Regional

water availability

report

Weekly edition

22 March 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-Darling River system ...... 22

7. Coastal valley based operational activities ...... 24

7.1 Bega river ...... 24

7.2 Hunter valley ...... 25

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 22 March 2021 was 49%. This is an increase of 0.4%. Please note that rural water supply figures now include Cochrane Dam, Lake Victoria and Lake Cargelligo.

The total storage level of urban water supplies on 22 March 2021 was 99.1%. This was an increase of 6.0% 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 coastal and southern NSW storages, with the positive seasonal rainfall forecasts, 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. 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 , while ensuring water availability for next year. 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 over most catchments in previous weeks has maintained stream flows and inflows to the dams and from tributaries below dams. Water availability has increased in several valleys and operational plans are being reviewed as these inflows accumulate.

Water availability weekly report 3

3. Climatic Conditions

A strong high-pressure system over the southern Tasman Sea is directing humid easterly winds across New South Wales and is leading to heavy rain in many areas. Meanwhile, a low-pressure system over the centre of the state is moving southeast and is expected to be off the south coast tonight before moving to Bass Strait on Wednesday morning. The rain is expected to clear most of the state by tonight. Strong north easterly winds in the east will ease tonight as the low moves further south. A break from the wet conditions is expected on Wednesday apart from a few showers along the western ranges and slopes but fresh to strong westerly winds are expected in the southeast. The low will continue to move away to the southeast on Thursday as a ridge of high pressure moves across the state.

For the first part of the week, much of the state is predicted to receive rainfall with falls of up to 100mm predicted. As the week progresses negligible rainfall is forecast across the coastal and southern regions.

Figure 2a – First 4-day forecast (23 – 26 March 21) Figure 2b – Following 4-day forecast (27 – 30 March 21)

Climate outlook overview

Issued 18 March 2021

End of March and April likely to be wetter than average

Water availability weekly report 4

• April to June is likely to be wetter than average (chance of exceeding median is more than 60%) across eastern parts of NSW.

• The fortnight of 22 March to 4 April is likely to be wetter than average (chance of exceeding median is greater than 60%) over the eastern half of Australia. Parts of the east coast are very likely to be wetter than average (greater than 80% chance).

Figure 3 – 3-month rainfall outlook

ENSO Outlook (16 March) The ENSO Outlook remains at LA NIÑA, but there are several signs that this event is nearing its end. Oceanic indices have weakened in recent weeks with most returning to El Niño–Southern Oscillation (ENSO) neutral values, however, some atmospheric indices persist at La Niña levels. Latest model outlooks and observations indicate that the tropical Pacific will return to ENSO-neutral levels (neither El Niño nor La Niña) by mid-autumn. There is little sign that there will be a resurgence of the 2020−21 La Niña during the southern winter. The ENSO Outlook remains at LA NIÑA, but there are several signs that this event is nearing its end. Oceanic indices have weakened in recent weeks with most returning to El Niño–Southern Oscillation (ENSO) neutral values, however, some atmospheric indices persist at La Niña levels. Latest model outlooks and observations indicate that the tropical Pacific will return to ENSO-neutral levels (neither El Niño nor La Niña) by mid-autumn. There is little sign that there will be a resurgence of the 2020−21 La Niña during the southern winter. Despite weakening, La Niña is still likely to influence Australian rainfall patterns, with above average rainfall forecast for parts of eastern and northern Australia during April. Bureau climatologists will continue to closely monitor model outlooks and conditions in the tropical Pacific as this current La Niña event decays.

Water availability weekly report 5

4. Southern valley based operational activities

4.1 Murray Valley

Storage and release status on: WaterInsights

• is currently at 48 percent of active capacity and releasing 4,400 ML/d. The release will vary to meet the regulated flow demands.

• Release downstream of Yarrawonga Weir is at approximately 9,100 ML/d and is likely to gradually decrease to about 7,000 ML/day over the next week.

• The Edward River offtake flow (about 1,580 ML/d) will remain within channel capacity of 1,600 ML/d.

• The Gulpa Creek offtake flow (230 ML/d) will remain below operational channel capacity of 250 ML/day.

• Stevens Weir level is at approximately 4.60 m and will vary marginally to supply environmental water to Wakool system. Currently, the water level upstream of Wakool District Main Canal Regulator is approximately 1.79 m.

• Flow downstream of Stevens Weir is approximately1,400 ML/d for MDBA flow requirements to address the Barmah choke capacity constraints. The target is being currently reviewed and is likely to reduce over the next week. The flow in the Edward River system is augmented by delivery via Edward River Escape (up to about 550 ML/day) of the Mulwala Canal to maintain the delivery targets below Stevens Weir.

• Water is also delivered via Perricoota Escape (about 70 ML/day) to meet the operational demands of the MDBA.

• Flows into Colligen Creek (294 ML/d) will decrease over the coming week to 170ML/d, Wakool River (target is 80 ML/d) and Yallakool Creek (target is 180ML/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 Niemur River at Mallan School is currently at approximately 200 ML/d and will remain steady over the week.

• Merran Creek flow upstream of its confluence with Wakool is approximately 40 ML/d with the flow forecast to remain steady over the week.

• Flow in Wakool River at Stoney Crossing is currently at approximately 420 ML/d and will remain relatively steady.

• Flow at Balranald is approximately 2,000 ML/d to meet end of system targets for March (180 ML/day). The delivery of IVT volumes ordered by MDBA for April 2021 is in transit. However, the flow at Balranald is likely to slow down in the last week of March 2021 and then will average at approximately 1,700 ML/day in first week of April 2021. MDBA is currently reviewing the IVT target for April following the recent rainfall in the valleys.

Water availability weekly report 6

• Lake Victoria is currently holding approximately 193GL or 16 percent of active capacity. The flow to South Australia is at approximately 7,000 ML/d.

Environmental water operations on: WaterInsights

• The e-Water delivery into Wakool 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 March 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

• Indicative allocations for the next water year i.e. 2021-22 on 1 July 2021 for the valley shows that full (100%) allocation can be expected for towns, domestic and stock access licences, and sub-category high security entitlements. It is forecast that high security allocation will be 97%. It is likely that full general security carryover commitments (estimated to be 42%) will be met on 1 July, 2021. However, commencing general security allocations will likely be low or zero. Water can be expected to be set aside for environmental requirements in accordance with the rules of the water sharing plan.

• The next water allocation statement will be published on Thursday 1 April 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 A Red Alert warning has been issued for the lower Murray River from Red Cliffs to Mildura Weir inclusive. Downstream high alerts are current at Wentworth, Fort Courage and at the Lake Victoria (outlet).

o In the Upper Murray a Red alert has been issued for Mannus Lake.

• 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.

Water availability weekly report 7

4.2 Lower Darling valley

Storage and release status: on: WaterInsights

• The system collectively holds approximately 300 GL of total volume of water (or 16 percent of active capacity), is releasing approximately 350 ML/d.

• Lake Wetherell releases have ceased with Lake Pamamaroo now releasing 350 ML/d. The storage release from Lake Wetherell has been switched to Lake Pamamaroo to balance storage height between both lakes.

• The status of individual lakes are as follows: Lake Wetherell –28 percent, Tandure – 46 percent and Lake Pamamaroo – 80 percent, Copi Hollow – 70 percent, while Lakes Menindee and Cawndilla remain dry.

Environmental water operations on: WaterInsights

• The Water Sharing Plan minimum flows for the months of January through to March 2021 is 350 ML/d measured at Weir-32.

Water availability on: WaterInsights

• Forecast inflows to the lakes from the current flows in the Darling River tributaries are expected to be approximately 45-50 GL. This does not include rainfall forecast for the week ahead.

• The total storage volume is below 640 GL and is not forecast to reach this trigger in the next few months. As such, the storage remains in NSW control and the resources are being managed for Lower Darling operations.

• The WAS by DPIE (dated 15 March 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 remains at 30 percent. Carryover of approximately 48 percent is fully available.

• Indicative allocations for 2021-22 on 1 July 2021 shows that cease-to-flow conditions will be experienced in the Lower Darling in March/April 2022 unless further inflows accrue. Full (100%) allocation can be expected for towns, domestic and stock access licences, and high security entitlements in 2021-22. At this stage opening Lower Darling General Security allocation is likely to be low or zero unless there is significant further recovery in coming months. Although carryover water is likely to be fully available at the commencement of the water year, should the inflows fail then restrictions may be necessary in 2021-22 to protect critical water needs.

• The next water allocation statement will be published on Thursday 1 April 2021.

Drought operation measures on: WaterInsights

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

Water availability weekly report 8

Water quality: water-quality-algae

• Green alerts are current for Lake Wetherall site1 & 3. Amber alerts are currrent for Lake Wetherall Sites 2 &4, Copi hollow and Darling River at Tapio.

• 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

• is currently at 63 percent of active capacity, releasing approximately 450 ML/d as minimum planned environmental flow.

• Blowering Dam is currently at 75 percent of active capacity releasing approximately 600 ML/d and will vary with tributary contributions to meet the system demands

• The Beavers Creek offtake flow is approximately 105 ML/d and the flows will marginally vary to meet the daily flow target of 80 ML/d at Kywong during the period from December 2020 through to April 2021.

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

• Bundidgerry storage is currently at approximately 4.334 m and will vary over the week depending on the diversions by Murrumbidgee Irrigation.

• Gogeldrie Weir is at approximately 6.0 m and will remain steady over the week.

• The Tombullen storage (3.7m) 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 8.58 m will be used to meet any downstream demands including eWater.

• The water level at Maude Weir is approximately 3.58 m and will remain steady to facilitate dry conditions in the Nimmie-Caira offtake structures, where maintenance work is being carried.

• Currently, the Redbank Weir is empty for annual general maintenance. The water level will naturally vary in line with the river flows below Maude Weir.

• Flow at Balranald is approximately 2,000 ML/d to meet end of system targets for March (180 ML/day). The delivery of IVT volumes ordered by MDBA for April 2021 is in transit. However, the flow at Balranald is likely to slow down in the last week of March 2021 and then will average at approximately 1,700 ML/day in first week of April 2021. MDBA is currently revieing the IVT target for April following the recent rainfall in the valleys.

• The current diversion into Yanco Creek is about 550 ML/day to meet system requirements. The flow into the Yanco arm below Tarabah Weir will stay steady at about 100 ML/d while the split into the Colombo arm is approximately 460 ML/d. With the rain falling over the last couple of days orders in the Yanco system has started dropping. CICL escapes and finley Escape from MIL are currently closed.

• Requirement of MDBA of 200 ML/day via Finley Escape has now ceased due to the rain.

• The end of system target at Darlot is currently 50 ML/day in addition to customer water orders below Darlot.

Water availability weekly report 10

Environmental water operations on: WaterInsights

• 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 would restart by mid-April. It is expected that about 25GL would be delivered during the event over a 9-week period.

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 March 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 10% per cent based on current forecasts.

• The next water allocation statement will be published on Thursday 15 April 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 In Burrinjuck Dam, Woolgarlo, Burrinjuck Waters State Park and at the Dam Wall sample sites remain on Red alert for blue-green algae. Good Hope site is also now back on Red alert.

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 Burrinjuck Dam downstream of the Dam Wall as well as the Murrumbidgee River at Hay Weir Buoy and Maude Weir Buoy are on Amber alert for blue-green algae.

o Blowering Dam at the dam wall, the Murrumbidgee River at Wagga Wagga Roaches Road, Gogeldrie

o Weir, Redbank Weir and at Balranald are on Green alert for blue-green algae.

o Lake Albert in Wagga Wagga is on Green alert for blue-green algae.

o There are no other blue-green algal alerts.

Water availability weekly report 11

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 would limit the maximum release capacity to about 9,000 ML/day through the low-level valves.

• 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 would be temporarily stopped. Any system demands on Murrumbidgee would be met from Burrinjuck Dam. Flows in the Tumut 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.

• Maintenance work is underway for the annual maintenance of Redbank Weir and Glendee offtake regulator. The work is expected to be finished by end of March. This would impact any deliveries to Lowbidgee via these offtakes until mid-April 2021.

• Maintenance work is underway for the essential maintenance work on North Caira offtake and Nimmie Creek offtake structures. The works are expected to be complete by June 2021. This would impact any deliveries to Lowbidgee via these offtakes until end of June 2021.

Water availability weekly report 12

5. Central valley based operational activities

5.1 Lachlan valley

Storage and release status on: WaterInsights

• is currently at 30 percent of capacity and is releasing approximately 5 ML/d.

• is currently at 59.9 percent of capacity and is releasing approximately 450ML/d to meet system demand.

• Lake Cargelligo is currently at approximately 66.7 percent of capacity and will be reduced to around 64 percent by end of this week.

• Releases downstream of the Brewster Weir are around 170 ML/d. Releases are forecast to remain between 150 – 180 ML/d during the week.

• Lake Brewster storage on 17th March 2021 was 6.82 percent of capacity with a volume of approximately 9,915 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 5.5 GL of the Lachlan Water Quality Allowance will be utilised to provide a flow of 100 ML/day at Booligal Weir during January 2021 to March 2021 to reduce the risk of low dissolved oxygen for fish.

Water Availability on: WaterInsights

• The WAS published by DPIE on 8th March 2021confirmed that an additional allocation of 6 percent has been made to GS licence holders, bringing the total allocation this year to 44 percent.

• 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.

• In Belubula, access to uncontrolled flow event recommenced at 9am Sunday 14 March and will cease at 9am Tuesday 23rd March 2021.

• The WAS published by DPIE on 21 October 2020 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 availability weekly report 13

• 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 (10th March 2021) show continuing low productivity at all sites. Detections of Dolichospermum circinale were observed at Station 1. The storage is now on Amber Alert Level.

• The Carcoar Storage latest samples (10th March 2021) show moderate productivity with some cyanobacteria detected in the upstream sample. Downstream showed no cyanobacteria detected. Storage at Amber Alert Level.

• The Lake Brewster Sample results from the 2nd March 2021 at lake Brewster inlet and at Regulator C are at Green Alert. However, due to presence of some potentially toxic substance Lake Brewster Outlet Channel is still now on Amber alert.

• Results from Lake Cargelligo on 3rd March 2021 show increasing productivity across the storage. Green and flood alga dominate the assemblage at all sites however Anabaena sp. is now present downstream in the Lachlan. Few other cyanobacteria were detected. System is now on amber alert.

Planned supply interruptions on: WaterInsights

• Nil

Water availability weekly report 14

5.2 Macquarie valley

Storage and release status on: WaterInsights

• is at 39.9 percent of active capacity and currently releasing approximately 100 ML/d. Releases are expected to be steady at around 100 - 150 ML/d this week.

• is currently at 29 percent of active capacity and releasing 10 ML/d. Releases are forecast to steady about 10 ML/d during 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 for a week.

• Due to recent rain and inflows into the dam and downstream of the dam, the translucent flow event was recently triggered and releases from Burrendong dam have been ongoing. The translucent release was stopped on 22nd March 2021 as the triggers were not met – increased Tributary flows d/s.

• 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. Windamere storage volume reached 110GL on 13 Nov 2020 but has now fallen below that trigger level. With forecast of rain the triggers are likely to be met soon and translucent will commence.

Water availability on: WaterInsights

• The WAS published by DPIE on 10th March 2021confirmed that an additional allocation of 4 percent has been made to GS licence holders, bringing the total allocation this year to 34 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 gained approximately 20,500 ML so far in the month of March 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 second quarter of the 2020-21 Water Year.

• A 3 percent carryover evaporation reduction was applied to Macquarie River and 1 percent to Cudgegong River.

Drought operation measures on: WaterInsights

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

• All S&D replenishments were completed in 2019-20 water year.

Water quality water-quality-algae

• Burrendong Dam: Results for the 9March show some productivity near the Dam. Storage is now at Amber alert.

• Windamere dam: Results for 9th March 2021 show that productivity has remained high across the storage. The assemblage has shifted to Microcystis sp. Downstream results showed very few cyanobacteria present. Windamere Dam is now on Red alert.

• The Cudgegong river d/s of Windamere dam is on Green alert. However, due to the Red 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.

• 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

• is at 17.82 percent of active capacity - up from 16.30 percent a week ago following rain across the catchment upstream of the storage. Current releases of 2ML/d are likely to increase to 35ML/d later this week.

• is at 44.81 percent of active capacity, up from 42.00 percent a week ago following rain across the catchment upstream of the storage. It is currently releasing about 8 ML/d.

• is at 45.00 percent of active capacity, up from 43.80 percent a week ago, 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 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 4% resulting in 24% 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 5 March 2021) confirmed no increase in allocations in the Lower Namoi Valley, the GS allocation the Lower Namoi Valley for a cumulative allocation to remain at 39.3 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 an Amber 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

• is at 21.7 percent of active capacity (up from 20.21 percent last week). Copeton Dam is currently releasing about 31ML/d

• This summer’s block releases have now ceased.

• Please see the Gwydir Valley Update

Environmental water operations on: WaterInsights

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

Water availability on: WaterInsights

• The latest Water Allocation Statement published by DPIE -Water (dated 5 March 2021) confirmed that general security allocation in the Gwydir received no increase so GS allocation remains at 15.68 percent of general security entitlement for the 2020-21 Water Year. Environmental Contingency Allowance (ECA) account also remains 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.

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

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

• is at 12.9 percent of capacity. Currently releasing around 50ML/day as translucent flow.

• Glenlyon Dam is at 14.5 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.

• Significant rainfall is forecast for next few days which is likely to provide additional supplementary access and some inflows to the dams.

• 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.

• Around 2.9 GL of environmental water has been delivered at Mungindi. That water started arriving at Mungindi on 4 January.

Water availability on: WaterInsights

• The latest WAS, published by DPIE -Water (dated 4 February 2021) confirmed 13.4 percent allocation for General Security A in the NSW Border Rivers regulated water source that totals 78 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.

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

• Block release from Pindari Dam commenced on 17 December 2020 and completed on 3 January 2021.

Drought operation measures on: WaterInsights

• The Border Rivers are in Drought Stage 2.

Water quality water-quality-algae

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

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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

• Inflows from different tributaries have been arriving in the Barwon- Darling since late December and water reached Lake Wetherell on 4 February 2021. There is now full connectivity along the Barwon-Darling river system.

• Based on current forecast (not including this week’s forecast rain), around 55-60 GL is expected at Wilcannia from this event (since 29 Jan 2021). Around 45 -50 GL is now forecast to reach Lake Wetherell.

• Significant rainfall has been observed across Barwon Darling and other tributary catchments during last few days with more in the forecast. Additional inflows are expected from Border, Namoi, Gwydir and Macquarie systems. This will provide additional inflow to Menindee Lakes.

Environmental water operations on: WaterInsights

• Environmental water delivery was made during this event. Around 2.9 GL at Mungindi from the Border Rivers and 5.1GL at Galloway from Gwydir system was ordered. Some water has been protected within Barwon Darling system. Part of that water reached Menindee Lakes.

• 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.

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Drought operation measures on: WaterInsights

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

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WaterNSW HYPLOT V134 Output 23/03/2021 Period 9 Month 01/07/2020 to 01/04/2021 2020-21 416001 BARWON R @ MUNGINDI 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 416050 BARWON U/S PRESBURY 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422004 BARWON @ MOGIL MOGIL 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422003 BARWON @COLLARENEBRI 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422025 BARWON @ TARA 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422001 BARWON @ DANGAR BDGE 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422026 BARWON @ BOOROOMA 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422027 BARWON @ GEERA 141.0012 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar

WaterNSW HYPLOT V134 Output 23/03/2021 Period 9 Month 01/07/2020 to 01/04/2021 2020-21 422002 BARWON @ BREWARRINA 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 422028 BARWON @ BEEMERY 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 425039 DARLING@WARRAWEENA 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 425003 DARLING@BOURKE TOWN 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 425004 DARLING@LOUTH 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 425900 DARLING@TILPA 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 425008 DARLING@WILC. MAIN C 141.00 12 Hour Mean Discharge (ML/d) CP 6000 5000 4000 3000 2000 1000 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar

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7. Coastal valley based operational activities

7.1 Bega river

Storage and release status on: WaterInsights

• is at 130 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 increased the General Security AWD 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

• is currently at 54 percent of capacity. Releases from the dam were ceased due to recent rain and increase in tributary inflows.

• is at 57 percent of capacity and releases were ceased due to rain and increase in tributary inflows.

• is at 104 percent of capacity and spilling.

Environmental Water operations on: WaterInsights

• Currently, all environmental flow targets are being met.

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.

• The EWA has been 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 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

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7.3 Toonumbar Dam

Storage and release status on: WaterInsights

• Toonumbar Dam is at 105 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.

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 is planned to start on the 12th of April 2021, outage is expected to be for 3 weeks.

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8. Rural Dam Levels

The following table shows the status of water supplies at 22 March 2021.

Weekly Likeliho Active River Valley Current Status change Comments od of fill Allocations for 2020/21 Capacity (GL) and 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 Glenlyon Dam, Stanthorpe 253 14% 36 2.96 Release ceased <20% 100% 6.5% 2% (Qld)

Pindari Dam, Inverell 312 13% 40 1.27 Translucent flow release <20% 100% 6.5% 2%

Gwydir Valley Copeton Dam, Inverell 1346 22% 292 24.72 Minimum releases <5% 100% 15.68% 5%

Namoi Valley

Keepit Dam, Gunnedah 419 45% 189 8.85 Releases ceased <20% 100% 39.3% 6%

Split Rock Dam, Manilla 394 18% 70 5.45 Regulated releases <5% 100% 100% N/A

Chaffey Dam, Tamworth 101 45% 45 1.52 Min release & d/s tribs <50% 100% 24% N/A

Macquarie Valley

Burrendong Dam, Wellington 1154 40% 461 0.00 Translucent flows ceased. <10% 100% 30% 16%

Windamere Dam, Mudgee 367 29% 107 0.86 Regulated releases <5% 100% 30% 58%

Lachlan Valley

Wyangala Dam, Cowra 1217 60% 729 13.48 Regulated releases <10% 100% 44% 6%

Trib flow, supp and UCF Carcoar Dam, Carcoar 36 30% 11 0.03 <10% 100% 0% 28% access

Lake Cargelligo 30 67% 20 -0.38

Murrumbidgee Valley Regulated releases Burrinjuck Dam, Yass 1025 61% 629 -2.91 <50% 100% 100% N/A including eWater Regulated releases Blowering Dam, Tumut 1604 75% 1198 -9.07 <25% 100% 100% N/A including eWater Murray Dartmouth, Mitta Mitta (Vic) 3837 62% 2375 2.50 Minimum releases N/A N/A N/A N/A Regulated releases Hume Dam, Albury 2982 47% 1401 -23.86 <25% 97% 50% 21% including eWater Lake Victoria 577 93% 535 -25.00 Lower Darling

Menindee Lakes, Broken Hill 1633 16% 260 -3.76 Min regulated releases <30% 100% 30% 48%

Hunter Valley Trib flows, access to Supp Glenbawn Dam, Scone 750 53% 395 13.13 <10% 100% 97% 23% and UCF in all sections Glennies Ck Dam, Singleton 282 55% 154 20.70 Trib Flows <20% 100% 97% 23%

Lostock Dam, Gresford 20 105% 21 -0.57 Spill 100% 100% 100% N/A

Coastal Area Toonumbar Dam, Kyogle 11 102% 11 0.11 Spill 100% 100% 100% N/A Spilling, access to Supp and UCF Brogo Dam, Bega 9 118% 10 1.53 100% 100% 40% N/A continues until further notice Cochrane Dam 3 79% 2 1.50 Total 18359 49.0% 8 992 33

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

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9. More Information

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

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