Monthly Water Update

small map representing the district Murray-Darling Basin

Murray–Darling Basin

December 2021 Summary

Rainfall was average or higher-then-average across 79 per cent of the area, spread throughout the drainage division, except for the southwest corner. Above-average rainfall was received across 18 per cent of the area, mainly in pockets in the northern half of the drainage division, as well as in the southeast corner. Below-average rainfall was experienced in 21 per cent of the area, mainly in the southwest corner of the drainage division, including 6 per cent of the area being very-much-below-average. Total rainfall was 45mm, 4 per cent lower than the long-term mean of 47mm for December.

Streamflows were higher-than-average for 89 per cent of the sites, distributed over the entire drainage division, including 78 per cent of the sites experiencing very-much-above-average streamflows. The continued wet conditions resulted in 12 sites experiencing their highest streamflows on record for December since 1980. Of the 72 sites with available streamflow data, only 3 sites experienced below-average streamflows for December.

Median streamflow salinity (electrical conductivity) varied between sites from 32 to 6 507 μS/cm. Streamflows were of high-quality for 73 per cent, fresh for 10 per cent, brackish for 5 per cent, moderately saline for 2 per cent, and saline for 3 per cent of sites. Burra Creek at Worlds End (Low Flow) had the highest salinity of all the reporting sites due to discharge from unconfined aquifers.

During December, storage volumes increased in 3 systems, decreased in 9 systems and remained stable in the other 5. By the end of the month, the volume of water stored was 92 per cent of the total accessible capacity, which is 37 percentage points higher than the previous year.

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map visualising rainfall details


map visualising streamflow details

Streamflow salinity

map visualising salinity details

Water storages

map visualising storage details


map visualising rainfall details for Murray-Darling Basin

Rainfall statistics

Rainfall decile group Percentage of area
Highest on record since 1900 0%
Very much above average 2%
Above average 16%
Average 61%
Below average 15%
Very much below average 6%
Lowest on record since 1900 0%

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