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
Barwon-Darling Operations Plan June 2019 3
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.
Barwon-Darling Operations Plan June 2019 4
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
Barwon-Darling Operations Plan June 2019 5
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
Barwon-Darling Operations Plan June 2019 6
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.
WaterNSW HYPLOT V133 Output 25/06/2019
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
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
0
200
400
600
800
1000
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Barwon-Darling Operations Plan June 2019 7
2.3 Recent salinity (EC)
WaterNSW HYPLOT V133 Output 19/06/2019
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
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Barwon-Darling Operations Plan June 2019 8
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.
Barwon-Darling Operations Plan June 2019 9
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.
Barwon-Darling Operations Plan June 2019 10
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.
Barwon-Darling Operations Plan June 2019 11
4.2 12-month rainfall
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.
Barwon-Darling Operations Plan June 2019 12
4.3 24-month rainfall
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.
Barwon-Darling Operations Plan June 2019 13
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
Barwon-Darling Operations Plan June 2019 14
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
Barwon-Darling Operations Plan June 2019 15
• 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
Barwon-Darling Operations Plan June 2019 16
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
Barwon-Darling Operations Plan June 2019 17
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.
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)
11-June-2019 0.20 0.30 Green Green
.
Keepit Dam Station 1 (Dam Wall)
11-June-2019 0.00 0.06 Green Green
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)
11-June-2019 0.04 0.05 Green Green
Split Rock Downstream (Manilla River)
11-June-2019 0.00 1.41 Amber Amber
Non-toxic Dominant sp.
Barwon Regional Algal Coordinating Committee (B-RACC) Blue-green Algae Report
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
Potentially toxic, taste & odour
Macintyre River at Boggabilla Weir
16-May-2019 1.64 2.18 Amber No
Alert Nostocaceae - sp.
Potentially toxic, taste & odour
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
Barwon Regional Algal Coordinating Committee (B-RACC) Blue-green Algae Report
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
(2006) guideline of 25,000 cells/mL should be used. Excess of this cell count will constitute a High
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)
Telephone: 02 6763 3910
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
(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
(2006) guideline of 25,000 cells/mL should be used. Excess of this cell count will constitute a High
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)
Telephone: 02 6763 3910