Melbourne Water

Weekly Water Report

5 February 2010

Hot, dry and usage high as dams down 0.4%

Minimal rain, hot weather and a spike in consumption has seen water storages fall by 0.4% of capacity in the past week.

The decrease, which represents an overall decline of 7.6 billion litres, came as the major catchments received very little rainfall.

The major catchments had between 0.0 and 3.8 mm of rain, with an average of 0.4 mm.

This was well below the long-term average for the period, 13.3 mm. The amount of water flowing into the major reservoirs was also down on historical levels.

The 1.9 billion litres of streamflow was 50% below the average of 3.8 billion litres.

Storages are now 35.9% (649.9 billion litres) full, compared with 32.8% (581.6 billion litres) at the same time last year – a difference of more than 68 billion litres.

The hot and dry weather saw residential water consumption increase, with Melburnians using an average of 189 litres per person per day.

This was much higher than the daily target of 155 litres per person.

More information on restrictions and tips on how to reach the target are available from Target 155 or by contacting the government water retailers.

Stage 3a restrictions and Target 155 are currently in place.

Daily residential water use for Melbourne

   PREVIOUS WEEKS
   CURRENT WEEK
   TARGET 155

All figures include non-metropolitan supply for Western Water (supplied since March 2000), which are not included in annual Melbourne metropolitan consumption figures.

Melbourne's water storages

View interactive storage graph for 1997-2010 (opens in a new window)

   2007-08     2008-09     2009-10  
100% capacity = 1810.5 GL
NB: Prior to 26 June 2009, 100% capacity = 1773 GL

Total system storage (as of 4 February 2010)

Reservoir	Capacity at full supply (ML)	Current Volume (ML)	% Full
Thomson	1,068,000	225,427	21.1%
Cardinia	287,000	108,368	37.8%
Upper Yarra	200,000	141,553	70.8%
Sugarloaf	96,000	66,775	69.6%
Silvan	40,000	35,590	89.0%
Tarago	37,500	23,030	61.4%
Yan Yean	30,000	7,870	26.2%
Greenvale	27,000	19,441	72.0%
Maroondah	22,000	19,387	88.1%
O'Shannassy	3,000	2,448	81.6%
Total	1,810,500	649,889	35.9%

Rainfall recorded at the reservoirs

Catchment	29 Jan - 4 Feb 2010	Average for the period*	Variation	29 Jan - 4 Feb 2009
Thomson	0 mm	12.9 mm	100.0% below	2.2 mm
Upper Yarra	0 mm	12.6 mm	100.0% below	0 mm
O'Shannassy	0.6 mm	14.2 mm	95.8% below	0.4 mm
Maroondah	3.8 mm	16.2 mm	76.5% below	1 mm

* Average (30 year mean 1980-2009)

Stream flow for the major catchments

Catchment	29 Jan - 4 Feb 2010	Average for the period*	Variation	29 Jan - 4 Feb 2009
Thomson	283 ML	1310 ML	78.4% below	517 ML
Upper Yarra	272 ML	790 ML	65.6% below	273 ML
O'Shannassy	812 ML	890 ML	8.8% below	392 ML
Maroondah	507 ML	820 ML	38.2% below	475 ML
Total	1874 ML	3810 ML	50.8% below	1657 ML

* Average (30 year mean 1980-2009)

Note: These results are preliminary and are validated at the end of the month.

Yarra Catchment
Report for period 28 January - 3 February 2010 (inclusive):

• Current seven day rolling average flows for Yarra River @ Yarra Glen = 168.1 ML/day (down 66.3 ML/day from the previous week)
• Current seven day rolling average flows for Yarra River @ Warrandyte = 183.6 ML/day (down 47.3 ML/day from the previous week)
• Current seven day rolling average flows for Little Yarra River @ Yarra Junction = 18.7 ML/day (down 6.8 ML/day from the previous week)
• Current seven day rolling average flows for Woori Yallock Creek @ Yellingbo = 21.2 ML/day (down 10.7 ML/day from the previous week)
• Total rainfall at Upper Yarra Reservoir for February is 0 mm (long-term monthly average for February is 45.4 mm)
• Total rainfall at Upper Yarra Reservoir for January is 82.6 mm (long-term monthly average for January is 61.7 mm)
• Total rainfall at Silvan Reservoir for February is 11.2 mm (long-term monthly average for February is 49.1 mm)
• Total rainfall at Silvan Reservoir for January is 56.4 mm (long-term monthly average for January is 58.2 mm)

Maribyrnong Catchment
Report for period 28 January - 3 February 2010 (inclusive):

Rosslyne Reservoir
Melbourne Water's Capacity Share of the storage as at 1 February 2010 was 34 Megalitres (ML)

• Current release from Rosslyne (as at 1 February 2010) to meet bulk entitlement demands = 0 ML/day
• Current seven day rolling average flows for Jacksons Creek @ Sunbury = 0 ML/day (no change from the previous week)
• Current seven day rolling average flows for Deep Creek @ Bulla = 0.2 ML/day (down 1.3 ML/day from the previous week)
• Current seven day rolling average flows for Maribyrnong River @ Keilor (Brimbank Park) = 0.6 ML/day (down 0.9 ML/day from the previous week)
• Total rainfall at Rosslyne Reservoir for February is 3.8 mm (long-term monthly average for February is 40.6 mm)
• Total rainfall at Rosslyne Reservoir for January is 76.2 mm (long-term monthly average for January is 46.7 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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