Regional

water availability

report

Weekly edition 20 July 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 ...... 20

7. Coastal valley based operational activities ...... 26

7.1 Bega river ...... 26

7.2 Hunter valley ...... 27

7.3 Toonumbar ...... 28

8. Rural Dam Levels ...... 29

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 20 July 2020 was 37.1 percent of the total active storage capacity. This was an increase of 0.8 percent since last week.

The total storage level of urban water supplies on 20 July 2020 was 80.2 percent of the total storage capacity. A decrease of 0.2 percent since last week.

2. System risks

The relatively small inflows to most Northern dams mean that drought measures and works are being reviewed, but most will likely remain in place, despite the larger flows downstream. This is particularly the case for Chaffey, Split Rock and Dams, where the risks to critical needs remains high. Risks are also increasing in the Hunter Valley as inflows to Glenbawn and Glennies Creek Dams continue to track well below previous drought records.

Water availability weekly report 3

3. Climatic Conditions

Figure 1 - Weekly rainfall totals for

This week’s weather forecast

A strong high-pressure system lies over the Bight, extending a ridge across New South Wales. This high will be the dominant feature as it gradually moves east over the coming days, reaching the Tasman Sea by Friday. Late on Friday, a trough is forecast to approach the far west of the state, and then continue to move east across inland districts during Saturday, accompanied by some unsettled conditions.

For the first part of the week, NSW is forecast to remain dry apart from the far north coastal region which is expected to receive negligible rainfall. As the week progresses, most regions of NSW should receive 1 – 50 mm of rainfall with the higher falls of 25 – 50 mm being predicted across the eastern to coastal regions of the state.

Figure 2a – First 4-day Forecast (21 – 24 July 2020) Figure 2b – Following 4-day forecast (25 - 28 July 2020)

Water availability weekly report 4

Climate outlook overview

Issued 16 July

• A wetter fortnight likely for New South Wales and a wetter 3 months likely for most of NSW.

Figure 3 – 3-month rainfall outlook

Water availability weekly report 5

4. 4Southern valley based operational activities

4.1 Murray Valley

Storage and release status

• is currently at 46 percent of active capacity and at minimum releases of 600 ML/d.

• Release downstream of Yarrawonga Weir is at approximately 8,200 ML/d and is likely to decrease to approximately 6,000 ML/d over the coming week.

• Tributary inflows downstream of Hume have continued to recede over recent days. With no significant rainfall forecast for the coming week, tributary inflow will continue to recede and as a result unregulated flows will cease to be available in the River Murray from Hume to Barmah and in the Edward- River system from the Edward river offtake to Stevens Weir. NSW Department of Planning, Industry and Environment (DPIE-Water) extended the period of unregulated flow for certain reaches of the River Murray System that started on the 27 June 2020 to 27 July 2020.

• The Edward River offtake flow is currently at approximately 1,562 ML/d, which is in the regulated channel capacity. The offtake flow would be gradually reduced in line with Edward-Wakool system demands and River Murray water levels.

• The Gulpa Creek offtake flow is at about 330 ML/d and likely to decrease to approximately 250 ML/d over the coming week.

• Stevens Weir level is at approximately 4.44 m and is likely to fluctuate while the supplementary continues in the upstream sections and then start to gradually lower to about 3.9 m. Water level upstream of Wakool Canal offtake is at approximately 0.9 m.

• Flow downstream of Stevens Weir is at approximately 550 ML/d and is forecast to vary between 500 and 600 ML/d. The flow would increase to approximately 2,000 ML/d when the supplementary access in the upstream sections cease later in the week.

• Flows in the Colligen Creek (250 ML/d), Creek (236 ML/d) and Wakool offtake (30 ML/d) are likely to marginally vary to manage the supplementary access demands in the system. The offtake flows into Wakool River may gradually reduce, eventually ceasing to flow when Stevens Weir is gradually lowered.

• Flow in Niemur River at Mallan School is currently at approximately 200 ML/d and the flow is likely to remain relatively steady over the course of the week.

• Merran Creek flows upstream of its confluence with Wakool is at approximately 106 ML/d and the flow is likely to fluctuate before it increases to about 140ML/d over the next week.

• Flow in Wakool River at Stoney Crossing is currently at approximately 490 ML/d and is likely to increase gradually over the coming weeks.

Water availability weekly report 6

• Flow at is currently at approximately 1,800 ML/d and will gradually decrease over the coming week to meet the end of system target for the July of 829ML/d. The target for August is 1,087 ML/d

• Lake Victoria is currently holding approximately 630 GL or 92 percent of active capacity. The lake is effectively full under the Lake Victoria operating strategy that maintains airspace in the lake while there are unregulated flow conditions. The flow to South Australia is approximately 12,600 ML/d.

Environmental water operations

• eWater delivery has now ceased into Wakool-Yallakool system and into Colligen-Niemur system.

Water availability

• The Water Allocation Statement by DPIE (dated 15th July 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. regulated River (RR) (conveyance) category allocation is at 51 percent. General Security (GS) allocation is at two percent with carryover equivalent to 21 percent of total GS share components. The allocations for all temporary critical Conveyance licences are also at 100 percent.

Drought operation measures

• The NSW Murray regulated river water source remains at Stage two, meaning drought operational planning has commenced in preparation for extreme dry conditions that may continue through 2020-21.

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 visit: Water Quality Algae.

Planned supply interruptions:

• Maintenance activities are underway in the Stevens Weir gates and super structure under the Coatings Program. However, the maintenance activity is not expected to impact the normal river operations and Weir levels.

Water availability weekly report 7

4.2 Lower Darling valley

Storage and release status

• system collectively holds approximately 27 percent of active capacity and is releasing approximately 220 ML/d.

• The status of individual lakes: Lake Wetherell - 67 percent, Tandure - 84 percent and Lake Pamamaroo – 119 percent, Copi Hollow – 134 percent, while Lakes Menindee and Cawndilla remain dry.

• As per the Water Sharing Plan, the planned minimum flows for the months of May to October will target 200 ML/d measured at Weir-32.

• Total inflows to the lakes measured at Wilcannia that commenced on 10 March 2020 is approximately 667 GL.

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 Water Allocation Statement by DPIE (dated 15th July 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 entitlements have received an opening allocation of 30 percent. Carryover of about 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

• Green alert 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).

o For more information visit: Water Quality Algae.

Planned supply interruptions:

• None

Water availability weekly report 8

4.3 Murrumbidgee valley

Storage and release status

• is currently at 44 percent of active capacity, releasing approximately 2,000 ML/d. The release is likely to vary in line with system demands especially when releases from the is stopped for maintenance activities.

• Blowering Dam is currently at 61 percent of active capacity releasing approximately 560 ML/d. There is a two-day outage this week on 21-22 July when there will be no water release from the dam. The dam release is expected to restart by the evening of 22 July 2020. See planned outage section below for details.

• The Beavers Creek offtake regulator is fully open as per the work approval conditions. Decreasing flows at (2,017 ML/d) are likely to vary in the Beavers Creek at Mundowey (16 ML/d) over the week.

• Berembed Weir (2.53 m) is being gradually filled at approximately 300 mm/d to approximately 3.3 m. Following this, the weir will be used for re-regulating any tributary inflows surplus to the requirements.

• Bundidgerry storage is currently at approximately 4.13 m and is likely to gradually reduce as per Murrumbidgee Irrigation water diversions and/or system losses. The storage will be replenished by early August or earlier on an as needed basis.

• Golgeldrie Weir is about 5.0 m and it will be relatively steady over the coming week.

• Tombullen storage level is approximately 1.3 m. Releases will be made at varying flow rates to meet downstream water demands over the next two weeks. The release rates will vary between 300 and 600 ML/d depending on the system demands. The storage is expected to be empty by the end of July/early August. Capture and re-regulation of any future system surplus in the Tombullen storage is subject to the availability of the infrastructure managed by Irrigation Corporation, especially the top section of their main canal.

• Hay Weir (4.6 m) is currently being lowered for routine winter maintenance at a rate of 250 to 300 mm/d. The gates are expected to be withdrawn later this week for annual essential maintenance that will commence on Monday 27 July 2020.

• Maude Weir is at 3.5 m and expected to be filled at a rate of approximately 300 mm/d by the middle of the week in order to commence environmental water delivery to Nimmie Creek.

• Currently, the Redbank Weir level is approximately 5.69 m. The level is to remain relatively steady for the next few weeks while environmental water is being delivered to Lowbidgee.

• Flow at Balranald is currently at approximately 1,800 ML/d and will gradually decrease over the coming week to meet the end of system target for the July that is 829 ML/d. The target for August is 1,087 ML/d.

Water availability weekly report 9

• The current diversion into Creek is approximately 250 ML/d and is likely to remain relatively steady over the week. The flow into the Yanco arm below Tarabah Weir will be maintained at approximately 80 ML/d, while the split into the Colombo arm will be approximately 120 ML/day.

Environmental water operations

• Planned environmental releases as per the Transparency Rules are being delivered from Blowering (except on 21 and 22 July 2020 due to maintenance) and Transparent/Translucent releases from Burrinjuck Dam.

• The Burrinjuck Dam Translucent Rules operate between 22 April and 21 October. These Rules mean that a proportion of daily inflows are released, which means releases can be large when inflows are higher.

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

• A significant eWater delivery of about 34,000 ML (Planned Environmental Water) over a period of approximately six-weeks was started on 6 July via Yanga 1AS into Lowbidgee.

• A second event to deliver about 6,000 ML of Held Environmental Water through Waugorah 1ES will start later this week at approximately 50 to 100 ML/d. The event is expected to run for more than 12-weeks.

• A third event to deliver approximately 5,000 ML of Planned Environmental Water will be carried out to the Nimmie Creek system no later than 27 July 2020. The event will continue for approximately three-weeks at a rate of approximately 250 ML/d.

Water availability

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

• The Water Allocation Statement by DPIE (dated 15 July 2020) confirmed that all high priority entitlements have received full opening allocations as per the Valley’s Water Sharing Plan. This includes all local WU, D&S and HS licences. GS users have received an increase in allocation of four percent taking the total allocation to-date to 14 percent. Carryover is fully available and estimated to be approximately 340 GL or 18 percent of GS entitlement on average. Conveyance entitlements have received full opening 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.

Water availability weekly report 10

o Blowering Dam on a 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:

• Planning is underway to commence regular winter maintenance of Hay Weir. In preparation of the planned maintenance, the Hay Weir is being gradually lowered. Gates are expected to be clear of water by 23 July 2020. The Weir is expected to be returned to normal service levels (approximately 6.0 m) by mid-August 2020.

• The planned works under the Coating Program at the Nimmie Creek offtake gates have been completed. The gates were re-installed on Monday 20 July 2020. Maude Weir level is being raised in order to commence the eWater delivery to the Nimmie Creek. Supply to Nimmie Creek is expected to restart by 27 July when Maude Weir has sufficient head.

• Painting of the Maude Weir Super Structure has started and will be completed by 30 October 2020. The Painting program for Gogeldrie started on the 30 June 2020 and will continue until mid- January 2021. However, the maintenance activity under the coating program is not expected to impact the normal River Operations and Weir levels.

• Planning is underway to carryout required works on the Emergency Coaster Gate in the Blowering Intake Tower. The closure will result in little or no flows in the River for approximately 48 to 72 hours, from 21-22 July and again from 4-6 August 2020. However, the flow in the will not be impacted, as any tributary flow would be augmented by additional releases from the Burrinjuck Dam to meet irrigation and environmental demands.

• Burrinjuck Dam planned maintenance work in the High-Level outlets and one of the four low level outlets have commenced. The works are expected to be complete by end of July 2020. Due to the maintenance activities, the maximum release capacity from Burrinjuck Dam is expected to be approximately 6,000 ML/d during the planned outage period. The projected release capacity is forecast to be sufficient to meet system demand during this time of the year.

Water availability weekly report 11

5. Central valley based operational activities

5.1 Lachlan valley

Storage and release status

• is currently at 16.9 percent of capacity and releasing 2 ML/d.

• Wyangala Dam is currently at 17.3 percent of capacity and releasing around 80 ML/d. Releases are forecast to remain at 60-80 M/d for rest of the week.

• Maintenance works have been completed on Jemalong Weir Gates, and the level is currently at approximately 5.8m.

• Lake Cargelligo is currently at approximately 77 percent of capacity and will reduced to 70 percent by end of the week, allowing for the construction of seepage monitoring devices. Once works have finished, the lake will be used to capture any tributary inflows downstream of Wyangala.

• Releases downstream of the Brewster Weir are approximately 40 ML/d. Releases are forecast to remain at approximately 40-50 ML/d during the week.

• Willandra Creek flow ceased from 1 December 2019 and releases may resume with any increase in tributary inflows.

• The recent rain and tributary flows downstream of the dam have produced some surplus flows. The flows are being diverted into Lake Brewster Outflow Wetlands and into the main cell from Lake Brewster Weir. The water coming from Lake Cargelligo storage due to maintenance works will also be captured in Brewster. The current Lake Brewster storage volume is 34 percent of capacity with a volume of around 50,000 ML.

Environmental water operations

• Due to drought conditions, end of system daily environmental flow requirements in the Belubula River have been suspended and are only being met intermittently with the contribution from tributaries.

Water Availability

• It is estimated that a combined dam and tributary inflow volume of more than 273 GL was required in June 2020 before a further allocation could be made in the . Inflows received in June were approximately 22 GL.

• The DPIE Water Allocation Statement (WAS) published on 1 July 2020 indicating water availability for the 2020-21 water year. • Full (100 percent) allocation for all LWU and D&S license holders. • 70 percent allocation for HS license holders.

• Conveyance will receive its commensurate allocation in accordance with the Water Sharing Plan.

Water availability weekly report 12

• No allocation to GS licence holders. • In addition, access to water in GS accounts on 1 July 2020 will be restricted to 50 percent of their active sub-account balance on 30 June 2020.

Inflows needed to improve deliverability of carryover

2019-20 inflow period Inflows (GL) 1 July Additional combined Additional inflows 2019 to 30 April 2020 inflows required to deliver required for new GS remaining usable allocations in 2020-21, Available Water begin to ease GS delivery restrictions and to start Determinations (AWD) increasing HS allocation (GL)

(no restrictions)

By end of June 177 95 273

By end of July 177 100

By end of August 177 168

Notes: Estimated water held in GS accounts on 1 July 2019 was 155,000 ML. Water delivery operations in 2019-20 provided under Drought Contingency Planning (Stage 3). Minimum storage level of five percent is targeted at the end of the 2019-20 water year to maintain critical supplies in 2020-21.

• These are indicative improvements only and are not guaranteed. Estimates may change based on weather variability, water management decisions and other events. This means that water users should use this information with caution and at their own risk, as it projects many months ahead.

• The assessment for the table above is based on water delivery operations in 2019-20 provided under Drought Stage 3 and 2020-21 under severe Drought Stage 4. NSW Extreme Events Policy can be viewed in the Extreme Events Policysection of the WaterNSW website

• 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. A Temporary Water Restriction under Section 324 of the Water Management Act 2000 has been gazetted on 1 October 2019. It allows access to 40 percent of the water in GS access licence account balance as at 30 September 2019. The remaining 60 percent is moved to a drought subaccount and cannot be used. Please see Belubula WAS Oct 2019.

• While allocations for the Belubula River system have been announced by DPIE Water, the delivery of water is restricted due to the ongoing drought. Please see Belubula Ops Update Oct 2019. • At the Belubula Landholders Association meeting on 21 January 2020 the following was agreed:

o HS and D&S access licence holders on the regulated Belubula will receive 100 percent allocation; and

o The DPIE – Water has now approved access to uncontrolled flows in the Belubula River during the recent tributary flow events.

Water availability weekly report 13

Water Quality

• Latest BGA samples show that the Lake Cargelligo Boatshed, Lake Cargelligo TWS, Lake Cargelligo Outlet and Lake Cargelligo intake d/s of Curlew Water are on a Green Alert.

• Wyangala Storage results (as at 25 June 2020) show that productivity has declined at all sites. Few cyanobacteria across the entirety of the storage have been noted except for a moderate Dolichospermum sp. detection at the Lachlan Abercrombie confluence. Downstream showed low level detections of benign cyanobacteria. The storage is now on Amber Alert.

• Some flow is being circulated through the Lake Cargelligo inlet and outlet with the intention of improving water quality in the channels connecting the lakes and the river.

Planned supply interruptions:

Wyangala Dam maintenance

• There will be an outage at Wyangala Dam starting the first week of June 2020 ending third week of July 2020. This outage will require all releases to be through the bypass line with a maximum dam release capacity during the outage of approximately 300 ML/d. The forecast demand in the upper Lachlan above lake Cargelligo is unlikely to be more than the release capacity of the bypass line.

Water availability weekly report 14

5.2 Macquarie valley

Storage and release status

• is at 24.7 percent of active capacity and currently releasing around 650 ML/d for translucent flows. Releases are forecast to remain between 400-500 ML/d depending on the inflows received in the dam. Downstream tributary flows continue to meet town water supply and D&S demands. Storage inflows in July 2020 are approximately 19 GL.

• is currently at 27.1 percent of active capacity (100 GL) and releasing 13 ML/d. Releases are forecast to stay at approximately 10- 20 ML/d during this week.

• The recent storms and isolated stream flows have delayed the second phase of the transfer from Windamere to Burrendong to at least March 2021. The transfer will leave a minimum of 70 GL in Windamere Dam, which provides a very secure s0upply 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 has started from Friday 17 July 2020.

• 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 DPIE Water Allocation Statement was published 1 July 2020.

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

• The temporary water restriction on Macquarie GS water accounts is being amended to allow the transfer of 40 percent of the drought sub-account balance to the active account for use.

• All HS licence categories received100 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.

Drought operation measures

• Due to recent rainfall and inflows into the dam and downstream of dam, Macquarie Regulated River Water Source has improved to Stage 3 Drought Criticality

Water availability weekly report 15

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

• The actual inflows to Burrendong Dam since the last AWD in August 2017 totalled about 351 GL to end of June 2020. This was just 64 percent of the previous record low inflow for the 35 months ending in June.

• This drier than historical minimum inflow confirms that the system has entered into a new drought of record for Burrendong Dam.

Water quality

• Burrendong Dam results for 17 June 2020 show few cyanobacteria at all upstream sites. A minor detection of Microcystis sp. was noted at the Dam Wall and small counts of benign cyanobacteria were detected both in the Mookerawa arm and downstream. The Cudgegong arm showed no cyanobacteria. Storage remains at Green Alert Level.

• Windamere dam results for 8 July 2020 show the assemblage continues to be dominated by Microcystis sp. at all upstream sites. However, the latest results show that numbers have declined near the Dam Wall but remain elevated mid-lake. Downstream showed a minor Microcystis sp.detection. Windamere Dam remains on Amber Alert Level.

• Works to reinstate the temperature curtain at Burrendong Dam have been completed and the Commissioning Phase has commenced. The curtain is fully lowered due to low storage levels.

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 4.6 percent of active capacity and is currently releasing 0.2 ML/d.

• is at 15.2 percent of active capacity and releases have ceased after recommencing briefly for limited D&S near the dam.

• is at 15.3 percent of active capacity and currently is not releasing water.

• 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.

Water availability

• The Water Allocation Statement by DPIE (dated 1 July 2020) confirmed that in the Peel Valley LWU and D&S allocation is 70 percent; HS and its sub categories are 50 percent, and GS is zero percent.

• There is a shortfall of more than 34.19 GL before there is likely to be an AWD increment in the Lower Namoi Valley.

• The latest Water Allocation Statement by DPIE (dated 1 July 2020) confirmed the allocations in the Upper Namoi Valley: local water utility and D&S have 100 percent, while HS has received 90 percent allocation and the GS a 0 percent allocation. About 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, HS have 90 percent and GS have zero 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 4. Commissioning of the Chaffey to Dungowan pipeline is complete and operation of the pipeline commenced on 17 June 2020. Operational flow targets below Chaffey will be for very low environmental flows.

• The Upper Namoi Valley is now at Drought Stage 2, down from Drought Stage 3. Releases recommenced on 30 March 2020 and will be used to supply water orders in the Manilla River from Split Rock Dam to the 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

Water availability weekly report 17

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, down from Drought Stage 4, the highest level under the Incident Response Guide.

• Deliverability of this water will rely on tributary flows and/or improved storage volumes. No further block releases are planned for the Lower Namoi Valley until further inflows occur.

Water quality

• Split Rock Dam is on Green Alert Level in storage;

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

• Chaffey Dam is on Green Alert Level in 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 13.5 percent of active capacity and is currently releasing 28 ML/d.

Environmental water operations

• No current environmental flow orders.

Water availability

• The latest Water Allocation Statement by DPIE -Water (dated 1 July 2020) confirmed zero percent allocation for GS water users of the Gwydir Regulated River water source. 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. HS licence holders have 100 percent and GS licence holders have access to approximately 5 percent carried over from the previous water year.

Water quality

• Recent Blue Green Algae (BGA) sampling at Copeton shows Copeton on a Red Alert Level in 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 Operations Update Gwydir 1-July section of the WaterNSW website.

Planned supply interruptions:

No supply interruptions are expected.

Water availability weekly report 19

6.3 Border rivers

Storage, release and inflow status

• is at 13.2% of capacity and releasing around 13 ML/d (minimum release).

• Glenlyon Dam is at 13.4% of capacity. Releases ceased.

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

• Flow arrived Mungindi Weir Pool on 15 February 2020 and continues to spill.

• Continued rainfall since February 2020 had generated significant flows across the Northern valleys. The catchment is wet now and responses from further rainfall will be faster.

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

Environmental water operations

• There are no current additional releases for environmental water orders.

Water availability

• The latest Water Allocation Statement by DPIE -Water (dated 1 July 2020) confirmed 7.3 percent allocation for GS A class water users in the NSW Border Rivers regulated water source. No allocation to GS B class is possible until A class 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.

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

Drought operation measures

• The Border Rivers is in Drought Stage 3. Customers are advised that if dry conditions persist, future deliveries, including essential supplies, will be grouped together (as block releases) and where possible with tributary flows, to improve delivery efficiencies.

Water quality

• Recent Blue Green Algae (BGA) sampling at Pindari shows an Amber Alert Level.

Planned supply interruptions:

• No supply interruptions are currently forecast.

Water availability weekly report 20

6.4 Barwon-Darling River system

River flow status

• Northern basin inflow event 2020 provided significant inflow to the Barwon Darling system and now approaching an end.

• 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 around 590GL inflow to the Menindee Lakes system.

• The Temporary Water Restriction Order for A, B and C class licences was removed for Mungindi to upstream of the Culgoa junction section on 27 February 2020. Temporary Water Restriction was removed from downstream of Culgoa junction to upstream of the Lake Wetherell section on 6 March 2020. For further details, please see

https://www.industry.nsw.gov.au/water/allocations-availability/temporary-water-restrictions

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 Water Allocation Statement 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 Water Sharing Plan, from 1 July 2020, flow class announcements will be made every day when the flow class availability is A class or above. 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.

Flow forecast

• The Barwon-Darling system is an unregulated river, which travels through a very arid environment with significant losses from the system 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.

• The below summaries are the current forecast estimates of flows along the system. This information is regularly updated as required.

Water availability weekly report 21

• Menindee inflow forecast is now for 589,500 ML to 591,000 ML.

• No significant changes in forecast inflows from the Border, Moonie, Namoi and Gwydir Rivers.

• Small inflow is expected from Castlereagh system.

• The Condamine Balonne has contributed around 177 GL from Culgoa River upstream of Warraweena and around 32 GL from Bokhara River upstream of Beemery.

• Around 45 GL inflow was observed at Dick’s Dam as inflow from the Warrego River, including flows from local rain that commenced on 6 March 2020. Additional Warrego flows also arrived at Louth from flows that bypass Dick’s Dam.

Water availability weekly report 22

Location Observed Total forecast Date of flow Comments about inflows to each volume volume – arrival section (ML) including observed (ML)

Mungindi 84,615 85,000 – 86,000 15 Feb 2020 Inflows are from the Border Rivers

Presbury 73,957 74,500-75,500 5 Feb 2020

Mogil Mogil 214,732 215,000-216,000 27 Jan 2020 Expected total inflows (observed and forecast) are 17-18 GL from Gil Gil and about 76 GL from Moonie. Gain from localised inflows.

Collarenberi 253,660 254,000 – 255,000 6 Feb 2020 Expected total inflows (observed (total flow and forecast) are 25 GL from Mehi.

including Old Total observed flows at Garwon Pockataroo (Old Pockataroo) are 10 GL anabranch)

Tara 274,111 274,500 – 276,000 7 Feb 2020 Gain from localised inflows

Walgett 377,722 378,000 –378,500 9 Feb 2020 Expected total inflows (observed and forecast) are about 92.5 GL from Namoi at Goangra

Boorooma 415,470 415,600 – 416,000 13 Feb 2020 Flows were out of bank

Geera 530,011 531,000 - 532,000 12 Feb 2020 Significant inflow from Castlereagh River and Marthaguy Creek from April rainfall

Brewarrina 496,467 497,000 – 498,000 16 Feb 2020

Beemery 635,276 635,500 – 636,000 18 Feb 2020 Around 32 GL inflow arrived from Bokhara. Gain from localised inflows.

Warraweena 773,903 774,300 – 775,000 19 Feb 2020 Around 176.6GL* inflow from Culgoa.

Bourke 720,281 720,500 – 721,000 20 Feb 2020

Louth 715,263 715,270 – 715,400 24 Feb 2020 Around 45 GL* inflow from Warrego

Tilpa 682,708 682,800 – 683,200 28 Feb 2020

Water availability weekly report 23

Wilcannia 671,508 671,800 – 672,500 5 Mar 2020

Lake Wetherell, 589,279 589,500 - 591,000 10 Mar 2020 Around 10-20 GL expected from Lake Tandure Dolo-Bonley Creek system and Lake downstream of Wilcannia. Higher Pamamaroo losses between Wilcannia and Lake Wetherell.

Water availability weekly report 24

WaterNSW HYPLOT V134 Output 21/07/2020 Period 7 Month 01/01/2020 to 01/08/2020 2020 416001 BARWON R @ MUNGINDI 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 416050 BARWON U/S PRESBURY 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422004 BARWON @ MOGIL MOGIL 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422003 BARWON @COLLARENEBRI 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422025 BARWON @ TARA 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422001 BARWON @ DANGAR BDGE 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422026 BARWON @ BOOROOMA 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422027 BARWON @ GEERA 141.008 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 Jan Feb Mar Apr May Jun Jul

WaterNSW HYPLOT V134 Output 21/07/2020 Period 7 Month 01/01/2020 to 01/08/2020 2020 422002 BARW ON @ BREW ARRINA 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 422028 BARWON @ BEEMERY 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425039 DARLING@W ARRAW EENA 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425003 DARLING@BOURKE TOW N 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425004 DARLING@LOUTH 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425900 DARLING@TILPA 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 425008 DARLING@WILC. MAIN C 141.00 8 Hour Mean Discharge (ML/d) CP 18000 14400 10800 7200 3600 0 Jan Feb Mar Apr May Jun Jul

Water availability weekly report 25

7. Coastal valley based operational activities

7.1 Bega river

Storage and release status

• is at 102 percent of capacity and spilling.

Environmental water operations

• 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.

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 7 May 2020 and provided the operational update to the group.

Water quality

• Recent BGA sampling at Brogo (23 June 2020) showed very low productivity across the storage. No Cyanobacteria were observed either upstream or downstream. The assemblage is dominated by green algae. Storage remains at Green Alert Level. Planned supply interruptions:

o Nil.

Water availability weekly report 26

7.2 Hunter valley

Storage and release status

• is currently at 39 percent of capacity and is releasing approximately 22 ML/d. Releases are forecast to remain at this minimum.

• is at 37 percent of capacity and releases are currently at approximately 20 ML/d. Releases are forecast to remain steady during the week after rainfall events contributed to instream flows and reduced demand.

• is at 100 percent of capacity and spilling.

Environmental water operations

• An Environmental Water Allowance (EWA) flow event in Hunter commenced on 5 June 2020 and finished on 30 June 2020. A total of up to 10,000 ML was delivered over and above the extractive water orders.

Water availability

• GS licenses in the Hunter Valley received 30 percent allocation on 1 July 2020 and carryover is equivalent to approximately 23 percent of the total share component. HS licences received a 90 percent allocation with carryover equivalent to 19 percent of the share component. All other categories received 100 percent allocation.

• The Environmental Water Allowance will be credited with 20 gigalitres (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, however if conditions remain dry the Drought Stage may escalate to Stage 2 or higher.

Water quality

• Recent BGA sampling at Glenbawn Dam shows that the Microcystis sp presence is continuing at all upstream sites and is the dominant taxa. Densities at all monitoring locations appear to be in decline. Downstream results also showed a minor Microcystis sp detection. Storage remains at Amber Alert Level awaiting another clear result. However Green Alert Level is maintained at Glennies Creek and Lostock Dams.

Planned supply interruptions:

o Nil

Water availability weekly report 27

7.3

Storage and release status

• Toonumbar Dam is at 68 percent of capacity and releasing approximately 7 ML/d. A small inflow is coming into the dam from recent rainfall.

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 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 criticality level has eased from Drought Stage 2 to Drought Stage 1 – normal operations.

Water quality

• Recent results for Toonumbar shows 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 28

8. Rural Dam Levels

The following table shows the status of water supplies at 20 July 2020.

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

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

Border Rivers

Glenlyon Dam, Stanthorpe (Qld) 253 13% 34 0 d/s trib flows continue <20% 100% 0.6% 2%

Pindari Dam, Inverell 312 13% 41 1 d/s trib flows continue <20% 100% 0.6% 2% Gwydir Valley Copeton Dam, Inverell 1346 14% 182 1 d/s trib flows continue <5% 100% 0% 5% Namoi Valley Keepit Dam, Gunnedah 419 15% 64 0 d/s trib flows continue <20% 100% 0% 6% Split Rock Dam, Manilla 394 5% 18 -0 d/s trib flows continue <5% 100% 0% 39% Chaffey Dam, Tamworth 98 16% 16 0 d/s trib flows continue <50% 50% 0% N/A Macquarie Valley d/s trib flows continue, Burrendong Dam, 1154 25% 285 7 <20% 100% 0% 6.7% Wellington translucent flow release Windamere Dam, Mudgee 367 27% 99 0 Low releases <5% 100% 0% 58% Lachlan Valley Wyangala Dam, Cowra 1217 17% 211 3 Minimum releases <20% 70% 0% 2.2% 0 d/s trib flows, access to UCF Carcoar Dam, Carcoar 36 17% 6 <10% 100% 0% 28% and Supp flows continues Murrumbidgee Valley Burrinjuck Dam, Yass 1025 44% 450 1 Regulated releases 40% 95% 14% 18% Blowering Dam, Tumut 1604 61% 977 33 WSP Plan min releases <10% 95% 14% 18% Murray Dartmouth, Mitta Mitta (Vic) 3837 51% 1972 14 WSP Plan min releases N/A N/A N/A N/A Hume Dam, 2982 46% 1358 85 WSP Plan min releases <25% 97% 2% 21% *Lower Darling Menindee Lakes, Broken Hill 1633 27% 431 -4 WSP Plan min releases <30% 100% 30% 48% Hunter Valley Glenbawn Dam, Scone 750 39% 293 1 Min release <20% 90% 30% 23% Glennies Ck Dam, Singleton 282 37% 104 0 Small d/s trib flows <20% 90% 30% 23% Lostock Dam, Gresford 20 100% 20 -0 spilling 100% 100% 100% N/A Coastal Area Toonumbar Dam, Kyogle 11 67% 7 -0 d/s trib flows continue 100% 100% 100% N/A Brogo Dam, Bega 9 102% 9 1 Spilling 100% 100% 40% N/A Total 17747 37.1% 6578 145

WaterNSW has water resources in Dartmouth, Hume and Glenlyon Dams. TWS = Town Water Supplies 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 29