Bulk water storage and supply report - 6 July 2006

During the week approximately 15 millimetres of rainfall was recorded on the Shoalhaven, Upper Nepean and Woronora catchments, 10 millimetres on the Blue Mountains Catchment and 5 millimetres on the Warragamba Catchment.

As at 3 p.m. Thursday, 6 July 2006, the inflow rate to Warragamba Dam including Shoalhaven transfers was 500 megalitres per day and to Tallowa Dam was 1200 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.

30.6.06

19°C

Nil

1 326 ML

1 078 500 ML

41.7%

Sat.

1.7.06

14°C

0.6 mm

1 243 ML

1 077 000 ML

41.7%

Sun.

2.7.06

19°C

Nil

1 481 ML

1 075 500 ML

41.6%

Mon.

3.7.06

18°C

Nil

1 432 ML

1 075 500 ML

41.6%

Tue.

4.7.06

19°C

37.0 mm

1 301 ML

1 077 000 ML

41.7%

Wed.

5.7.06

16°C

5.0 mm

1 223 ML

1 079 500 ML

41.8%

Thu.

6.7.06

20°C

Nil

1 308 ML

1 079 500 ML

41.8%

 

Total supply for the week

9 314 ML

Average daily supply during week

1 331ML

Volume pumped from Shoalhaven for the week

4 350 ML

Net weekly storage change (megalitres)

-570 ML

Net weekly storage change (percentage)

0.0%

 

 


Available Water Storage as at 6 July 2006

Storage

Full Operating Storage (ML)

Storage Level (m)

Available Storage (ML)

Available Storage (%)

Net Weekly Change (ML)

Cataract

94,300

- 10.90

27,890

29.6

-80

Cordeaux

93,640

- 8.72

41,710

44.5

-180

Avon

146,700

- 10.92

50,170

34.2

-720

Nepean

69,810

- 8.90

44,740

64.1

2,750

Woronora

71,790

- 19.92

21,610

30.1

-190

Warragamba

2,027,000

- 20.23

827,460

40.8

-5,990

Prospect

8,870

- 1.16

3,130

35.3

0

Wingecarribee

24,100

- 1.44

18,010

74.7

100

Fitzroy Falls

10,000

- 0.43

7,830

78.3

650

Tallowa*

35,300*

- 0.08

34,780*

98.5*

3,070

Blue Mountains

2,790

 

1,960

70.3

20

Total

2,584,300

 

1,079,290

41.8

-570


*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.