1

•

Regional

water availability

report Weekly edition

5 October 2020

Water availability weekly report 2

Contents

1. Overview ................................................................................................................................................. 3

2. System risks ............................................................................................................................................. 3

3. Climatic Conditions ............................................................................................................................... 4

4. Southern valley based operational activities ..................................................................................... 6

4.1 Murray valley .................................................................................................................................................... 6

4.2 Lower Darling valley ........................................................................................................................................ 8

4.3 Murrumbidgee valley ...................................................................................................................................... 9

5. Central valley based operational activities ..................................................................................... 12

5.1 Lachlan valley ................................................................................................................................................ 12

5.2 Macquarie valley ........................................................................................................................................... 15

6. Northern valley based operational activities ................................................................................... 17

6.1 Namoi valley ................................................................................................................................................... 17

6.2 Gwydir valley .................................................................................................................................................. 19

6.3 Border rivers ..................................................................................................................................................... 20

6.4 Barwon-Darling River system ........................................................................................................................ 21

7. Coastal valley based operational activities ..................................................................................... 23

7.1 Bega river ........................................................................................................................................................ 23

7.2 Hunter valley ................................................................................................................................................... 24

7.3 Toonumbar Dam ............................................................................................................................................ 26

8. Rural Dam Levels .................................................................................................................................. 27

9. More Information…………………………………………………………………………………………… ... 28

Water availability weekly report 3

1. Overview

WaterNSW manages and operates 42 dams and storages to deliver water for environmental,

domestic, town water, stock, industrial and irrigation purposes across the state. WaterNSW storages

provide supplies to all the major river systems in Western NSW, Greater Sydney, the Southern

Highlands, Shoalhaven Bay as well as the Hunter, Bega, and Iron Pot valleys in coastal NSW.

The total active storage percentage of rural water supplies on 5 October 2020 was 50.9 percent of

the total active storage capacity. This was an increase of 0.5 percent since last week.

The total storage level of urban water supplies on 5 October 2020 was 94.3 percent of the total

storage capacity. This was a decrease of 0.2 percent since last week.

2. System risks

WaterNSW is working with BOM in assessing the likelihood of filling storages, with the positive

seasonal rainfall forecasts, particularly for Burrinjuck Dam, and preparing for pre-releases and flood

operations. All floodplain landholders are recommended to review their flood operations plans and

be aware of any notifications from BoM and SES.

Any floods and floodplain flows that occur in the coming months may also trigger poor water

quality, particularly low dissolved oxygen for fish, as floodwaters may pick up significant amounts of

accumulated leaf litter.

Rainfall along the southern and central west slopes and ranges over recent months has maintained

stream flows and inflows to the dams in the Murray, Murrumbidgee, Lachlan and Macquarie

valleys. Operational plans are being reviewed as these inflows accumulate.

Water availability weekly report 4

3. Climatic Conditions

Figure 1 - Weekly rainfall totals

A strong high-pressure system over the Tasman Sea is maintaining a ridge towards northeast New

South Wales, while a slow-moving cold front and trough lie over the far southwest. This front is

bringing cooler conditions and some rain to the southern and western inland today and on

Tuesday. On Wednesday, the trough will deepen over inland New South Wales and then shift

southeast on Thursday, bringing unsettled weather to most areas. For the first part of the week, most

parts of NSW are predicted to receive rainfall of 10 – 50mm apart from the north east of the state

which is forecast to remain dry. As the week progresses, the majority of the state is forecast to

remain largely dry with negligible rainfall predicted for the coastal fringes.

Figure 2a – First 4-day forecast (5 - 8 October 2020) Figure 2b – Following 4-day forecast (9 – 12 October 2020)

Water availability weekly report 5

Climate outlook overview

Issued 1 October 2020

Wetter September to November for much of NSW

• The fortnight of 5 September 2020 to 18 October 2020 is likely to be wetter than average for

much of NSW.

• The outlook for October 2020 to December 2020 indicates a wetter than average three-month

period for western NSW (a greater than 75 - 80 percent chance).

Figure 3 – 3-month rainfall outlook

A La Niña ALERT remains.

The ENSO Outlook has been moved to LA NIÑA.

All key indicators of the El Niño–Southern Oscillation have now reached or exceed La Niña

thresholds. Central and eastern tropical Pacific Ocean sea surface temperatures meet La

Niña thresholds. Atmospheric indicators including the Southern Oscillation Index (SOI), trade wind

strength, and equatorial cloudiness are also at La Niña values. The latest 90-day

SOI ending 27 September was +8.1.

All climate models surveyed by the Bureau indicate further cooling is likely, and that La Niña

thresholds will likely be sustained at least into January 2021.

Bureau climatologists will continue to closely monitor model outlooks and conditions in the tropical

Pacific for further changes to this La Niña event.

Water availability weekly report 6

4. 4Southern valley based operational activities

4.1 Murray Valley

Storage and release status

• Hume Dam is currently at 68 percent of active capacity and at

regulated/environmental releases of about 2,700 ML/d. The release

varies in response to rain forecast this week and subsequent environmental demands

subject to downstream tributary inflows.

• Release downstream of Yarrawonga Weir is at approximately 8,500 ML/d and is likely to

increase to channel capacity by early next week, if Kiewa and Owens river catchments

receive the rain forecast in the next couple of days.

• The Edward River offtake flow (1,200 ML/d) varies in line with Murray River water levels.

• The Gulpa Creek offtake flow (350 ML/d) will remain steady until third week of October and

then will ramp up to target 700 ML/day to deliver environmental flow to Gulpa Creek

wetlands.

• Stevens Weir level is at approximately 4.5 m and is likely to vary marginally. The water level

upstream of Wakool Canal offtake is at approximately 1.74 m.

• Flow downstream of Stevens Weir is approximately 1,080 ML/d and is likely to reduce

gradually to about 600 ML/day for the next two weeks.

• Flows into Colligen Creek (195 ML/d), Yallakool Creek (210 ML/d) and Wakool River (30 ML)

will continue to be relatively steady, until the environmental water deliveries commence by

mid-October.

• Flow in Niemur River at Mallan School is currently at approximately 120 ML/d and the flow is

likely to remain relatively steady over the week.

• Merran Creek flows upstream of its confluence with Wakool at approximately 110 ML/d and

the flow is likely to vary marginally.

• Flow in Wakool River at Stoney Crossing is currently at approximately 430 ML/d and is likely to

marginally decrease to about 410 ML/d over the week.

• Flow at Balranald is currently at approximately 1,160 ML/d and will gradually decrease to

meet the October 2020 end of system target flow of 1,030 ML/d.

• Lake Victoria is currently holding approximately 650 GL or 95 percent of active capacity.

The flow to South Australia is at approximately 10,600 ML/d.

Environmental water operations

• Plans to commence eWater spring flow delivery into Wakool-Yallakool system and into the

Colligen-Niemur system have been proposed to fit in with the proposed Murray watering

event, the dates of which are not yet finalised.

Water availability weekly report 7

• eWater delivery to Gulpa Creek wetlands has commenced this week. The flows will

gradually ramp up from the current 350 ML/day to a maximum of 700 ML/day by third week

of October 2020. The event is targeting water birds, specifically Australasian Bittern.

Water availability

• The Water Allocation Statement (WAS) by the NSW Department of Planning, Industry and

Environment (DPIE) (dated 1 October 2020) confirmed that in the NSW Murray Valley Local

Water Utility (LWU) and Domestic and Stock (D&S) allocation are at 100 percent. High

Security (HS) allocation is at 97 percent. There is a two percent increase to all General

Security (GS) entitlements with a commensurate increase in the Conveyance entitlement in

the NSW Murray Regulated River water source. As such, the total allocation for 2019-20 is

brought to 17 percent, with an average GS carryover of 21 percent, this means the NSW

Murray total GS water availability has reached 38 percent of entitlement.

Drought operation measures

• The NSW Murray Regulated River water source remains at Drought Stage 1, meaning all

allocated water can now be delivered under normal regulated river operations. Despite the

small improvements, drought conditions persist.

Water quality

• Potential Blue Green Algae issues:

o Recent Blue Green Algae (BGA) sampling at Lake Hume shows Lake Hume is on a Green

Alert Level. The sites at Heywoods and Ebden indicate an Amber Alert Level.

o For more information, please visit the Water Quality Algae section of the WaterNSW

website.

Planned supply interruptions:

• Maintenance activities are underway in the Stevens Weir gates and super structure under

the Coatings Program. However, the maintenance activities are not expected to impact

normal river operations or weir levels.

Water availability weekly report 8

4.2 Lower Darling valley

Storage and release status

• The Menindee Lakes system collectively holds approximately 467 GL of

total volume of water (or 26.5 percent of active capacity) and is

releasing approximately 420 ML/d.

• The status of individual lakes are as follows: Lake Wetherell – 68 percent, Tandure – 84

percent and Lake Pamamaroo – 119 percent, Copi Hollow – 133 percent, while Lakes

Menindee and Cawndilla remain dry.

• Transfer of additional inflows arriving at Lake Wetherell to Lake Pamamaroo is likely to cease

this week, the levels have now equalised and in closing Lake Pamamaroo inlet we can

maximise caputured storage capacity. The action has been taken to minimise lake

evaporation (Lake Pamamaroo has relatively smaller surface area and greater mean

depth).

Environmental water operations

• The Water Sharing Plan minimum flows for the months of May 2020 to October 2020 is 200

ML/d measured at Weir-32. An additional 200 ML/d is being delivered at Weir-32 as ordered

by the environmental water holder until the end of October 2020.

Water availability

• To date the current inflows have not resulted in the total storage volume reaching 640 GL

and are currently not forecast to reach this trigger in the next few months. As such, the

storage remains in NSW control and the resources shall be managed for Lower Darling

operations.

• The WAS by DPIE (dated 1 October 2020) confirmed that all high priority entitlements have

received a full allocation including all LWU, D&S and HS licences, in accordance with the

Water Sharing Plan. GS allocation remains at 30 percent. Carryover of approximately 48

percent is fully available.

Drought operation measures

• The Lower Darling Regulated River water source is assessed to be in Drought Stage 2.

Water quality

• A Green Alert Level has been assessed for Lake Wetherell (Site 1, 2, 3 and 4), Copi Hollow

(Site N1094), Wilcannia (N1042), Darling River at Weir 32 (N1086), Darling River u/s of Weir 32

(Site N1171 and Daring River Pumping Station at Menindee (N1095).

• For more information visit the Water Quality Algae section of the WaterNSW website.

Planned supply interruptions:

Nil.

Water availability weekly report 9

4.3 Murrumbidgee valley

Storage and release status

• Burrinjuck Dam is currently at 79 percent of active capacity, releasing

approximately 4,900 ML/d to meet the system demands for irrigation

and environmental orders. To meet the increasing system demands the release is expected

to vary between 4,000 and 5,000 ML/d over the week.

• Blowering Dam is currently at 80 percent of active capacity releasing approximately 2,500

ML/d to meet the system demands. The releases are expected to vary in response to rainfall

forecast this week.

• The Beavers Creek offtake regulator gates are controlling flows and are aimed at achieving

an average flow of about 400 M/d at Kywong during the month of October 2020 as per the

work approval conditions.

• Berembed Weir is at full supply level (4.96 m) and will remain relatively steady. However, the

weir may be drawn down to 3.7 m, only if required to meet downstream system demands.

• Bundidgerry storage is currently at approximately 4.0 m and will vary over the week

depending on the diversions by Murrumbidgee Irrigation.

• Golgeldrie Weir is at approximately 6.00 m and will remain relatively steady. However, the

weir may be drawn down to 5.7 m, only if required to meet downstream system demands.

• The Tombullen storage (2.9 m) will be used to actively re-regulate any excess flows or rain

rejections and subsequently drawn down to meet downstream irrigation and environmental

demands as required.

• Hay Weir is at approximately 8.3 m. The water level is likely to vary within 300 mm/d over the

next few weeks as the weir is used for active re-regulation. The water stored in the Weir will

be used to meet downstream demands until the Weir level reaches 6.0 m before restoring

to 6.5 m, which is the operational target until the start of summer season.

• The water level at Maude Weir 5.9 m to deliver environmental water into the Nimmie Creek

(350 ML/d) and North Caira (1,100 ML/d). The weir level is likely to vary between 5.7 m and

5.9 m over the next few weeks.

• Currently, the Redbank Weir water level is at approximately 5.68 m. The Weir will remain

relatively steady over the next few weeks to deliver environmental water to assets in the

Lowbidgee area.

• Flow at Balranald is currently at approximately 1,160 ML/d and will gradually decrease to

meet the October 2020 end of system target flow of 1,030 ML/d.

• The current diversion into Yanco Creek is at between approximately 600 to 650 ML/d and

will remain relatively steady for the rest of the week. The flow into the Yanco arm below

Tarabah Weir will remain approximately 50 ML/d, while the split into the Colombo arm will

Water availability weekly report 10

be approximately 400 ML/d to supply water to increasing irrigation orders and to Forest

Creek for environmental flows.

Environmental water operations

• The Burrinjuck Dam Translucent Rules operate between 22 April 2020 and 21 October 2020.

These rules mean that a proportion of daily inflows are released, which means releases can

be larger when inflows are higher.

• Planned Environmental Water Flow Rules are fully complied with at both Balranald and

Darlot.

• A significant eWater delivery of approximately 68,200 ML (34,000 ML of Planned

Environmental Water, 28,000 ML of Held eWater and 6,200 ML of supplementary) over a

period of approximately 15 weeks commenced on 6 July 2020, via Yanga 1AS into

Lowbidgee.

• A second event to deliver approximately 10,800 ML (9,800 ML of Held eWater and 1,000 ML

of supplementary) through Waugorah 1ES, commenced on 23 July 2020 and will continue

at a rate of approximately 50 to 100 ML/d. The event is expected to run for more than 18-

weeks.

• A third event to deliver approximately 26,500 ML (10,000 ML of Planned Environmental

Water, 12,500 ML of Held eWater and 4,000 ML of supplementary flows) commenced on 28

July 2020 at the Nimmie Creek offtake. The event will continue for ten weeks.

• A fourth event to deliver approximately 31,000 ML (9,500 ML of Planned Environmental

Water, 17,500 ML of Held eWater and 4,000 ML of supplementary flows) commenced on 17

August 2020 to Lowbidgee assets via North Redbank Channel.

• A fifth event to deliver approximately 5,800 ML (800 ML of supplementary flows and 5,000 ML

of Planned Environmental Water) commenced on 31 August 2020 at the Warriston Weir in

the Forest Creek.

• A sixth event to deliver 59,900 ML (45,000 ML of Planned Environmental Water, 6,500 ML of

Held eWater and 8,000 ML of supplementary flows) is being delivered to North Caira

channel since the end of August 2020.

• Total combined environmental water orders for the current events stand at approximately

206,000 ML including planned eWater, held eWater and supplementary (Lowbidgee

category).

Water availability

• For the Inter Valley Transfer (IVT) account from Murray to Murrumbidgee, please refer to the

Murrumbidgee IV Account Status section of WaterNSW website.

• The WAS by DPIE (dated 1 October 2020) confirmed that all high priority entitlements have

received full opening allocations as per the Valley’s Water Sharing Plan. This includes all

LWU, D & S and HS licences. GS licence holders have received an increase in allocation of

Water availability weekly report 11

two percent taking the total allocation to-date to 48 percent. Carryover is fully available

and estimated to be approximately 348 GL or 18 percent of GS entitlement on average.

Conveyance entitlements have received commensurate increase in allocations as per the

Water Sharing Plan.

Drought operation measures

• The Murrumbidgee Regulated River Water Source is at Drought Stage 1, meaning all

allocated water can now be delivered under normal regulated river operations. Despite the

small improvements, drought conditions persist.

Water quality

• Potential Blue Green Algae issues:

o Burrinjuck Dam at Station One (Dam Wall), Downstream, Burrinjuck Water State Park,

Woogarlo and Goodhope are at Green Alert Level. Blowering Dam is at Green Alert

Level.

o For more information please visit the Water Quality Algae section of the WaterNSW

website.

Unplanned supply interruptions:

• Nil

Planned supply interruptions:

• Painting of the Maude Weir Super Structure has started and will be completed by end of

November 2020. The Painting program for Gogeldrie started on 30 June 2020 and will

continue until mid-January 2021. However, the maintenance activity under the coating

program is not expected to impact normal River Operations and Weir levels.

Water availability weekly report 12

5. Central valley based operational activities

5.1 Lachlan valley

Storage and release status

• Carcoar Dam is currently at 30.8 percent of capacity and is releasing

approximately 2 ML/d.

• Wyangala Dam is currently at 61.1 percent of capacity and is releasing approximately 23

ML/d. Releases are forecast to remain at 20-30 ML/d for the rest of the week as downstream

tributary flows are meeting all demands.

• Lake Cargelligo is currently at approximately 67 percent of capacity and will remain steady

at approximately 67 percent for the rest of the week.

• Releases downstream of the Brewster Weir are around 1,550 ML/d. Releases are forecast to

vary between 1,300 -1,600 ML/d towards end of the week. Translucent flows have ceased

and the flows passing through Lake Brewster weir are now licenced environmental water

releases to provide a smooth recession at Booligal.

• Good tributary inflows have resulted from recent rain events. The delivery of S&D

replenishment flows have been delivered into Willandra Ck (stopped on 24 September

2020), Merrowie Ck (stopped on 26 September 2020), Merrimajeel and Muggabah ceased

on 6 October.

• The current Lake Brewster storage volume is 46.9 percent of capacity with a volume of

approximately 68,100 ML.

Environmental water operations

• Due to drought conditions last year, the end of system daily environmental flow

requirements in the Belubula River was suspended and were only met intermittently with

contribution from tributaries. However, due to rain and tributary inflows since February 2020,

flows past Helensholme are more than minimum required.

• Under the environmental water provisions of the Lachlan Water Sharing Plan, once 250 GL

of inflows are reached for the calendar year, translucent flow rules are triggered. With the

recent rain that commenced from the weekend of 8 - 9 August 2020 the translucent

condition was triggered and translucent water was delivered from Lake Brewster instead of

Wyangala Dam. Translucent environmental water delivery has now ceased and a total of

129 GL of translucent flows have been delivered at Brewster Weir between 21 August 2020

to 16 September 2020. For more information on trigger and delivery of translucent flow,

please visit the relevant section of the WaterNSW website.

• The rules require release of a portion of the inflows from each event as environmental water

to meet target flows below Lake Brewster.

Water availability weekly report 13

• Flows currently downstream of Lake Brewster are Licenced Environmental water releases

which are providing a smooth recession from translucent flows, which ceased 16 September

2020 and maintain steady flows at Booligal at around 1,200 ML/d.

Water Availability

• The DPIE WAS published on 4 September 2020, confirmed that an initial allocation of 28

percent has been made to GS licence holders.

• There has also been commensurate increase in Conveyance allocation, in accordance

with the Water Sharing Plan. In addition, all temporary water restrictions have been lifted,

enabling full access to GS water in accounts.

• In Belubula, GS water access licence holders have zero percent allocation but will have

access to account water that has been carried over from the previous Water Year (2019-

20).

• Water operations update for Belubula can be found at the Belubula operations section of

the WaterNSW website.

• Supplementary and Uncontrolled flows in Belubula are continued to be available for

access.

Water Quality

• The Latest BGA samples show that the Lake Cargelligo Boatshed, Lake Cargelligo Outlet

and Lake Cargelligo intake downstream of Curlew Water are on Green Alert Level.

However, Lake Cargelligo TWS is on Amber alert.

• The Wyangala Storage results (17 September 2020) show low productivity at all sites. Few

cyanobacteria were observed across the entirety of the lake. Assemblage is dominated by

flood and green alga. Downstream showed no cyanobacteria were detected. The storage

remains at Green Alert Level.

• The Lake Brewster sample results (8 September 2020) showed few cyanobacteria upstream

and within the system. Minor counts of cyanobacteria were noted at inflow, inflow wetland

and Willandra weir. Assemblage is mainly dominated by green alga. Lake Brewster remains

at Green Alert Level.

• Results from Lake Cargelligo 8 September 2020 show a very mixed assemblage across the

system. Productivity is generally low and cyanobacteria were only detected at a few sites in

the few sites in the system. A detection of Lyngby asp. Was noted at the town water supply,

whilst the cell count was low the biovolume/cell is large, hence the Amber Alert Level. Few

other cyanobacteria were detected. System is now on Amber Alert Level.

Water availability weekly report 14

Planned supply interruptions:

• Booberoi Ck desilting work is now finished and the flows are being diverted into the creek

from the offtake.

Water availability weekly report 15

5.2 Macquarie valley

Storage and release status

• Burrendong Dam is at 46.5 percent of active capacity and currently releasing

approximately 1,000 ML/d for translucent flows. Releases are forecast to remain

between 1,000 – 1,500 ML/d depending on the inflows to the dam and downstream.

• Windamere Dam is currently at 29.2 percent of active capacity (108 GL) and releasing 20

ML/d. Releases are forecast to stay at approximately 10 -15 ML/d during this week.

• The recent storms and isolated stream flows have delayed the second phase of the transfer

from Windamere to Burrendong. The transfer will leave a minimum of 70 GL in Windamere

Dam, which provides a very secure supply for local demand for the next five to seven years.

Environmental Water operations

• Environmental water in both active and translucent accounts is available.

• Translucent environmental water delivery from Burrendong Dam restarted from 31 August

2020 and is ongoing. The downstream tributary flows are receding.

• Planning has commenced for additional environmental releases of over 100 GL in October

2020 and November 2020 for native fish breeding and continued inundation of the

Macquarie Marshes.

• Translucent environmental water from Windamere Dam is deliverable all through the year

when inflows to the Dam meet the relevant triggers, subject to storage volume being more

than 110 GL.

Water availability

• The WAS published by DPIE on 8 September 2020 confirmed that an initial allocation of 12

percent AWD has been made to GS licence holders and Improved the Macquarie Drought

Stage from Drought Stage 2 to Drought Stage 1.

• LWU, S&D licences and HS allocations have 100 percent entitlement.

• The temporary water restriction on Macquarie GS and EWA water accounts is lifted.

• All HS licence categories received 100 percent allocation on 1July 2020.

• Trade from the Cudgegong Valley down to the Macquarie water source can resume in

accordance with the Water Sharing Plan.

• Given that GS water users have been prevented from accessing their water during the

drought, protection from account reductions due to evaporation or spills from Burrendong

Dam will be provided until the end of February 2021.

• Burrendong Dam gained approximately 69,000 ML in the month of September 2020.

Water availability weekly report 16

Drought operation measures

• Due to recent rainfall and inflows into the Dam and downstream of the Dam, the

Macquarie Regulated River Water Source has improved to Drought Stage 1.

• All S&D replenishments were completed from the recent rainfall events and contributions

from downstream tributaries.

Water quality

• Results for the 21st September show an increasing presence of Dolichospermum circinalis near

the Dam Wall. Few cyanobacteria were detected at any of the other upstream sites. No

cyanobacteria were detected downstream. Storage is now at Amber Alert Level.

• Results for 22 September 2020 show that the Microcystis sp. bloom has declined but remains

present. The storage continues to show moderate productivity but is now dominated by

Microcystis sp. at the Dam Wall and green alga mid-lake. Downstream results showed no

cyanobacteria present. Windamere Dam remains on Green Alert Level.

• Works to reinstate the temperature curtain at Burrendong Dam have been done. The

curtain is now operational and is currently 10 m below the surface, d/s temperatures are

being monitored.

Planned supply interruptions:

• Nil.

Water availability weekly report 17

6. Northern valley based operational activities

6.1 Namoi valley

Storage, release and inflow status

• Split Rock Dam is at 4.8 percent of active capacity and is currently

releasing 26 ML/d.

• Keepit Dam is at 25.8 percent of active capacity and releases have ceased.

• Chaffey Dam is at 26.1 percent of active capacity and is currently releasing 0 ML/d.

• The Pian Creek replenishment flow has been completed from flows below Keepit Dam.

• For regular updates, refer to the Operations Update section of WaterNSW website.

Environmental water operations

• There are no current orders for the release of environmental water in the Namoi Valley.

• Planned environmental releases of 3 ML/d from Chaffey Dam have recommenced as the

dam has risen above the 20 percent trigger in the Chaffey pipeline authorisation.

Water availability

• The WAS, published by DPIE (dated 6 August 2020) confirmed that in the Peel Valley LWU

and D&S allocation are 70 percent; HS and its sub-categories are 50 percent, and GS is zero

percent.

• Current resource deficit for current commitments in the Peel Valley is 10.6 GL

• The latest Water Allocation Statement, published by DPIE (dated 8 September 2020)

confirmed resource improvements high enough to warrant increase in allocations in the

Upper Namoi Valley: local water utility and D&S have 100 percent, while HS has received

additional 10 percent (100 percent total) allocation and the GS 50 percent allocation.

Approximately 39 percent of the GS has been carried over into 2020-21 Water Year.

• Lower Namoi local water utility and D&S have 100 percent while HS has received additional

10 percent (100 percent total) allocation and GS has received 4.2 percent. The restrictions

on access to carryover have been repealed and this volume is equivalent to approximately

6 percent of total GS share components.

Drought operation measures

• The Peel Valley is in Drought Stage 3, downgraded from 4. Commissioning of the Chaffey to

Dungowan pipeline is complete and operation of the pipeline commenced on 17 June

2020 and have now ceased as the dam is above 20 percent. Operational flow targets

below Chaffey will be for very low environmental flows of 3 ML/d.

• The Upper Namoi Valley is at Drought Stage 2. Releases recommenced on 30 March 2020

and will be used to supply water orders in the Manilla River from Split Rock Dam to the

Water availability weekly report 18

junction with the Namoi River. For customers located on the Namoi River (below Manilla),

water orders will be supplied (where possible) using the inflows from the Namoi Unregulated

River. Customers wishing to take water from their HS, GS or S&D licences are reminded to

place an order for their water.

• The Lower Namoi is at Drought Stage 3 under the Incident Response Guide.

• A block release survey and expressions of interest for potential supplementary access is

open until 4 October 2020. customer survey

Water quality

• Split Rock Dam is on a Green Alert Level in the storage.

• Keepit Dam is on an Amber Alert Level in the storage; and

• Chaffey Dam is on a Green Alert Level in the storage.

Planned supply interruptions:

• Mollee Fishway is currently unavailable due to infrastructure failure.

Water availability weekly report 19

6.2 Gwydir valley

Storage, release and inflow status

• Copeton Dam is at 16.3 percent of active capacity and is currently

releasing 21 ML/d.

Environmental water operations

• No environmental flow orders are currently in place.

Water availability

• The latest Water Allocation Statement published by DPIE -Water (dated 7 September 2020)

confirmed an increase of 3.07 per cent for general security water users in the Gwydir (in

total it is at 4.77 percent of the entitlement).

• Approximately 5 percent of the GS has been carried over the 2020-21 Water Year.

• LWU licence holders and D&S access licence holders have 100 percent entitlement and HS

licence holders have 100 percent.

Water quality

• Recent Blue Green Algae (BGA) sampling at Copeton shows Copeton on a Red Alert Level

in the storage.

Drought operation measures

• The Gwydir Valley is in Drought Stage 2. Management action will focus on ensuring water is

available for critical needs for as long as possible.

• However, deliverability will rely on downstream tributary contributions and infrequent block

releases. Please see the 1 July 2020 Operations Update for Gwydir Operations Update

section of the WaterNSW website.

• A block release survey and expressions of interest for potential supplementary access is

open until 4 October 2020. customer survey

Planned supply interruptions

• No supply interruptions are expected.

Water availability weekly report 20

6.3 Border rivers

Storage, release and inflow status

• Pindari Dam is at 16.8 percent of capacity. Currently releasing stimulus

flow.

• Glenlyon Dam is at 14.5 percent of capacity and releases have ceased.

• Boggabilla Weir is full from tributary inflows and currently passing all inflows.

• For regular updates, please refer to the Operations Update section of WaterNSW website.

Environmental Water operations

• Stimulus Flow release from Pindari Dam has started from 1 October 2020. Releases are

planned to peak at about 200 ML/d by 8 October 2020 and around 4,400ML is planned to

be released throughout October 2020.

Water availability

• The latest WAS, published by DPIE -Water (dated 21 August 2020) confirmed 6.9 percent

allocation for General Security A in the NSW Border Rivers regulated water source that totals

14.2 percent. No allocation to General Security B is possible until A receives a full (100

percent) allocation, in accordance with the Water Sharing Plan.

• There are no temporary water restrictions, but low storage levels mean deliverability of

account water is challenging and depends on drought operational measures and tributary

inflows.

• WaterNSW is planning for a block release for Border, Gwydir and Namoi regulated valleys

and initiated a survey for the customers to provide their water requirements for the season

ahead to manage water supplies efficiently. Details of the survey is available on the

operations update section of the WaterNSW website.

• All licence categories, except GS, have received full allocations.

Drought operation measures

• The Border River is in Drought Stage 2.

• A block release survey and expressions of interest for potential supplementary access have

been completed recently. customer survey

Water quality

• Recent Blue Green Algae (BGA) sampling at Pindari shows a Red Alert Level.

Planned supply interruptions:

• Pindari dam low level valve maintenance work has been completed.

Water availability weekly report 21

6.4 Barwon-Darling River system

River flow status

• The 2020 Northern Basin inflow event provided significant inflow to

the Barwon Darling system. Inflows arrived from the Border,

Moonie, Gwydir, Namoi, Culgoa, Bokhara, Castlereagh, Bogan and Warrego systems.

• The Barwon-Darling is now flowing from Mungindi to Wilcannia. Flow arrived at Lake

Wetherell on 10 March 2020 and contributed approximately 711 GL inflow at Wilcannia.

• Flows are receding and access availability is now “low flow” class for all the management

zones.

Environmental water operations

• Planned Environmental Water (PEW) is water in the system that is below the Commence to

Pump conditions for access licences.

Water Availability

• The latest WAS, published by DPIE -Water (dated 1 July 2020) confirmed 100 percent

allocation for all licence classes in the Barwon Darling Unregulated River water source.

• Flow has resumed between Mungindi and Wilcannia and access is allowed, as per licence

conditions, for customers for all management zones.

• According to the amended WAS, published 1 July 2020, flow class announcements will be

made every day when the flow class availability is A class or above. Please refer to the

WaterInsights Portal for recent flow class announcements.

Drought operation measures

• The Barwon Darling unregulated river water source is assessed to be in Drought Stage 2.

Water availability weekly report 22

WaterNSW HYPLOT V134 Output 07/10/2020

Period 10 Month 01/01/2020 to 01/11/2020 2020416001 BARWON R @ MUNGINDI 141.0012 Hour Mean Discharge (ML/d) CP

416050 BARWON U/S PRESBURY 141.0012 Hour Mean Discharge (ML/d) CP

422004 BARWON @ MOGIL MOGIL 141.0012 Hour Mean Discharge (ML/d) CP

422003 BARWON @COLLARENEBRI 141.0012 Hour Mean Discharge (ML/d) CP

422025 BARWON @ TARA 141.0012 Hour Mean Discharge (ML/d) CP

422001 BARWON @ DANGAR BDGE 141.0012 Hour Mean Discharge (ML/d) CP

422026 BARWON @ BOOROOMA 141.0012 Hour Mean Discharge (ML/d) CP

422027 BARWON @ GEERA 141.0012 Hour Mean Discharge (ML/d) CP

036007200

108001440018000

036007200

108001440018000

036007200

108001440018000

036007200

108001440018000

036007200

108001440018000

036007200

108001440018000

036007200

108001440018000

036007200

108001440018000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct

WaterNSW HYPLOT V134 Output 07/10/2020

Period 10 Month 01/01/2020 to 01/11/2020 2020

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

3600

7200

10800

14400

18000

0

3600

7200

10800

14400

18000

0

3600

7200

10800

14400

18000

0

3600

7200

10800

14400

18000

0

3600

7200

10800

14400

18000

0

3600

7200

10800

14400

18000

0

3600

7200

10800

14400

18000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct

Water availability weekly report 23

7. Coastal valley based operational activities

7.1 Bega river

Storage and release status

• Brogo Dam is at 100.4 percent of capacity and spilling.

Environmental water operations

• There are no current additional operations.

Water availability

• An AWD of 40 percent for GS, and 100 percent for all other licence categories was

announced on 1 July 2020.

• Access to Supplementary flows in river reach 1A and 1B has ceased. However, access to

Supplementary flows in river reach 1C and 2 continued to be available. Access to

Uncontrolled flows in all river sections continued to be available until further notice.

Drought operation measures

• The Bega/Brogo Regulated River water source is assessed to be in normal conditions now,

improved from Drought Stage 4 to Drought Stage 1.

• WaterNSW held an online River Operations Stakeholder Consultation Committee (ROSCCo)

meeting on 9 September 2020 and provided the operational updates to the group.

Water quality

• Recent BGA sampling at Brogo (8 September 2020) ) showed very low productivity across

the storage. No cyanobacteria were observed either upstream or downstream. The

assemblage is dominated by small counts of flood alga. Storage remains at Green Alert

level.

Planned supply interruptions

• Nil.

Water availability weekly report 24

7.2 Hunter valley

Storage and release status

• Glenbawn Dam is currently at 46 percent of capacity and releases

are around 70 ML/d. Releases are forecast to remain in steady, due to

increase in demand in the upper section of Hunter River. The demand in the lower sections

is largely met by downstream tributary flows.

• Glennies Creek Dam is at 39.1 percent of capacity and releases are currently averaging 20

ML/d. Releases are forecast to remain around 20 ML/d for rest of the week.

• Lostock Dam is at 100 percent of capacity and spilling.

Environmental Water operations

• Currently, all environmental flow targets are being met by the tributary flows.

Water availability

• The recent WAS published by DPIE confirms that HS and GS licence categories have

received allocation increase.

• GS licenses in the Hunter Valley received an additional 23 percent allocation on 1 August

2020, bringing the total AWD to 53 percent in this year. Carryover is equivalent to

approximately 23 percent of the total share component. HS licences received an additional

10 percent allocation bringing total AWD to 100 percent this year. All other categories

received 100 percent allocation.

• The EWA will be credited with 20 GL in accordance with the Water Sharing Plan.

• Paterson Valley allocations are at 100 percent for all licence categories.

Drought operation measures

• The Hunter Regulated River water source is assessed to be at Drought Stage 1 normal

operations.

Water quality

• Recent BGA sampling at Glenbawn Dam shows that the Microcystis sp presence is

continuing at all upstream sites with decreasing productivity. Downstream results showed no

cyanobacteria present. Storage is now at Amber Alert Level.

• Recent BGA sampling at Glennies Ck Dam show that productivity has rapidly declined at

the Dam wall but remains higher near the recreation area. This is likely due to sampling

coinciding with weather fronts coming through the area. No cyanobacteria were detected

at the Dam Wall however Dolichospermum circinale at amber alert levels was observed

upstream. A minor Microcystis sp. detection was recorded downstream. Storage remains at

amber alert.

Water availability weekly report 25

• Recent BGA results for Lostock dam shows the upstream assemblage is dominated by flood

alga. No cyanobacteria were observed. Downstream results showed a minor Microcystis sp.

detection. Storage remains at green alert.

• Planned supply interruptions:

• Nil

Water availability weekly report 26

7.3 Toonumbar Dam

Storage and release status

• Toonumbar Dam is at 65 percent of capacity and releasing approximately 12 ML/d. The

release is expected to remain in between 12-16 ML/d.

Environmental water operations

• No current additional operations.

Water availability

• All licence categories have 100 percent availability.

• WaterNSW held an online ROSCCo meeting on 24 June 2020 and advised the stakeholders

present of the current situation and future operations plan.

• Full allocations already announced for all entitlement holders in the 2020-21 Water Year.

Drought operation measures

• The Drought Stage level has eased from Drought Stage 2 to Drought Stage 1 with normal

operations resuming.

Water quality

• Recent results for Toonumbar shows that productivity is moderate across the storage. Minor

counts of Microcystis sp. were noted however the assemblage is dominated by flood alga.

A similar assemblage of cyanobacteria was observed downstream. The storage remains on

green alert.

Planned supply interruptions:

• Scheduled works to commence on 5 August 2020 for replacement of the 610” valve have

been cancelled, until further notice.

Water availability weekly report 27

8. Rural Dam Levels

The following table shows the status of water supplies at 5 October 2020.

River Valley Active

Capacity Current Status

Weekly

change

(GL)

Comments

Likely-

hood of

fill and

spill

Allocations for 2020/21

Storage Dam, Nearest Town (GL)

percent of

active

capacity

Active

(GL)

Weekly

Change

(GL)

Supply Issues High

Security

Gen.

Security

C’over

avail @

1/7/20

Border Rivers

Glenlyon Dam, Stanthorpe

(Qld) 253 14% 36 -0 Release ceased <20% 100% 1.2% 2%

Pindari Dam, Inverell 312 17% 52 -0 Stimulus releases <20% 100% 1.2% 2%

Gwydir Valley

Copeton Dam, Inverell 1346 16% 220 -0 Min release & some d/s tribs <5% 100% 4.77% 5%

Namoi Valley

Keepit Dam, Gunnedah 419 26% 108 1 Min release & good d/s tribs <20% 100% 4.2% 6%

Split Rock Dam, Manilla 394 5% 19 -0 Min release & good d/s tribs <5% 100% 50% 39%

Chaffey Dam, Tamworth 101 26% 26 0 Min release & good d/s tribs <50% 50% 0% N/A

Macquarie Valley

Burrendong Dam, Wellington 1154 47% 538 0

d/s trib flows reduced

translucent flow cont’d <40% 100% 12% 16%

Windamere Dam, Mudgee 367 29% 107 0 Low releases <5% 100% 12% 58%

Lachlan Valley

Wyangala Dam, Cowra 1217 61% 743 11

Min release. S&D

replenishment flows

complete;

<50% 100% 28% 6%

Carcoar Dam, Carcoar 36 31% 11 0

D/s trib flows, access to UCF

and Supp flows continues <10% 100% 0% 28%

Murrumbidgee Valley

Burrinjuck Dam, Yass 1025 79% 813 -7

Regulated releases

including eWater <25% 95% 48% 18%

Blowering Dam, Tumut 1604 80% 1284 38

Regulated releases

including eWater <10% 95% 48% 18%

Murray

Dartmouth, Mitta Mitta (Vic) 3837 55% 2122 16 WSP Plan min releases N/A N/A N/A N/A

Hume Dam, Albury 2982 68% 2030 39

Regulated releases

including eWater <25% 97% 17% 21%

Lower Darling

Menindee Lakes, Broken Hill 1633 26% 431 -0

Regulated releases

including eWater <30% 100% 30% 48%

Hunter Valley

Glenbawn Dam, Scone 750 46% 346 0

receding d/s tribs, supp &

UCF available in some

sections <20% 100% 53% 24%

Glennies Ck Dam, Singleton 282 39% 110 -0

Release to meet d/s

demand. <20% 100% 53% 24%

Lostock Dam, Gresford 20 100% 20 -0 spilling 100% 100% 100% N/A

Coastal Area

Toonumbar Dam, Kyogle 11 64% 7 -0 Regulated releases 100% 100% 100% N/A

Brogo Dam, Bega 9 100% 9 0

Spilling, access to Supp in

some sections ceased and

UCF continues in all sections 100% 100% 40% N/A

Total 17749 50.9% 9034 97

WaterNSW has water resources in Dartmouth, Hume and Glenlyon Dams. TWS = Town Water Supplies

Water availability weekly report 28

9. More Information

1 Gigalitre (GL) = 1,000 Megalitres (ML) 1 ML = 1,000,000 litres

More information

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

at waternsw.com.au/subscribe.