Bulk water storage and supply report - 29 June 2006

During the week approximately 10 millimetres of rainfall was recorded on the Upper Nepean and Woronora catchments and 5 millimetres on the Warragamba, Shoalhaven and Blue Mountains catchments.

As at 3 p.m. Thursday, 29 June 2006, the inflow rate to Warragamba Dam including Shoalhaven transfers was 440 megalitres per day and to Tallowa Dam was 410 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.

23.6.06

15°C

12.0 mm

1 237 ML

1 083 500 ML

41.9%

Sat.

24.6.06

18°C

3.0 mm

1 206 ML

1 083 500 ML

41.9%

Sun.

25.6.06

18°C

Nil

1 483 ML

1 083 000 ML

41.9%

Mon.

26.6.06

16°C

Nil

1 489 ML

1 082 500 ML

41.9%

Tue.

27.6.06

17°C

2.0 mm

1 246 ML

1 082 000 ML

41.9%

Wed.

28.6.06

19°C

Nil

1 293 ML

1 081 000 ML

41.8%

Thu.

29.6.06

19°C

Nil

1 273 ML

1 080 000 ML

41.8%

 

Total supply for the week

9 226 ML

Average daily supply during week

1 318 ML

Volume pumped from Shoalhaven for the week

4 800 ML

Net weekly storage change (megalitres)

-3 930 ML

Net weekly storage change (percentage)

-0.1%

 

Available Water Storage as at 29 June 2006

Storage

Full Operating Storage (ML)

Storage Level (m)

Available Storage (ML)

Available Storage (%)

Net Weekly Change (ML)

Cataract

94,300

- 10.88

27,970

29.7

0

Cordeaux

93,640

- 8.68

41,890

44.7

-340

Avon

146,700

- 10.82

50,890

34.7

-650

Nepean

69,810

- 10.05

41,990

60.1

2,570

Woronora

71,790

- 19.80

21,800

30.4

-60

Warragamba

2,027,000

- 20.09

833,450

41.1

-4,280

Prospect

8,870

- 1.16

3,130

35.3

0

Wingecarribee

24,100

- 1.46

17,910

74.3

180

Fitzroy Falls

10,000

- 0.56

7,180

71.8

380

Tallowa*

35,300*

- 0.49

31,710*

89.8*

-1,740

Blue Mountains

2,790

 

1,940

69.5

10

Total

2,584,300

 

1,079,860

41.8

-3,930


*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.