Barwon-Darling Operations Plan - WaterNSW...Barwon-Darling Operations Plan June 2019 3 1. Highlights...

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Barwon-Darling Operations Plan

June 2019

http://www.waternsw.com.au/

Barwon-Darling Operations Plan June 2019 2

Contents

1. Highlights ................................................................................................................................................. 3

2. Summary of recent conditions ............................................................................................................. 4

2.1 Flow volumes at major locations .............................................................................................................. 4

2.2 Recent flows ................................................................................................................................................. 5

2.3 Recent salinity (EC) ..................................................................................................................................... 7

3. Current access arrangements .............................................................................................................. 8

3.1 Access availability in 2018-19 .................................................................................................................... 8

4. Rainfall ................................................................................................................................................... 10

5. Current upstream storage status ........................................................................................................ 13

5.1 Northern valleys storage status ............................................................................................................... 13

5.2 Northern valleys storage breakdown .................................................................................................... 14

6. Current operating condition ............................................................................................................... 14

7. Forecast flow condition ....................................................................................................................... 15

8. Rainfall outlook ..................................................................................................................................... 16

Appendix A ..................................................................................................................................................... 18

Blue-green algae alert reports ..................................................................................................................... 18


1. Highlights

• Rain in the Namoi and Macquarie valleys in late March resulted in small inflows into these systems.

Flows from the Namoi reached Walgett Weir while the Macquarie flows reached the Barwon to

refill the Brewarrina Weir pool with a small flow over Brewarrina weir.

• The Northern Fish Flow event started mid-April with environmental water releases from Glenlyon

and Copeton Dams in the Border and Gwydir Valleys. A total of 36 GL was released; 7.4GL from

Glenlyon and 28.6 GL from Copeton Dam. Water has travelled through these valleys and

reached the Barwon River. Releases from Border reached Mogil Mogil. The Gwydir flow has

reached Walgett and expected to reach at least up to Brewarrina weir pool.

• Flows from the Nebine/Culgoa River reached the Darling River upstream of Bourke on 9 May and

Bourke Weir has risen about 1.2 m.

• Flows in the Darling had recommenced between Bourke and Louth because of local rainfall over

the Easter weekend and ongoing inflows from the Warrego River that are contributing to the flow

at Louth. This flow reached Wilcannia on 15 June and may contribute a small volume to Lake

Wetherell.

• The NSW Government issued a section 324 temporary pump restriction order for Mungindi to Tilpa

on 17 April to protect environmental releases from Copeton Dam and Glenlyon Dam. The

restriction was extended up to Lake Wetherell on 8 may to allow the Warrego water to establish

flow as far down the system as possible.


2. Summary of recent conditions

2.1 Flow volumes at major locations

Gauging station Mungindi Collarenebri Walgett Brewarrina Bourke Tilpa Wilcannia

Flow from 1 July 2018 to

24 June 2019 (ML) 8,722 12,666 4,874 2,374 5,037 17,975 5,775

Northern Fish

flow/Warrego Inflow (ML) 1,199 12,160 4,795 0 0 14,510* 1,910*

Number of days when the

flow was less than

20ML/day (from 1 July

2018 to 24 June 2019)

(Days)

251 324 347 327 323 283 307

*Inflows from Warrego


The above table shows the total flows at major locations along the river reach as well as the

number of days with flows of less than 20 ML/day from 1 July 2018 to 18 June 2019. Operational

surplus from the Border Rivers contributed to the flow at Mungindi.

2.2 Recent flows

WaterNSW HYPLOT V133 Output 25/06/2019

Period 12 Month 01/07/2018 to 01/07/2019 2018-19416001 BARWON R @ MUNGINDI 141.00 12 Hour Mean Discharge (ML/d) CP

416050 BARWON U/S PRESBURY 141.00 12 Hour Mean Discharge (ML/d) CP

422004 BARWON @ MOGIL MOGIL 141.00 12 Hour Mean Discharge (ML/d) CP

422003 BARWON @COLLARENEBRI141.00 12 Hour Mean Discharge (ML/d) CP

422025 BARWON @ TARA 141.00 12 Hour Mean Discharge (ML/d) CP

422001 BARWON @ DANGAR BDGE141.00 12 Hour Mean Discharge (ML/d) CP

422026 BARWON @ BOOROOMA 141.00 12 Hour Mean Discharge (ML/d) CP

422027 BARWON @ GEERA 141.00 12 Hour Mean Discharge (ML/d) CP

0200400600800

1000

0200400600800

1000

0200400600800

1000

0200400600800

1000

0200400600800

1000

0200400600800

1000

0200400600800

1000

0200400600800

1000

Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun


The above figures show the observed flows at river stations from Mungindi to Wilcannia since July

2018. The river system has been mostly dry since last year’s Northern Connectivity event apart from

some minor flows in the upper reaches. Geera also received some flow from Macquarie/Castlereagh

during April 2019. The Northern Fish flow event is progressing through the system and currently is at

Walgett. Inflows from the Warrego system also generated some flow and currently is at Wilcannia.


Period 12 Month 01/07/2018 to 01/07/2019 2018-19

422002 BARWON @ BREWARRINA 141.00 12 Hour Mean Discharge (ML/d) CP

422028 BARWON @ BEEMERY 141.00 12 Hour Mean Discharge (ML/d) CP

425039 DARLING@WARRAWEENA 141.00 12 Hour Mean Discharge (ML/d) CP

425003 DARLING@BOURKE TOWN 141.00 12 Hour Mean Discharge (ML/d) CP

425004 DARLING@LOUTH 141.00 12 Hour Mean Discharge (ML/d) CP

425900 DARLING@TILPA 141.00 12 Hour Mean Discharge (ML/d) CP

425008 DARLING@WILC. MAIN C 141.00 12 Hour Mean Discharge (ML/d) CP

0

200

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600

800

1000

0

200

400

600

800

1000

0

200

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600

800

1000

0

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0

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0

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1000



2.3 Recent salinity (EC)


Period 12 Month 01/07/2018 to 01/07/2019 2018-19416001 BARWON R @ MUNGINDI 2012.00 12 Hour Mean EC (uS/cm) CP

422003 BARWON @COLLARENEBRI2012.00 12 Hour Mean EC (uS/cm) CP

422001 BARWON @ DANGAR BDGE2012.00 12 Hour Mean EC (uS/cm) CP

422027 BARWON @ GEERA 2012.00 12 Hour Mean EC (uS/cm) CP

422002 BARWON @ BREWARRINA 2012.00 12 Hour Mean EC (uS/cm) CP

425003 DARLING@BOURKE TOWN2012.00 12 Hour Mean EC (uS/cm) CP

425004 DARLING@LOUTH 2012.00 12 Hour Mean EC (uS/cm) CP

425900 DARLING@TILPA 2012.00 12 Hour Mean EC (uS/cm) CP

425008 DARLING@WILC. MAIN C 2012.00 12 Hour Mean EC (uS/cm) CP

0

100200300

400

0100200

300400

0100200300400500

040008000

120001600020000

0100020003000400050006000

0

500

1000

1500

50300550800

10501300

100300500700900

1100

500900

1300170021002500



3. Current access arrangements

• Barwon-Darling management zone flow class map is available on the WaterNSW website with

real time data including management zones and flow classes for each licence category.

• Customers can check the WaterNSW web site to determine if access triggers have been met.

• Access conditions are outlined in the Barwon-Darling Unregulated Water Sharing Plan.

3.1 Access availability in 2018-19

The following table shows the access availability (in number of days) for each of the management

zones from 1 July 2018 to 24 June 2019 based on flow. A s324 Order has been in place since 17 April

2019 to protect the Northern connectivity flow. The 324 Order was extended on 8 May 2019 to Lake

Wetherell to allow the Warrego water to flow as far down the system as possible.

The observed flows would normally provide access but access is currently unavailable due to the 324

Order.

Few days of access was available in early July 2018 after previous s324 Order ended on 22 June 2018.

Those days are separately mentioned in the table.

https://www.waternsw.com.au/supply/regional-nsw/barwon-darling

https://www.waternsw.com.au/about/newsroom/2019/rain-extends-barwon-darling-temporary-pump-restriction


Management zone Gauging station Access availability (days)

A-Class B-Class C-Class

Mungindi to Boomi River

Confluence

416001 - 416050 0 0 0

Boomi River Confluence to U/S

Mogil Mogil Weir

416050-422004 0 0 0

Mogil Mogil Weir 422004 0 0 0

D/S Mogil Mogil to Collarenebri 422004-422003 0 0 0

Collarenebri to U/S Walgett

Weir

422003-422025 19* 0 0

Walgett Weir 422001 0 0 0

D/S Walgett to Boorooma 422001-422026 0 0 0

Geera to Brewarrina 422027-422002 0 0 0

Brewarrina to Culgoa River

Junction

422002-422028 0 0 0

Culgoa River Junction to Bourke 425039-425003 3** 0 0

Bourke to Louth 425003-425004 0 0 0

Louth to Tilpa 425004-425900 27**+3* 0 0

Tilpa to Wilcannia 425900-425008 0 0 0

Wilcannia to U/S Lake Wetherell 425008 9**+9* 0 0

* Access is restricted due to s324 order. Access is not available even though observed flows would

normally indicate access. Theses flows are from northern fish flow 2019 and Warrego inflows.

**Access was available in July 2018 after previous s324 order ended on 22 June 2018. Flows are

from Northern connectivity flow 2018 and local rainfall event near Bourke.


4. Rainfall

4.1 3-month rainfall

During the last 3-months, total rainfall has ranged from 25 to 200 mm which is below average to

above average compared to the historical rainfall. The lower part of the catchment received above

average rainfall during last three months.



During the last 12-months, total rainfall has ranged from 10 to 300 mm which is average to very much

below average and lowest on record for some places.



Rainfall over the last 24 months has ranged from 200 to 600mm, which is mostly below average to

very much below average compared to the historical rainfall and lowest on record for some places.


5. Current upstream storage status

5.1 Northern valleys storage status

This information was current as 3 June 2019.

The Barwon-Darling river system receives inflows from four NSW regulated river valleys; Border Rivers,

Gwydir, Namoi and Macquarie. In addition, it receives inflows from several Queensland catchments;

Weir, Moonie, Culgoa, Warrego and Paroo. The above figure shows the total volumes available in

Dams of all four NSW regulated valleys (stated as Northern Valleys). This includes Pindari, Glenlyon,

Copeton, Keepit, Split Rock, Chaffey, Burrendong and Windamere Dams.

390

Northern valleys storage status(GL)

Storage volume Airspace


5.2 Northern valleys storage breakdown

This information is based on Northern Valley resource assessments as at the end of May 2019.

The above figure shows the account balances of different license categories in the Northern valleys.

A total of 157 GL is available in General Security (GS) accounts – 104 GL is for irrigation and 53 GL is

for environment. About 60 GL of the GS irrigation volume in Macquarie valley is suspended due to

drought. Similarly, 32 GL of GS environmental water also quarantined for drought. A total of 27 GL is

available in High security, Stock and Domestic accounts and the combined account balance for

planned environmental water is 96 GL. About 59 GL of planned environmental water is also

quarantined in Macquarie valley. Other reserves such as storage loss, delivery loss, minimum releases

and replenishment flows are not included in this diagram.

6. Current operating condition

• Environmental releases from the Border and Gwydir plus inflows from the Warrego generated

flows in the Barwon-Darling after a long dry period.

• These events have provided flow connectivity between Mungindi and Walgett as well as from

the Warrego junction downstream of Bourke to Wilcannia

• Weir pool levels are expected to be replenished due to this flow event.

44

60

2132

27

59

37

Northern valleys storage breakdown

(GL)

GS - Irrigation GS - Irrigation Drought

GS -Env GS - Env Drought

HS, S&D Planned Environmental

Planned Environmental-Drought


• A small section downstream of Mogil Mogil to near Collarenebri where the Mehi River joins the

Barwon has not received the flows.

• Regular monitoring and gauging are done to measure the flows accurately.

7. Forecast flow condition

• The Barwon-Darling experiences significant transmission losses due to high evaporation and long

travel times. It is very difficult to accurately forecast downstream flows as local conditions can

vary significantly over the number of weeks it takes the water to travel along the river. In

addition, sections of the river have ceased to flow for an extended time and significant losses

will occur with wetting up the river bed along these sections and refilling of weir pools and

natural holes in the river. The below summarises the current forecast estimates of flows along the

system and timing of the flows reaching these sections. This information will be regularly updated

as the event progresses. This forecast is prepared on 24 June 2019.

River station Gauging station Observed volume

(ML)

Total forecast

volume – including

observed (ML)

Flow

arrival/expected

arrival date

Barwon at Mungindi 416001 1,199 1,200 -1,220 23 May 2019

Barwon upstream of

Presbury 416050 623 623 27 May 2019

Barwon at Mogil Mogil 422004 279 279 9 June 2019

Barwon at Collarenebri 422033 12,160 13,000-15,000 27 May 2019

Barwon at Tara

422025

8,635 10,000-12,000 5 June 2019

Barwon at Danger Bridge

(Walgett) 422001 4,795 6,000-8,000 12 June 2019

Barwon at Boorooma 422026 0 2,500-5,000 24-28 June 2019

Barwon at Geera 422027 0 2,000-4,000 26 – 30 June 2019

Barwon at Brewarrina 422002 0 0 -1,000 3 – 10 July 2019

Barwon at Bemeery 422028 0 0


Darling at Warraweena 425039 0* 0

Darling at Bourke 425003 0 0

Darling at Louth 425004 23,550 23,580 -23,700 29 April 20019

Darling at Tilpa 425900 14,510 14,600-15,000 13 May 2019

Darling at Wilcannia 425008 1,910 2,500-4,000 14 June 2019

Lake Wetherell 425020 0 0-1,000 25-30 June 2019

*Currently small flow exists. Inflow from Culgoa generated flow at Warraweena.

8. Rainfall outlook


More information

Subscribe to our customer information (weekly water availability reports, e-newsletters, etc.)

at waternsw.com.au/subscribe. For more information on algae alerts visit us at

waternsw.com.au/water-quality/algae or call us at 1800 999 457.

waternsw.com.au

Appendix A

Blue-green algae alert reports

http://www.waternsw.com.au/

Barwon Regional Algal Coordinating Committee (B-RACC) Blue-green Algae Report

Blue Green Algae Report for the Barwon Region

18th June 2019

This blue-green algal alert report is based on routine monitoring at sites in the Barwon Algae

Reporting Area. These sites are monitored by WaterNSW and local councils.

Summary These alert levels apply to non-consumptive or recreational contact. Drinking water safety

These alert levels apply to non-consumptive or recreational contact. Drinking water safety

thresholds are much more stringent.

Copeton Dam is on Red Alert. Algae concentrations are still decreasing, however another low

result at Wonulla is required to lift the Red Alert. A Green Alert is in place for the Gwydir River

below the storage indicating that the water below the storage remains safe for stock and

domestic use. However, water users should use caution. If blue-green algae are suspected or

scums become visible, water should be sourced from alternate supplies.

Macintyre River at Lake Inverell continues to be on Red Alert. Algae concentrations are

continuing to reduce, another red alert is required to lift he alert.

Macintyre River downstream of Lake Inverell has been on red Alert since January 2019. I am

please to report the Red Alert has finally be lifted and is now on Amber Alert. Water users

downstream of the township of Inverell should apply caution for stock and domestic uses.

Split Rock Dam is on Amber Alert. Manilla River downstream Split Rock is also on Amber Alert.

The dominant algae recorded is not known to be a toxin producer.

Keepit Dam is on Amber Alert. The species composition is non-toxic. The Namoi River downstream

Keepit is on Amber Alert. The dominant algae recorded here is also not known to be a toxin

producer.

Malpas Dam is on Amber Alert.

Boggabilla Weir is on Amber Alert. Stock and domestic users should be on the lookout for algae

scums, stock users should consider the use of alternate water supplies for stock watering.

Narrabri Creek at Narrabri is on Amber Alert.

Pindari Dam is on a Green Alert and there is also a Green Alert in place for the Severn River below

the storage indicating that the water below the storage remains safe for stock and domestic use.

If blue-green algae are suspected or scums become visible, water should be sourced from

alternate water supplies.

Chaffey Dam remains clear of any alerts.

Results Table

Note: * indicates that sampling results show algal numbers have reduced however another low

sampling result is required to reduce the alert to a lower level.

Site Description Latest

Sample Date

Toxic BGA

Biovolume

(mm3/L)

BGA

Biovolume

(mm3/L)

Current

Status

(based on

Latest

Sample)

Previous

Status

BGA Dominant

Toxic Taxa

Comments

Chaffey Downstream

12-June-2019 0.00 0.00 No Alert Amber

Chaffey Dam Station 2 (Mid storage)

04-Jun-2019 0.00 0.00 No Alert No

Alert

.

Chaffey Dam Station 1 (Aerator)

04-Jun-2019 0.00 0.00 No Alert No Alert

Copeton Dam Kiosk

11-June-2019 0.42 0.49 Amber Amber Dolichospermum - sp. Potentially toxic, taste

& odour

Copeton Dam Northern Foreshore

11-June-2019 0.24 0.30 Green Red

Copeton Dam Station 1 (Dam Wall)

11-June-2019 0.24 0.25 Green Green

Copeton Dam Wonulla

11-June-2019 0.99 1.12 Red * Red Dolichospermum - sp. Potentially toxic, taste

& odour

Copeton Downstream (Gwydir River)


.

Keepit Dam Station 1 (Dam Wall)


Keepit Recreation Area

11-June-2019 0.00 0.59 Amber Amber Non-toxic dominant sp.

Keepit Downstream (Namoi River)

11-June-2019 0.00 0.68 Amber Amber Non-toxic dominant sp.

Pindari Dam Station 1 (Dam Wall)

11-June-2019 0.00 0.00 No Alert Red

Pindari Dam Station 2/3

11-June-2019 0.15 0.15

Green Red

Pindari Dam Station Boat Ramp

---- -- --

-- --- site no longer suitable

for algae sampling

Pindari Downstream (Severn River)


Split Rock Downstream (Manilla River)

11-June-2019 0.00 1.41 Amber Amber

Non-toxic Dominant sp.


Split Rock Dam Station 1 (Dam Wall)

11-June-2019 0.00 0.90 Amber Amber

Non-toxic Dominant sp.

Split Rock Recreation Area

11-June-2019 0.02 1.90 Amber Amber Non-toxic Dominant sp.

Macintyre River at Lake Inverell

06-Jun-2019 2.67 3.85 Red * Red Microcystis - Unknown

Potentially toxic, taste & odour

Macintyre River at Inverell (Middle Ck)

06-Jun-2019 1.37 1.41 Amber Red Microcystis – Unknown


Macintyre River at Boggabilla Weir

16-May-2019 1.64 2.18 Amber No

Alert Nostocaceae - sp.


Narrabri Creek at Narrabri

20-May-2019 0.00 0.00 No Alert No

Alert

Barwon River at Mungindi

15-May-2019 0.00 0.01 No Alert No

Alert

Namoi River at Walgett

-- --- --- --- --- Dry

Malpas Dam 14-May-2019 --- 0.09 Amber * Amber

Note: * indicates that sampling results show algal numbers have reduced however another low

sampling result is required to reduce the alert to a lower level.

Alert Definitions for Recreational Waters

Alert Definitions as specified in The National Health and Medical Research Council (NHMRC)

Guidelines for Managing Risks in Recreational Water 2008.

The use of these guidelines is endorsed by the Scientific Subcommittee of the NSW Algal Advisory

Group.

RED ALERT

These alert levels represent 'bloom' conditions. Water will appear green or discoloured and clumps

or scums could be visible. It can also give off a strong musty or organic odour.

Algae may be toxic to humans and animals. Contact with or use of water from red alert areas

should be avoided due to the risk of eye and skin irritation. Drinking untreated or boiled water from

these supplies can cause stomach upsets. Alternative water supplies should be sought or activated

carbon treatment employed to remove toxins. People should not fish when an algal scum is present.

Owners should keep dogs away from high alert areas and provide alternative watering points for

stock.

AMBER ALERT

Blue-green algae may be multiplying and the water may have a green tinge and musty or organic

taste and odour. The water should be considered as unsuitable for potable use and alternative

supplies or prior treatment of raw water for domestic purposes should be considered. The water may

also be unsuitable for stock watering. Generally suitable for water sports, however people are

advised to exercise caution in these areas, as blue-green algal concentrations can rise to red alert

levels quickly under warm, calm weather conditions. GREEN ALERT

Blue-green algae occur naturally at low numbers. At these concentrations, algae would not

normally be visible, however some species may affect taste and odour of water even at

low numbers and does not pose any problems for recreational, stock or household use.

Table 2: Key to Alerts For Recreational Waters

RED Alert ≥ 50 000 cells/mL toxic M. aeruginosa

OR

biovolume equivalent of ≥4 mm3/L for the

combined total of all cyanobacteria where a

known toxin producer is dominant

OR

The total biovolume of all cyanobacteria

exceeds 10 mm3/L

OR

Cyanobacterial blooms are consistently

present

• High levels of Blue Green Algae detected

• Indicates “bloom” conditions

• Toxicity should be presumed

• Water will appear green or brownish and may

have a strong musty taste and odour

• Surface scums could occur

Extreme care should be exercised, and contact with the water should be avoided

Action

• Issue Media Release

• Water supply authorities to increase filtering with

activated carbon as appropriate

Local authority and health authorities to warn the public

that the water body is considered to be unsuitable for

primary contact recreation


AMBER Alert ≥5000 to <50 000 cells/mL M. aeruginosa

OR

biovolume equivalent of ≥ 0.4 to < 4 mm3/L

for the combined total of all cyanobacteria

• Indicates blue-green algae are multiplying

• Water may have a green tinge and musty taste

and odour

Action

• Water supply authorities to consider filtering with

activated carbon

Investigations into the causes of the elevated levels and

increased sampling to enable the risks to recreational users

to be more accurately assessed.

GREEN Alert > 500 to < 5000 cells/mL M. aeruginosa

OR

biovolume equivalent of > 0.04 to < 0.4

mm3/L for the combined total of all

cyanobacteria

• Low levels of potentially toxic species detected – suggesting base crop of blue green algae may be on the increase

Action

Continue/increase routine sampling to measure

cyanobacterial levels

Livestock Drinking Water Guidelines Based on ARMCANZ (2000), Orr and Schneider

(2006) and WQRA (2010)

This guideline should be used when water is used for livestock drinking water purposes.

• If visual scums are present, then a High alert should be declared. This would be applicable for

both farm dams and publicly managed water bodies (streams, rivers, etc). Such advice should

also be given to farmers who phone the department seeking information on managing blooms

in their dams.

• Where blooms dominated by Microcystis aeruginosa are present, then the ANZECC/ARMCANZ

(2000) guideline of 11,500 cells/mL should be used. Excess of this cell count will constitute a High

alert.

• Where blooms dominated by Dolichospermum circinale are present, then the Orr and Schneider


alert.

• Blooms of blue-green algae other than M. aeruginosa and D. circinale are also common in NSW.

These can be of either known potentially toxic species, or of species not considered to be toxin

producers. When these blooms are present, a total blue-green algal biovolume in excess of 6

mm3/L will constitute a High alert. (These are based on Very High alert recommendations for raw

water sourced for potable human supply published by WQRA (2010), in lieu of there being

nothing else available).

Further Information and Contacts Go to the WaterNSW Algal Website http://www.waternsw.com.au/water-quality/algae

Call NSW algae hotline 1800 999 457

Contacts Tracy Fulford (Barwon RACC coordinator)

[email protected]

Telephone: 02 6763 3910

http://www.waternsw.com.au/water-quality/algae

mailto:[email protected]

Far West - Algal Coordinating Committee (FW-RACC)

Blue-green Algae Report

Algae Alerts for the Far West Region

18th June 2019

The Far West Blue-Green Algal Reports are based on samples collected by various councils; Moree

Plains, Walgett, Brewarrina, Bourke and Central Darling Shire Councils and WaterNSW.

Summary

Recent river flows entering the Darling River system from the Warrego River has provided much needed

relief to the Darling River system below Bourke, resulting in the lifting of the Amber Alert at Tilpa. Water users

should apply caution with water from the first flush as this water has a concentrated front of algae that has

been pushed from existing waterholes. The level of toxicity of this water remains uncertain.

Bogan River at Gongolgon is on Red Alert. Algae numbers have reduced, another low result is needed to

lift the Red Alert. It is recommended that this water not be used for stock watering and that stock access

be restricted to the river. Domestic water users sourcing water from Bogan River should seek alternate

water supplies.

The Darling River at Wilcannia is on Red Alert. Algae numbers have reduced, another low result is needed

to lift the Red Alert. It is recommended that this water not be used for stock watering and that stock access

be restricted to the river. Domestic water users sourcing water from the section of the river should seek

alternate water supplies.

Barwon River at Collarenebri is on Amber Alert.

Note: Due to the dual reticulated water systems (water pumped directly from the river to the garden tap) in

the townships of the Far West, residents where there are red alert in place are strongly urged to find

alternate water supplies for their pets and to avoid letting children play with the water from garden taps.

The water should be suitable for garden purposes, however avoid spraying the water directly onto editable

fruits.

Areas of low flows, standing water holes and weir pools may become an ideal environment for algae

production. Stock owners and managers should be vigilant and be on the lookout for signs of algae scums.

Due to the expanse of the Darling River, there are many areas for which we do not have BGA results.

Therefore, water users should treat the Barwon - Darling River with caution, especially when conditions for

algal growth are favourable such as low river flows combined with persistent hot and sunny weather

conditions. Use the closest sites that have results as a guide to your location of interest.

These alert levels apply to non-human consumptive or recreational contact and stock alert

warnings. Drinking water safety thresholds are much more stringent.

Results Table

Note:

• New results are shown in bold.

• * indicates that sampling results show that algal numbers have reduced, however another low

sampling result is required to reduce the alert status to a lower level.

Site Description Latest Sample Date

Toxic BGA Biovolume (mm3/L)

BGA Biovolume (mm3/L)

Current Status (based on Latest Sample)

Previous

Status BGA Dominant

Toxic Taxa Comments and River Flows (ML/day)

Namoi River at

Walgett --- --- -- No Alert Flow: 0

Barwon River at

Mungindi 15-May-2019 0.00 0.01 No Alert No Alert Flow: 31

Barwon River at

Collarenebri 15-May-2019 0.00 0.44 Amber Green

Flow: 428

Barwon River at

Walgett

Dangar Bridge

--- --- --- No Alert No Alert

Flow: 0

Barwon River at

Brewarrina 28-May-2019 0.00 0.03 No Alert Amber

Flow: 0

Bogan River at

Gongolgon 30-May-2019 0.00 0.48 Red * Red Flow: 0

Algae reducing.

Darling River at

Bourke/

Boat Ramp

29-May-2019 0.00 0.01 No Alert Amber

Flow: 0

Darling River at

Bourke Weir ---- -- -- ----

Darling River at

‘Rose Isle’ ---- -- -- ---- Red

Darling River at

Louth 29-May-2019 0.00 0.00 No Alert Green

Flow: 440

Darling River at

Tilpa (Tilpa Weir) --- --- --- --- Amber

Flow: 452

Darling River at

‘Trevallyn’ ---- --- --- ---- Red

Darling River at

Wilcannia 16-May-2019 0.48 1.25 Red * Red

Nostocaceae -

sp. Flow: 0

Darling River at

‘Caulpaulin’ ---- --- --- ---- Red

Note: * indicates that sampling results show that algal numbers have reduced, however another low

sampling result is required to reduce the alert status to a lower level.

Alert Definitions for Recreational Waters Alert Definitions as specified in The National Health and Medical Research Council (NHMRC)

Guidelines for Managing Risks in Recreational Water 2008.

The use of these guidelines is endorsed by the Scientific Subcommittee of the NSW Algal Advisory

Group.

RED ALERT

These alert levels represent 'bloom' conditions. Water will appear green or discoloured and clumps or

scums could be visible. It can also give off a strong musty or organic odour.

Algae may be toxic to humans and animals. Contact with or use of water from red alert areas

should be avoided due to the risk of eye and skin irritation. Drinking untreated or boiled water from

these supplies can cause stomach upsets. Alternative water supplies should be sought or activated

carbon treatment employed to remove toxins. People should not fish when an algal scum is present.

Owners should keep dogs away from high alert areas and provide alternative watering points for

stock.

AMBER ALERT Blue-green algae may be multiplying and the water may have a green tinge and musty or organic

taste and odour. The water should be considered as unsuitable for potable use and alternative

supplies or prior treatment of raw water for domestic purposes should be considered. The water may

also be unsuitable for stock watering. Generally suitable for water sports, however people are

advised to exercise caution in these areas, as blue-green algal concentrations can rise to red alert

levels quickly under warm, calm weather conditions.

GREEN ALERT

Blue-green algae occur naturally at low numbers. At these concentrations, algae would not

normally be visible, however some species may affect taste and odour of water even at low

numbers and does not pose any problems for recreational, stock or household use.

Table 2: Key to Alerts For Recreational Waters

RED Alert ≥ 50 000 cells/mL toxic M. aeruginosa

OR

biovolume equivalent of ≥4 mm3/L for the

combined total of all cyanobacteria where a

known toxin producer is dominant

OR

The total biovolume of all cyanobacteria

exceeds 10 mm3/L

OR

Cyanobacterial blooms are consistently

present

• High levels of Blue Green Algae detected

• Indicates “bloom” conditions

• Toxicity should be presumed

• Water will appear green or brownish and may

have a strong musty taste and odour

• Surface scums could occur

Extreme care should be exercised, and contact with the water should be avoided

Action

• Issue Media Release

• Water supply authorities to increase filtering with

activated carbon as appropriate

Local authority and health authorities to warn the

public that the water body is considered to be

unsuitable for primary contact recreation

AMBER Alert ≥5000 to <50 000 cells/mL M. aeruginosa

OR

biovolume equivalent of ≥ 0.4 to < 4 mm3/L for

the combined total of all cyanobacteria

• Indicates blue-green algae are multiplying

• Water may have a green tinge and musty taste

and odour

Action

• Water supply authorities to consider filtering with

activated carbon

Investigations into the causes of the elevated levels

and increased sampling to enable the risks to

recreational users to be more accurately assessed.

GREEN Alert > 500 to < 5000 cells/mL M. aeruginosa OR

biovolume equivalent of > 0.04 to < 0.4 mm3/L

for the combined total of all cyanobacteria

• Low levels of potentially toxic species detected – suggesting base crop of blue green algae may be

on the increase Action

Continue/increase routine sampling to measure

cyanobacterial levels

Livestock Drinking Water Guidelines Based on ARMCANZ (2000), Orr and Schneider

(2006) and WQRA (2010) This guideline should be used when water is used for livestock drinking water purposes.

• If visual scums are present, then a High alert should be declared. This would be applicable for

both farm dams and publicly managed water bodies (streams, rivers, etc). Such advice should

also be given to farmers who phone the department seeking information on managing blooms

in their dams.

• Where blooms dominated by Microcystis aeruginosa are present, then the ANZECC/ARMCANZ


alert.

• Where blooms dominated by Dolichospermum circinale are present, then the Orr and Schneider


alert.

• Blooms of blue-green algae other than M. aeruginosa and D. circinale are also common in NSW.

These can be of either known potentially toxic species, or of species not considered to be toxin

producers. When these blooms are present, a total blue-green algal biovolume in excess of 6

mm3/L will constitute a High alert. (These are based on Very High alert recommendations for raw

water sourced for potable human supply published by WQRA (2010), in lieu of there being

nothing else available).

Further Information and Contacts Go to the WaterNSW Algal Website

http://www.waternsw.com.au/water-quality/algae Call NSW algae hotline 1800 999 457

Contacts Tracy Fulford (Far West RACC Coordinator)

[email protected]

Telephone: 02 6763 3910





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