Melbourne Water

Weekly Water Report

2 September 2010

Storages make strong start to spring

Melbourne’s dams have banked 24 billion litres in the past week, as the strong rally in storage levels continues into spring.

The increase, which represents 1.3% of total capacity, came as catchment rainfall and runoff were well above the 30-year averages.

The major catchments had between 22 and 70 mm of rain (an average of 36 mm) – which was 57% above the long-term average for this time of year (22.9 mm).

The 27 billion litres of streamflow into the major reservoirs was 47.5% above the long-term average of 18.3 billion litres.

The catchments are wet and typically produce the most streamflow during spring, so the storage increase is expected to continue.

Storages are now 41.7% (756.1 billion litres) full, compared with 28.6% (518.0 billion litres) at the same time last year – a difference of 238.1 billion litres.

The wet week helped keep residential water use low, with Melburnians using a daily average of 131 litres per person per day - 24 litres below Target 155.

This week also saw water restrictions eased from Stage 3 to 2, effective from 1 September.

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

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)

   2008     2009     2010  
100% capacity = 1,812,175 ML
NB: Prior to 1 July 2010, 100% capacity = 1,810,500 ML

Total system storage (as of 2 September 2010)

Reservoir	Capacity at full supply (ML)	Current Volume (ML)	% Full
Thomson	1,068,000	289,034	27.1%
Cardinia	286,911	124,092	43.3%
Upper Yarra	200,579	139,148	69.4%
Sugarloaf	96,253	80,294	83.4%
Silvan	40,445	36,120	89.3%
Tarago	37,580	22,696	60.4%
Yan Yean	30,266	16,381	54.1%
Greenvale	26,839	17,857	66.5%
Maroondah	22,179	22,480	100.0%
O'Shannassy	3,123	3,243	100.0%
Total	1,812,175	751,345	41.5%
Non-catchment sources
Sugarloaf Pipeline Allocation		4,793
Grand Total	1,812,175	756,138	41.7%

Rainfall recorded at the reservoirs

Catchment	27 Aug - 2 Sep 2010	Average for the period*	Variation	27 Aug - 2 Sep 2009
Thomson	22 mm	19.2 mm	14.6% above	24.4 mm
Upper Yarra	45.6 mm	24.9 mm	83.1% above	19 mm
O'Shannassy	70 mm	31 mm	125.8% above	35.8 mm
Maroondah	30.2 mm	23.9 mm	26.4% above	25.4 mm

* Average (30 year mean 1980-2009)

Stream flow for the major catchments

Catchment	27 Aug - 2 Sep 2010	Average for the period*	Variation	27 Aug - 2 Sep 2009
Thomson	10508 ML	7400 ML	42.0% above	6057 ML
Upper Yarra	7754 ML	5400 ML	43.6% above	3168 ML
O'Shannassy	6020 ML	3110 ML	93.6% above	2253 ML
Maroondah	2693 ML	2380 ML	13.2% above	1393 ML
Total	26975 ML	18290 ML	47.5% above	12871 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 26 August - 1 September 2010 (inclusive):

• Current seven day rolling average flows for Yarra River @ Yarra Glen = 2831 ML/day (up 478.9 ML/day from the previous week)
• Current seven day rolling average flows for Yarra River @ Warrandyte = 2020.6 ML/day (up 487.9 ML/day from the previous week)
• Current seven day rolling average flows for Little Yarra River @ Yarra Junction = 150.8 ML/day (up 15.7 ML/day from the previous week)
• Current seven day rolling average flows for Woori Yallock Creek @ Yellingbo = 380.9 ML/day (up 111.8 ML/day from the previous week)
• Total rainfall at Upper Yarra Reservoir for September is 0 mm (long-term monthly average for September is 118.1 mm)
• Total rainfall at Upper Yarra Reservoir for August is 173.2 mm (long-term monthly average for August is 120.4 mm)
• Total rainfall at Silvan Reservoir for September is 0.2 mm (long-term monthly average for September is 115.6 mm)
• Total rainfall at Silvan Reservoir for August is 183.4 mm (long-term monthly average for August is 114.9 mm)

Maribyrnong Catchment
Report for period 26 August - 1 September 2010 (inclusive):

Rosslyne Reservoir
Melbourne Water's Capacity Share of the storage as at 30 August 2010 was 91 Megalitres (ML)

• Current release from Rosslyne (as at 30 August 2010) to meet bulk entitlement demands = 0.23 ML/day
• Current seven day rolling average flows for Jacksons Creek @ Sunbury = 41 ML/day (down 11.7 ML/day from the previous week)
• Current seven day rolling average flows for Deep Creek @ Bulla = 517 ML/day (down 218.1 ML/day from the previous week)
• Current seven day rolling average flows for Maribyrnong River @ Keilor (Brimbank Park) = 439.9 ML/day (down 211.0 ML/day from the previous week)
• Total rainfall at Rosslyne Reservoir for September is 0 mm (long-term monthly average for September is 66.6 mm)
• Total rainfall at Rosslyne Reservoir for August is 103.2 mm (long-term monthly average for August is 62.4 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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