River Murray Operations Weekly Report 25Th November 2015
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RIVER MURRAY WEEKLY REPORT FOR THE WEEK ENDING WEDNESDAY, 25TH NOVEMBER 2015 Trim Ref: D15/86414 Rainfall and inflows Very hot weather affected most of the southern Murray–Darling Basin during the last week. This was due to a slow-moving high pressure system over the Tasman Sea which drew dry and hot air across from central Australia. At Renmark Airport the temperature reached 42.7 degrees on Thursday; whilst Broken Hill Airport and Griffith Airport AWS saw temperatures above 41 degrees. Conditions were mostly dry across the Basin, with the only significant rain occurring in the northeast (see Map 1 below). The highest weekly rainfall totals were in Queensland with 57 mm at Clifton, 38 mm at Pratten and 37 mm at Ellangowan. In NSW, Glen Innes Airport AWS received 19 mm in the past week. Map 1 - Murray-Darling Basin rainfall week ending 25th November 2015 (Source: Bureau of Meteorology) With the hot, dry weather over the past week, inflows have continued to reduce. Despite a small spike in inflows due to the rain earlier in the month, the past few weeks of dry weather have seen inflows to the Murray system for November continue to track well below the long-term average – approximately the same position as last year (see graph on page six of this report). With the current El Niño conditions and the recent BoM estimate that 2015 will be in the top 10 hottest years on record for Australia, it is unlikely that the inflow trend will change. GPO Box 1801 Canberra ACT 2601 Telephone: 02 6279 0100 Facsimile: 02 6248 8053 Email: [email protected] Web: www.mdba.gov.au ABN 13679821382 Page 1 of 7 River Operations Hot and dry conditions continue throughout the Basin. Trade temporarily opens out of the Murrumbidgee, then is closed following unprecedented trading activity. After a week of hot, dry conditions, MDBA total storage decreased by 55 GL, with the active storage now 4,009 GL (48% capacity). At Dartmouth Reservoir, the storage volume decreased 47 GL to 2,225 GL (58% capacity). The flow at Colemans increased from 7,300 ML/day to 7,900 ML/day as water continues to be transferred downstream to Hume Reservoir. Over the coming week, the flow will begin gradually reducing to target approximately 6,500 ML/day on the weekend of 12th December (see attached flow advice). Storage at Hume Reservoir decreased 23 GL this week to 1,375 GL (46% capacity). Releases from Hume have remained steady over the week, averaging 13,500 ML/day. At Yarrawonga Weir, the pool has been steady at around 124.74 m AHD for the past week. Releases have been targeting 10,000 ML/day to meet downstream demand and to assist filling Lake Victoria. A reduction in release to 9,600 ML/day is planned for the coming week to provide flow variability to encourage silver perch spawning. Diversions from Lake Mulwala to Mulwala Canal and Yarrawonga Main Channel have included water bypassing the Barmah choke to meet downstream demands. Yarrawonga Main Channel diversions have decreased from 1,600 ML/day to 1,100 ML/day, which includes 150 ML/day of bypass water going into Broken Creek. Mulwala Canal diversions have increased from 2,100 ML/day to 2,600 ML/day, which includes 1,600 ML/day going through the Edward Escape. Figure 1 – Recently rolled hay bales in the Southern Riverina (near Blighty) (source: Adam McLean, MDBA). On the Edward River system, the flow through the Edward Offtake is steady at just under 1,600 ML/day. Flow through the Gulpa Offtake has decreased from 800 ML/day to 720 ML/day and will continue to GPO Box 1801 Canberra ACT 2601 Telephone: 02 6279 0100 Facsimile: 02 6248 8053 Email: [email protected] Web: www.mdba.gov.au ABN 13679821382 Page 2 of 7 decrease to 500 ML/day over the next month. Diversions to the Wakool Main Canal have averaged 200 ML/day over the past week. The flow downstream of Stevens Weir will be steady over the coming week at channel capacity (around 2,600 ML/day) due to the addition of water from the Edward Escape. On the Goulburn River, the flow at McCoys Bridge has reduced from an average of 640 ML/day last week to 500 ML/day this week. Flow in the Campaspe River at Rochester has remained steady this week at 40 ML/day. The flows in the Goulburn and Campaspe include inter valley trade (IVT) water targeting around 200 ML/day and 20 ML/day, respectively. At Torrumbarry Weir, the diversion to National Channel is 2,450 ML/day. The flow in the Murray downstream of Torrumbarry has steadied around 5,400 ML/day. At Swan Hill the flow has dropped to just under 6,000 ML/day, down from 7,300 ML/day at the beginning of the week. Inflow entering the Murray from the Murrumbidgee River at Balranald has reduced from around 2,000 ML/day to 650 ML/day. The flow at Balranald is expected to increase to 1,450 ML/day in December due to the delivery of water traded from the Murrumbidgee to the Murray. The planned delivery of this water enabled a further 50 GL to be traded out of the Murrumbidgee. NSW temporarily lifted the trade restrictions, but reinstated them quite quickly as the additional 50 GL were traded out of the valley within 24 hours. On the Murray at Euston, the weir pool is 35 cm above the Full Supply Level (FSL) of 47.6 m AHD and the downstream release is 9,500 ML/day and falling. Moving into December, the Euston weir pool will begin lowering to target FSL. At Wentworth Weir, the release has reduced from 9,800 ML/day to 8,800 ML/day and is expected to continue falling over the coming week. Lock 9 is being held steady at around 10 cm below FSL (27.4 m AHD); the Lock 8 weir pool has decreased to around 50 cm below FSL (24.6 m AHD); and Lock 7 has remained steady at around 50 cm above FSL (22.1 m AHD). At Menindee Lakes, the storage volume has decreased 2 GL to 81 GL (5% capacity). At Lake Victoria, the storage volume increased 17 GL to 603 GL (89% capacity). Flow to South Australia has been targeting around 6,000 ML/day over the past week. From the start of December, the flow to South Australia will be targeting 6,500 ML/day. The flow over Lock 1 averaged 4,200 ML/day this week and, at the Lower Lakes, the five-day average water level in Lake Alexandrina is 0.82 m AHD. The barrage releases have averaged 850 ML/day for the past week. For media inquiries contact the Media Officer on 02 6279 0141 DAVID DREVERMAN Executive Director, River Management GPO Box 1801 Canberra ACT 2601 Telephone: 02 6279 0100 Facsimile: 02 6248 8053 Email: [email protected] Web: www.mdba.gov.au ABN 13679821382 Page 3 of 7 Water in Storage Week ending Wednesday 25 Nov 2015 Change in Full Current Total Full Supply Dead Active MDBA Storages Supply Storage Current Storage Storage Volume Storage Storage Level Level for the Week (m AHD) (GL) (m AHD) (GL) % (GL) (GL) (GL) Dartmouth Reservoir 486.00 3 856 456.90 2 225 58% 71 2 154 -47 Hume Reservoir 192.00 3 005 181.99 1 375 46% 23 1 352 -23 Lake Victoria 27.00 677 26.39 603 89% 100 503 +17 Menindee Lakes 1 731* 81 5% (- -) # 0 -2 Total 9 269 4 284 46% - - 4 009 -55 Total Active MDBA Storage 48% ^ Major State Storages Burrinjuck Reservoir 1 026 705 69% 3 702 -6 Blowering Reservoir 1 631 690 42% 24 666 +1 Eildon Reservoir 3 334 1 748 52% 100 1 648 -24 * Menindee surcharge capacity – 2050 GL ** All Data is rounded to nearest GL ** # NSW takes control of Menindee Lakes when storage falls below 480 GL, and control reverts to MDBA when storage next reaches 640 GL ^ % of total active MDBA storage Snowy Mountains Scheme Snowy diversions for week ending 24 Nov 2015 Active Storage Weekly Change From 1 May Storage Diversion (GL) This Week (GL) (GL) 2015 Lake Eucumbene - Total 2 357 -7 Snowy-Murray +3 257 Snowy-Murray Component 1 149 -5 Tooma-Tumut +3 135 Target Storage 1 450 Net Diversion 0 122 Murray 1 Release +6 429 Major Diversions from Murray and Lower Darling (GL) * From 1 July From 1 New South Wales This Week Victoria This Week 2015 July 2015 Murray Irrig. Ltd (Net) 8.2 195 Yarrawonga Main Channel (net) 6.9 103 Wakool Sys Allowance 2.2 25 Torrumbarry System + Nyah (net) 0.2 206 Western Murray Irrigation 0.9 2 Sunraysia Pumped Districts 3.9 35 Licensed Pumps 5.1 66 Licensed pumps - GMW (Nyah+u/s) 1.3 15 Lower Darling 0.3 4 Licensed pumps - LMW 10.5 96 TOTAL 16.7 292 TOTAL 22.8 455 * Figures derived from estimates and monthly data. Please note that not all data may have been available at the time of creating this report. ** All data above is rounded to nearest 100 ML for weekly data and nearest GL for cumulative data** Flow to South Australia (GL) Entitlement this month 180.0 * * Flow to SA will be greater than normal Flow this week 42.3 (6 000 ML/day) entitlement for this month due to the delivery of Flow so far this month 181.1 additional environmental water.