Bulk water storage and supply report - 11 May 2006

During the week less than 5 millimetres of rainfall was recorded on the SCA’s catchments.

As at 3 p.m. Thursday 11 May 2006, the inflow rate to Warragamba Dam was 20 megalitres per day and to Tallowa Dam was 30 megalitres per day.

Date

24 hours to 8 a.m.

As at 3 p.m.

Sydney Max. Temp.

Sydney Rainfall

Bulk Water Supply

Available Storage

% Storage

Fri.

5.5.06

24°C

Nil

1 587 ML

1 120 500 ML

43.4%

Sat.

6.5.06

23°C

Nil

1 417 ML

1 119 000 ML

43.3%

Sun.

7.5.06

22°C

Nil

1 537 ML

1 117 500 ML

43.2%

Mon.

8.5.06

26°C

Nil

1 805 ML

1 116 000 ML

43.2%

Tue.

9.5.06

20°C

Nil

1 495 ML

1 114 000 ML

43.1%

Wed.

10.5.06

22°C

Nil

1 440 ML

1 112 000 ML

43.0%

Thu.

11.5.06

23°C

Nil

1 567 ML

1 110 500 ML

43.0%

 

Total supply for the week

10 848 ML

Average daily supply during week

1 550 ML

Volume pumped from Shoalhaven for the week

50 ML

Net weekly storage change (megalitres)

-11 690 ML

Net weekly storage change (percentage)

-0.4%

 

Available Water Storage as at 11 May 2006

Storage

Full Operating Storage (ML)

Storage Level (m)

Available Storage (ML)

Available Storage (%)

Net Weekly Change (ML)

Cataract

94,300

- 9.98

31,600

33.5

-850

Cordeaux

93,640

- 7.63

46,710

49.9

-1,190

Avon

146,700

- 10.14

55,840

38.1

-1,120

Nepean

69,810

- 12.07

37,410

53.6

-130

Woronora

71,790

- 19.16

22,830

31.8

-250

Warragamba

2,027,000

- 19.08

877,640

43.3

-8,420

Prospect

8,870

- 1.15

3,180

35.9

-140

Wingecarribee

24,100

- 2.11

15,320

63.6

-120

Fitzroy Falls

10,000

- 0.70

6,480

64.8

650

Tallowa*

35,300*

- 3.28

11,680*

33.1*

-90

Blue Mountains

2,790

 

1,780

63.8

-30

Total

2,584,300

 

1,110,470

43.0

-11,690


*NOTE: The "full operating storage" for Tallowa Dam refers only to the amount of water in the dam that is available to be transferred to Sydney and the Illawarra.  When full, the dam can hold 90,000 ML but only 35,300 ML is available to be transferred.

Other water from Tallowa Dam is provided to Shoalhaven City Council for supply to local communities.  Water is also released from the dam as environmental flows for the Shoalhaven River.

 

‘Expanded storage’ levels

On Saturday 15 April 2006, the SCA reached a major milestone in our deep-water storage projects when a water supply access point was created at the base of Warragamba Dam.

Combined, the deep storage projects at Warragamba and Nepean dams add around six months of water supply to the system for use in the present drought. They also add about 40 billion litres a year to the available supply. The SCA will complete the final stages of the projects between now and August this year.

The establishment of the new access point in the Warragamba Dam wall represents the major engineering milestone in these projects.  As a result, we can now report available storage against the volume of the expanded system.  All reports will now relate to the expanded system.

The Government’s Metropolitan Water Plan February 2006 Progress Report uses this expanded storage level to determine the trigger points for further drought management actions:

  • Around 40 per cent of the expanded supply system is the trigger for moving forward with the construction of borefields to access groundwater;
  • ·         Around 30 per cent of the expanded supply system is the trigger for moving forward with the construction of a desalination plant.