Melbourne Water

Weekly Water Report

3 July 2009

Rain ineffective as storages resume drop

Storages have resumed their decline after a week of below average rainfall and minimal streamflow.

After a 22 billion litre boost from the reconnection of Tarago Reservoir last month, storages then fell by 0.2% of capacity (3.8 billion litres) in the past week.

The drop came as 21.1 mm of rain fell over the major catchments, below the average for the period, 31.5 mm.

The intermittent rain had little effect on the dry catchments. The 3.4 billion litres of streamflow into the major reservoirs was 73% below average (12.6 billion litres).

The catchments need persistent rain before we see a sustained increase in storage levels.

Storages are now 26.0% (470.6 billion litres) full, compared with 29.6% (524.2 billion litres) at the same time last year.

Residential water consumption was low. Melburnians used an average of 130 litres each per day – the 17th week in a row that Target 155 has been met.

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 1997-2009 (opens in a new window)

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

Total system storage (as of 2 July 2009)

Reservoir	Capacity at full supply (ML)	Volume (ML)	% Full
Thomson	1,068,000	173,065	16.2%
Upper Yarra	200,000	82,239	41.1%
O'Shannassy	3,000	2,106	70.2%
Maroondah	22,000	6,217	28.3%
Sugarloaf	96,000	14,949	15.6%
Yan Yean	30,000	5,721	19.1%
Greenvale	27,000	19,984	74.0%
Silvan	40,000	34,847	87.1%
Cardinia	287,000	109,402	38.1%
Tarago	37,500	22,025	58.7%
Total	1,810,500	470,555	26.0%

Rainfall recorded at the reservoirs

Catchment	26 Jun - 2 Jul 2009	Average for the period*	Variation	26 Jun - 2 Jul 2008
Thomson	17.4 mm	32.8 mm	47.0% below	39.6 mm
Upper Yarra	30.8 mm	28.7 mm	7.3% above	37.6 mm
O'Shannassy	21.4 mm	39.1 mm	45.3% below	48.8 mm
Maroondah	6.2 mm	25.4 mm	75.6% below	9.6 mm

* Average (30 year mean 1979-2008)

Stream flow for the major catchments

Catchment	26 Jun - 2 Jul 2009	Average for the period*	Variation	26 Jun - 2 Jul 2008
Thomson	1646 ML	5560 ML	70.4% below	2995 ML
Upper Yarra	438 ML	3060 ML	85.7% below	883 ML
O'Shannassy	885 ML	1950 ML	54.6% below	1093 ML
Maroondah	464 ML	1990 ML	76.7% below	1072 ML
Total	3433 ML	12560 ML	72.7% below	6043 ML

* Average (30 year mean 1979-2008)

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

Yarra Catchment
Report for period 25 June - 1 July 2009 (inclusive):

• Current seven day rolling average flows for Yarra River @ Yarra Glen = 407.5 ML/day (up 22.8 ML/day from the previous week)
• Current seven day rolling average flows for Yarra River @ Warrandyte = 230.3 ML/day (down 28.5 ML/day from the previous week)
• Current seven day rolling average flows for Little Yarra River @ Yarra Junction = 33.2 ML/day (down 1.8 ML/day from the previous week)
• Current seven day rolling average flows for Woori Yallock Creek @ Yellingbo = 53.2 ML/day (up 5.4 ML/day from the previous week)
• Total rainfall at Upper Yarra Reservoir for July is 3.21 mm (long-term monthly average for July is 105.2 mm)
• Total rainfall at Upper Yarra Reservoir for June is 66.66 mm (long-term monthly average for June is 103.9 mm)
• Total rainfall at Silvan Reservoir for July is 0 mm (long-term monthly average for July is 107.4 mm)
• Total rainfall at Silvan Reservoir for June is 71.6 mm (long-term monthly average for June is 118.5 mm)

Maribyrnong Catchment
Report for period 25 June - 1 July 2009 (inclusive):

Rosslyne Reservoir
Melbourne Water's Capacity Share of the storage as at 29 June 2009 was 20 Megalitres (ML)

• Current release from Rosslyne (as at 29 June 2009) to meet bulk entitlement demands = 0.4 ML/day
• Current seven day rolling average flows for Jacksons Creek @ Sunbury = 1.2 ML/day (up 1.0 ML/day from the previous week)
• Current seven day rolling average flows for Deep Creek @ Bulla = 0.6 ML/day (down 0.1 ML/day from the previous week)
• Current seven day rolling average flows for Maribyrnong River @ Keilor (Brimbank Park) = 1.6 ML/day (up 0.2 ML/day from the previous week)
• Total rainfall at Rosslyne Reservoir for July is 5 mm (long-term monthly average for July is 57.8 mm)
• Total rainfall at Rosslyne Reservoir for June is 34.2 mm (long-term monthly average for June is 59.9 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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