Bulk water storage and supply report - 27 April 2006

Negligible rainfall was recorded on the SCA’s catchments during the week.

As at 3 p.m. Thursday 27 April 2006, the inflow rates to Warragamba Dam including Shoalhaven transfers was 50 megalitres per day and to Tallowa Dam was 45 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.

21.4.06

29°C

Nil

1 434 ML

1 144 500 ML

44.3%

Sat.

22.4.06

24°C

Nil

1 470 ML

1 143 000 ML

44.2%

Sun.

23.4.06

21°C

Nil

1 618 ML

1 141 000 ML

44.2%

Mon.

24.4.06

22°C

1.0 mm

1 739 ML

1 139 000 ML

44.1%

Tue.

25.4.06

21°C

0.4 mm

1 436 ML

1 137 500 ML

44.0%

Wed.

26.4.06

20°C

1.0 mm

1 352 ML

1 136 000 ML

44.0%

Thu.

27.4.06

21°C

3.0 mm

1 461 ML

1 134 000 ML

43.9%

 

Total supply for the week

10 511 ML

Average daily supply during week

1 502 ML

Volume pumped from Shoalhaven for the week

2050 ML

Net weekly storage change (megalitres)

-11 850 ML

Net weekly storage change (percentage)

-0.4%

 

Available Water Storage as at 27 April 2006

Storage

Full Operating Storage (ML)

Storage Level (m)

Available Storage (ML)

Available Storage (%)

Net Weekly Change (ML)

Cataract

94,300

- 9.52

33,580

35.6

-520

Cordeaux

93,640

- 7.14

49,060

52.4

-1,180

Avon

146,700

- 9.87

57,850

39.4

-910

Nepean

69,810

- 11.97

37,620

53.9

-90

Woronora

71,790

- 18.88

23,290

32.4

-230

Warragamba

2,027,000

- 18.71

894,060

44.1

-7,770

Prospect

8,870

- 1.10

3,400

38.3

-160

Wingecarribee

24,100

- 2.06

15,520

64.4

1,570

Fitzroy Falls

10,000

- 0.82

5,920

59.2

-2,300

Tallowa*

35,300*

- 3.23

11,960*

33.9*

-180

Blue Mountains

2,790

 

1,890

67.7

-80

Total

2,584,300

 

1,134,150

43.9

-11,850


*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.

As of today, the expanded supply system storage level is 43.9 per cent.