New temporary management plan for Wivenhoe and Somerset dams

Low flow releases from Somerset Dam began this week to lower the drinking water full supply level of the dam.

Since the releases started on Wednesday, the dam level has reduced from 98.5% to 97.5%.

Somerset and Wivenhoe are being temporarily lowered as part of Seqwater's Dam Improvement Program.

Wivenhoe Dam releases will start next Wednesday, 27 January. The releases to lower both dams are being undertaken at low rates to minimise any impact on the community.

The latest assessment of Somerset Dam has indicated improvement works may be required earlier than previously planned to ensure the highest safety standards are maintained.

While Seqwater undertakes further work to determine the detailed scope, design and timing of any necessary works, a new flood operations strategy will be adopted for Somerset Dam.

This is a precautionary approach to best manage Somerset Dam while further assessments can be undertaken to confirm the final nature and detail of any necessary future works.

Somerset Dam is being lowered to 80% of its full water supply storage volume. To maintain the flood management benefits provided by Wivenhoe and Somerset dams, Wivenhoe Dam’s full water supply storage volume will also be lowered to 90%. This will increase the temporary flood storage space in Wivenhoe Dam to allow additional flood waters to be stored if required.

Seqwater Chief Executive Officer Peter Dennis said lowering water supply storage levels in dams was an industry accepted practice to protect the safety of communities while dam upgrade works are completed.

“The preliminary assessment of Somerset Dam has significantly improved our knowledge and understanding of the dam structure and highlighted the possibility of an earlier upgrade to ensure Somerset continues to perform as required,” he said.

Mr Dennis said as much of the released water as is practicable would be used to reduce the draw down on the region’s other major water supply dams, including North Pine and Hinze dams, by increasing production at the Mt Crosby water treatment plants and using the Water Grid.

 

Lake Borumba remains closed due to blue-green algae

Fast-tracked test results show algae levels remain high, meaning Lake Borumba will not be re-opened to water-based recreation ahead of Australia Day.

The lake is currently closed to recreation activities due to the presence of blue-green algae. The latest water quality samples indicate algae levels remain too high to re-open the lake.

Seqwater Chief Executive Officer Peter Dennis said the health and safety of visitors was a key priority.

“We have been contacted by a family who reported falling ill after swimming in Lake Borumba at the start of last week, just before the closure,” Mr Dennis said.

“We have a duty of care to safeguard other visitors from exposure to blue-green algal blooms and the health conditions which can result.

“There are a number of symptoms associated with exposure to blue-green algae such as abdominal cramps, diarrhoea, vomiting, nausea, rashes, swelling, sores, irritation, earache, eye irritation, cough and congestion.”

Mr Dennis said Seqwater recognised the impact of water-based recreation closures on the community, including local business, and would continue to accelerate its sampling and analysis in an effort to re-open the lake as soon as it is safe to do so.

“Seqwater considers the National Health and Medical Research Council Guidelines for Recreation Management and the Department of Environment and Heritage Protection blue-green algae guidelines, in determining whether to restrict access to water-based activities when our regular water testing shows algae levels are high,” he said.

“Recreation is a core service of our business and we have specialist in-house water quality expertise to apply the best science and knowledge available. As such, our standard of testing and monitoring is high.

“We will re-open the lake as soon as it is safe to do so.”

The Seqwater website (www.seqwater.com.au) and Facebook and Twitter pages will be updated as conditions change at Lake Borumba.

Visitors are asked to observe signage in place at Lake Borumba and follow the direction of staff.

For more information, a fact sheet on blue-green algae is available on our website www.seqwater.com.au/about/publications/fact-sheets.

 

Recreation update

Partial closure of Cormorant Bay recreation area on Saturday 23 January

The Cormorant Bay recreation area at Lake Wivenhoe will be partially closed to public use on Saturday 23 January due to the Somerset Australia Day Festival.

The Cormorant Bay Café will remain open. Those with bookings for breakfast or lunch will be directed to a parking area close to the café.

Visitors to the recreation area on Saturday 23 January will be informed at the entrance of the accessible areas. The Somerset Australia Day Festival will begin at 4pm.

For more information about the Somerset Australia Day Festival, phone Somerset Regional Council on 5424 4000.

 

Lake Atkinson closed to water-based recreation

Lake Atkinson is temporarily closed to all water-based recreation due to the detection of blue-green algae.

Blue-green algae blooms generally occur in the warmer months due to increased water temperature, abundant nutrients and optimal light conditions.

Seqwater is closely monitoring algae levels and will re-open the lake when water quality results indicate it is appropriate to do so.

Visitors are requested to observe the direction of staff and signage at the site.

 

Lake Dyer closed to water-based recreation

Lake Dyer is temporarily closed to all water-based recreation due to the detection of blue-green algae.

Seqwater is closely monitoring algae levels and will re-open the lake when water quality results indicate it is appropriate to do so.

Please observe all signage and directions of Seqwater staff on-site.

 

Lake Clarendon closed to water-based recreation

Lake Clarendon is temporarily closed to all water-based recreation due to the detection of blue-green algae.

Seqwater is performing regular water quality testing and will re-open Lake Clarendon to water-based activities as soon as possible.

Visitors are requested to observe the direction of staff and signage at the site.

 

Western reaches of Lake Wyaralong closed to water-based activity

The western reaches of Lake Wyaralong remain temporarily closed to water-based activity due to the presence of blue green algae.

The Knher Road canoe launch point is closed to public access. Signage has been erected at the site and also in the Lilybrook Recreation Area to advise of the closure.

All visitors are requested to observe signage and follow the direction of staff on-site.

We will re-open the site as soon as it is safe to do so.

 

Northern boat ramp at Lake Baroon closed

The boat ramp at the Northern Recreation Area at Lake Baroon is closed to boats and trailers until further notice.

For your safety, please use the boat ramp at the Southern Recreation Area.

The ramp will be opened as soon as it is appropriate to do so.

People with paddle craft are still permitted to use the ramp.

 

SEQ dam levels

The current drinking water supply capacity of the Grid Twelve is 90.6%, down 0.6% from last week. The Grid Twelve makes up nearly 90% of South East Queensland’s total water storage volume. See below for further breakdowns:

Dam

Current drinking water volume

Change in volume past 7 days

(%)

Catchment rainfall past 7 days

(mm)*

(ML)

(%)

Wivenhoe

1,047,506 ML

89.9%

0.3 % 

0.2

Somerset

370,215 ML

97.5%

1.4% 

0.9

North Pine**

159,218 ML

82.4%

0.6

0.3

Hinze**

289,632 ML

93.2%

0.5% 

1.7

Baroon Pocket

43,676 ML

71.6%

1.2 % 

11.9

Leslie Harrison**

10,966 ML

83.0%

1.8

0.7

Ewen Maddock

16,301 ML

98.3%

0.8% 

7.2

Cooloolabin

6,366 ML

79.3%

1.6% 

4.8

Lake Kurwongbah**

8,699 ML

100.5%

1.3% 

0.3

Lake Macdonald

7,186 ML

89.6%

1.5 % 

13.2

Little Nerang

6,596 ML

98.4%

1.3% 

1.7

Wappa

4,497 ML

95.8%

1.3 % 

4.8

* Catchment rainfall is the average of rainfalls recorded in and around the dam catchment.

**The capacity of North Pine, Hinze, Cooloolabin, Sideling Creek and Leslie Harrison have been temporarily decreased

 

The current flood storage capacity:

Dam

Current flood storage volume

Available storage
(%)

Wivenhoe

1,967,000 ML

100%

Somerset

721,000 ML

100%

 

 

SEQ water consumption figures

Average daily residential water consumption across South East Queensland for the 14 day period ending 20 January 2016 was 179 litres per person. This is an increase on the average for the previous period of 168 litres per person (calculated over 14 days ending 13 January 2016).

Average daily residential water consumption for a similar time last year was 153 litres per person. Across South East Queensland, residents are currently consuming about 26 litres more water per person per day as they did this time last year.

See below for further breakdowns:

Water consumption summary for the 14 day period ending Wednesday, 20 January 2016

Zone

SEQ

Central
SEQ

Gold
Coast

Redland

Scenic
Rim

Sunshine Coast

Average daily production (ML)

855

543

174

39

5

93

Average daily residential consumption (L/person)

179

167

204

197

133

198

Total rainfall (mm)

 

1.0

0.8

5.0

3.6

23.6

Temperature oC

 

30.0

28.8

29.4

31.8

29.2

 

Residential water consumption for similar time last year (14 day period ending Wednesday 21 January 2015)

Zone

SEQ

Central
SEQ

Gold
Coast

Redland

Scenic
Rim

Sunshine Coast

Average daily residential consumption (L/person)

153

133

191

199

120

187