Welcome to the first river ops update for October. If you want to know what’s been happening at Dartmouth and Hume this week, you’ve come to the right place!
We’ll start with a quick look back at the Basin in September, but feel free to skip straight to the latest storage and flow info in the River Operations section.
September 2013 Summary
Rainfall in September was close to average across much of the Murray-Darling Basin, with areas above average in the ACT, and south-eastern and central NSW. Below average rainfall was recorded in southern Queensland, the Victorian Alps and parts of NSW. The Bureau of Meteorology (BOM) reported that overall average rainfall across the Basin was 26% below the long-term mean, with a total of 25 mm.
Keep your eye out between 9 and 30 October when we’ll be seeking your ideas and feedback on ways to improve the delivery of environmental water in the Basin. The draft strategy on river constraints will be on the Murray-Darling Basin Authority website soon.
MDBA active storage decreased by 16 GL this week to 7,931 GL (92% capacity).
At Dartmouth Reservoir, the storage volume increased by 5 GL to 3,807 GL (99% capacity). The volume in the reservoir is expected to continue to slowly rise towards “effectively full” (about 3,820 GL which provides nearly 40 GL airspace at a level about 60 cm below the spillway crest). The release, measured at Colemans, increased to 4,600 ML/day, but is expected to reduce in the coming week. For the foreseeable future, Dartmouth releases and flows along the lower Mitta Mitta River will continue to depend on rainfall forecasts, inflows and any changes in release to manage the airspace in the reservoir. Keep reading the river ops update…
Welcome to the first river ops update for September. Before we take a look at the last week in river ops, let’s have a quick look at what the Basin was like in August.
A look back at August
Through the central and northern parts of the Basin, conditions were dry with large areas recording rainfall that was ‘very much below average’. In far southern NSW and northern Victoria, rainfall was close to average, while over the south-east ranges rain was mostly above average. However, with the vast majority of the region recording below-average rainfall, the total area-averaged rain for the Basin during August was reported by the Bureau of Meteorology at just 17.1 mm, which is 55% below the long-term mean.
Temperatures across the Basin were some of the highest ever recorded for the late winter period. The Bureau of Meteorology noted particularly high maximum temperatures through NSW and Queensland, with most of this area reported as ‘very much above average’. Minimum temperatures were also higher than the long-term August average, with the largest anomalies reported in Victoria. Wetter and cloudier weather helped push the state as a whole to its second highest average August minimum temperature on record.
For this week’s river ops update, we’ll start with a look back at how wet or not June 2013 was in the Basin, before we look at how the Murray has been flowing this week. If you like maps and graphs, make sure you download a copy of the full River Ops Report.
For those interested in the Mildura Weir repairs, the repairs are nearly complete and work will begin next week to begin reassembling the weir. The work has gone so well that it looks like everything will be wrapped up a little ahead of schedule. Read more about it on the MDBA website.
Don’t forget to tune in to ABC Riverina (which includes 102.7 FM Wagga Wagga, 89.9 FM South West Slopes, 100.5 FM MIA, 675 AM NSW/Victoria Border, 97.9 FM Tumut, 96.3 FM Young and 88.1 FM Hay) this Thursday (11 July) after the 7:30am news to hear David Dreverman, our Executive Director of River Management.
June 2013 Summary
Rainfall for June 2013 was well above average for the Basin as a whole, with the Bureau of Meteorology reporting the month as the 19th wettest in 114 years of records with a total of 55.4 mm (65% above the mean). Regionally, however, there was considerable variation with much of the northern Basin recording below average rain, while areas in central NSW recorded very much above average rain including some areas of ‘highest on record’ rain. Most of the southern Basin was also relatively wet, with the notable exception being the Victorian ranges where rain was average to slightly below average.
The gradual decrease of flows at Weir 32 from today back to the normal winter minimum flow rate by the end of May. This is because of further reductions in operational demands on the River Murray as the 2012‐13 watering season draws to a close.
You can also find flow advices in the media releases section of our newly made-over website. While you’re over there, let us know what you think of the site. Is it easier to find information? Do you have any suggestions on how we can make the site even better? We want to know!
MDBA active storage increased during the week by 36 GL to 5,803 GL (68% capacity). A portion of this rise was due to a hydrographic correction of the water level at Lake Victoria. Routine checks of water monitoring sites and equipment across the River Murray System revealed that the actual level in the lake was higher than previously monitored.
Before we get to this week’s River Murray Ops Update (which includes the monthly summary for February), we wanted to take a moment to talk about the Menindee Lakes releases.
The main purpose of these releases is to meet state requirements (a mix of water for irrigators and water for the environment). The recent releases have provided both economic and environmental benefits along the Lower Darling River and the River Murray.
The Menindee Lakes system was built as a water storage for the lower Darling that could be managed in harmony with the River Murray to assist in meeting the water needs of NSW, Victoria and South Australia. The MDBA and its predecessor agencies (the Murray-Darling Commission and River Murray Commission) have operated Menindee Lakes in conjunction with the NSW Government since 1963.
The joint governments have held a long-standing view that when water is available in Menindee Lakes, it should be used in preference to reserves in the Hume and Dartmouth Reservoirs. This approach was reiterated in the River Murray System Annual Operating Plan, which was developed in consultation with the Basin states and the Commonwealth. The lakes have a very high evaporation rate in summer compared to the dams, so it’s really a case of ‘use it or lose it’. Added to this, this summer has been particularly dry (especially after three relatively wet years).
By using water from Menindee (when it is available), it increases overall water security for all three states because it leaves more water available in Hume Reservoir to meet the needs of entitlement holders along the River Murray, such as in the irrigation centres of Deniliquin, Mildura and Wentworth.
Inflows from the Darling River are currently rising and this will boost the levels of the Menindee Lakes.
Before we get to the Ops update, just a reminder that higher flows may occur in the Mitta Mitta River. Please read the flow advice in the full river ops weekly report.
A look back at October
Following the relatively dry conditions of August and September, below average rainfall in the Basin continued in October.
Inflows to the River Murray system (excluding Darling River and Snowy inflows) continued to recede during October, with a monthly total of about 775 GL. This is well below the long-term average of nearly 1,400 GL, although still slightly above the average for the past 10 years, and fairly similar to the inflow total recorded in October 2011. Continue reading this week’s River Murray Ops Update…