-green algae. A low concentration of the algal toxin Cylindrospermopsin was detected in the sample collected from Karoola Reach.

The algae levels detected fall within the ‘green’ to ‘amber’ alert levels. An amber alert remains in place at Menindee and Pooncarie as of 24 April 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples at both locations. Both samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Sample (total acid-extractable metals)

Recreational Water Guidelines

Sample 1

Sample 2

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

5.7

5.3

Arsenic

0.07

0.006

0.006

Chromium

0.5

0.008

0.007

Cobalt

No value

0.0031

0.0026

Copper

20

0.0063

0.0060

Lead

0.1

0.0024

0.0022

Nickel

0.2

0.0085

0.0079

Zinc

30

0.012

0.012

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Sample (dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

Sample 1

Sample 2

(mg/L)

(mg/L)

(mg/L)

Aluminium

0.055

<0.04

<0.04

Arsenic

0.013

0.005

0.005

Cadmium

0.0002

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

Cobalt

No value

0.0003

0.0002

Copper

0.0014

0.0018

0.0018

Lead

0.0034

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

Nickel

0.011

0.0031

0.0030

Selenium

0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

Zinc

0.008

0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

 

WaterNSW collected five water samples for the EPA on 3 April 2023.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorous levels remain high. The water samples were taken after many fish had died so the high levels could be due to rotting fish. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae and algal toxins

Algae, including blue-green algae, were detected in all five samples. An ‘amber alert’ remains in place for the Darling-Barka River at Menindee and Pooncarie as of 24 April 2023. No algal toxins were detected.

Information about algae alerts is available at https://www.waternsw.com.au/water-services/water-quality/algae-alerts

Metals

Copper remains slightly above the level set to protect water life but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled on 3 April 2023 from five locations on the Darling-Barka River between Main Weir and Weir 32:

  • Sample 1 – Downstream of the main weir at Menindee
  • Sample 2 – Menindee Water Treatment Plant
  • Sample 3 – Upstream of Menindee Creek
  • Sample 4 – Downstream of Menindee Creek
  • Sample 5 – Upstream of Weir 32 at Menindee
Menindee fish kill sampling sites, 3 April 2023 

More sampling

The EPA and WaterNSW have collected more water samples from the Darling-Barka River downstream in the Pooncarie area on 11 April 2023. The test results from these samples will also be published on the EPA webpage.

In-field measurements

At the time of sampling, WaterNSW collected in-field measurements for pH, dissolved oxygen, conductivity and temperature.

Dissolved oxygen ranged from 1.82mg/L to 7.04mg/L at the five locations. Native fish and other large aquatic organisms require at least 2mg/L of dissolved oxygen to survive but may begin to suffer if levels are below 4 to 5mg/L for prolonged periods. One of the five sample locations detected dissolved oxygen levels below 2 mg/L.

All other parameters are within the expected ranges.

Sample name

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

1

Downstream Main Weir

19.4

7.04

515

7.72

2

Water treatment plant

20.5

2.79

508

7.63

3

Upstream Menindee Creek

20.5

1.82

506

7.62

4

Downstream several kms of Menindee Creek

19.1

6.68

439.3

8.08

5

 

Upstream of Weir 32

19.4

6.39

437.6

8.04

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at four times higher than the guideline value while total phosphorous was detected at seven times higher.  Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. The water samples from 3 April show high levels of nitrite and nitrate, and there is a potential for further harm to aquatic organisms.

Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and aquatic plants. The ammonia is likely to be from river sources including rotting fish and flood organic matter rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae.

The algae levels detected fall within the ‘green’ to ‘amber’ alert levels. An amber alert remains in place at Menindee and Pooncarie as of 24 April 2023. No algal toxins were detected.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all five locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Sample (total acid-extractable metals)

Recreational Water Guidelines

(mg/L)

Sample 1

Sample 2

Sample 3

Sample 4

Sample 5

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2.2

3.5

3.3

4.7

4.7

Arsenic

0.07

0.003

0.003

0.003

0.005

0.005

Chromium

0.5

0.002

0.004

0.004

0.005

0.005

Cobalt

No value

0.0016

0.0021

0.0020

0.0019

0.0019

Copper

20

0.0028

0.0037

0.0035

0.0051

0.0052

Lead

0.1

0.0010

0.0017

0.0015

0.0016

0.0016

Nickel

0.2

0.0051

0.0063

0.0060

0.0063

0.0062

Zinc

30

0.005

0.007

0.007

0.009

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water

ANZG 20183

Sample (dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

(mg/L)

Sample 1

(mg/L)

Sample 2

(mg/L)

Sample 3

(mg/L)

Sample 4

(mg/L)

Sample 5

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.003

0.003

0.003

0.003

0.003

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

0.0002

0.0002

0.0002

Copper

0.0014

0.0012

0.0011

0.0010

0.0019

0.0020

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0032

0.0034

0.0034

0.0026

0.0026

Selenium

0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.

The EPA collected two water samples on 30 March downstream of Menindee at Pooncarie and approximately 60 kilometres upstream of Pooncarie.

Samples were checked for pesticides, excess nitrogen and phosphorus, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorus remain at high levels. The water samples were taken after many fish had died so the high levels could be due to rotting fish. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae

Algae, including blue-green algae, were detected in both samples. An ‘amber alert’ remains in place for the Darling River at Menindee and Pooncarie as of 20 April 2023.

Information about algae alerts is available here https://www.waternsw.com.au/water-services/water-quality/algae-alerts

Metals

Copper remains slightly above the level set to protect water life but well below the level lethal to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled on 30 March from two locations on the Darling River downriver of Menindee:

  • Sample 1 – Approximately 60 kilometres upstream of Pooncarie. This site is identified as DRKR on the full sample results.
  • Sample 2 – Old Wharf Pooncarie. This site is identified at DRPW on the full sample results.

Menindee fish kill water sampling sites, Pooncarie 30 March 2023

More sampling

The EPA and WaterNSW have collected more water samples from the Darling River in the Menindee area and downstream in the Pooncarie area on 3, 4 and 11 April. The test results from these samples will also be published on the EPA webpage.

In-field measurements

At the time of sampling, the EPA collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Dissolved oxygen ranged from 2.75 mg/L to 3.56mg/L at the two locations. Native fish and other large aquatic organisms require at least 2mg/L of dissolved oxygen to survive but may begin to suffer if levels are below 4 to 5mg/L for prolonged periods.

All other parameters are within the expected ranges.

Sample name

Location

Temp (°C)

Dissolved oxygen (mg/L)

Conductivity

(µS/cm)

pH

Turbidity (NTU)

1

Approximately 60km upstream of Pooncarie (Karoola Reach)

21.9

3.56

417

7.73

148

2

Old Wharf Pooncarie

22.2

2.75

420

7.65

114

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at six times higher than the guideline value while total phosphorous was detected at nine times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. The water samples from 30 March show high levels of nitrite and nitrate, and there is a potential for further harm to aquatic organisms.

Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and macrophytes. The ammonia is likely to be from river sources including rotting fish and flood detritus rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae, and common toxins produced by blue-green algae.

The algae levels detected fall within the ‘green’ to ‘amber’ alert levels. An amber alert remains in place at Menindee and Pooncarie as of 20 April 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from both locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Sample (total acid-extractable metals)

Recreational Water Guidelines

(mg/L)

Sample 1
(mg/L)

Sample 2
(mg/L)

Aluminium

No value

3.4

3.3

Arsenic

0.07

0.005

0.006

Chromium

0.5

0.004

0.004

Cobalt

No value

0.0018

0.0019

Copper

20

0.0048

0.0049

Lead

0.1

0.0016

0.0015

Nickel

0.2

0.0061

0.0065

Zinc

30

0.008

0.008

2NHMRC (2008) Guidelines for managing risks in recreational waters (10x drinking water guideline value, Table 9.3)

 

Metal in Water

ANZG 20183

Sample (dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

(mg/L)

Sample 1

(mg/L)

Sample 2

(mg/L)

Aluminium

0.055

<0.04

<0.04

Arsenic

0.013

0.005

0.006

Cadmium

0.0002

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0002

Copper

0.0014

0.0019

0.0018

Lead

0.0034

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

Nickel

0.011

0.0029

0.0031

Selenium

0.011

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. 

WaterNSW collected five water samples for the NSW Environment Protection Authority (EPA) on 30 March.

Samples were checked for pesticides, excess nitrogen and phosphorus, metals, algae and algal toxins.

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorus remain at high levels. The water samples were taken after many fish had died so the high levels could be due to rotting fish. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae

Algae, including blue-green algae, were detected in five samples. An ‘amber alert’ remains in place for the Darling River at Menindee and Pooncarie as of 20 April 2023.

Information about algae alerts is available here https://www.waternsw.com.au/water-services/water-quality/algae-alerts

Metals

Copper remains slightly above the level set to protect water life but well below the level lethal to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled on 30 March from five locations on the Darling River between Main Weir and Weir 32:

  • Sample 2– Downstream of the main weir at Menindee.
  • Sample 3 – Menindee Water Treatment Plant
  • Sample 4 – Upstream of Menindee Creek
  • Sample 6 – Several kilometres downstream of Menindee Creek
  • Sample 7 – Downstream of Weir 32 

Menindee fish kill sampling sites 30 March 2023

Menindee fish kill sampling sites 30 March 2023

In-field measurements

At the time of sampling, WaterNSW collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Dissolved oxygen ranged from 0.73mg/L to 5.85mg/L at the five locations. Native fish and other large aquatic organisms require at least 2mg/L of dissolved oxygen to survive but may begin to suffer if levels are below 4 to 5mg/L for prolonged periods. Two of the five sample locations detected dissolved oxygen levels below 2 mg/L.

All other parameters are within the expected ranges.

Sample name

Location

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

2

Downstream Main Weir

21.5

5.85

515

7.69

50

3

Water treatment plant

22.3

1.4

519

7.44

55

4

Upstream Menindee Creek

22.2

0.73

499

7.46

68.1

6

Downstream several kms of Menindee Creek

21.5

5.01

443.6

7.78

97

7

 

Downstream of Weir 32

21.7

4.78

443.1

7.69

101.4

 

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorous are higher than the acceptable levels given for lowland river ecosystems in NSW (ANZG 2018, which are in agreement with the regionally specific set of guideline values for the Murray-Darling outlined in the Basin Plan 2012). Total nitrogen was detected at five times higher than the guideline value while total phosphorous was detected at seven times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. The water samples from 30 March show high levels of nitrite and nitrate, and there is a potential for further harm to aquatic organisms.

Ammonia was well below the Australian and New Zealand water quality guidelines for toxicity. While the levels would not be expected to be harmful to fish, the ammonia could promote growth in algae and aquatic plants. The ammonia is likely to be from river sources including rotting fish and flood detritus rather than diffuse inputs from surrounding land.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all samples for a range of algal species, including blue-green algae, and common toxins produced by blue-green algae.

The algae levels detected fall within the ‘green’ to ‘amber’ alert levels. An amber alert remains in place at Menindee and Pooncarie as of 20 April 2023.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all five locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per the National Health and Medical Research Council (NHMRC) recreational and Australian and New Zealand Water Quality (ANZG) guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Sample (total acid-extractable metals)

Recreational Water Guidelines

(mg/L)

Sample 2

Sample 3

Sample 4

Sample 6

Sample 7

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Aluminium

No value

2

2.2

2.7

3.9

4.1

Arsenic

0.07

0.003

0.003

0.004

0.005

0.005

Chromium

0.5

0.003

0.003

0.003

0.005

0.005

Cobalt

No value

0.0019

0.0020

0.0018

0.0019

0.0019

Copper

20

0.0031

0.0030

0.0033

0.0049

0.0050

Lead

0.1

0.0012

0.0014

0.0015

0.0016

0.0018

Nickel

0.2

0.0054

0.0055

0.0059

0.0062

0.0065

Zinc

30

0.005

0.005

0.007

0.008

0.009

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

Metal in Water

ANZG 20183

Sample (dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

(mg/L)

Sample 2

(mg/L)

Sample 3

(mg/L)

Sample 4

(mg/L)

Sample 6

(mg/L)

Sample 7

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.003

0.003

0.003

0.005

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0002

0.0003

0.0002

0.0002

0.0002

Copper

0.0014

0.0011

0.0007

0.0009

0.0018

0.0018

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

<0.001

<0.001

<0.001

Nickel

0.011

0.0031

0.0032

0.0035

0.0028

0.0029

Selenium

0.011

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia. 

Summary

Pesticides

Samples were scanned for more than 600 pesticides. None were detected.

Nitrogen and phosphorus

Nitrogen and phosphorus were at high levels. The water samples were taken after many fish had died so the high levels could be due to rotting fish. If nitrogen and phosphorus stay high they can cause algal blooms.

Algae

Algae, including blue-green algae, were detected in all six samples. An ‘amber alert’ is now in place for this part of the river. This means:

  • people should not drink untreated river water.
Avoid contact with river water if you see scum on top.

Metals

Levels of metals were within the limits set for recreational use – that is, swimming and canoeing are OK. Copper was above the level set to protect water life but well below the level harmful to fish. All other metals were under the levels set to protect water life.

Sample locations

Water was sampled on 21 March from six locations on the Darling River between the outlet at Main Weir and Weir 32:

  • Sample 1 – Outlet to Lake Pamamaroo
  • Sample 2 – Downstream Main Weir
  • Sample 3 – Darling River at the Menindee Rail Bridge
  • Sample 4 – Darling River upstream of Menindee Creek
  • Sample 5 – Darling River several kilometres downstream from Menindee outlet. 
  • Sample 6 – Weir 32

map of Meninde area showing points on the Murray river where samples were collected between the outlet at Main Weir and Weir 32

In-field measurements

At the time of sampling, WaterNSW collected in-field measurements for pH, dissolved oxygen, conductivity, temperature and turbidity.

Dissolved oxygen ranged from 0.41mg/L to 5.97mg/L at the six locations. Native fish and other large aquatic organisms require at least 2mg/L of dissolved oxygen to survive but may begin to suffer if levels are below 4 to 5mg/L for prolonged periods. Three of the six sample locations detected dissolved oxygen levels below 3 mg/L.

One sample taken from the Darling River, upstream of Menindee Creek detected dissolved oxygen levels below 1mg/L. Dissolved oxygen lower than 1 mg/L can be lethal for animals that can’t move to oxygen-rich areas.

All other parameters are within the expected range.

Sample name

Location

Temp (°C)

Dissolved oxygen (mg/L)

Conductivity compensated (SPC – µS/cm)

pH

Turbidity (NTU)

1

Outlet to Lake Pamamaroo

22.6

5.97

478

7.8

109

2

DS Main Weir

23.0

1.83

529

7.5

73.3

3

Darling River at the Menindee rail bridge/town water offtake

24.5

1.21

671

7.6

61.0

4

Darling River u/s of Menindee Creek

24.4

0.41

478

7.5

45.4

5

Darling River several km downstream of Menindee outlet

22.6

4.84

420

7.9

120

6

Weir 32

22.9

4.18

421

7.8

123

Nitrogen and phosphorus

Sample results show that Total Nitrogen and Total Phosphorous are higher than the trigger values given for lowland river ecosystems in NSW (ANZG 2018). Total nitrogen was detected at eight times higher than the guideline value while total phosphorous was detected at eleven times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. These compounds can harm aquatic organisms. The water samples from 21 March show high levels of ammonia, nitrite and nitrate, and there is a potential for harm to aquatic organisms.

Algae and algal toxins

A wide variety of algae was tested for. There were positive detections in all six samples for a range of algae species, including blue-green algae.

WaterNSW has advised that the algae levels detected fall within the ‘green’ to ‘amber’ alert levels. An amber alert is currently in place.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed for samples from all six locations. All samples came back negative for pesticide detection.

Metals

Many metals are vital for humans and animals to stay healthy and only pose a risk if they are found at high levels in the environment. Concentrations of key metals found in water are below.

Total metals have been compared to recreational water quality guidelines and dissolved metals have been compared to ecological water quality guidelines as per NHMRC and ANZECC guidelines, respectively.

Total metals provide a more conservative estimate of exposure from recreational use whereas dissolved metals are used for ecological assessments as this is the bioavailable fraction of the metal (the part that is toxic to organisms).

Metal in Water

NHMRC (2008)2

Sample (total acid-extractable metals)

Recreational Water Guidelines

(mg/L)

Water1

(mg/L)

Water2

(mg/L)

Water3

(mg/L)

Water4

(mg/L)

Water5

(mg/L)

Water6

(mg/L)

Aluminium

No value

4.1

0.88

2.1

0.73

1.9

1.4

Arsenic

0.07

0.005

0.004

0.005

0.004

0.006

0.005

Chromium

0.5

0.005

<0.001

0.002

<0.001

0.002

0.002

Cobalt

No value

0.0023

0.0006

0.0011

0.0008

0.0006

0.0005

Copper

20

0.0050

0.0026

0.0033

0.0017

0.0041

0.0091

Lead

0.1

0.0018

0.0004

0.0009

0.0004

0.0005

0.0004

Nickel

0.2

0.0071

0.0042

0.0054

0.0044

0.0040

0.0037

Zinc

30

0.009

0.002

0.004

0.002

0.003

0.003

2NHMRC (2008) Guidelines for managing risks in recreational waters (10 x drinking water guideline value, Table 9.3)

 

Metal in Water

ANZG 20183

Sample (dissolved metals)

Water Quality Guideline for aquatic ecosystems (95% species protection)

(mg/L)

Water1

(mg/L)

Water2

(mg/L)

Water3

(mg/L)

Water4

(mg/L)

Water5

(mg/L)

Water6

(mg/L)

Aluminium

0.055

<0.04

<0.04

<0.04

<0.04

<0.04

<0.04

Arsenic

0.013

0.004

0.004

0.005

0.004

0.006

0.005

Cadmium

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Cobalt

No value

0.0003

0.0003

0.0003

0.0006

0.0002

0.0001

Copper

0.0014

0.0025

0.0018

0.0019

0.0018

0.0016

0.0016

Lead

0.0034

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Manganese

1.9

<0.001

<0.001

0.008

0.073

<0.001

<0.001

Nickel

0.011

0.0037

0.0034

0.0037

0.0036

0.0028

0.0029

Selenium

0.011

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

Silver

0.0005

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Zinc

0.008

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

3ANZG (2018). Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Australian and New Zealand Governments and Australian state and territory governments, Canberra ACT, Australia.