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

The EPA has concluded an investigation into the cause of the Darling-Baaka major fish deaths in February and March 2023.

Water and fish samples were tested to determine if any offence, including any water pollution offence, under the Protection of the Environment Operations Act 1997 (POEO Act) was the cause.

After careful consideration, the likely cause of both incidents was low dissolved oxygen (hypoxic water) in the Weir Pool where the fish deaths occurred. This finding aligns with the Chief Scientist and Engineer report.

Several environmental factors, including weather, algae, fish biomass and the long-term decline in river health contributed to the conditions. 

No regulatory action will be taken at this time.

The EPA will consider the recommendations of the Chief Scientist and Engineer Report and continue to work with other NSW Government agencies to monitor Menindee Lakes.

Results of sampling in 2023 are provided below.

2023 summary reports

Further sampling will be carried out until mid-2025 through the EPA’s Darling-Baaka flood recovery program.

 

The Department of Planning and Environment (DPE) collected twenty-two water samples on 7, 18, 19, and 20 December 2023 at Menindee along the Darling-Baaka River, downstream along the lower Darling-Baaka River, and the Greater Darling Anabranch. 

Surface and bottom water samples were checked for nitrogen, phosphorus, total suspended solids, and ammonia. Surface water samples collected from Menindee Weir Pool on 7 December were also checked for algae and algal toxins. 

Pesticides and metals samples were not collected (see below).

Surface samples were collected at shallow sites (samples 1, 2, 3-9, 11-20). Surface and bottom samples were taken for five deep sites E1-5 (samples 3 to 7). 

The real-time data from four buoys deployed in the Darling-Baaka River by DPE under the River Health Project can be found here.

Summary

Pesticides and metals

Pesticides and metal analysis in water were completed routinely between March 2023 and July 2023 with no pesticide detections, and all metals except copper measuring below levels set to protect water life.  For these reasons both pesticide and metals sampling have been reduced to occur approximately every three months. Pesticides and metals were last sampled in November 2024. No pesticides or metals were sampled in December. 

Nitrogen and phosphorus

Nitrogen and phosphorus 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 all samples collected on 7 December, with the exception of the sample collected from the outlet of Lake Pamamaroo. The algal toxin Cylindrospermopsin was not detected in any samples collected on 7 December. 

Amber alerts are in place in Menindee as of December 2023.

See WaterNSW for current information about alerts 

Sample locations

Water was sampled on 7 December from eight locations on the Darling-Baaka River at Menindee, and between 18 to 20 December from fourteen locations on the Darling-Baaka River at Menindee, downstream along the lower Darling-Baaka River, and along the Great Darling Anabranch. Surface samples were collected from the uppermost 50 cm of water, while bottom water was sampled from within 50 cm of the riverbed. The correlating sample identifications are given in brackets for reference to the full laboratory report data.

On 7 December 2023, eight sites in the Menindee Weir Pools in the Darling-Baaka River were sampled.

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

On 18 December 2023, one sample was collected from the Lower Darling-Baaka River between Weir 32 and Pooncarie.

  • Sample 20 (E15) (Surface only) – Old wharf at Pooncarie

On 19 December 2023, three samples were collected from the Great Darling Anabranch region and three samples from the Lower Darling-Baaka River between Weir 32 and Pooncarie. 

  • Sample 9 (B4) (Surface only) – Lake Cawndilla outlet into the Anabranch of Darling River 
  • Sample 11 (E6.5) (Surface only) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake) 
  • Sample 12 (E7) (Surface only) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake) 
  • Sample 16 (E11) (Surface only) – Bindara Station Reach 
  • Sample 18 (E13) (Surface only) – Coona Point Reach 
  • Sample 19 (E14) (Surface only) – Mullingar Station Reach 

On 20 December 2023, three samples were collected from the Menindee Weir Pools in the Darling-Baaka River and four samples from the Lower Darling-Baaka River between Weir 32 and Pooncarie 

  • Sample 1 (B1) (Surface only) – Lake Wetherell upstream of the Main Weir 
  • Sample 2 (B2) (Surface only) – Outlet of Lake Pamamaroo into Darling River 
  • Sample 8 (B3) (Surface only) – Outlet of Lake Menindee into Darling-Baaka River 
  • Sample 13 (E8) (Surface only) – Kinchega National Park upper 
  • Sample 14 (E9) (Surface only) – Kinchega National Park mid (incorporating inflows from Emu Lake) 
  • Sample 15 (E10) (Surface only) – Kinchega National Park lower (upstream of Anabranch offtake) 
  • Sample 17 (E12) (Surface only) – Karoola Station Reach 

December 2032 map

Figure 1: Sample locations where samples were taken December 2023. See Figures 2 & 3 below for more detail. Note, not all locations were sampled this round.   

December 2023 map

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

December 2023 map

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Baaka River between Weir 32 and Pooncarie regions. Note, not all locations were sampled this round.   

More sampling

The DPE are conducting regular water quality monitoring on the Darling-Baaka River from upstream of Menindee to Pooncarie. The test results from these samples will also be published on this website. The format for reporting will be changing for samples taken from 2024 onwards. Future reports will consist of 3-monthly summaries of water quality, with test results still available on this website.

Through the River Health Project, DPE Science have installed four telemetered loggers which collect real-time data on water quality in the project area. View the real-time water quality data from the River Health Project here. 

In-field measurements – 7 December

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

pH was outside the guideline value for some samples in the Menindee and Lower Darling-Baaka regions but are consistent with previous measurements.    

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

28.0

9.1

955

8.7

55.8

2 (B2)

Outlet of Lake Pamamaroo into Darling River

24.8

7.2

700

8.6

55.3

3 (E1)

Upper weir pool

25.5

6.8

721

8.5

47.7

4 (E2)

Mid weir pool

26.1

5.2

821

8.3

34.9

5 (E3)

Menindee town

26.2

5.2

702

8.4

31.8

6 (E4)

Downstream Menindee town

29.3

8.8

740

8.6

27.4

7 (E5)

Lower weir pool downstream Lake Menindee inflow

27.5

6.0

687

8.5

39.8

8 (B3)

Outlet of Lake Menindee into Darling-Baaka River

27.6

6.1

558

8.8

87.0

In-field measurements – 18 to 20 December

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

pH was outside the guideline value for some samples in the Menindee and Lower Darling-Baaka regions but are consistent with previous measurements. 

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

25.0

7.8

1004

8.6

29.3

2 (B2)

Outlet of Lake Pamamaroo into Darling River

23.9

7.3

923

8.5

42.3

8 (B3)

Outlet of Lake Menindee into Darling-Baaka River

20.7

9.1

559

8.8

101.1

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

23.2

8.1

529

8.9

37.7

11 (E6.5)

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

29.0

8.4

533

8.9

50.3

12 (E7)

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

26.9

9.9

558

8.8

66.0

13 (E8)

Kinchega National Park upper

25.5

7.7

614

8.7

66.7

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

24.5

7.2

619

8.7

66.4

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

24.9

7.6

684

8.5

73.5

16 (E11)

Bindara Station reach

27.5

8.4

733

8.5

61.3

17 (E12)

Karoola Station reach

24.6

7.0

742

8.4

60.7

18 (E13)

Coona Point reach

27.0

7.0

588

8.4

72.7

19 (E14)

Mullingar Station reach

26.8

6.2

594

8.4

56.4

20 (E15)

Old wharf at Pooncarie

26.7

6.3

595

8.1

56.6

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).

For samples taken on 7 December, the total nitrogen was detected up to 2 times higher than the guideline value while total phosphorus was detected at up to 4 times higher. Total nitrogen for samples taken between the 18 to 20 December was up to 2 times higher than the guideline value while total phosphorus was detected at up to 5 times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. Some of these compounds can harm aquatic organisms. The average ammonia was below the Australian and New Zealand water quality guidelines for toxicity in all samples. 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.  

Nutrient data for samples 1, 13, 16, 17, 19, and 20 have been removed from analysis due to possible compromise in the sample.  

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) collected seventeen water samples between 7 to 9 November 2023 at Menindee along the Darling-Baaka River, downstream along the lower Darling-Baaka River, and along the Great Darling Anabranch.

Surface and bottom water samples were checked for excess nitrogen, phosphorus, and ammonia. Surface samples were collected at shallow sites (samples 1, 2, 6-8 and 9-20). Surface and bottom samples were collected at three deep sites (samples 3 to 5).

Surface water samples were also checked for pesticides, algae and algae toxins. Samples 9 to 12 and 16 to 20 were additionally examined for algae identification.

Total metals were tested in all surface water samples at all sites and bottom water samples in Samples 3, 4, and 5.

Summary

Pesticides

Samples were scanned for more than 100 pesticides. The herbicide atrazine was found in very low concentrations and below the level set to protect water life.  No other pesticides or herbicides were detected.

Metals

Total chromium and copper are slightly above the level set to protect water life in five and seven sites, respectively.  All other metals were under the levels set to protect water life.

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 six of the seventeen samples. The algal toxin Cylindrospermopsin was not detected.

Sample locations

On 7 November 2023, eight samples were collected from the Menindee Weir Pool. The correlating sample identifications are given in brackets for reference to the full laboratory report data. Surface samples were collected from the uppermost 50 cm of water, while bottom water samples were obtained from the layer of water situated within 50 cm above the sediment bed.

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

On 9 November 2023, nine samples were collected in the Great Darling Anabranch region and Lower Darling-Baaka River between Weir 32 and Pooncarie.

  • Sample 9 (B4) (surface) – Lake Cawndilla outlet into the anabranch of Darling River
  • Sample 10 (E6) (surface) – Redbank Creek upstream of Cawndilla Channel confluence
  • Sample 11 (E6.5) (surface) – Tandou Creek at Tandou Woolshed Rd (incorporating inflows from Kangaroo Lake)
  • Sample 12 (E7) (surface) – Tandou Creek at Packers Crossing (incorporating inflows from Packers Lake)
  • Sample 16 (E11) (surface) – Bindara Station Reach
  • Sample 17 (E12) (surface) – Karoola Station reach
  • Sample 18 (E13) (surface) – Coona Point reach
  • Sample 19 (E14) (surface) – Mullingar Station reach
  • Sample 20 (E15) (surface) – Old wharf at Pooncarie

Map November 2024

Figure 1: Sample locations where samples were taken between 7 and 9 November 2023. See Figures 2 and 3 below for more detail. Note, not all locations were sampled this round. 

Map November 2024

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

Map November 2024

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Baaka river between Weir 32 and Pooncarie regions. Note, not all locations were sampled this round. 

More sampling

The DPE are conducting regular water quality monitoring on the Darling-Baaka River from upstream of Menindee to Pooncarie. The test results from these samples will also be published on this website. Through the River Health Project, DPE Science have installed four telemetered loggers which collect real-time data on water quality in the project area.

In-field measurements

At the time of sampling, the DPE collected in-field measurements for pH, dissolved oxygen, conductivity, temperature, and turbidity. All samples collected on the 9 November (Samples 9-12, 16-20) were impacted by a probe malfunction resulting in no pH measurement. The pH sensor was replaced for subsequent trips.

pH was outside the guideline value for some samples in the Menindee and Lower Darling-Baaka regions but results were consistent with previous sampling events.

Dissolved oxygen was low in samples collected from Redbank Ck upstream of Cawndilla Channel confluence (Sample 10 - E6), with a measurement of 2.4 mg/L.  This site had ceased flow at the time of the sampling and recorded high turbidity and chlorophyll concentrations, indicating the presence of a large algal bloom and the potential for fish harm to occur.  Under these conditions, dissolved oxygen concentrations can vary widely over a 24-hour period due to photosynthesis during the light and respiration during the dark.

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

1 (B1)

Lake Wetherell upstream of the Main Weir

22.6

9.1

725

8.8

35.7

2 (B2)

Outlet of Lake Pamamaroo into Darling River

20.9

6.5

696

8.5

34.8

3 (E1)

Upper weir pool

24.1

13.5

711

9.1

17.2

4 (E2)

Mid weir pool

24.1

11.0

652

8.9

14.9

5 (E3)

Menindee town

25.5

11.7

664

8.8

24.9

6 (E4)

Downstream Menindee town

22.5

7.5

622

8.6

25.4

7 (E5)

Lower weir pool downstream Lake Menindee inflow

21.4

8.8

493

8.8

51.5

8 (B3)

Outlet of Lake Menindee into Darling-Baaka River

21.0

7.9

458

8.8

75.9

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

19.8

7.4

448

nm

42.2

10 (E6)

Redbank Ck upstream of Cawndilla Channel confluence

21.9

2.4

477

nm

160.7

11 (E6.5)

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

22.9

8.2

481

nm

81.6

12 (E7)

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

23.4

5.8

504

nm

66.2

16 (E11)

Bindara Station reach

25.2

8.8

565

nm

70.3

17 (E12)

Karoola Station reach

26.0

9.1

566

nm

68.4

18 (E13)

Coona Point reach

26.1

9.3

586

nm

62.1

19 (E14)

Mullingar Station reach

25.8

10.0

619

nm

58.5

20 (E15)

Old wharf at Pooncarie

27.0

12.2

676

nm

31.6

 nm = not measured

Nitrogen, phosphorus and ammonia

Sample results show that total nitrogen and total phosphorus 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 up to 3 times higher than the guideline value while total phosphorus was detected at up to 5 times higher. Algal blooms are possible if these nutrients remain elevated.

Bacteria convert nitrogen compounds such as ammonia into nitrite and nitrate. Some of these compounds can harm aquatic organisms. Ammonia was 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

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in only six of the surface water samples (samples 11 and 16 to 20). The algal toxin Cylindrospermopsin was not detected.

Pesticides

Sixteen samples were screened for more than 100 pesticides in November (Sample 1 was not tested). The herbicide atrazine was found in very low concentrations (ranging from 0.11 to 0.27 µg/L). The concentrations detected were below the ecological water quality  guideline of 0.7 µg/L set for a 99% protection level (ANZG 2018).  Atrazine is a widely used herbicide which is used to control grass and broadleaved weeds in crops.  High concentrations of atrazine can cause negative environmental effects but given the low concentrations detected in November, it is not likely to have caused biological stress.

No other pesticides or herbicides 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. Total metals have been compared to recreational water quality guidelines and 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. The use of total metal concentrations for ecological assessments is conservative as it’s overestimating the bioavailable fraction of the metal (the part that is toxic to organisms).

Total chromium was slightly above the level set to protect water life in the Menindee Lake outflow (sample 8; site B3) and at the site immediately downstream of the Menindee Creek junction (sample 7; site E5), as well as at sites downstream of weir 32 (samples 16-18).  Total copper was slightly above the level set to protect water life in seven of the samples with no apparent spatial trends in exceedances. All other metals were under the levels set to protect water life.  Full metal results are provided in the below table.

Metal in Water NHMRC (2008) ANZG 2018 Samples from the Menindee Weir Pools along the Darling-Baaka River (total acid-extractable metals)
Recreational Water Guidelines 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) (mg/L)

Aluminium

No value

0.055

0.13

0.51

0.26

0.33

0.38

0.42

2.56

2.6

Arsenic

0.07

0.013

0.002

0.002

0.003

0.004

0.003

0.003

0.006

0.006

Cadmium

No value

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.5

0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

0.002

0.002

Cobalt

No value

No value

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Copper

20

0.0014

<0.001

<0.001

0.002

0.002

0.001

0.001

0.002

0.001

Lead

0.1

0.0034

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Manganese

No value

1.9

0.023

0.036

0.023

0.015

0.014

0.015

0.034

0.02

Nickel

0.2

0.011

0.001

0.002

0.002

0.002

0.002

0.002

0.002

0.002

Selenium

No value

0.005

<0.01

<0.01

<0.01

<0.01

<0.01

<0.01

<0.01

<0.01

Silver

No value

0.0005

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

<0.001

Zinc

30

0.008

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

<0.005

 

Metal in Water NHMRC (2008) Water Quality Guideline for aquatic ecosystems (95% species protection)

 

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

 

(mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

0.055

0.36

2.02

1.94

1.91

Arsenic

0.07

0.013

0.006

0.005

0.005

0.005

Cadmium

No value

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.5

0.001

<0.001

0.001

0.001

0.001

Cobalt

No value

No value

<0.001

<0.001

<0.001

<0.001

Copper

20

0.0014

<0.001

0.002

0.002

0.001

Lead

0.1

0.0034

<0.001

<0.001

<0.001

<0.001

Manganese

No value

1.9

0.024

0.026

0.009

0.009

Nickel

0.2

0.011

<0.001

0.002

0.002

0.002

Selenium

No value

0.005

<0.01

<0.01

<0.01

<0.01

Silver

No value

0.0005

<0.001

<0.001

<0.001

<0.001

Zinc

30

0.008

<0.005

<0.005

<0.005

<0.005

 

Metal in Water NHMRC (2008)2 Water Quality Guideline for aquatic ecosystems (95% species protection)

 

Samples from the lower Darling-Baaka River between Weir 32 and Pooncarie (total acid-extractable metals)
Recreational Water Guidelines 16 17 18 19 20
(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (mg/L)

Aluminium

No value

0.055

2.18

2.36

2.07

1.68

0.63

Arsenic

0.07

0.013

0.006

0.006

0.005

0.004

0.004

Cadmium

No value

0.0002

<0.0001

<0.0001

<0.0001

<0.0001

<0.0001

Chromium

0.5

0.001

0.002

0.002

0.002

0.001

<0.001

Cobalt

No value

No value

<0.001

<0.001

<0.001

<0.001

<0.001

Copper

20

0.0014

0.002

0.002

0.001

<0.001

<0.001

Lead

0.1

0.0034

<0.001

<0.001

<0.001

<0.001

<0.001

Manganese

No value

1.9

 

 

 

 

 

Nickel

0.2

0.011

0.002

0.003

0.002

0.002

0.002

Selenium

No value

0.005

<0.01

<0.01

<0.01

<0.01

<0.01

Silver

No value

0.0005

<0.001

<0.001

<0.001

<0.001

<0.001

Zinc

30

0.008

<0.005

<0.005

<0.005

<0.005

<0.005

 

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

Atrazine in freshwater and marine water (2000), 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: Atrazine in freshwater and marine water (waterquality.gov.au)

Atrazine Chemical Review (2008) Australian Pesticides and Veterinary Medicines Authority. Available at: https://www.apvma.gov.au/chemicals-and-products/chemical-review/listing/atrazine.

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

The Department of Planning and Environment (DPE) collected eleven water samples between 11 to 12 October 2023 at Menindee, and further downstream along the Darling-Baaka River.

Surface and bottom water samples were checked for excess nitrogen, phosphorus, and ammonia. Surface water samples were also checked for the presence of algae and algal toxins.

Surface samples were taken for shallow sites (samples 1 - 8 and 13 -14). Surface and bottom samples were taken for deep sites (samples 3 to 7).

Samples were not collected from the Great Darling Anabranch, and some of the routine locations along the Lower Darling Baaka during this sampling round (samples 9 to 12 and 16 to 20).

Nitrogen and phosphorus

Nitrogen and phosphorus 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 six of the surface samples (samples 1 and 4 to 8). The algal toxin Cylindrospermopsin was not detected in any samples.

See WaterNSW for current information about alerts

Sample locations

On 11 October 2023, eight samples were collected from the Menindee Weir Pools in the Darling-Baaka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data. Surface samples were collected from the uppermost 50 cm of water, while bottom water samples were obtained from the layer of water situated within 50 cm above the sediment bed.

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

On 12 October 2023, three samples were collected from the Lower Darling-Baaka River between Weir 32 and Pooncarie.

  • Sample 13 (E8) – Kinchega National Park upper (Surface)
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake) (Surface)
  • Sample 15 (E10) – Kinchega National Park lower (upstream of Anabranch offtake) (Surface)

Map October 2024

Figure 1: Sample locations where samples were taken between 11 and 12 October 2023. See Figures 2 and 3 below for more detail. Note, not all locations were sampled this round.

Map October 2024

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

Figure 3: Sample locations for the Great Darling Anabranch and lower Darling-Baaka river between Weir 32 and Pooncarie regions. Note, not all locations were sampled this round.

More sampling

The DPE are conducting regular water quality monitoring on the Darling-Baaka River from upstream of Menindee to Pooncarie. The test results from these samples will also be published on this website. Through the River Health Project, DPE Science have installed four telemetered loggers which collect real-time data on water quality in the project area.

In-field measurements

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

pH was outside the guideline value for some samples in the Menindee and Lower Darling-Baaka regions.

All other parameters were within the expected ranges.

Site

Site
name

Temp (°C)

Dissolved oxygen (mg/L)

Electrical conductivity (µS/cm)

pH

Turbidity (NTU)

1 (B1)

Lake Wetherell upstream of the Main Weir

25.1

13.5

718

8.9

21.4

2 (B2)

Outlet of Lake Pamamaroo into Darling River

19.4

8.8

558

8.6

38.8

3 (E1)

Upper weir pool

24.1

11.6

618

8.7

32.3

4 (E2)

Mid weir pool

24.6

12.5

625

8.9

18.7

5 (E3)

Menindee town

24.0

12.2

616

8.9

25.6

6 (E4)

Downstream Menindee town

20.6

7.8

579

8.5

32.2

7 (E5)

Lower weir pool downstream Lake Menindee inflow

22.2

9.4

533

8.7

41.3

8 (B3)

Outlet of Lake Menindee into Darling-Baaka River

20.0

8.0

421

8.8

73.1

13 (E8)

Kinchega National Park upper

21.2

9.4

514

8.6

49.9

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake

22.0

9.5

535

8.6

59.7

15 (E10)

Kinchega National Park lower (upstream of Anabranch offtake)

22.5

9.4

547

8.5

63.1

Nitrogen, phosphorus, and ammonia

Sample results show that total nitrogen and total phosphorus 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 up to 2 times higher than the guideline value while total phosphorus was detected at up to 4 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 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.

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) collected thirteen water samples between 13 to 14 September 2023 at Menindee, and further downstream along the lower Darling-Barka River.

Surface and bottom water samples were checked for excess nitrogen, phosphorus, and ammonia. Surface water samples were also checked for algae and algal toxins.

Surface water samples were collected at shallow sites (samples 1, 2, 8, and 16 to 20). Surface and bottom samples were collected at deep sites (samples 3 to 7).

Samples were not collected from the Great Darling Anabranch, and some of the routine locations along the Lower Darling Barka during this sampling round (samples 9 to 15).

Summary

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 only six of the surface water samples (samples 1, 8 and 10-13). The algal toxin Cylindrospermopsin was not detected in any samples.

Sample locations

On 13 to 14 September 2023, thirteen samples were collected from the Menindee Weir Pools and the lower Darling-Barka River. The correlating sample identifications are given in brackets for reference to the full laboratory report data. Surface samples were collected from the uppermost 50 cm of water, while bottom water samples were obtained from the layer of water situated within 50 cm above the sediment bed.

  • Sample 1 (B1) – Lake Wetherell upstream of the Main Weir (Surface)
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River (Surface)
  • Sample 3 (E1) – Upper weir pool (Surface and Bottom)
  • Sample 4 (E2) – Mid weir pool (Surface and Bottom)
  • Sample 5 (E3) – Menindee town (Surface and Bottom)
  • Sample 6 (E4) – Downstream Menindee town (Surface and Bottom)
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow (Surface and Bottom)
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River (Surface)
  • Sample 16 (E11) – Bindara Station Reach (Surface)
  • Sample 17 (E12) – Karoola Station Reach (Surface)
  • Sample 18 (E13) – Coona Point Reach (Surface)
  • Sample 19 (E14) – Mullingar Station Reach (Surface)
  • Sample 20 (E15) – Old wharf at Pooncarie (Surface)

Map showing  locations where samples were taken between 13 and 14 September 2023. See Figures 2 and 3 below for more detail.

map of sample locations for the Menindee Weir Pools region along the Darling-Barka River

Map showing sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions. Note, not all locations were sampled this round.

More sampling

The DPE are conducting regular water quality monitoring on the Darling-Barka River from upstream of Menindee to Pooncarie. The test results from these samples will also be published on this website. Through the River Health Project, DPE Science have installed four telemetered loggers which collect real-time data on water quality in the project area. 

In-field measurements

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

pH was outside the guideline value for some samples in the Menindee and Lower Darling-Barka regions.

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

16.9

11.4

591

8.7

10.0

2 (B2)

Outlet of Lake Pamamaroo into Darling River

15.1

9.4

513

8.5

21.7

3 (E1)

Upper weir pool

15.1

9.8

512

8.5

23.4

4 (E2)

Mid weir pool

15.7

10.0

560

8.5

17.0

5 (E3)

Menindee town

16.6

10.2

552

8.5

17.1

6 (E4)

Downstream Menindee town

16.4

10.1

542

8.5

21.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

16.6

9.5

544

8.4

27.0

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

13.5

9.1

352

8.3

52.7

16 (E11)

Bindara Station reach

17.1

9.5

545

8.3

42.8

17 (E12)

Karoola Station reach

18.0

11.2

578

8.5

36.4

18 (E13)

Coona Point reach

17.0

11.7

553

8.8

43.6

19 (E14)

Mullingar Station reach

nm

nm

nm

nm

nm

20 (E15)

Old wharf at Pooncarie

16.7

11.9

515

8.9

57.5

nm = Not measured

Nitrogen, Phosphorus, and Ammonia

Surface and bottom 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 up to 2.5 times higher than the guideline value while total phosphorous was detected at up to 3.5 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 ammonia was also 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.

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) collected twenty water samples between 22 to 24 August 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 excess nitrogen and phosphorus, ammonia, algae and algal toxins. Surface and bottom samples were taken.

Pesticides and metals samples were not collected (see below).

Summary

Pesticides and metals

Pesticide and metal analyses in water have been completed routinely between March and July 2023 with no pesticide detections, and all metals except copper measuring below levels set to protect water life. Copper has consistently measured above the level set to protect water life in various samples across the regions, yet well below the level harmful to fish. For these reasons, both pesticides and metals sampling have been reduced to occur approximately every three months. All other routine analyses will continue at the same frequency.

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 only detected in twelve of the surface samples (samples 1, 6, and 11 to 20). The algal toxin Cylindrospermopsin was also detected in several of the surface samples (10 to 12 and 18 to 20).

Sample locations

Water was sampled between 22 and 24 August 2023 from twenty locations on the Darling-Barka River at Menindee, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch. Surface samples were collected from the uppermost 50 cm of water, while bottom water samples were obtained from the layer of water situated within 50 cm above the sediment bed.

On 22 August 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 (surface)
  • Sample 2 (B2) – Outlet of Lake Pamamaroo into Darling River (surface)
  • Sample 3 (E1) – Upper weir pool (surface and bottom)
  • Sample 4 (E2) – Mid weir pool (surface and bottom)
  • Sample 5 (E3) – Menindee town (surface and bottom)
  • Sample 6 (E4) – Downstream Menindee town (surface and bottom)
  • Sample 7 (E5) – Lower weir pool downstream Lake Menindee inflow (surface and bottom)
  • Sample 8 (B3) – Outlet of Lake Menindee into Darling-Barka River (surface)

On 23 August 2023, four surface samples were collected from the Great Darling Anabranch region and three surface 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 24 August 2023, five surface 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 showing Sample locations for the Menindee Weir Pools region along the Darling-Barka River

 

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

More sampling

The DPE 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. Through the River Health Project, DPE Science have installed four telemetered loggers which collect real-time data on water quality in the project area.

In-field measurements

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

pH was outside the guideline value for some samples in the Great Darling Anabranch and Lower Darling-Barka regions.

Dissolved oxygen at the Redbank Ck upstream of Cawndilla Channel confluence was 3.9mg/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.

Sample 12, collected from the Great Darling Anabranch region at Tandou Ck at Packers Crossing, was super-saturated with oxygen and had very high nutrient concentrations. 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 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

5.3

546

7.9

12.7

2 (B2)

Outlet of Lake Pamamaroo into Darling River

15.0

10.0

517

8.4

24.5

3 (E1)

Upper weir pool

14.9

9.8

537

8.4

25.3

4 (E2)

Mid weir pool

14.4

9.6

480

8.3

30.0

5 (E3)

Menindee town

14.2

8.8

507

8.1

22.5

6 (E4)

Downstream Menindee town

14.8

9.4

520

8.2

24.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

14.3

8.7

550

8.1

23.3

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

14

8.4

346.2

8.3

34.3

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

14.3

12.1

366.1

8.9

21.1

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

13.5

3.9

449.9

8.2

203.6

11 (E6.5)

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

17.3

13.0

399.3

9.1

37.9

12 (E7)

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

17.0

17.2

416.8

9.3

17.4

13 (E8)

Kinchega National Park upper

14.0

9.1

524.0

8.1

23.3

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

13.5

9.0

544.0

8.1

27.4

15 (E10)

Kinchega National Park lower

14.1

9.2

544.0

8.1

37.2

16 (E11)

Bindara Station reach

13.8

5.3

546.2

7.9

12.7

17 (E12)

Karoola Station reach

nm

nm

nm

nm

nm

18 (E13)

Coona Point reach

nm

nm

nm

nm

nm

19 (E14)

Mullingar Station reach

nm

nm

nm

nm

nm

20 (E15)

Old wharf at Pooncarie

nm

nm

nm

nm

nm

mm = not measured      nr = no reliable measurement

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). The average total nitrogen was detected to be up to three times higher than the guideline value while the average total phosphorous was detected at up to five 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.

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) collected 8 water and 15 sediment samples between 8 to 9 August 2023 at Menindee along the Darling-Barka River.

Samples were checked for excess nitrogen and phosphorus, ammonia, and algae. Sediment samples were checked for metals and pesticides.

The remaining 12 sites usually collected from the Great Darling Anabranch and lower Darling-Barka River were not sampled due to sampling teams being assigned to collect sediment samples at Menindee along the Darling-Barka.  The sediment sampling sites are marked in Figure 1.

Pesticide and metal analyses in water have been completed routinely between March and July 2023 with no pesticide detections, and all metals except copper measuring below levels set to protect water life. Copper has consistently measured above the level set to protect water life in various samples across the regions, yet well below the level harmful to fish. For these reasons, both pesticides and metals sampling have been reduced to occur approximately every three months. All other routine analyses will continue at the same frequency.

Summary

Nitrogen and phosphorus

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

Algae

Blue-green algae were detected in all samples, but potentially toxic blue-green algae were detected in only three of the samples.

See current information about alerts at WaterNSW

Sediment contaminants

All metals but Nickel were below sediment quality guidelines threshold values outlined within the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG (2018)).

Stable isotope data indicated that sediments in this region varied with a low-moderate carbon content (0.1 - 2.0%).

Sample locations

On 8 August 2023, 15 sediment samples were collected from the Menindee Weir Pools, to understand how sediment effects oxygen concentrations in the water column, and the accumulation of potential contaminants (metals, pesticides and herbicides) after the floods. Fifteen sites were sampled along the weir pool, between the outlet of Lake Pamamaroo into Darling River and Lower weir pool downstream Lake Menindee inflow. Seven of the fifteen sediment samples aligned with previous water sampling sites (samples 2-8).  Samples were analysed for sediment properties such as grain size, stable isotopes, metals and pesticides.

On 9 August 2023, eight water samples were collected from the Menindee Weir Pools in the Darling-Barka River (samples 1-8). The correlating sample identifications are given in brackets for reference to the full laboratory report data.

  • Sample 1 (B1) (water only) – Lake Wetherell upstream of the Main Weir
  • Sample 2 (B2) (sediment and water) – Outlet of Lake Pamamaroo into Darling River
  • Sample 3 (E1) (sediment and water) – Upper weir pool
  • Sample 4 (E2) (sediment and water) – Mid weir pool
  • Sample 5 (E3) (sediment and water)  – Menindee town
  • Sample 6 (E4) (sediment and water) – Downstream Menindee town
  • Sample 7 (E5) (sediment and water) – Lower weir pool downstream Lake Menindee inflow
  • Sample 8 (B3) (sediment and water) – Outlet of Lake Menindee into Darling-Barka River
  • Sample 21 (P1) (sediment only) – Downstream of Menindee Main Weir
  • Sample 22 (P2) (sediment only) – Upstream of upper weir sample site/li>
  • Sample 23 (P3) (sediment only) – Weir pool north of Menindee Hut Waterhole
  • Sample 24 (P4) (sediment only) – Northeast of Orchard Rd upstream of mid weir pool sample site
  • Sample 25 (P5) (sediment only) –Northeast of Menindee golf club downstream of mid weir pool site
  • Sample 26 (P6) (sediment only) – Southeast of loop road
  • Sample 27 (P7) (sediment only) – Downstream and close to the outlet of Lake Menindee into the Darling-Barka River
  • Sample 28 (P8) (sediment only) – In between outlet of Lake Menindee and Lower Weir Pool site

Map showing sample locations for sediment samples from downstream of the Main Weir to upstream of Weir 32, for samples taken on 8 August 2023.

 

Map of water sampling sites from the Main Weir to upstream of Weir 32 for samples taken on 9August 2023

More sampling

The DPE 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.

Through the Darling Barka River Health Project, DPE Science have installed four telemetered loggers which collect real-time data on water quality in the project area.

In-field measurements

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

All parameters were within the expected ranges.

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

1 (B1)

Lake Wetherell upstream of the Main Weir

nm

nm

nm

nm

nm

2 (B2)

Outlet of Lake Pamamaroo into Darling River

13.6

9.4

535

8.2

21.9

3 (E1)

Upper weir pool

13.6

9.0

551

8.2

23.7

4 (E2)

Mid weir pool

14.2

9.9

585

8.2

13.8

5 (E3)

Menindee town

14.4

9.4

579

8.2

13.3

6 (E4)

Downstream Menindee town

14.0

9.9

605

8.3

10.2

7 (E5)

Lower weir pool downstream Lake Menindee inflow

13.8

9.5

568

8.3

18.3

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

12.8

6.1

334

7.9

40.3

nm = Not measured this round

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 agree 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 two 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

There were positive detections in all samples for blue-green algae. However, only the blue-green algae detections found in sample 3, 6 and 7 were considered potentially toxic.

Sediment Contaminants

Metals and pesticides were compared to ANZG (2018) default sediment quality guideline values (DGV) and high guideline values (GV-High).

The metals, with guidelines listed in ANZG (2018), had measured concentrations below all sediment quality guideline (DGV) threshold values except nickel. Nickel measured slightly higher than the DGV for some sites, but all these sites recorded well below the high guideline values (GV-High). This is suggesting there is a low risk of effects to the Darling-Barka aquatic ecosystem associated with post-flood deposition or localised inputs. 

Sediment carbon contents (0.1 - 2.0%) were in the low to moderate range for riverine sediments  and did not indicate excessive organic enrichment.  Sediment carbon and nitrogen stable isotopes were measured to provide an indication of organic matter sources.  Stable isotope values were not consistent with the accumulation of fish biomass, and in contrast suggested that main sources of organic matter to sediments was phytoplankton detritus and terrestrial organic matter.  

A range of pesticides were analysed in the collected sediment samples.  No pesticides were detected, therefore the risk posed by these contaminants is likely to be low, however, in some cases the detection limit exceeds the DGVs.

 

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 (Australian Capital Territory), 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) collected nineteen water samples between 1 to 3 August 2023 at Menindee along the Darling-Barka River, downstream along the lower Darling-Barka River, and along the Great Darling Anabranch.

Sampling was reduced during this period following direction to investigate further reported fish deaths.  All samples were checked for ammonia, excess nitrogen and phosphorus. Samples from Menindee along the Darling-Barka River were also checked for pesticides, algae and algal toxins. Metals were unable to be reported on for this round due to a laboratory error. Future monitoring and reporting will include metals.

Pesticide and metal analyses have been completed routinely between March and July 2023 with no pesticide detections, and all metals except copper measuring below levels set to protect water life. Copper has consistently measured above the level set to protect water life in various samples across the regions, yet well below the level harmful to fish. For these reasons, both pesticides and metals analysis will continue on a less regular basis. All other routine analyses will continue at the same frequency.

One of the samples usually collected from the lower Darling-Barka region was unable to be sampled on this occasion, interrupted by road closures due to inclement weather.

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 only two of the samples. The algal toxin Cylindrospermopsin was not detected in any of the samples.

Sample locations

Water was sampled between 1 and 3 August 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 1 August 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 2 August 2023, two samples were collected from the Great Darling Anabranch region.

  • 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)

On 3 August 2023, two samples were collected from the Great Darling Anabranch region and seven samples were collected 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 13 (E8) – Kinchega National Park upper
  • Sample 14 (E9) – Kinchega National Park mid (incorporating inflows from Emu Lake)
  • 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

Sample 15 (E10) Kinchega National Park lower was unable to be sampled on this occasion, due to accessibility issues following heavy rain.

Map of sample locations where samples were taken between 1 and 3 August 2023. See Figures 2 and 3 below for more detail.

 

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

 

Map of sample locations for the Great Darling Anabranch and lower Darling-Barka river between Weir 32 and Pooncarie regions

More sampling

The DPE 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 DPE 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

13.6

6.8

624

7.9

7.5

2 (B2)

Outlet of Lake Pamamaroo into Darling River

13.8

9.1

570

8.0

23.6

3 (E1)

Upper weir pool

14.2

9.6

600

8.2

16.6

4 (E2)

Mid weir pool

13.8

9.9

556

8.2

14.2

5 (E3)

Menindee town

13.9

11.3

636

8.4

8.3

6 (E4)

Downstream Menindee town

14.6

11.3

689

8.4

7.0

7 (E5)

Lower weir pool downstream Lake Menindee inflow

13.5

10.3

589

8.3

18.3

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

16.5

6.7

362

7.9

43.5

9 (B4)

Lake Cawndilla outlet into the anabranch of Darling River

15.0

10.4

377

8.5

13.8

10 (E6)

Redbank Creek upstream of Cawndilla Channel confluence

15.5

16.1

349

9.5

14.6

11 (E6.5)

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

16.4

14.1

404

9.1

30.1

12 (E7)

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

16.5

13.4

428

9.2

31.7

13 (E8)

Kinchega National Park upper

12.8

9.1

580

8.1

19.2

14 (E9)

Kinchega National Park mid (incorporating inflows from Emu Lake)

12.7

10.0

571

8.1

21.4

16 (E11)

Bindara Station reach

14.0

10.7

494

8.2

36.9

17 (E12)

Karoola Station reach

12.8

8.5

519

7.9

35.3

18 (E13)

Coona Point reach

12.9

10.4

495

8.1

32.9

19 (E14)

Mullingar Station reach

13.0

10.0

471

8.1

44.8

20 (E15)

Old wharf at Pooncarie

12.0

9.5

436

8.0

43.5

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 five times higher than the guideline value while total phosphorous was detected at up to eight times higher, with the exception of Sample 12 which was twelve 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 in the Menindee region. However, only the blue-green algae detections found in samples 3 and 8 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’ to ‘red’ alert levels. A red alert is in place along parts of the lower Darling-Barka River.

A red alert and amber alert is in place along at Menindee and further downstream, as of 3 November 2023. See WaterNSW for information about alerts.

Pesticides

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

Metals

Metals were unable to be reported on for this round due to a laboratory processing error. Future monitoring and reporting will include metals.

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) collected eight water samples on 25 and 26 July 2023 at Menindee along the Darling-Barka River.

Samples were checked for pesticides, excess nitrogen and phosphorus, ammonia, algae and algal toxins. Metals were unable to be reported on for this round due to a laboratory error.

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 only two of the samples. The algal toxin Cylindrospermopsin was not detected in any of the samples.

Sample locations

On 25 July 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

More sampling

The DPE 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 DPE 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

12.6

9.6

635

8.5

8.4

2 (B2)

Outlet of Lake Pamamaroo into Darling River

11.9

10.4

509

8.5

20.6

3 (E1)

Upper weir pool

12.2

9.7

575

8.4

19.9

4 (E2)

Mid weir pool

12.3

10.2

580

8.4

12.8

5 (E3)

Menindee town

12.5

10.8

643

8.5

11.3

6 (E4)

Downstream Menindee town

12.9

10.2

629

8.4

11.8

7 (E5)

Lower weir pool downstream Lake Menindee inflow

12.2

10.3

506

8.4

19.7

8 (B3)

Outlet of Lake Menindee into Darling-Barka River

12.0

4.8

327

7.9

42.1

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 two times higher than the guideline value while total phosphorous was detected at up to four times higher, with the exception of Sample 8 which was 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 5 and 6 were considered potentially toxic. The algal toxin Cylindrospermopsin was not detected in any samples from this region.

Pesticides

As noted above, a pesticide screening test that scanned for over 600 pesticides was completed. 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 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