Water Availability Report

Transcription

1 Water Availability Report Authorised by Dan Berry Manager Water System Operations (2) April 218 Table of Contents Overview... 2 System Risks... 2 Climatic Conditions Month Forecast Climatic Conditions... 3 Valley Based Operational Activities... 3 Murray Valley... 5 Lower Darling Valley... 5 Murrumbidgee Valley... 6 Lachlan Valley... 8 Macquarie Valley Namoi Valley... 8 Gwydir Valley Border Rivers Barwon Darling River System... 2 Bega River Hunter Valley Toonumbar Dam WaterNSW (Rural) Dam Levels Subscribe here for updates to the Water Availability Report. For Greater Sydney Water Availability, please follow the below link: Page 1 of 28

2 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 of 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 16 April 218 was 49.4% of the total active storage capacity. This was a decrease of.4% from last week. The total storage level of urban water supplies on 16 April 218 was 74.1% of the total storage capacity. This was a decrease of.6% from last week. System Risks The Temporary Water Restrictions are still in place in the Barwon Darling system downstream of Boorooma to reinstate connectivity of flow to Wilcannia and Menindee. Cease-to-flow continues from downstream of Wilcannia still exist though flow connectivity is expected to occur over the coming weeks to Wilcannia. Cease to flow conditions are current at Walgett, though connectivity will recommence in within the next three weeks due to environmental water deliveries. Menindee Lakes continues to be below the 48GL trigger for NSW control, and reduced releases have been implemented to extend drought security. These lower releases increase the possibility of; access problems with very low flows, and decreasing water quality. Releases for a significant environmental water order for the Barwon Darling have commenced from Copeton Dam. Drought contingency measures (block releases) will be needed in the Namoi and Gwydir valleys to deliver the small volumes remaining in customer accounts if conditions remain dry in 218/19. Cease to flow conditions have commenced in parts of the Gwydir and Lower Namoi Valleys. Low flows in the Lower Murrumbidgee in general and possible cease to flow conditions in anabranches such as Beavers Ck Old Man Creek. Page 2 of 28

3 Climatic Conditions Figure 1 - Weekly rainfall totals for New South Wales (w/e 16 April 218) A low pressure system southeast of Tasmania is moving slowly east and a series of associated troughs are crossing southeastern Australia. During Tuesday a high pressure system will move near Tasmania extending a ridge along the New South Wales coast. The high is expected to move over the southern Tasman Sea on Wednesday and continue to move east, maintaining the ridge to the northwest. Figure 2a First 4 day Forecast (16-19 April 18) Figure 2b Following 4 day forecast (2 April 23 Apr 18) Page 3 of 28

4 3 Month Forecast Climatic Conditions The May to July rainfall outlook, issued 12 April 218, shows the far southeast of Australia is likely to have a wetter than average three months. The rest of New South Wales has roughly equal chances of a wetter or drier than average three months. May to July daytime temperatures are likely to be warmer than average for southern Australia. Night-time temperatures are likely to be warmer than average for southern parts of Australia. May days and nights are likely to be warmer for all of New South Wales. The El Niño Southern Oscillation in the tropical Pacific Ocean is neutral, and is expected to remain so for the coming season. The Indian Ocean Dipole (IOD) is also neutral, with the possibility of a negative IOD event from June. With mostly neutral climate drivers, there is no strong push towards broad scale wetter or drier conditions across the country. Figure 3 - Three-month rainfall outlook Page 4 of 28

5 Valley Based Operational Activities Murray Valley Storage Status Hume Dam is currently at 34% of active capacity, releasing about 13,5 ML/d. Predicted Release Patterns Releases from Hume Dam are likely to marginally vary in line with downstream environmental/irrigation demands. Planning is underway to lower Lake Mulwala in late autumn and winter; the draw down is aimed at managing invasive water weed and also to undertake works on the lake foreshore. The flow at downstream Yarrawonga Weir is approximately 8,15 ML/d and close to the channel capacity limit through the Barmah choke. The releases are likely to remain around this level until end of April. Edward River Offtake is currently near the channel capacity limit of 1,6ML/d. Gulpa Creek Offtake is near the channel capacity limit of 35ML/d. Edward River Escape of the Mulwala Canal is being used to meet all the Wakool Canal orders. The Escape orders are about 7 ML/d. The arrangement would cease from 1 May 218, when the Mulwala Canal and Wakool Canal offtakes are closed by Murray Irrigation (end of season closure). Stevens Weir is likely to be maintained at the current level of about 4.6m. The flow at downstream Stevens Weir is currently about 7 ML/d to assist meeting demands in the Lower Murray and to transfer water from Hume to meet the Lake Victoria end of year target of 35GL. The Stevens weir flow is expected to vary between 7 and 9 ML/d. Operating Conditions Diversions into Colligen Creek (35ML/d), Yallakool Creek (425ML/d) and Wakool River offtake (5ML/d) will be managed as per the environmental demands. Flow at Moulamein is currently about 93 ML/d and is likely to remain relatively steady over the next week. Flow at Mallan School is currently about 24ML/d and is likely to gradually increase over the next week. Inflows from the Murrumbidgee River are about 21 ML/d at Balranald, and likely to remain relatively steady. Lake Victoria is currently holding about 28 GL or 19% of active capacity. End of system flows to South Australia is currently about 6,1 ML/d. Potential Blue Green Algae issues. o Hume Dam: Results for 3/4 were again at Green Alert levels at each lake site. o Lake Victoria outlet regulator (26/3) is at Amber alert. o Edward R. at Deniliquin and Moulamein are at Green alert level o For more information visit: Planned Supply Interruptions: Lowering of Lake Mulwala is being planned for the late autumn and winter season. However, it is not expected to impact the water supply to meet the forecast demands, which are expected to be low with end of irrigation season for MIL (set for 1 May 218). Page 5 of 28

6 Lower Darling Valley Storage Status The lakes currently hold an active volume of about 162 GL or about 1% of active capacity. The total storage is about 245 GL. Lake Menindee has been dry since 6 Feb 218. Predicted Release Patterns Release from Lake Pamamaroo is about 25ML/d, primarily to meet the flow targets of about 18ML/d at Weir 32 and at least 2ML/d at Burtundy. Release from Lake Cawndilla outlet to Redbank Creek has now ceased. Operating Conditions The net evaporation loss over the last week was about 7,28ML. The average pan evaporation rate at Menindee over the last week was about 9.4mm, which is about 65% higher than the climatic average for the month of April. The total storage of Menindee Lakes reached the 48GL trigger for NSW control of the lakes on 16 December 217. The releases from the storages will be managed as per the Lower Darling Annual Operations Plan until the storage volume next exceeds 64GL. For more information visit: data/assets/pdf_file/6/129831/lower- Darling-Operational-Plan-December-217.pdf The current flow rate at Burtundy is about 65ML/d and is expected to remain relatively steady over the next week. As planned, a temporary bank has been installed between Lake Wetherall and Lake Tandure. Pumping started on 25 March 218 to transfer water at 16ML/day into Lake Wetherell as part of the measures to reduce evaporation losses from Lake Tandure. Potential Blue Green Algae issues. The following warnings are current for the various sampling locations within the Menindee Lake System and Lower Darling River immediately downstream of the storages. o Results to the 4 April show a red alert at Lake Wetherill Site 3 and Tandure site 8 o The Wetherell sites 1,2, and 4 are now at amber alerts o Darling R at Pooncarie and Burtundy are at Red Alert. o For more information visit: Planned Supply Interruptions Nil Page 6 of 28

7 Murrumbidgee Valley Storage Status Burrinjuck Dam is currently at about 4% releasing about 45 ML/d. Blowering Dam is about 46% releasing about 2,8 ML/d. Predicted Release Patterns While the required release from Burrinjuck Dam as per the Plan rules are about 3ML/day, the current releases are being managed to maintain the minimum flow to operate the Hydro Electric Power Station (HEPS). Hence the releases are likely to stay around 45ML/day. The system demand is primarily being met from Blowering Dam. It is estimated that the release from Blowering Dam is likely to stay around 3,ML/d for the next couple of weeks. The current diversion into the Yanco Creek is about 55 ML/d. The delivery through Coleambally escapes averages about 1 ML/d to meet demands in the Yanco Creek / Billabong system. The Beavers Creek Offtake is fully open and the flow is about 17 ML/d, which is expected to fall to about 1ML/day later this week. The current flow at Kywong is around 3 ML/d. The operational flow target to end of April at Kywong is 6 ML/d. The lower levels in Murrumbidgee River may lead to lower flows or cease to flow conditions in the Beavers Ck and Old Man Ck systems over coming weeks. A customer notice has been issued on 27 March 218 to alert the customers and landholders on the flow situation. data/assets/pdf_file/15/131523/beavers-creek-low-flows- 27-March-218.pdf Operating Conditions The mid-april resource assessment resulted in Dept of Industry- Water (DOI-W) announcing 3% allocation increase to general security licences. The resource improvements were mainly due to continued releases from Snowy Hydro. Re-regulation storages are being actively used to capture any excess system flows and to meet the downstream demands. Bundidgerry is currently about 5%, Tombullen at about 7%, Hay Weir at about 1%, Maude Weir at about 96% and Redbank Weir at about 37% of capacity. There has been very little rain in the catchments with only about 16-2mm rain recorded over the weekend. The weather has generally been very dry in the irrigation areas. Watering is mainly for horticulture and other permanent plantings. A small demand exists for watering soy, pasture, and some pre-watering for winter cereals. The water levels at Darlington Point gauge is currently about.7m and is likely to fall to about.5m while meeting the lower demands downstream of Gogeldrie Weir. The river sections downstream of Gogeldrie Weir to the Murray confluence may experience low river levels, particularly between Gogeldrie Weir to the influence of the Hay Weir, and downstream of Redbank Weir to the Murray confluence. Customers should take the necessary steps to adjust their pumping activities accordingly and monitor the river level closely. data/assets/pdf_file/17/131525/murrumbidgee-low-levelriver-forecasts-ds-gogeldrie-march pdf Flows at Balranald are currently about 21 ML/d and are expected to remain marginally above the end of system flow target (18ML/d) in order to maintain a steady level at Balranald Weir. At this time, regular monitoring of the Balranald Weir pool will occur and operations adjusted as necessary in an effort to maintain the weir pool. Page 7 of 28

8 Jul-16 Aug-16 Oct-16 Dec-16 Feb-17 Apr-17 Jun-17 Aug-17 Oct-17 Dec-17 Feb-18 Apr-18 Jun-18 Aug-18 Oct-18 Dec-18 Feb-19 Apr-19 Jun-19 End of Month Storage (GL) The current flow at Darlot is about 3ML/d and is likely to gradually reduce to about 22ML/day over the next week. Inter Valley Transfer (IVT) account from Murray to Murrumbidgee closed on 2 October 217. The current balance is GL. Potential Blue Green Algae issues. o There are Green alerts for Burrinjuck Dam at Woolgarlo, Burrinjuck Station 1 (Dam Wall), Burrinjuck Downstream, Blowering Station 1 (Dam Wall), Redbank Weir Buoy and Murrumbidgee River at Balranald. o Lake Albert in Wagga Wagga is still in a state of Red alert o o Amber alerts are current for Burrinjuck Dam at Goodhope and the Murrumbidgee at Carathool. Red alerts are current for the Hay Weir Pool including Leonard Street and Hay Weir Boy Sites. o Samples from other sites have no alert. o Note: The alert levels apply to non-consumptive or recreational contact. Drinking water safety thresholds are much more stringent o For more information visit: Planned Supply Interruptions Activities for the seasonal maintenance of Redbank Weir are being planned. The gates are expected to be completely withdrawn from water by the last week of April. Burrinjuck Dam Forecast Storage Capacity Updated mid-april Extreme dry scenario (99%) Dry Scenario (8%) Average scenario (5%) Wet scenario (2%) Actual * Including Snowy releases Page 8 of 28

9 Blowering Dam Forecast Storage Capacity Updated mid-april Jul-16 Aug-16 Oct-16 Dec-16 Feb-17 Apr-17 Jun-17 Aug-17 Oct-17 Dec-17 Feb-18 Apr-18 Jun-18 Aug-18 Oct-18 Dec-18 Feb-19 Apr-19 End of Month Storage (GL) Jun-19 Extreme dry scenario (99%) Dry Scenario (8%) Average scenario (5%) Wet scenario (2%) Actual * Including Snowy releases Page 9 of 28

10 Lachlan Valley Storage Status Carcoar Dam is at 58% and releases have averaged about 63 ML/d during the last week. Wyangala Dam is at 67% and releases have averaged about 1,25 ML/d during the last week. Predicted Release Patterns The releases from Carcoar dam are expected to be around 65 ML/d during the week. The releases from Wyangala Dam are at 125ML/d and are expected to stay the same for next day or two and reduce to around 1ML/d later in the week. In the Lower Lachlan, the releases at Brewster have been averaging 235ML/d to meet irrigation demands and to meet the minimum flow target. Demand is predicted to reduce further in the coming weeks. Operating Conditions As releases from Wyangala Dam are receding, a minimum flow target of 35 ML/d has been set at downstream Jemalong Weir to ensure adequate flows into Island Creek and Wallamundry Ck system to meet demand for autumn watering. It is estimated that a combined dam and tributary inflow volume in excess of 39, ML is required in April before a further allocation could be made in the Lachlan River. Lake Cargelligo storage is currently at 51% and it is planned to maintain the storage under 5% in autumn to maximise the capture of any surplus flows from tributaries. Landholders along the foreshores of Lake Cargelligo are advised to fill their stock and domestic storages prior to the drawdown in lake level. As of 16 April 218, Lake Brewster is at 2.6% holding about 3.7 GL totally with about.9 GL in the main storage. Latest BGA samples from Lake Brewster show that Willandra Weir, Lake Brewster Regulator C, Lake Brewster outlet channel, Lake Cargelligo Outlet and Boatshed are all on green alert. As of 12 March no more water has been drawn from Lake Brewster storage as the remaining water is set aside to be delivered as Environmental Contingency Allowance (ECA) from Lake Brewster. Consequently releases from Lake Cargelligo have been managed to meet more of the demand in the lower Lachlan. Delivery of licenced environmental water to replenish the Lake Brewster outflow wetlands has finished on 13 th April. A total of nearly 3,ML has been delivered to replenish the outflow wetlands. The next delivery of S&D replenishment flows in the lower Lachlan will be in late autumn 218. Carryover into in Lachlan River is expected to be about 372GL, equivalent to about 63% of general security share components. As of 31 March 218, net allocation assignment (temp trade) from upstream to downstream of Lake Cargelligo Weir was 48,517 ML. As the net allocation assignment to downstream is limited to 82, ML, there is room for another 33,483 ML to be traded down. This higher trade across the Lake Cargelligo barrier has been made possible due to the amendment of the original WSP trade limit of 32, ML to 82, ML in December 212. Planned Supply Interruptions Planned maintenance works on Jemalong Weir is scheduled for June/July 218. The Jemalong Weir pool is likely to be drawn down from mid June and restored on completion of Page 1 of 28

11 works at the end of July. During this period a very low flow is likely to be maintained past the weir. Account spill and reset of general security allocations If WaterNSW were to commence dam releases to maintain airspace in Wyangala Dam, it will trigger an account spill and reset of general security allocation accounts, high security spillable sub-accounts and the conveyance licence account as per section 56 of the Lachlan WSP. The Department of Industry - Water has announced that if there is an account spill and reset there will be no further reset in the following 6 months. Page 11 of 28

12 Macquarie Valley Storage Status Burrendong Dam is currently at 38% and Windamere Dam is at 42% capacity. Predicted Release Patterns Currently releases from Burrendong are around 1, ML/d and are planned to gradually reduce to around 3-4ML/d during the week. The releases have increased mainly due to increase in irrigation orders and also to restore minimal flows in the regulated sections below Marebone Weir and Marebone Break. Releases from Windamere are currently around 65ML/d and are planned to stay at 65ML/d for rest of the week. Operating Conditions All the current releases from Burrendong Dam are for irrigation and town water demand and minimum flow targets. WaterNSW have been conserving water in the dam and releasing very low flows since the first week of March. These dam releases were intended to maintain minimal flows past Marebone Weir and the Marebone Break Due to the unusual warm conditions so far in April, the flows past Marebone Weir and Marebone Break have ceased, which was not intended. Dam releases have been increased since 8th April, to restore and maintain the flows past the Marebone Weir and Marebone Break. However, due to slow travel time associated with low flows in the river it will take more time thanusual for flows to reach Marebone and downstream. It is estimated that an additional 185 GL of inflow was required in March to trigger an increment in Available Water Determination. Inflows to Burrendong Dam in March were about 7.5 GL. It is forecasted that a total of less than 4 GL of licenced water may be extracted for irrigation and environment this water year. Algal sampling results from 4 th April 218 at Burrendong have detected a large red alert level bloom of potential toxic species at the Dam wall. However this does not appear at the downstream. The storage is now at Red Alert. Sampling results from 28 th March 218 at Windamere shows a mixed assemblage of potential toxic species at Amber level. Downstream results show Green Alert Level of mixed assemblage. However the storage is remains at Red alert. The position of the trash rack at Windamere Dam is currently 9-12 m below the surface. Deep water diving work at the intake tower to reinstate the CWP temperature curtain has been completed. All 8 guide wire cables have been installed to the anchors on the floor of the dam, in readiness for curtain reinstatement in autumn 218. Carryover evaporation reduction was applied to remaining carryover balances in HS and GS sub-accounts in Macquarie and Cudgegong Rivers for March quarter of A 3.% reduction was applied to Macquarie River Water Source and a 1.8% reduction was applied on Cudgegong River water source. Carryover balances in EWA incurred the 3.% reduction. The Dept of Industry (water) water allocation statement (WAS) dated 14 March 218 confirmed that the forecast usage in 218/19, including environmental watering plans, is deliverable from the stored water currently in Burrendong and Windamere Dams. A bulk water Page 12 of 28

13 transfer from Windamere Dam may be required, commencing in January 219, if conditions remain dry. Stock and domestic replenishment flows will be scheduled for delivery in late autumn/winter 218. The timing of deliveries thereafter in 219 will depend on rainfall events, dam inflows, and contributions from downstream tributaries. Carryover into in Macquarie River is forecast to be equivalent to about 54% of general security share component. Carryover into in Cudgegong River is forecast to equivalent to about 114% of share component. Planned Supply Interruptions Maintenance and repair work at Marebone Bk offtake is scheduled to commence in the last week of April 218 and is planned for completion by the third week of May 218. During this time a minimum flow will be made available through the regulator to meet Stock and Domestic (S&D) requirements in the regulated Bulgeraga Creek. Page 13 of 28

14 Namoi Valley Storage Status Keepit Dam is at 13%, Split Rock Dam is at 15% and Chaffey Dam is at 68% of active capacity. Predicted Release Patterns The release of water for the Commonwealth Environmental Water Holder from Keepit Dam for stream connectivity to Narrabri continues. Releases to maintain this connectivity are forecast to be about 5-8 ML/d. Split Rock Dam is releasing around 5 ML/d to deliver about 2 ML/d to Upper Namoi water users. Releases are expected to remain relatively stable for the next week. Chaffey Dam releases have decreased to around 1 ML/d and are forecast to stay around this level for the next week. Demand has been split evenly between Tamworth City of approximately 3 ML/d and industry use of around 3ML/d. Operating Conditions There was no significant rainfall during the past week with temperatures in the mid 3 s. There is no significant rain forecast for the next week, and temperatures are forecast to reduce to the high 2 s. Irrigation demand in the lower Namoi has ceased, though environmental deliveries continue to maintain stream connectivity to Narrabri. On completion of environmental (general security) releases, intermittent releases from Keepit will be required to satisfy mining requirements in the upper river sections. It is likely that some additional environmental deliveries may commence in April/May in both the Peel and Lower Namoi Valleys. Recent sampling for BGA indicates that Split Rock and Keepit remain at amber alert, whilst Chaffey has moved to green. Under minimum inflows and forecast demand the combined storage levels of Split Rock and Keepit are forecast to be below 12GL by June this year. If inflow is better than minimum and or demand is less than forecast the combined storage may be above 12GL. If the combined storage is above 12GL, the end of system flows will be required to be delivered while the combined storage is above 12GL. Water deliveries have ceased in the first week of March 218, and if conditions remain dry, remaining water in licences will be delivered via a complete block release strategy throughout 218/19. It is likely that only one release will occur during the winter months and up to three releases during spring and summer below Mollee Weir. Release upstream of Mollee will occur every 6 to 8 weeks. Flow in the lower reaches of the Namoi and Pian Ck systems has ceased. Cease to flow conditions are now present at multiple locations. Supply on demand will continue for the Upper Namoi and the Peel Valley, though customers will notice reduced river levels. Planned Supply Interruptions Mollee fish way is currently unavailable due to infrastructure failure. Page 14 of 28

15 Apr-17 May-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-2 Feb-2 Mar-2 Gigalitres (GL) Apr-17 May-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-2 Feb-2 Mar-2 Gigalitres (GL) Planning is underway to determine the appropriate time to undertake inspections of Mollee fish way as well as Mollee and Gunidgera weir gates. Keepit forecast storage volume Actual Minimum 99% COE DRY 8% COE Median 5% COE WET 2% COE 3 Split Rock - forecast storage volume Actual Minimum 99% COE DRY 8% COE Page 15 of 28

16 Apr-17 May-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-2 Feb-2 Mar-2 Chaffey Dam - forecast storage volume actual Minimum 99% COE DRY 8% COE Median 5% COE WET 2% COE Page 16 of 28

17 Gwydir Valley Storage Status Copeton Dam is at 29% of active capacity. Predicted Release Patterns Releases for Commonwealth and OEH environmental deliveries have commenced 17 April 218 at about 1,5 ML/day. Releases are expected to stay around 1,5ML/day for the next week delivering approximately 1,ML/day. Approximately 21 GL is currently forecast to be delivered as part of this environmental delivery in the Gwydir valley over the next four weeks. Operating Conditions No significant rainfall was recorded over the past week and temperatures were mostly in the mid 3s. Forecast temperatures are to reduce to the low 3 s. Summer crop demand has ceased. Following the current environmental releases there is unlikely to be any significant irrigation demand throughout autumn 218. Recent Blue Green Algae (BGA) sampling at Copeton shows a continuation of amber alert. A customer notice will be sent out this week to determine what autumn and winter demand is likely and to schedule in with current deliveries. Consultation with customers in relation to limited water deliveries next season has begun. It is forecast that there will be less than 5GL (about 1% of general security share components) available for industry production at the end of 218 summer growing season and approximately 145GL of environmental water. If conditions remain dry the delivery of remaining volumes will need to be managed so that essential supplies can be met going forward. Block releases will be required on western effluent streams and discussions will continue with customers around delivery options through winter. Stream flows have ceased in lower stream sections and the system continues to naturally dry down to a series of waterholes. Planned Supply Interruptions No supply interruptions are expected, though planning is underway to undertake inspections and maintenance activities during late May/June. Page 17 of 28

18 Apr-17 May-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-2 Feb-2 Mar-2 Gigalitres (GL) Copeton - forecast storage volume Actual Minimum 99% COE DRY 8% COE Median 5% COE WET 2% COE Page 18 of 28

19 Border Rivers Storage Status Pindari Dam is at 59%. Glenlyon is at 54%. Predicted Release Patterns Pindari releases remain at minimums of 1 ML/d. Releases are expected to maintain at this level for the next week. Glenlyon releases for environmental deliveries have commenced at 8 ML/day and are expected to remain at this level for the next week. Environmental deliveries are underway and will be delivered to Mungindi weir over the coming weeks, with a volume of between 4 and 5GL expected. Operating Conditions Falls up to 18mm were recorded near Glenlyon, though largely no significant rainfall occurred across the catchment in the last week. Temperatures were predominantly in the mid 3 s. Temperatures are forecast to reduce to the low 3 s for the next 7 days. Large irrigation demand in the Border has ceased and it is likely only minor releases from Pindari and Glenlyon will be required to satisfy the smaller irrigation enterprises east of Goondiwindi. Approximately 8 to 9 GL is currently forecast to be released for environmental deliveries. End of system flows are gradually declining in line with reducing tributary flows and the lowering of Boggabilla weir, though these will increase in about 18 days as environmental deliveries begin to reach end of system. A customer notice will be sent out this week to determine what autumn and winter demand is likely and to schedule in with current deliveries. Recent BGA sampling at Pindari maintain the amber alert. Customers and landholders are encouraged to ensure that they have adequate stock and domestic supplies while there are current flows available. Planned Supply Interruptions No supply interruptions are currently forecast. Page 19 of 28

20 Apr-17 May-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-2 Feb-2 Mar-2 Gigalitres (GL) Apr-17 May-17 Jul-17 Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18 Sep-18 Oct-18 Nov-18 Dec-18 Jan-19 Feb-19 Mar-19 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Jan-2 Feb-2 Mar-2 Gigalitres (GL) Pindari forecast storage volume Actual Minimum 99% COE DRY 8% COE Glenlyon forecast storage volume Actual Minimum 99% COE DRY 8% COE Page 2 of 28

21 Barwon Darling River System River Flow Status Flows at Mungindi have averaged 19 ML/d during the past week with end of system flow requirements reducing. Flows are currently around 2 ML/d and will reduce slightly throughout the week. Flows will continue to decrease until the environmental deliveries reach Mungindi in early May, when flows will increase to approximately 4ML/day for a total flow of between 4 and 5GL No additional flows are present from the Moonie river. Flows from the Carole/Gil Gil have averaged 3ML/d and are expected to reach cease to flow conditions during the next 7 days and will remain at this level until early May when environmental deliveries will commence at between 2 and 22ML/day. Cease to flow conditions are possible for the next three weeks until the environmental deliveries arrive. Flows from the Mehi have ceased and no increase is expected until late April/early May when environmental deliveries will begin to enter the Barwon system at around 7ML/day. Flows from the lower Namoi have ceased and no increase is expected to occur until at least June. Walgett Weir has ceased to flow and is likely to stay at cease to flow levels for the next three weeks until the environmental deliveries arrive. No inflows from the Macquarie valley are current or are expected in the coming weeks without additional rainfall. Flows from the Culgoa system reached the Darling on the 24 March. Flows peaked at St George at approximately 13,ML/d on the 1/3/218 with a total flow volume of approximately 54,ML. This peaked at approximately 3,22ML/d at the Brenda Gauge just inside the NSW Border, with a forecast volume of about 13,5ML. It is expected that total inflow from the Culgoa River system will be approximately 11,5ML, inflows have reduced to below 2ML/day and will continue to decrease. Bourke peaked at 1,8ML/d on 28 March, with a total flow volume of approximately 19,5ML to pass Bourke. Flows recommenced at Louth on 1 April with a total flow of approximately 11,5 to 12,5ML expected over the next few weeks. Flow reached Tilpa on Sunday 8 th April with a flow peak of around 8ML/day, and an expected total flow volume of between 6,5ML and 7,5ML is forecast over the coming weeks. Preliminary forecast indicate that there may be a small volume of water from the Warrego system. Flows peaked at Wyandra Gauge upstream of Cunnamulla in QLD on 12 March at just under 18,ML/d, with a total flow of approximately 8,ML. Forecasts indicate that there could be up to 1,ML may reach the Darling in late-april. Flows are expected to reach Wilcannia in late April with a total flow volume of between 1, and 2,ML expected. Predicted Flow Patterns Connectivity is likely to extend beyond Wilcannia, from the current flow event. Cease to flow conditions will start to commence as natural flow continues to reduce, this will continue until either environmental deliveries reach individual sites over the next 2 months or there is additional rainfall. Page 21 of 28

22 Operating Conditions A section 324 Temporary Water Restriction order is extended. Temporary restrictions on A, B and C class water access licences in the Barwon-Darling Unregulated River announced on 9 March have been extended to 28 April. From 1 April - the pump restrictions only apply to A, B and C water access licence holders downstream from Boorooma - midway between Walgett and Brewarrina to Lake Wetherell at the top of the Menindee lakes system. From 1 April - The pump restrictions no longer apply to A, B and C class licence holders upstream from Boorooma to Mungindi. Flows from Queensland from the Moonie and Culgoa Rivers reached the Barwon-Darling in mid-march and are making their way down the system. These flows have replenished town water supplies and provided stock and domestic supply for landholders, being the primary objective of the temporary pump restriction announced on 9 March. The pump restriction limits the taking of water to: o Town water supply o Domestic use o Stock watering o Irrigation of existing permanent plantings such as vineyards and orchards The temporary pump restrictions have been extended to bring benefit further along the Darling River in coming weeks. A further 324 order will be issued to manage the environmental deliveries from the Border Rivers and Gwydir Valleys, though if there is additional inflow from rainfall events access will be managed to ensure usual access to any additional flows above the environmental water. The following table shows access conditions over the last week, however the Temporary Water Restriction applies to the sections downstream of Boorooma. Page 22 of 28

23 WaterNSW HYPLOT V133 Output 17/4/218 Period 1 Month 1/7/217 to 1/5/ BARWON MUNGINDI 141. Discharge (ML/d) CP BARWON U/S PRESBURY 141. Discharge (ML/d) CP 4224 MOGIL MOGIL 141. Discharge (ML/d) CP 4223 Discharge (ML/d) CP TARA 141. Discharge (ML/d) CP 4221 DANGAR BDGE141. Discharge (ML/d) CP BOOROOMA 141. Discharge (ML/d) CP GEERA 141. Discharge (ML/d) CP Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr WaterNSW HYPLOT V133 Output 17/4/218 Period 1 Month 1/7/217 to 1/5/ BREWARRINA 141. Discharge (ML/d) CP BEEMERY 141. Discharge (ML/d) CP DARLING@WARRAWEENA 141. Discharge (ML/d) CP 4253 DARLING@BOURKE TOWN 141. Discharge (ML/d) CP 4254 DARLING@LOUTH 141. Discharge (ML/d) CP 4259 DARLING@TILPA 141. Discharge (ML/d) CP 4258 DARLING@WILC. MAIN C 141. Discharge (ML/d) CP Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr Page 23 of 28

24 1/2/12 1/6/12 1/1/12 1/2/13 1/6/13 1/1/13 1/2/14 1/6/14 1/1/14 1/2/15 1/6/15 1/1/15 1/2/16 1/6/16 1/1/16 1/2/17 1/6/17 1/1/17 1/2/18 1/6/18 1/1/18 1/2/19 1/6/19 1/1/19 1/2/2 Storage % capacity Bega River Storage Status Brogo is currently at 99% of active capacity. Predicted Release Patterns Releases are currently at about 3 ML/d via valves and will likely remain relatively stable between 3 and 4ML/d throughout the week. Operating Conditions Regulated conditions are present throughout the system. Temperatures are forecast to be in the mid 2 s throughout the week. No rainfall is currently forecast for the next week. Recent BGA sampling at Brogo indicates a green alert level is maintained Brogo Dam - Forecast Storage Levels 14% 12% 1% 8% 6% 4% 2% % Actual Dry 8% COE Median 5% COE Wet 2% COE Minimum 99% COE Page 24 of 28

25 1/2/12 1/6/12 1/1/12 1/2/13 1/6/13 1/1/13 1/2/14 1/6/14 1/1/14 1/2/15 1/6/15 1/1/15 1/2/16 1/6/16 1/1/16 1/2/17 1/6/17 1/1/17 1/2/18 1/6/18 1/1/18 1/2/19 1/6/19 1/1/19 1/2/2 Storage % capacity Hunter Valley Storage Status Glenbawn Dam is at 74%, while Glennies Creek Dam is at 7%, and Lostock Dam is 1% of active capacity. Predicted Release Patterns Releases at Glenbawn Dam are likely remain around 8ML/d meeting AGL demand. Glennies Creek Dam releases are likely to remain around 2 ML/day. Lostock Dam releases via hydro are currently set at around 2 ML/day. Operating Conditions No significant rainfall occurred throughout the past week. Recent BGA sampling at Hunter storages indicates a green alert is maintained at Glenbawn and Glennies Creek dam whilst Lostock has also reduced to green alert. No further significant rain is forecast for the valleys throughout the next week. Planned Supply Interruptions Nil 12% Hunter Dams - Forecast Storage Levels % 1% 8% 6% 4% 2% % Actual Dry 8% COE Median 5% COE Wet 2% COE Minimum 99% COE Page 25 of 28

26 1/2/12 1/5/12 1/8/12 1/11/12 1/2/13 1/5/13 1/8/13 1/11/13 1/2/14 1/5/14 1/8/14 1/11/14 1/2/15 1/5/15 1/8/15 1/11/15 1/2/16 1/5/16 1/8/16 1/11/16 1/2/17 1/5/17 1/8/17 1/11/17 1/2/18 1/5/18 1/8/18 1/11/18 1/2/19 1/5/19 1/8/19 1/11/19 1/2/2 Storage % capacity 12.% Lostock Dam - Forecast Storage Level 1.% 8.% 6.% 4.% 2.%.% Actual Dry 8% COE Median 5% COE Wet 2% COE Drought Page 26 of 28

27 1/2/12 1/6/12 1/1/12 1/2/13 1/6/13 1/1/13 1/2/14 1/6/14 1/1/14 1/2/15 1/6/15 1/1/15 1/2/16 1/6/16 1/1/16 1/2/17 1/6/17 1/1/17 1/2/18 1/6/18 1/1/18 1/2/19 1/6/19 1/1/19 1/2/2 Storage % capacity Toonumbar Dam Storage Status Toonumbar Dam is currently at 1%. Predicted Release Patterns Passing flows of approximately 3 ML/d. Operating Conditions Recent BGA sampling at Toonumbar indicates that an amber alert is maintained. 12% Toonumbar Dam- Forecast Storage Level 1% 8% 6% 4% 2% % Actual Dry 8% COE Median 5% COE Wet 2% COE Minimum 99% COE Page 27 of 28

28 WaterNSW (Rural) Dam Levels The following table shows the current status of water supplies at 16 April 218 River Valley Capacity Current Status Storage Dam, Nearest Town Border Rivers (GL) % of active capacity Active (GL) Weekly change (GL) Comments Likelihood Allocations for 217/18 Supply Issues of fill and spill High Security General Security 1/7/17 Glenlyon Dam, Stanthorpe Qld % 138 Environmental releases commenced <2% 1% 19.62% 9% Pindari Dam, Inverell % 185 Minimum releases 2% 1% 19.62% 9% Gwydir Valley Copeton Dam, Inverell % Environmental releases commenced <5% 1% 17.59% 6% Namoi Valley Keepit Dam, Gunnedah % 55 Environmental deliveries <2% 1% 7% 8% Split Rock Dam, Manilla % 6 Releases for upper Namoi users only <5% 1% 1% N/A Chaffey Dam, Tamworth 1 68% 67 Regulated releases steady 5% 1% 1% N/A Macquarie Valley Burrendong Dam, Wellington % Releases reducing 2% 1% 38% 73% Windamere Dam, Mudgee % Irrigation deliveries <5% 1% 38% 137% Lachlan Valley Wyangala Dam, Cowra % Releases reducing 2% 1% 2% 18% Carcoar Dam, Carcoar 36 58% 21 Irrigation deliveries 1% 1% % 95% Murrumbidgee Valley Burrinjuck Dam, Yass 123 4% 41-1 Minimum releases through power station 5% 95% 41% 27% Blowering Dam, Tumut % Irrigation / environmental releases <2% 95% 38% 27% Murray Valley Dartmouth, Mitta Mitta (Vic) % Minimum releases N/A N/A N/A N/A Hume Dam, Albury % Irrigation / environmental releases <25% 97% 51% 44% Lower Darling Menindee Lakes, Broken Hill % Minimum releases N/A 1% 1% 77% Hunter Valley Glenbawn Dam, Scone 75 74% Regulated releases primarily power station use 2% 1% 1% 28% Glennies Ck Dam, Singleton 282 7% Regulated releases 2% 1% 1% 28% Lostock Dam, Gresford 2 1% 2 Regulated releases 9% 1% 1% N/A Coastal Area Toonumbar Dam, Kyogle 11 1% 11 - Dam spilling - reducing 1% 1% 1% N/A Brogo Dam, Bega 9 99% 9 - Regulated flow conditions 1% 1% 75% N/A TOTALS 17, % WaterNSW has water resources in Dartmouth, Hume and Glenlyon Dams. TWS = Town Water Supplies 1 Gigalitre (GL) = 1, Megalitres (ML) 1 ML = 1,, litres For information on WaterNSW (Urban) Dam Levels, follow this link: Page 28 of 28