•

Regional

water availability

report

Weekly edition

28 September 2020

1

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 ...... 26

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

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

Water availability weekly report 2

1. Overview

WaterNSW manages and operates 42 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 , 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 28 September 2020 was 50.4 percent of the total active storage capacity. This was an increase of 0.7 percent since last week.

The total storage level of urban water supplies on 28 September 2020 was 94.5 percent of the total storage capacity. This was a decrease of 0.1 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 , 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 3

3. Climatic Conditions

Figure 1 - Weekly rainfall totals

A high-pressure system is situated over southeast Australia today, promoting generally benign weather in the region. By Tuesday the high is expected to be over the Tasman Sea, while a trough of low-pressure approaches from the west. This trough is forecast to bring a period of unsettled weather as it moves across the state mid-week. For the first part of the week, the majority of the state is forecast to receive negligible rainfall. As the week progresses, the state is forecast to remain largely dry with negligible rainfall predicted for the southern half.

Figure 2a – First 4-day forecast (28 September – 1 October 2020) Figure 2b – Following 4-day forecast (2 – 5 October 2020)

Water availability weekly report 4

Climate outlook overview

Issued 24 September 2020

Wetter September to November for much of NSW

• The fortnight of 28 September 2020 to 11 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 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 5

4. 4Southern valley based operational activities

4.1 Murray Valley

Storage and release status

• is currently at 67 percent of active capacity and at regulated releases of about 3,100 ML/d.

• Release downstream of Yarrawonga Weir is at approximately 8,500 ML/d and is likely to remain steady over next week.

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

• The Gulpa Creek offtake flow (250 ML/d) will generally remain below the operational channel capacity of 250 ML/d. However, it is expected that the flow will gradually ramp up to target 700 ML/day from third week of October 2020 for delivery of 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 1.77 m.

• Flow downstream of Stevens Weir is approximately 1,180 ML/d and is likely to remain relatively steady over the week.

• Flows into Colligen Creek (185 ML/d), Yallakool Creek (220 ML/d) and Wakool River (30 ML) will continue to be relatively steady.

• Flow in Niemur River at Mallan School is currently at approximately 140 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 140 ML/d and the flow is likely vary marginally.

• Flow in Wakool River at Stoney Crossing is currently at approximately 490 ML/d and is likely to marginally decrease to about 470 ML/d over the week.

• Flow at Balranald is currently at approximately 1,320 ML/d meeting the September 2020 end of system target; The flow is expected to gradually reduce to target a flow of 1,030 ML/d during October 2020.

• Lake Victoria is currently holding approximately 670 GL or 99 percent of active capacity. The flow to South Australia is at approximately 7,700 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.

• eWater delivery to Gulpa Creek wetlands will commence in first week October 2020. The flows will gradually ramp up from the current 250 ML/day to a maximum of 700 ML/day by

Water availability weekly report 6

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 15 September 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 three 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 15 percent, with an average GS carryover of 21 percent, this means the NSW Murray total GS water availability has reached 36 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 7

4.2 Lower Darling valley

Storage and release status

• The system collectively holds approximately 470 GL of total volume of water (or 27 percent of active capacity) and is releasing approximately 420 ML/d.

• The status of individual lakes are as follows: Lake Wetherell – 68 percent, Tandure – 85 percent and Lake Pamamaroo – 118 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 continue over the week or until the levels in both these lakes equalise. 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 15 September 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 8

4.3 Murrumbidgee valley

Storage and release status

• Burrinjuck Dam is currently at 80 percent of active capacity, releasing approximately 2,900 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 next week.

• is currently at 78 percent of active capacity releasing approximately 560 ML/d as transparent releases. The releases are expected to increase to about 3,500 ML/d to meet the system demands for irrigation and environmental orders.

• The Beavers Creek offtake regulator gates are controlling flows and are aimed at achieving an average flow of about 600 M/d at Kywong during the month of September 2020 as per the work approval conditions. The Kywong target will reduce to 400ML/d during October 2020.

• 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 3.8 m and will vary marginally 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 (3.6 m) will be drawn down to meet downstream irrigation and environmental demands as required.

• Hay Weir is at approximately 7.3 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 1,320 ML/d meeting the September 2020 end of system target; The flow is expected to gradually reduce to target a flow of 1,030 ML/d during October 2020.

• 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 9

• be approximately 500 ML/d to supply water to increasing irrigation orders and to Forest Creek for environmental flows.

October Long Weekend Recreation

• In view of the recreational needs of the community over the October long weekend (2 – 5 October 2020) efforts will be made to maintain the weir pools at Gogeldrie and Hay to be nearly steady closer to their Fully Supply levels.

• Further, the releases from Blowering Dam will be maintained at or below 3,500 ML/d to provide conducive conditions for the Trout Fishing season over the long weekend.

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.

Water availability weekly report 10

• 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 15 September 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 two percent taking the total allocation to-date to 46 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 30 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 11

5. Central valley based operational activities

5.1 Lachlan valley

Storage and release status

• is currently at 30.5 percent of capacity and is releasing approximately 2 ML/d.

• is currently at 60.3 percent of capacity and is releasing approximately 25 ML/d. Releases are forecast to remain at 25-30 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 1,500 ML/d. Releases are forecast to reduce gradually to around1,300 -1,400 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.

• Good tributary inflows have resulted from recent rain events. The delivery of S&D replenishment flows have been commenced into Willandra Ck (stopped on 24 September 2020), Merrowie Ck (stopped on 26 September 2020), Merrimajeel and Muggabah likely to continue till 6 September.

• The current Lake Brewster storage volume is 51.3 percent of capacity with a volume of approximately 74,600 ML.

Environmental water operations

• Due to drought conditions last year, the end of system daily environmental flow requirements in the Belubula River have been suspended and were only met intermittently with contribution from tributaries. However, due to recent 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 12

• 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.

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 on green alert.

• 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 on green alert.

• 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. Few other cyanobacteria were detected. System is now on amber alert.

Water availability weekly report 13

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 14

5.2 Macquarie valley

Storage and release status

• is at 46.5 percent of active capacity and currently releasing approximately 1,750 ML/d for translucent flows. Releases are forecast to remain between 1,500 – 2,000 ML/d depending on the inflows to the dam and downstream.

• Windamere Dam is currently at 29.1 percent of active capacity (108 GL) and releasing 8 ML/d. Releases are forecast to stay at approximately 8-10 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 Improve 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 within 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 has gained approximately 66,000 ML so far this month.

Water availability weekly report 15

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 testing which took place on 18 August 2020 showed few cyanobacteria detected across the . Minor counts were observed in the Mookerawa and Cudgegong arms, but no potentially toxic species were detected. Green and flood alga are present in low numbers suggesting current low productivity. No cyanobacteria were detected downstream. Storage remains at Green Alert Level.

• Results for 5 August 2020 show that the Microcystis sp. bloom has declined. The storage continues to show elevated productivity but is now dominated by green alga. Downstream showed a minor Dolichospermum sp. detection. Windamere Dam is now at 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 16

6. Northern valley based operational activities

6.1 Namoi valley

Storage, release and inflow status

• is at 4.9 percent of active capacity and is currently releasing 24 ML/d.

• is at 25.7 percent of active capacity and releases have ceased.

• is at 26.1 percent of active capacity and is currently releasing 3 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 17

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 Green Alert Level in the storage.

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

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

Planned supply interruptions:

• Mollee Fishway is currently unavailable due to infrastructure failure.

Water availability weekly report 18

6.2 Gwydir valley

Storage, release and inflow status

• 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 19

6.3 Border rivers

Storage, release and inflow status

• is at 16.9 percent of capacity. Pindari low level valve maintenance work has been completed and transparent releases have resumed.

• Glenlyon Dam is at 14.6 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 of about 4,400ML is planned to start from 1 October 2020. Releases are planned to peak at about 200 ML/d by 9 October 2020 before a gradual recession into early November 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 is open until 4 October 2020. 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 20

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 707 GL inflow at Wilcannia.

• Flows are receding now and access availability is forecast to drop below A class for all management zone by the end of this week.

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 21

WaterNSW HYPLOT V134 Output 08/09/2020 Period 9 Month 01/01/2020 to 01/10/2020 2020 416001 BARWON R @ MUNGINDI 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 416050 BARWON U/S PRESBURY 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422004 BARWON @ MOGIL MOGIL 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422003 BARWON @COLLARENEBRI 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422025 BARWON @ TARA 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422001 BARWON @ DANGAR BDGE 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422026 BARWON @ BOOROOMA 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422027 BARWON @ GEERA 141.0012 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 Jan Feb Mar Apr May Jun Jul Aug Sep

WaterNSW HYPLOT V134 Output 29/09/2020 Period 9 Month 01/01/2020 to 01/10/2020 2020 422002 BARWON @ BREWARRINA 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422028 BARWON @ BEEMERY 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425039 DARLING@WARRAWEENA 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425003 DARLING@BOURKE TOWN 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425004 DARLING@LOUTH 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425900 DARLING@TILPA 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425008 DARLING@WILC. MAIN C 141.00 12 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 Jan Feb Mar Apr May Jun Jul Aug Sep

Water availability weekly report 22

7. Coastal valley based operational activities

7.1 Bega river

Storage and release status

• is at 101 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 (1 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 green alga. Storage remains on green alert.

Planned supply interruptions

• Nil.

Water availability weekly report 23

7.2 Hunter valley

Storage and release status

• is currently at 46 percent of capacity and releases are around 60 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.

• is at 39.2 percent of capacity and releases are currently averaging 6-8 ML/d. Releases are forecast to remain in between 6-8 ML/d for rest of the week.

• 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 and Glennies Ck Dam shows that the Microcystis sp presence is continuing at all upstream sites with increasing productivity. Visual amenity of the water body has been impacted. Downstream results showed a moderate Phormidium sp. detection however being benthic this result is likely to be intermittent. Storage is now at Amber Alert Level.

• Recent BGA sampling at Glennies Ck Dam show that productivity is increasing across the storage. A detection of Dolichospermum circinale at amber alert level was noted at Station 1. A similar assemblage was observed at the recreation area and downstream but at lower densities. Storage is now at Amber Alert Level.

Water availability weekly report 24

• 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 25

7.3

Storage and release status

• Toonumbar Dam is at 66 percent of capacity and releasing approximately 12 ML/d. The release is expected to remain in between 12-15 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 show that productivity is still reducing across the storage. Minor counts of benign Cyanobacteria and green algae were noted. Small counts of Microcystis sp were observed. A similar assemblage of Cyanobacteria was observed downstream. The storage remains at Green Alert Level.

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 26

8. Rural Dam Levels

The following table shows the status of water supplies at 28 September 2020.

Likely- Weekly Active hood of River Valley Current Status change Comments Allocations for 2020/21 Capacity fill and (GL) spill

percent of Weekly C’over Active High Gen. Storage Dam, Nearest Town (GL) active Change Supply Issues avail @ (GL) Security Security capacity (GL) 1/7/20

Border Rivers Release ceased & good d/s Glenlyon Dam, Stanthorpe <20% 100% 1.2% 2% (Qld) 253 15% 37 -0 tribs Stimulus releases to <20% 100% 1.2% 2% Pindari Dam, Inverell 312 17% 53 -0 commence

Gwydir Valley

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

Namoi Valley Min release & good d/s tribs Keepit Dam, Gunnedah 419 26% 108 0 <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

d/s trib flows reduced <40% 100% 12% 16% translucent flow cont’d Burrendong Dam, Wellington 1154 47% 537 19

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

Lachlan Valley Min release. S&D <50% 100% 28% 6% Wyangala Dam, Cowra 1217 60% 732 12 replenishment flows started; D/s trib flows, access to UCF <10% 100% 0% 28% Carcoar Dam, Carcoar 36 30% 11 0 and Supp flows continues

Murrumbidgee Valley Regulated releases <25% 95% 46% 18% Burrinjuck Dam, Yass 1025 80% 820 12 including eWater Regulated releases <10% 95% 46% 18% Blowering Dam, Tumut 1604 78% 1246 22 including eWater

Murray

Dartmouth, Mitta Mitta (Vic) 3837 55% 2106 16 WSP Plan min releases N/A N/A N/A N/A Regulated releases <25% 97% 15% 21% Hume Dam, Albury 2982 67% 1991 45 including eWater

Lower Darling Regulated releases <30% 100% 30% 48% Menindee Lakes, Broken Hill 1633 27% 431 -2 including eWater

Hunter Valley receding d/s tribs, supp & UCF available in some <20% 100% 53% 24% Glenbawn Dam, Scone 750 46% 346 0 sections Release to meet d/s <20% 100% 53% 24% Glennies Ck Dam, Singleton 282 39% 111 -0 demand. spilling Lostock Dam, Gresford 20 100% 20 -0 100% 100% 100% N/A

Coastal Area

Toonumbar Dam, Kyogle 11 65% 7 -0 Regulated releases 100% 100% 100% N/A Spilling, access to Supp in some sections ceased and 100% 100% 40% N/A Brogo Dam, Bega 9 100% 9 -0 UCF continues in all sections

Total 17749 50.4% 8938 124 WaterNSW has water resources in Dartmouth, Hume and Glenlyon Dams. TWS = Town Water Supplies

Water availability weekly report 27

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 .com.au/subscribe.

Water availability weekly report 28