River Murray operations 22-29 April

Welcome to our weekly report of river operations on the Murray including rainfall, inflows and operations for the river week ending 29 April.

Live river data improved

It’s accessed by 100,000 people a year so we’ve given our online river data a major facelift and made it compatible with smartphones and tablets.

A dedicated site now matches current and historic river data using an interactive map showing information from more than 60 places on the River Murray system. View the new webpage for information on storage levels, river heights, water release rates and salinity data and we welcome feedback.

Rainfall

A cold front and associated low pressure system traversed south-eastern Australia this week bringing rainfall to southern parts of the Murray-Darling Basin. The system also heralded the arrival of cooler southerly winds but delivered little or no rain to northern areas.

The highest weekly rain totals were recorded over the south-east ranges and in South Australia (more detail in the full river ops report).

Drying banks of lock eight (source Scott Jaensch, April 2015).

Drying banks of lock eight (source Scott Jaensch, April 2015).

Continue reading the update…

River Murray Ops Update – 24 April

Welcome to our weekly report of river operations on the Murray which covers rainfall, inflows and operations for the river week ending 22 April.

Rainfall

Wet conditions returned to the Murray-Darling Basin this week with significant rainfall across many regions, particularly throughout the southern Basin. The rain was associated with a surface trough that extended north-south along the entire length of the Basin. As the trough tracked eastwards it combined with a cold front pushing up from the Southern Ocean, delivering moderate to heavy rainfall across eastern South Australia, southern New South Wales and north-eastern Victoria. When this complex system reached the NSW coast, it intensified into an east coast low, producing very heavy rainfall and strong winds east of the great divide, as well as some moderate rainfall inland around the Macquarie-Castlereagh catchment.

The pattern of rainfall in this event was very similar to an event almost exactly one year ago in April 2014. As was the case with the 2014 event, this week’s rain has dramatically reduced the demand for irrigation water throughout the Murray system. Rainfall totals are provided in the full river ops report. Continue reading the update…

The role of forecasts in operating the Murray

Weather has a major influence on river operations.

This can be quite evident after significant rainfall events or hot spells but when managing the River Murray, MDBA considers a wide range of forecasts over short, intermediate to long term time periods.

In a recent weekly report, our river operators discussed some examples of the current Bureau of Meteorology outlooks and how they are being factored into our operations of the River Murray.

We have reproduced this excerpt of the report as an interesting insight into how we run the river.

Storms gather along the Murrumbidgee (source Russell James, MDBA).

Storms gather along the Murrumbidgee (source Russell James, MDBA).

Continue reading the update…

River Murray Ops Update – 17 April

Welcome to our weekly report of river operations on the Murray. In this one, we’ve explained a bit about the role of weather forecasts in river operations and covered rainfall, inflows and operations for the week ending 15 April.

Rainfall and inflows this week

Consecutive slow-moving high pressure systems brought stable weather to the Murray-Darling Basin this week, with little to no rainfall recorded across most areas. The most significant rain totals fell around Carnarvon National Park in Queensland and the Victorian Alps, including 10 mm at Lake Eildon.

Stream flows in the upper catchments receded this week, following small responses to rain the previous week. Upstream of Dartmouth, the Mitta Mitta at Hinnomunjie reduced from 430 to 160 ML/day. On the Upper Murray, the flow at Biggara fell from 430 to 240 ML/d; and on the Ovens River, the flow at Wangaratta decreased from 300 to 200 ML/day.

Photo 1: Lake Victoria on 8 April 2015 (source Hugo Bowman). This photo depicts the large area of Lake Victoria’s foreshore that can be colonised by vegetation to assist in conservation of Aboriginal cultural heritage material.

Continue reading the update…

River Murray Ops Update – 10 April

Welcome to our weekly report of river operations on the Murray. This one covers the river week ending 8 April.

Rainfall and inflows

Rain fell across almost the entire Murray-Darling Basin this week with only the far north-west remaining dry. Totals in excess of 25 mm were widespread over eastern areas and in the lower Murray region and eastern Mt Lofty Ranges of South Australia. Lighter totals were recorded through central and southern parts of the Basin (see map in full report). The rain fell in association with a trough system in the north and with the passage of a complex slow moving low pressure system across south-eastern Australia during the past few days.

The highest rain totals were recorded either side of the NSW-Queensland border. This rain has triggered sharp stream flow responses along stretches of the Border Rivers, including peaks around the minor flood level along the Macintyre and Weir Rivers near Boggabilla and Goondiwindi.

Stream flows along the upper Murray tributaries increased only a small amount, with most of the higher rain totals falling in adjacent catchments.

Hume Reservoir storage level at 22% over the Easter weekend (source Sean Kelly, MDBA).

Hume Reservoir storage level at 22% over the Easter weekend (source Sean Kelly, MDBA).

Continue reading the update…

River Murray Ops Update – 2 April

Welcome to our weekly report of river operations on the Murray. This one looks back at the month of March and then covers the river week ending 1 April.

A look back at the month of March

Rainfall for March was below average across most of the Basin, with very much below average rain in parts of the south-east and through central, western and northern NSW, where many locations received no rain at all for the month. Totals were generally closer to average in the north. Across the Basin as a whole, the Bureau of Meteorology reported area-averaged rain totalling 16.1 mm. This is 58% below the long-term March mean and the 22nd driest March in 116 years of record.

Temperatures during March were variable across the Basin, with significantly above-average conditions in the north and temperatures more typical of early autumn in the south.

River Murray System inflows (excluding Snowy Scheme, Darling River and managed environmental inflows) were around only 50 GL for March. This volume is less than a quarter of the long-term monthly average (see the graph in the full river ops report) and only slightly more than the record lowest March inflows of 1998 (~40 GL) and 2009 (~50 GL).

Estimated evaporation losses from MDBA storages for March 2015 are reported in the full river ops report. Evaporation at Dartmouth and Hume reservoirs was similar to February, reflecting the dry and sunny weather in this part of the Basin. Volumes evaporated at Lake Victoria and the Menindee Lakes have reduced since last month. This would be expected due to the smaller volumes of water in these two storages (reducing surface areas), and the reduced temperatures and day length in March compared to February.

Lake Victoria dry 2 April 2015

Several decades of high lake levels resulted in considerable vegetation loss around Lake Victoria in SW NSW. A more favourable wetting and drying regime implemented over the last 15 years has led to revegetation in many areas. However in some low areas (such as pictured here) that are still inundated for much of the year, vegetation recovery is occurring more slowly. Vegetation plays an important role in trapping sand and stabilising the beach, which assists the conservation of Aboriginal cultural heritage material. Photo: Hugo Bowman, MDBA.

Continue reading the update…

River Murray Ops Update – 27 March

Welcome to our weekly report of river operations on the Murray. This one covers the river week ending 25 March.

Rainfall and inflows

There was contrasting weather across the Murray-Darling Basin this week, although temperatures remained warm in most areas and generally dry conditions continued through central, western and southern areas. Conditions in the east and north-east were wetter, with showers and storms bringing some rainfall along the NSW ranges and to south-east Queensland with the passage of two trough systems.

The rain across the east was also quite patchy meaning some areas recorded worthwhile rain, while other locations missed out.

Small amounts of rain over the upper Murray catchments had little impact on flows, with most gauges remaining close to the relatively low levels of one week ago. Continue reading the update…