Annual Operations Plan Murrumbidgee Valley 2019-20 Acronym Definition Available Water Contents AWD Determination Introduction 2 BLR Basic Landholder Rights The Murrumbidgee River System 2 Regulated and unregulated system flow trends 3 BoM Bureau of Meteorology Rainfall trends 3 CWAP Critical Water Advisory Panel Inflows to dam 4 Critical Water Technical Water users in the valley 4 CWTAG Advisory Group Water availability 7 Department of Primary Current drought conditions 9 DPI CDI Industries - Combined Blowering Dam storage 10 Drought Indicator Burrinjuck Dam storage 10 Department of Planning, Inter valley transfer 11 Industry and Environment - DPIE EES Operational surplus 12 Environment, Energy & Science Transmission losses 12 Resource assessment 15 DPI Department of Primary End of System flow targets 17 Fisheries Industries - Fisheries Department of Planning, Water resource forecast 18 DPIE Industry and Environment - Water Murrumbidgee catchment - past 24 month rainfall 18 Water Blowering Dam - past 24 month inflows/statistical inflows 19 FSL Full Supply Level Burrinjuck Dam - past 24 month inflows/statistical inflows 19 Weather forecast - 3 month BoM forecast 20 HS High Security Murrumbidgee storage forecast 20 IRG Incident Response Guide Annual operations 22 Infrastructure State ISEPP Environmental Planning Operational rules 22 Policy Deliverability 24 Overall scenario assumptions 24 LGA Local Government Areas River Operations Stakeholder ROSCCo Critical dates 25 Consultation Committee S&D Stock & Domestic Potential projects 26 Valley Technical Advisory vTAG Group Introduction The annual operations plan provides an outlook for the coming year in the Murrumbidgee Valley and considers the current volume of water in storages and weather forecasts. This plan may be updated as a result of significant changes to the water supply situation. This year’s plan outlines WaterNSW’s response to the drought in the Murrumbidgee Valley including: • identification of critical dates • our operational response • potential projects to mitigate the impact of the drought on customers and communities within the valley. The NSW Department of Planning, Industry and Environment’s Extreme Events Policy and Incident Response Guides outline 4 stages of drought. The Murrumbidgee Regulated River system is assessed to be in stage 1, which is reflecting the normal operation of the river in 2019-20. The Murrumbidgee River System The Murrumbidgee River, a major tributary of the Murray-Darling River system, drains much of southern New South Wales and most of the Australian Capital Territory. It spans almost 1,600 kilometres (km), rising in the Fiery Range of the Snowy Mountains and flowing generally westward towards its junction with the Murray River downstream of Balranald. The Murrumbidgee is regulated downstream of Burrinjuck Dam. The total catchment above Burrinjuck Dam is about 13,000 km2. Below Burrinjuck Dam, the Murrumbidgee River initially flows in a rugged, narrow gorge before emerging into a widening valley near Gundagai. The Tumut River joins Murrumbidgee River upstream of Gundagai. Tumut River, with a catchment area of about 4,000 km2, is the Murrumbidgee River’s largest tributary. The source of Tumut is around the snow-capped Mount Jagungal. Most of the Tumut River catchment is controlled by the Snowy Hydro Scheme and through a series of small reservoirs and power stations. The Tumut River is regulated by Blowering Dam, which is located near Tumut town. There are several uncontrolled tributaries that contribute to the Murrumbidgee River flows between Burrinjuck and Blowering Dams, and Wagga Wagga city as follows: • Goobaragandra River • Adjungbilly Creek • Jugiong Creek • Muttama Creek • Adelong Creek • Tarcutta Creek • Kyemba Creek. In addition to the above, there are numerous ungauged tributaries. The approximate catchment area of the downstream tributaries is about 6,400 km². Below Wagga Wagga there are no significant tributary inflows to the system. The river is characterised by Beavers Creek and Old Man Creek anabranch near Wagga Wagga. The anabranch takes off downstream of Wagga Wagga and re-joins the Murrumbidgee between Berembed Weir and Narrandera town. 2 The most important effluent stream in the Murrumbidgee Valley is the Yanco Creek system. Yanco Creek leaves the main river downstream of Narrandera and is about 800 km in length. Yanco Creek bifurcates at Morundah into Yanco and Colombo Creeks. Colombo Creek joins Billabong Creek near Jereldrie, while Yanco Creek also joins Billabong Creek upstream of Conargo. Billabong Creek continues its journey until it joins Edwards River near Moulamein. The Murrumbidgee River below Narrandera continues to flow westwards until it joins Murray River. The river is regulated mainly to the town of Balranald. The lower part of the Murrumbidgee Valley is also characterised by Lowbidgee floodplain which is listed as a nationally important wetland within the Directory of Important Wetlands (Environment Australia 2011). GOGELDRIE WEIR STURT CANAL MIA MAIN CANAL LACHLAN RIVER MURRUMBIDGEE GREAT CUMBUNG RIVER SWAMP MAUDE HAY BILLABUNG CREEK WEIR WEIR BARREN BOX MUTTAMA CREEK SWAMP HOULAGHANS MAUDE WEIR CREEK REDBANK WEIR YANCO WEIR JUGIONG CREEK BEREMBED COOTAMUNDRA BARRENBACK DAM TALA LAKE GRIFFITH WEIR LEETON BURRINJUCK DAM N BALRANALD MAUDE HAY BALRANALD WEIR NARRANDERA YASS YASS RIVER Key JUNEE LAKE GEORGE GUNDAGAI Major towns YANGA LAKE WAGGA TUMUT CANBERRA COLEAMBALLY WAGGA Major dams OUTFALL DRAIN JERILDERIE QUEANBEYAN HENTY WEIR River system WANGANELLA SWAMP REGULATOR & EUSTUARY CREEK LAKE URANA Channel system REGULATOR MORTIMERS BLOCK DAM TARABAH WEIR River catchment & JUNCTION WEIR LACMALAC BEAVERS CREEK WEIR COOMA WARRISTON WEIR TUMUT RIVER QUEANBEYAN Regulated weirs BILLABONG CREEK RIVER HARTWOOD WEIR BLOWERING DAM KYEAMBA CREEK Unregulated weirs JERILDERIE WEIR HILLAS CREEK YANCO CREEK TARCUTTA CREEK Water bodies COLOMBO CREEK GOOBARRAGANDRA RIVER Regulated and unregulated system flow trends Murrumbidgee is a regulated river system which receives inflows from different tributaries and the Snowy Hydro Scheme in the upstream. In a normal year, Murrumbidgee receives around 1,026,000 megalitres (ML) from the Snowy Hydro Scheme. Burrinjuck Dam receives 1,239,000 ML and Blowering Dam receives 347,000 ML natural inflows on average. Murrumbidgee also receives on average 750,000 ML from tributaries which join down stream of Blowering and Burrinjuck Dams. Rainfall trends For the period April 2017 to March 2019, lowest-on-record rainfall was observed over southern inland Queensland and areas of northwestern New South Wales. Over most of this area, rainfall for the period was less than 50% of the 1961-1990 average. Large areas from central to southwestern Queensland, and northcentral and northwestern New South Wales, into northeastern South Australia, have seen rainfall totals between 40% to 60% of this average, implying that nearly one year’s worth of average rainfall has been missed over this two-year period. The recent dry periods have been especially severe during the cooler months of April to September, an important time for agriculture and the replenishment of surface and groundwater storages 3 across southern Australia. Averaged over the Murray-Darling Basin (MDB), the total rainfall over two consecutive April to September periods was the lowest on record, at 217.5 millimetres (mm). This is around 15% below the previous record, which saw 255.7 mm over the 1940-41 April to September period. It was also the only instance of an April to September rainfall total below 125 mm in two consecutive years. Rainfall for the combined two-year 2017 and 2018 April to September period was the lowest on record and very much below average (lowest 10% of all such periods) for large parts of south eastern and southwestern Australia. Around 50% of New South Wales was lowest-on-record for these two periods combined. The 2019 winter continued to see dry conditions, which means three consecutive winters of below average rainfall. Inflows to dam In the 28 months since the previous allocation in July 2017, inflows to Burrinjuck and Blowering Dams have been approximately 688,000 ML and 584,000 ML respectively. In the 2017-18 water year, system inflows to Burrinjuck and Blowering Dams have been at just 407,000 ML and 250,000 ML respectively. In addition, Blowering Dam received 1,079,000 ML of water from Snowy Hydro Limited as required annual release (RAR) and Burrinjuck Dam received 41,000 ML of water under the Snowy-Montane release. In the 2018-19 water year, system inflows to Burrinjuck and Blowering Dams have been low at just 200,000 ML and 180,400 ML respectively. In addition, Blowering Dam received 682,000 ML of water from Snowy Hydro Limited as RAR and Burrinjuck Dam received 10,000 ML of water under the Snowy- Montane release. Water users in the valley Basic Land Holder Rights (BLR) BLR includes water for Domestic and Stock extracted from a water source fronting a landholder’s property, or from any aquifer underlying the land, and for native title rights. It is estimated that the volume of BLR in the Murrumbidgee is 1,690 megalitres per year (ML/year). The water supply system shall be managed so that it would be capable of maintaining supply to those exercising Domestic and Stock rights through a repeat of the worst period of low inflows into this water source (based on historical flow information held by the Department of Planning, Industry and Environment - Water, as at 1 July 2004). Sufficient volumes of water