Bulk water storage and supply report - 15 June 2006

During the week approximately 35 millimetres of rainfall was recorded on the Shoalhaven Catchment, 20 millimetres on the Warragamba and Blue Mountains catchments, 15 millimetres on the Upper Nepean Catchment and 10 millimetres on the Woronora Catchment.

As at 3 p.m. Thursday, 15 June 2006, the inflow rate to Warragamba Dam including Shoalhaven transfers was 360 megalitres per day and to Tallowa Dam was 1250 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.

9.6.06

19°C

8.0 mm

1 364 ML

1 085 000 ML

42.0%

Sat.

10.6.06

16°C

3.0 mm

1 271 ML

1 085 000 ML

42.0%

Sun.

11.6.06

14°C

10.0 mm

1 277 ML

1 086 500 ML

42.0%

Mon.

12.6.06

13°C

0.2 mm

1 356 ML

1 090 500 ML

42.2%

Tue.

13.6.06

17°C

Nil

1 473 ML

1 091 500 ML

42.2%

Wed.

14.6.06

19°C

Nil

1 323 ML

1 092 000 ML

42.3%

Thu.

15.6.06

18°C

Nil

1 339 ML

1 090 500 ML

42.2%

 

Total supply for the week

9 403 ML

Average daily supply during week

1 343 ML

Volume pumped from Shoalhaven for the week

2 400 ML

Net weekly storage change (megalitres)

3 920 ML

Net weekly storage change (percentage)

+0.2%

 

Available Water Storage as at 15 June 2006

Storage

Full Operating Storage (ML)

Storage Level (m)

Available Storage (ML)

Available Storage (%)

Net Weekly Change (ML)

Cataract

94,300

- 10.84

28,120

29.8

-510

Cordeaux

93,640

- 8.56

42,410

45.3

-170

Avon

146,700

- 10.63

52,260

35.6

-650

Nepean

69,810

- 11.89

37,800

54.1

680

Woronora

71,790

- 19.67

22,010

30.7

-170

Warragamba

2,027,000

- 19.84

844,150

41.6

-4,720

Prospect

8,870

- 1.16

3,140

35.4

0

Wingecarribee

24,100

- 1.94

15,990

66.3

610

Fitzroy Falls

10,000

- 0.51

7,430

74.3

1,300

Tallowa*

35,300*

+ 0.05

35,300*

100.0*

7,500

Blue Mountains

2,790

 

1,900

68.1

50

Total

2,584,300

 

1,090,510

42.2

3,920


*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.