Regional

water availability

report

Weekly edition

19 April 2021

WaterInsights now presents most of the content from this report and is updated in real time. This report will be phased out over coming weeks. To assist this transition to WaterInsights this report includes links to the relevant sections on WaterInsights.

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 ...... 10

5. Central valley based operational activities ...... 13

5.1 Lachlan valley ...... 13

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- system ...... 21

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

7.1 Bega river ...... 23

7.2 Hunter valley ...... 24

7.3 Toonumbar Dam ...... 25

8. Rural Dam Levels ...... 26

9. More Information ...... 26

Water availability weekly report 2

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 19 April 2021 was 57%. Which is the same as last week. Please note that rural water supply figures now include Lake Brewster, Cochrane Dam, Lake Victoria and Lake Cargelligo.

The total storage level of urban water supplies on 19 April 2021 was 95.7 %. This was a decrease of 0.3% since last week.

2. System risks

Algal alerts are current for many storages and river sections. Algae WaterNSW is working with BOM in assessing the likelihood of filling NSW storages, with high storage levels the wet catchment conditions, and preparing for airspace operations and flood operations. All floodplain landholders are recommended to review their flood operations plans and be aware of any notifications from BoM and SES. WaterNSW is working with DPIE-W and Snowy Hydro to reduce the risks of filling and spilling Blowering and Burrinjuck Dams this winter/spring. This includes limiting releases from Snowy into Blowering Dam, while ensuring water availability for next year. Any floods and floodplain flows that occur in the coming months, including the current flood flows in the Barwon-Darling system, may also trigger poor water quality, particularly low dissolved oxygen for fish, as floodwaters may pick up significant amounts of accumulated leaf litter. Forecast inflows to Menindee lakes from the current flows in the Upper Darling River and tributaries are expected to be approximately 650-850 GL. Recent rainfall over most catchments has resulted in increased allocation in most valleys and the additional inflow is likely to contribute to the commencing allocations in the next water year. Operational plans are being reviewed as a result of the inflows. Essential maintenance activities are planned across most valleys as irrigation demand is dropping over next few months.

Water availability weekly report 3

3. Climatic Conditions

A ridge of high pressure extends across the state from the west and will remain the dominant feature across northern for the coming week. Meanwhile, a cold front is crossing southern parts of the state today, with another expected to skim across the south on Thursday.

For the first part of the week, much of the state is predicted to remain dry. As the week progresses negligible rainfall is predicted along the coastal regions with up 10mm in the north east.

Figure 2a – First 4-day forecast (20 – 23 April 21) Figure 2b – Following 4-day forecast (24 – 27 April 21)

Climate outlook overview

Drier than average May to July for north and south-east Australia

Issued: 15 April 2021

Rainfall for May to July is likely to be below average (chance of exceeding median is less than 40%) for NSW.

The fortnight of 19 April to 2 May is likely to be drier than average (chance of exceeding median is less than 40%) over most of the state.

Water availability weekly report 4

Figure 3 – 3-month rainfall outlook

ENSO Outlook: INACTIVE

The ENSO Outlook is INACTIVE. This means the El Niño–Southern Oscillation (ENSO) is neutral with no indication that El Niño or La Niña will develop in the coming months. During this time, other influences, such as the Madden–Julian Oscillation or localised sea surface temperatures, are likely to play a bigger role in affecting Australian rainfall patterns. All seven climate models surveyed by the Bureau suggest a neutral ENSO state is the most likely scenario through the remainder of the southern hemisphere autumn and winter. Bureau climatologists routinely monitor the tropical Pacific for any signs of developing ENSO events, regardless of the ENSO Outlook status.

Water availability weekly report 5

4. Southern valley based operational activities

4.1 Murray Valley

Storage and release status on: WaterInsights

• is currently at 44 percent of active capacity and releasing 11,230ML/d. The release will vary to meet the regulated flow demands.

• Release downstream of Yarrawonga Weir is at approximately 8,526 ML/d and is likely to remain steady over the next week.

• The offtake gates are now back controlling the flows. The Edward River offtake flow (about 1,500 ML/d) will remain below the channel capacity of 1,600 ML/day.

• The Gulpa Creek offtake flow (250 ML/d) and will remain below the channel capacity of 250 ML/d while watching picnic point levels stay below the 2.6m.

• Stevens Weir level is at approximately 4.69 m and will vary to supply environmental water to system. Currently, the water level upstream of Wakool District Main Canal Regulator is approximately 1.79 m.

• Flow downstream of Stevens Weir is approximately 895ML/d. The flow in the Edward River system is augmented by delivery via Edward River Escape (up to about 500 ML/day) of the Canal to maintain the delivery targets below Stevens Weir.

• Flows into Colligen Creek (target 170 ML/d), (target is 110 ML/d) and Yallakool Creek (target is 280ML/d) will be varied to meet the operational requirements and to match the hydrograph required for the environmental water delivery in the Wakool River.

• Flow in the at Mallan School is currently at approximately 102 ML/d and will remain steady over the week.

• Merran Creek flow upstream of its confluence with Wakool is approximately 32 ML/d with the flow forecast to increase steady over the week.

• Flow in Wakool River at Stoney Crossing is currently at approximately 341 ML/d and will remain relatively steady.

• Flow at is approximately 988 ML/d to meet the IVT volumes ordered by MDBA for April 2021. The flow at Balranald will gradually reduce over the next two weeks to match the end of system targets for April (180 ML/day). Delivery of IVT ordered for May will then recommence from first week of May 2021. The native fish pulse water orders placed by DPIE- EES will be on top of the IVT delivery meaning the flows at Balranald will reach up to about 5,900 ML/day by second week of May.

• Lake Victoria is currently holding approximately 195GL or 16 percent of active capacity. The flow to South Australia is at approximately 5,400 ML/d.

Water availability weekly report 6

Environmental water operations on: WaterInsights

• The e-Water delivery into Wakool, Yallakool and Colligen system is continuing, as per the hydrograph provided by the water holder.

Water availability on: WaterInsights

• The Water Allocation Statement (WAS) by the NSW Department of Planning, Industry and Environment (DPIE) (dated 15 April 2021) 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. The total allocation for 2020-21 to the general security category increased to 50 percent, with an average GS carryover of approximately 21 percent, this means the NSW Murray total GS water availability has reached approximately 71 percent of entitlement. Starting allocations

• The next water allocation statement will be published on Monday, 3 May 2021.

Drought operation measures on: WaterInsights

• 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 on water-quality-algae

• Potential Blue Green Algae issues:

o New red alerts are in place for the at , Euston Weir, and Fort Courage. A red alert remains in place on the Murray River from Merbein to Fort Courage. The red alert for Mildura has been lifted following two consecutive results from Mildura Weir Pool (LMW).

o A red alert has also been issued for the Niemur River at Barham – Rd, following results from ad hoc sampling last week.

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

Planned supply interruptions on: WaterInsights

• Maintenance activities are nearing completion 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.

• Planning is underway for essential maintenance of Stevens Weir, Edward River Offtake, Gulpa Creek Offtake, Yallakool Creek Offtake, Wakool Offtake, Colligen Creek Offtake, New Merran Cutting Regulators between Mid-May, and end of July. The actual dates of maintenance will be finalised in consultation with key stakeholders.

Water availability weekly report 7

4.2 Lower Darling valley

Storage and release status: on: WaterInsights

• The Menindee Lakes system collectively holds approximately 371 GL of total volume of water (or 21 percent of active capacity), is releasing approximately 310 ML/d.

• Pamamaroo Inlet Regulator has been fully opened to increase the storage level with inflows into lake Wetherell.

• Menindee Inlet Regulator is scheduled open this week to commence transfer of water into Lake Menindee

• The status of individual lakes are as follows: Lake Wetherell –43 percent, Tandure – 68 percent, Lake Pamamaroo – 96 percent, Copi Hollow – 93 percent, while Lakes Menindee and Cawndilla are currently remaining dry.

Environmental water operations on: WaterInsights

• The Water Sharing Plan minimum flows for the months of April is 300ML/d and May 200ML/d 2021 measured at Weir-32.

Water availability on: WaterInsights

• Forecast inflows to the lakes from the current flows in the Upper Darling River and tributaries are expected to be approximately 650-850GL. There is significant uncertainty in the forecast inflows due to flow breakout onto the flood plains in the Barwon-Darling System.

• WaterNSW is monitoring the situation closely, based on flows seen upstream, it is possible that Pamamaroo and Wetherell Lakes will be surcharged. Any additional inflows will be stored in Lake Menindee.

• The WAS by DPIE (dated 15 April 2021) 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 has increased by 70%. Bringing the total allocation to GS entitlements in the Lower Darling to 100%. Availability of allocation on individual licences is subject to account limits as per the rules in the Water Sharing Plan.

• The next water allocation statement will be published on Monday 3 May 2021.

Drought operation measures on: WaterInsights

• The Lower Darling Regulated River water source is assessed to be in Drought Stage 1

Water quality: water-quality-algae

• Blooms reported for the Darling River at Menindee and Pooncarie were sampled routinely and low numbers of cyanobacteria were recorded.

• Amber alerts have been reported for the Darling River at Menindee and Pooncarie.

• Amber alerts are current for Lake Wetherell site 4, Lake Tandure site 8, and Copi hollow

• Green alter is current for Darling River at Tapio.

Water availability weekly report 8

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

Planned supply interruptions on: WaterInsights

• Nil.

Water availability weekly report 9

4.3 Murrumbidgee valley

Storage and release status on: WaterInsights

• Burrinjuck Dam is currently at 86 percent of active capacity, releasing approximately 7,500 ML/d. The flow will increase this week to meet the system demands especially IVT orders and native fish pulse orders at Balranald.

• Blowering Dam is currently at 79 percent of active capacity with minimum environmental releases of approximately 580 ML/d as per Water Sharing Plan conditions.

• The Beavers Creek offtake flow is approximately 100 ML/d and the flows will marginally vary to meet the daily flow target of 60 ML/d at Kywong during April 2021.

• Berembed Weir is approximately 4.86 m and will remain steady over the week.

• Bundidgerry storage is currently at approximately 4.00 m and will vary over the week depending on the diversions by Murrumbidgee Irrigation.

• Gogeldrie Weir is at approximately 5.79 m and will vary marginally over the week.

• The Tombullen storage (1.3 m) will be used to meet any downstream demands including eWater. The storage is expected to be empty by the end of April.

• Hay Weir is at approximately 6.76 m will be used to meet any downstream demands including eWater. The minimum operating level for Hay Weir is 6.0m for the month of April 2021.

• The water level at Maude Weir is approximately 1.3 m and will be steady at this level while essential annual Maintenance works are being completed. Maintenance works commenced Monday 19th April and are expected to be completed by Wednesday 28th April.

• Currently, the Redbank Weir is currently at 5.52 m to supply environmental water to Western Lakes in Lowbidgee via North Redbank Channel which commenced on Thursday 15th April.

• Flow at Balranald is approximately 990 ML/d to meet the IVT volumes ordered by MDBA for April 2021. The flow at Balranald will gradually reduce over the next two weeks to match the end of system targets for April (180 ML/day). Delivery of IVT ordered for May 2021 will then recommence from first week of May 2021. The native fish pulse water orders placed by DPIE- EES will be on top of the IVT delivery meaning the flows at Balranald will reach up to about 5,900 ML/day by second week of May.

• The current diversion into Creek is about 330 ML/day to meet system requirements. The flow into the Yanco arm below Tarabah Weir will stay steady at about 60 ML/d while the split into the Colombo arm is approximately 230 ML/d.

• The end of system target at Darlot is currently 50 ML/day in addition to customer water orders below Darlot. Part of the IVT clearance (up to say 9 GL) will be made via Darlot during April 2021 and up to about 2 GL during May 2021.

Environmental water operations on: WaterInsights

Water availability weekly report 10

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

• The eWater delivery to Western Lakes in Lowbidgee via North Redbank Channel have commenced. It is expected that about 25GL will be delivered during the event over a 9- week period.

• The eWater orders for the native fish pulse at Balranald is scheduled to be delivered as a piggyback event on top of the IVT delivery in the first three weeks of May 2021. A total volume of about 30 GL under The Living Murray account and up to 5 GL of Commonwealth eWater is planned to be delivered during the event.

Water availability on: WaterInsights

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

• The WAS by DPIE (dated 15 April 2021) confirmed that all licence categories receive full allocation for the current water year.

• Indicative allocation for 2021-22 on 1 July 2021 shows that full (100%) allocation can be expected for towns, domestic and stock access licences, and subcategory high security entitlements. It is forecast that high security allocation will receive 95% of entitlement in accordance with the water sharing plan and carryover commitments (estimated to be 30%) should be met on 1 July. General security allocations may start around 25% per cent based on current forecasts.

• The next water allocation statement will be published on Monday 17 May 2021.

Drought operation measures on: WaterInsights

• The Murrumbidgee Regulated River Water Source is at Drought Stage 1, meaning all allocated water can now be delivered under normal regulated river operations.

Water quality water-quality-algae

• Potential Blue Green Algae issues:

o Burrinjuck Dam at is back on Red alert for blue-green algae.

o Lake Wyangan North has a Red status for blue green algae.

o Lake Wyangan South in Griffith has a Red status for blue green algae.

o In Burrinjuck Dam, Good Hope, Burrinjuck Waters State Park and at the Dam are on Amber alert.

o The at , Hay Weir Buoy, Redbank Weir and at Balranald are on Amber alert.

o The Murrumbidgee River at Mittagang Crossing, downstream of Burrinjuck Dam Wall, Roaches Road and Gogeldrie Weir are on Green alert.

o Lake Albert in Wagga Wagga is on Green alert.

o There are no other blue-green algal alerts.

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

Unplanned supply interruptions on: WaterInsights

• Nil

Planned supply interruptions on: WaterInsights

• Planning is underway for the inspection of emergency coaster gates including hydraulic cylinder fittings; essential annual works on HEPS 5 branch, 90” FDC and penstock inspection and patch painting in three stages over a period of up to 9-weeks starting from end of April 2021. The planned maintenance will limit the maximum release capacity to about 9,000 ML/day through the low-level valves and approximately 5,000 via High Level Outlet No. 3 (Stony Sluice) depending on the storage level.

• Planning is underway to carryout essential maintenance in the bifurcate works at the Blowering Dam during the third week of July 2021. During the proposed work, release of water from the Blowering Dam will be temporarily stopped. Any system demands on Murrumbidgee will be met from Burrinjuck Dam. Flows in the River, downstream of Blowering Dam, will be disrupted during the planned maintenance for about 48 to 72 hours. The break in supply is likely to cause moderate impacts on downstream water users – especially in the absence of tributary flows from Basin Creek and Goobarragandra River.

• Work is underway for the essential maintenance on the channel below Nimmie Creek offtake structure. The works are expected to be complete by June 2021. This will impact any deliveries to Lowbidgee via these offtakes until end of June 2021.

• Essential maintenance is underway at Maude Weir, the weir has been lowered to a level of approximately 1.3 m. Maude Weir is expected to be returned to service by early May 2021. However, the maximum water level will still be limited to 3.7m until all maintenance works are complete at Nimmie Creek offtake structure.

• Planning is underway to carryout essential winter maintenance of Berembed and Gogeldrie Weirs between late May and early July 2021. This will impact the delivery of water to MI Main Canal, MI Sturt Canal and CICL Main Canal. Berembed Weir maintenance is scheduled between 30/6/21 and 9/7/21, while the Gogeldrie Weir maintence is scheduled between 14/6/21 and 5/7/21. The water levels in the weirs will be low for about two to three weeks prior and after the above maintenance windows.

Water availability weekly report 12

5. Central valley based operational activities

5.1 Lachlan valley

Storage and release status on: WaterInsights

• Carcoar Dam is currently at 31.5 percent of capacity and is releasing approximately 3 ML/d.

• is currently at 70 percent of capacity and is releasing approximately 210 ML/d to meet system demand.

• Lake Cargelligo is currently at approximately 70 percent of capacity and will slightly reduce to about 69 % to the end of this week.

• Releases downstream of the Brewster Weir are around 580 ML/d. Releases are forecast to increase to around 950 ML/d during the week as the delivery of Stock and Domestic replenishments in lower Lachlan continues.

• Lake Brewster storage on 19th April 2021 was 27.52 percent of capacity with a volume of approximately 40,006 ML.

Environmental water operations on: WaterInsights

• As a result of the rain, the tributary flows in Belubula are continuing. Currently, end of system flow condition is met by flow provided by tributaries.

• Translucent period in Lachlan ended on 15 November 2020.

• Approximately 6 GL of the Lachlan Water Quality Allowance was utilised to provide a flow of 100 ML/day at Weir during January 2021 to 31st March 2021 to reduce the risk of low dissolved oxygen for fish.

• Delivery of EWA water has been started on Tuesday 20 April d/s of Brewster weir with an initial target of 130ML/d at Booligal. The delivery will continue to end of June 2021 and approximately over 8GL will be used.

Water Availability on: WaterInsights

• The WAS published by DPIE on 12th April 2021confirmed that an additional allocation of 20 percent has been made to GS licence holders, bringing the total allocation this year to 64 percent.

• This allocation increase also elevates the total volume of water in GS accounts above 75%, which means that the Wyangala and Brewster Environmental Water Allowances (EWAs) are credited with a total of 20 gigalitres (GL) in line with the water sharing plan.

• Based on historical inflows, there is about a 10% chance that the major storages within the system will spill by the end of June 2021. Should a spill occur, general security accounts will be reset and equalised in accordance with the water sharing plan.

Water availability weekly report 13

• In Belubula, access to uncontrolled flow event has been extended and will cease at 9am on Wednesday 21 April 2021.

• The WAS published by DPIE on 25 March 2021 for Belubula confirmed that there is no change to allocations in the Belubula regulated river water source.

• 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.

Water Quality water-quality-algae

• The Wyangala Storage results (17th March 2021) show continuing low productivity at all sites. The storage is now on Amber Alert Level.

• The Carcoar Storage latest samples (6th April 2021) show moderately increased productivity with cyanobacteria detected in the upstream sample. Downstream showed no cyanobacteria detected. Storage at Amber Alert Level.

• The Lake Brewster Sample results from the 7th April 2021 show lake Brewster inlet and regulator C are on Green Alert, while the Outlet Channel is are on Red alert.

• Results from Lake Cargelligo on 6th & 7th April 2021 show increased productivity across the storage. Green and flood alga dominate the assemblage at all sites, however Sphaerospermopsis Aphanizomenoides, and Dolichospermum flos-aqua/planctonicum sp. are now present downstream in the Lachlan. Some other cyanobacteria were detected. System is now on amber alert.

Planned supply interruptions on: WaterInsights

• Maintenance on Wyangala Dam penstock is planned to begin in the first week of May and end in early July 2021. The penstock outage will reduce the maximum release capacity to 250 ML/day.

• Irrigation demand will be low throughout these months, so this dam release capacity combined with continued high tributary flows should be adequate to meet water orders. Water users are encouraged to check with WaterNSW for more details.

Water availability weekly report 14

5.2 Macquarie valley

Storage and release status on: WaterInsights

• Burrendong Dam is at 56.8 percent of active capacity and currently releasing approximately 60 ML/d. Releases are expected to be steady at around 60 ML/d this week.

• Windamere Dam is currently at 33.7 percent of active capacity and currently releasing 25 ML/d. Releases are forecast to remain steady at about 25 ML/d at the end of this week.

• Rainfall and inflows this year have delayed the second phase of the transfer from Windamere to Burrendong February 2022. 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 on: WaterInsights

• Environmental watering event at Marebone finished on 4th Feb 2021, and planning was underway for a small autumn event to start around 15th March. However, due to recent Translucent flows the event was put on hold.

• Due to recent rain and inflows into the dam and downstream of the dam, the translucent flow event triggered and releases from Burrendong dam were made.

• The translucent flow period runs from 15 March to 30 November at Burrendong Dam.

• 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. Translucent environment water condition was triggered on 23rd March 2021, translucent releases were made up to 1st April; however, the release has since ended as the inflow triggers were not met .

Water availability on: WaterInsights

• The WAS published by DPIE on 14th April 2021confirmed that an additional allocation of 29 percent has been made to GS licence holders, bringing the total allocation this year to 63 percent.

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

• 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.

• Burrendong Dam didn’t spill by the end of February 2021; therefore, the general security and EWA carryover volumes spill protection was not necessary. The general security and EWA carryover volumes spill protection ended on 28th February 2021.

• Burrendong Dam has so far gained approximately 24,500 ML in the month of April 2021.

Water availability weekly report 15

• Carryover evaporation reduction in Macquarie and Cudgegong has been applied on carryover balances of General Security and High Security accounts at the end of the third quarter of the 2020-21 Water Year.

• A 2 percent carryover evaporation reduction was applied to GS and HS licence carryover balance in Macquarie and Cudgegong.

Drought operation measures on: WaterInsights

• Macquarie Regulated River Water Source is assessed to be at Drought Stage 1, normal operations.

• Due to recent rainfall and tributary inflows, all S&D replenishment for 20-21 have been completed.

Water quality water-quality-algae

• Burrendong Dam: Results for the 23 March show reducing productivity near the Dam. Algae numbers appear to be reducing. Storage is still at Amber alert.

• Windamere dam: Results for 24 March 2021 show that productivity is reducing across the storage. The assemblage has shifted to Microcystis sp. Downstream results showed very few cyanobacteria present. Windamere Dam is still on Amber alert.

• The Cudgegong river d/s of Windamere dam is on Green alert. However, due to the Amber Alert on Windamere dam, stock and domestic users should be vigilant and be on the lookout for algae scums and use alternate water if algae sums become evident.

• The cold-water pollution curtain at Burrendong is damaged and the curtain is not in operation. WaterNSW is assessing the damage.

Planned supply interruptions on: WaterInsights

• Burrendong Penstock Maintenance outage 3rd May to 2nd July 2021- During this outage releases from Burrendong dam will be made through a bypass outlet with the max discharge capacity of 220ML/d.

• Any inability to deliver translucent releases triggered during the maintenance outage will be subsequently made good in consultation with environmental water holders.

• As a result of limited release, if water enters FMZ before 31 August 2021, the carryover allocations remaining in the water accounts in Macquarie will not spill until 31 August 2021.

• Water users intending to store carryover allocations in on-farm storages will be able to order water from any tributary flows during the outage and also on completion of the outage in mid-July.

Water availability weekly report 16

6. Northern valley based operational activities

6.1 Namoi valley

Storage, release and inflow status on: WaterInsights Upper Namoi and Lower Namoi

• Split Rock Dam is at 28.84 percent of active capacity - up from 28.7 percent a week ago. It is currently releasing about 5 ML/d.

• Keepit Dam is at 64.44 percent of active capacity, up from 63.9 percent a week ago following rain across the catchment upstream of the storage. It is currently releasing about 4 ML/d.

• Chaffey Dam is at 57.9 percent of active capacity, up from 57.4 percent a week ago. It 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 on: WaterInsights Upper Namoi and Lower Namoi

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

Water availability on: WaterInsights Upper Namoi and Lower Namoi

• Uncontrolled flow access was allowed in Peel Valley due to recent rainfall event.

• The Water Allocation Statement, published by DPIE (dated 9 Mar) confirmed that in the Peel Valley both Local water utility (LWU), Domestic and Stock (D&S) allocations total 100 percent and Peel General Security (GS) allocation has received an increase by 37% resulting in 61% allocation for the current water year. Environmental Contingency Allowance (ECA) account also increases by the same percentage.

• The latest Water Allocation Statement, published by DPIE (dated 9 April 2021) confirmed an increase in GS allocations in the Lower Namoi Valley by 43.3 per cent. GS allocation the Lower Namoi Valley is at 82.6 per cent for the current water year.

• All other categories of licence in the Upper and Lower Namoi Regulated River Water Source remain unchanged as well.

Water availability weekly report 17

Drought operation measures on: WaterInsights Upper Namoi and Lower Namoi

• The Peel Valley is in Drought Stage 1. 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 water-on-order and release will increase when needed.

• The Upper Namoi Valley is at Drought Stage 1. Releases 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 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 1 under the Incident Response Guide.

• The Lower Namoi Operations updates.

Water quality water-quality-algae

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

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

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

Planned supply interruptions on: WaterInsights Upper Namoi and Lower Namoi

• Mollee Fishway is currently unavailable due to infrastructure failure.

Water availability weekly report 18

6.2 Gwydir valley

Storage, release and inflow status on: WaterInsights

• Copeton Dam is at 40.64 percent of active capacity (up from 40.5 percent last week following a recession of a significant rainfall event upstream of the Dam). Copeton Dam is currently releasing about 31ML/d.

Environmental water operations on: WaterInsights

• Planned environmental “3 Tributary” water continues to be delivered as per water sharing plan rules.

Water availability on: WaterInsights

• Supplementary access was allowed in Gwydir Valley due to recent rainfall event. Refer to supplementary announcement page in WaterNSW website for details

• The latest Water Allocation Statement published by DPIE -Water (dated 9 April 2021) confirmed that general security allocation in the Gwydir received increase by 39.12% so GS allocation is at 54.8 percent of general security entitlement for the 2020-21 Water Year. Environmental Contingency Allowance (ECA) account increased by the same.

• 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 water-quality-algae

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

Drought operation measures on: WaterInsights

• The Gwydir Valley is in Drought Stage 1. Management action will focus on ensuring water is available for critical needs for as long as possible.

Planned supply interruptions on: WaterInsights

• No supply interruptions are expected.

Water availability weekly report 19

6.3 Border Rivers

Storage, release and inflow status on: WaterInsights

• Pindari Dam is at 48.9 percent of capacity. Currently releasing around 50ML/day as translucent flow.

• Glenlyon Dam is at 53.2 percent of capacity. Releases ceased

• Boggabilla Weir is full from tributary inflows and currently spilling.

• Recent rainfall has generated significant inflow and triggered supplementary access in Border Rivers. For supplementary access announcements, please refer to the Supplementary Announcements section of WaterNSW website.

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

Environmental Water operations on: WaterInsights

• Stimulus flow release from Pindari Dam started on 1 October 2020 and around 4,500 ML was released throughout October 2020. Please visit the Operational Update section of the WaterNSW website for more details.

• Translucent flow release of about 50 ML/d from Pindari Dam has commenced again after the completion of the block release.

Water availability on: WaterInsights

• The latest Water Allocation Statement, published by DPIE -Water (dated 1 April 2021) provided an interim allocation update based on rapid increase in resources due to widespread rainfall during March. Initial estimates indicate that the available resources will be sufficient to allocate 100% to General Security A and 40% to General Security B class licences.

• There are no temporary water restrictions and operations is now returned to normal condition.

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

Drought operation measures on: WaterInsights

• The Border Rivers are in Drought Stage 1.

Water quality water-quality-algae

• Recent Blue Green Algae (BGA) sampling at Pindari shows a red alert level.

Planned supply interruptions on: WaterInsights

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

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6.4 Barwon-Darling River system

River flow status on: WaterInsights

• Significant rainfall and flooding across the catchments of Northern NSW and Southern Queensland during late March 2021 has generated substantial inflows into the Barwon-Darling. This event will also provide significant inflows to the Menindee Lakes system.

• Most of the inflows are expected from the Border, Gwydir and Namoi catchments and notable volumes are also expected from the Culgoa, Bogan, Macquarie and the Moonie.

• Based on current forecast, around 700-900 GL is expected at Wilcannia from this event (since 29 Jan 2021). Around 650-850GL is now forecast to reach Lake Wetherell.

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

Environmental water operations on: WaterInsights

• Environmental licence holders have also elected to ‘protect’ their share of access and this Active Environmental Water (AEW) is being actively managed down the river system.

• Planned Environmental Water (PEW) is water in the system that is below the Commence to Pump conditions for access licences. From 9am 12th January 2021 to 24 January, access was not available in all Management Zones because of the activation of the Resumption of Flow rule which was relaxed on 9am 24 January.

• Barwon Darling full Active Management has commenced. The flow class announcements indicate the amount of Active Environmental Water at each location.

Water Availability on: WaterInsights

• The 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.

• 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 Water Insights Portal for recent flow class announcements.

• From 9:00am, 12th January 2021, access was not available in all Management Zones because of the activation of the Resumption of Flow rule. • The Resumption of Flow rule is further relaxed from 9:00am, 29 January 2021 and currently normal access is available for all management zones. The relaxation of the Resumption of Flow rule is based on the current forecast exceeding the flow requirements under the Water Sharing Plan.

Drought operation measures on: WaterInsights

• The Barwon Darling unregulated river water source is assessed to be in Drought Stage 1.

Water availability weekly report 21

WaterNSW HYPLOT V134 Output 21/04/2021 Period 10 Month 01/07/2020 to 01/05/2021 2020-21 416001 BARWON R @ MUNGINDI 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 416050 BARWON U/S PRESBURY 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422004 BARWON @ MOGIL MOGIL 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422003 BARWON @COLLARENEBRI 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422025 BARWON @ TARA 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422001 BARWON @ DANGAR BDGE 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422026 BARWON @ BOOROOMA 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422027 BARWON @ GEERA 141.0012 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr

WaterNSW HYPLOT V134 Output 21/04/2021 Period 10 Month 01/07/2020 to 01/05/2021 2020-21 422002 BARWON @ BREWARRINA 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 422028 BARWON @ BEEMERY 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 425039 DARLING@WARRAWEENA 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 425003 DARLING@BOURKE TOWN 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 425004 DARLING@LOUTH 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 425900 DARLING@TILPA 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 425008 DARLING@WILC. MAIN C 141.00 12 Hour Mean Discharge (ML/d) CP 80000 64000 48000 32000 16000 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr

Water availability weekly report 22

7. Coastal valley based operational activities

7.1 Bega river

Storage and release status on: WaterInsights

• Brogo Dam is at 101.1 percent of capacity and spilling.

Environmental water operations on: WaterInsights

• There are no current additional operations.

Water availability on: WaterInsights

• Water Allocation Statement published by DPIE on 19 March 2021 confirms that the General Security AWD to is increased to 50 percent, and 100 percent for all other licence categories.

• Access to Supplementary and Uncontrolled flows has recommenced in all river sections until further notice.

Water quality water-quality-algae

• Recent sampling (3 November 2020) continue to show very low productivity across the storage. No cyanobacteria were observed upstream. The assemblage is dominated by small counts of diatoms. Downstream showed a minor cyanobacterial detection. Storage remains on green alert.

Planned supply interruptions

• Nil.

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7.2 Hunter valley

Storage and release status on: WaterInsights

• Glenbawn Dam is currently at 56.5 percent of capacity. Releases from the dam were ceased due to recent rain and increase in tributary inflows.

• Glennies Creek Dam is at 57.7 percent of capacity and releases were ceased due to rain and increase in tributary inflows.

• Lostock Dam is at 101 percent of capacity and spilling.

Environmental Water operations on: WaterInsights

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

Water availability on: WaterInsights

• Supplementary and uncontrolled flow access in available in all sections.

• The recent WAS published by DPIE on 15 March 2021 confirms that an additional 3 percent increase in allocation has been made to GS licences.

• The new allocation has increased total GS AWD to 100 percent for this water year. Carryover is equivalent to approximately 23 percent of the total share component. HS and all other categories received 100 percent allocation.

• At the beginning of the year EWA account has been credited with 20 GL in accordance with the Water Sharing Plan. However, no usage from EWA so far this year.

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

Drought operation measures on: WaterInsights

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

Water quality water-quality-algae

• Recent samples (8 Mar 2021) at Glenbawn shows that Microcystis sp. is still present at all upstream sites however overall productivity has declined. Downstream results showed no cyanobacteria present. Storage is now at Amber Alert Level. • Recent sampling results (8 March 2021) at Glennies Creek Dam show that productivity is increasing again across the storage. Assemblage is mixed with small counts of cyanobacteria and green alga present. Storage is now at Amber alert level. • 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 is now at Amber Alert Level.

• Planned supply interruptions:

• Nil

Water availability weekly report 24

7.3 Toonumbar Dam

Storage and release status on: WaterInsights

• Toonumbar Dam is at 101.5 percent of capacity and spilling.

Environmental water operations on: WaterInsights

• No current additional operations.

Water availability on: WaterInsights

• All licence categories have 100 percent availability.

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

• WaterNSW held the ROSCCO meeting in CASINO on 1 April 2021 and provided an updated- on water operation.

• WaterNSW invited guest speakers from various organisations who provided information to the group on Compliance issues (NRAR), rural metering framework (DPIE) and regional water strategy (DPIE).

Drought operation measures on: WaterInsights

• The Drought Stage level has eased from Drought Stage 2 to normal operations.

Water quality water-quality-algae

• Sample results for Toonumbar Dam (15 Mar 21). The storage is remaining on Red alert.

Planned supply interruptions:

• Scheduled works for replacement of the 610” valve started on the 19th of April 2021as per the plan. The outage is expected to be for 3 weeks. During this time no water will be released from the valves.

• Outage communication plan was discussed with customers in recent ROSCCo meeting held at Casino on 1 April 2021.

Water availability weekly report 25

8. Rural Dam Levels

Rural Dam levels are available on WaterInsights

9. More Information

More information Subscribe to our customer information (weekly water availability reports, e-newsletters, etc.) at waternsw.com.au/subscribe.

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