Weekly Water Update
21 August 2008
STORAGES UP BY 21.9 BILLION LITRES
More winter rain has helped lift Melbourne’s storages by almost 22 billion litres this week, representing an increase of 1.23% of total system capacity.
Storages are now 32.7% (579,244 million litres) full, compared with this time last year when they were 38.3% (678,401 million litres) full.
The week’s rain, helped by falls in the previous two weeks that wet the catchments, resulted in runoff that was slightly above average – representing a significant turnaround of conditions from the start of winter. About 30mm fell across the major catchments since last Thursday, compared with the long-term average of 24mm.
Wet weather and continued savings kept water consumption down to an average of 951 million litres a day, compared with the winter average of 1,108 million litres per day in the 1990s.
Stage 3a restrictions are in place until at least 30 November 2008. Further details on water restrictions are available by visiting the Our Water Our Future website or by contacting the government water retailers.
Please note that:
- All figures include non-metropolitan supply for Western Water (supplied since March 2000), which are not included in annual Melbourne Metropolitan consumption figures.
- The 1990s Winter average is based on data for the period 1992 to 1999 (8 years).
Water storage data
| Reservoir | Capacity(at Full Supply) | Volume ( ML ) | % Full |
|---|---|---|---|
| Thomson | 1,068,000 | 201,707 | 18.9 |
| Upper Yarra | 200,000 | 127,710 | 63.9 |
| O'Shannassy | 3,000 | 3,157 | 100.0 |
| Maroondah | 22,000 | 17,240 | 78.4 |
| Sugarloaf | 96,000 | 30,464 | 31.7 |
| Yan Yean | 30,000 | 5,565 | 18.6 |
| Greenvale | 27,000 | 20,352 | 75.4 |
| Silvan | 40,000 | 36,631 | 91.6 |
| Cardinia | 287,000 | 136,418 | 47.5 |
| Total | 1,773,000 | 579,244 | 32.7 |
Rainfall For The Major Harvesting Catchments
| Catchment | 15 Aug - 21 Aug 2008 |
Long Term Ave* | Variation | 15 Aug - 21 Aug 2007 |
|---|---|---|---|---|
| Thomson | 30 mm | 20.2 mm | 48.5% above | 0.6 mm |
| Upper Yarra | 30 mm | 25.8 mm | 16.3% above | 3.2 mm |
| O'Shannassy | 25.6 mm | 36.2 mm | 29.3% below | 4.6 mm |
| Maroondah | 29.4 mm | 25 mm | 17.6% above | 6.4 mm |
* Long Term Weekly Average (30 year mean 1978-2007)
Streamflow For The Major Harvesting Catchments
| Catchment | 15 Aug - 21 Aug 2008 |
Long Term Ave* | Variation | 15 Aug - 21 Aug 2007 |
|---|---|---|---|---|
| Thomson | 6861 ML | 7730 ML | 11.2% below | 6228 ML |
| Upper Yarra | 6658 ML | 5880 ML | 13.2% above | 4894 ML |
| O'Shannassy | 2721 ML | 3230 ML | 15.8% below | 1994 ML |
| Maroondah | 3942 ML | 2560 ML | 54.0% above | 1662 ML |
| Total | 20182 ML | 19400 ML | 4.0% above | 14778 ML |
* Long Term Weekly Average (30 year mean 1978-2007)
Note: These results are preliminary and are validated at the end of the month.
Yarra Catchment
Report for period 14 August - 20 August 2008 (inclusive):
- Current seven day rolling average flows for Yarra River @ Yarra Glen = 1512 ML/day (up 826.0 ML/day from the previous week)
- Current seven day rolling average flows for Yarra River @ Warrandyte = 553.9 ML/day (up 187.1 ML/day from the previous week)
- Current seven day rolling average flows for Little Yarra River @ Yarra Junction = 195 ML/day (up 91.3 ML/day from the previous week)
- Current seven day rolling average flows for Woori Yallock Creek @ Yellingbo = 250.8 ML/day (up 111.3 ML/day from the previous week)
- Total rainfall at Upper Yarra Reservoir for August is 92.76 mm (long-term monthly average for August is 123.4 mm)
- Total rainfall at Silvan Reservoir for August is 91.8 mm (long-term monthly average for August is 118.3 mm)
Maribyrnong Catchment
Report for period 14 August - 20 August 2008 (inclusive):
Rosslyne Reservoir
Melbourne Water's Capacity Share of the storage as at 18 August 2008 was 27 Megalitres (ML)
- Current release from Rosslyne (as at 18 August 2008) to meet bulk entitlement demands = 0.51 ML/day
- Current seven day rolling average flows for Jacksons Creek @ Sunbury = 8.5 ML/day (down 5.6 ML/day from the previous week)
- Current seven day rolling average flows for Deep Creek @ Bulla = 4.1 ML/day (up 0.1 ML/day from the previous week)
- Current seven day rolling average flows for Maribyrnong River @ Keilor (Brimbank Park) = 27.1 ML/day (up 4.7 ML/day from the previous week)
- Total rainfall at Rosslyne Reservoir for August is 28 mm (long-term monthly average for August is 64.4 mm)
Note: Passing flows at Keilor, as per the bulk entitlement agreement, require 5.0 ML/day or natural, whichever is the lesser, to be passed at Keilor. Natural flows are based on flows at Deep Ck @ Bulla gauging station.
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