Shoalhaven transfers

After considering community feedback, scientific investigations and social, economic and cultural heritage assessments, the Government announced in March 2007, important improvements for the health of the Shoalhaven and Southern Highlands rivers.

The announcement includes:

new environmental flow rules for the lower Shoalhaven River from the SCA’s Tallowa Dam
changed operation of Tallowa Dam
new infrastructure at Tallowa Dam to allow native fish passage and improve the quality of water releases downstream for the environment
three options for possible future increased water supply transfers from Tallowa Dam for Sydney and the Illawarra, which will be investigated in more detail by the SCA.

Environmental flows

New environmental flows from Tallowa Dam to the lower Shoalhaven River ensure more water is protected for the health of the river.

The new flow arrangements reflect the significant work to assess river health needs. They replace the interim flow rules, which have been in place since 1999, where up to 90 million litres of water is released daily from the dam for the health of the Shoalhaven River.

The new environmental flow rules will contribute to improving the health of the lower Shoalhaven River by:

ensuring more water is released for river health, particularly during times of low flows
better mimicking the natural river flow, which will benefit native plants and animals.

The new rules for environmental flow releases from Tallowa Dam to the lower Shoalhaven River are:

all dam inflows less than or equal to the 80th monthly inflow percentile will be passed through the dam to protect low flows in the river downstream
twenty percent of dam inflows greater than the 80th monthly inflow percentile will be passed through the dam to protect a portion of medium and high river flows downstream
contingent or special purpose flow releases will be made from the dam to manage identified river health issues downstream, such as in periods of drought when the minimum operating level of the dam may be lowered to three metres – such releases will be determined in consultation with affected parties.

This water protects one hundred percent of critical low river flows. Medium flows will be partially protected and a large proportion of high flows, which flush the river, will continue to flow over the dam wall. When Tallowa Dam is full, inflows will continue to spill over the dam wall.

The SCA and Department of Water and Energy (DWE) are to monitor, assess and report on the effectiveness of the new environmental flow rules and reports will be made publicly available.

Furthermore, the new environmental flow rules will be incorporated into the draft Greater Metropolitan Region Water Sharing Plan, which is normally reviewed on a 10 year cycle.

The new environmental flows will be implemented when water restrictions are lifted in Sydney, Blue Mountains and the lllawarra.

Tallowa Dam operations

The Government has also approved the following operational arrangements for Tallowa Dam:

the ‘pump mark’, which is the level that Sydney’s dams drop to before the SCA starts transferring water from Tallowa Dam, will be increased from the current 60 percent to 70-75 percent. This will be implemented once the new environmental flow rules begin
further increases in the pump mark, flagged in the Metropolitan Water Plan, would only happen if additional water is needed to balance Sydney’s water supply needs
the SCA will not draw Tallowa Dam below more than one metre below full storage level for the purpose of transfer to Sydney’s water supply except in emergencies
environmental flows will be implemented once water restrictions are lifted in Sydney.

Fish passage

New Tallowa Dam infrastructure will allow native fish passage and improve the quality of water releases downstream for the environment. The detailed design is now finished. Contracts for the construction will be let in mid 2007 and construction work will be finished in late 2008.

A fish lift will allow for upstream movement of native fish, while a new gated slot through the dam spillway will allow the fish to move downstream, while releasing better quality surface water for the increased environmental flows.

This arrangement will also supply suitable ‘attraction flows’ (for fish travelling upstream) for the fish lift under all dam levels and most flow conditions.

Once the dam modifications are complete and the new environmental flow rules have been implemented, Tallowa Dam will be the first dam in NSW to have a fish passage and variable environmental flow rules. Environmental and other benefits include:

better mimicking of the natural river flow, benefiting native plants and animals, which prefer a naturally variable river environment
ten native fish species being able to migrate between the lower and upper Shoalhaven River including a 50/50 probability that a native fish species (the endangered Grayling) will re-establish in the river
improved water quality in the freshwater river reaches below the dam
additional tourism to the dam to view the new equipment that will transport fish across the dam wall
an increase in the times when river flows are in a range suitable for canoeing.

Water supply transfer options

In late 2006, the Government asked the community to comment on six options for possibly transferring water from Tallowa Dam to Sydney and the Illawarra in the future.

Based on community feedback, scientific and engineering investigations, and social, economic and cultural heritage assessments, the Government has narrowed this short list down to three options:

Upper Nepean tributaries bypass underground pipeline (short or long)
Wingecarribee Reservoir to Lake Avon underground pipeline
Burrawang to Lake Avon tunnel.

The Government will not investigate further the options that would have greatly increased the use of rivers for water supply transfers.

The SCA will now conduct further technical investigations on the three options and report back to the Government. The Government will then decide on a way forward including whether to proceed with the increased water transfers.

Upgrades to Bendeela camping ground and Tallowa Dam picnic area

The Government has also announced that upgrades will be made to visitor facilities at Bendeela camping ground and Tallowa Dam picnic area. The SCA will consult with the community on a new masterplan for the upgrade of these recreational facilities in the coming months.

Community consultation

The river health and water supply announcements followed the extensive community consultation on the SCA and Department of Natural Resources’ (DNR – now the Department of Water and Energy) Shoalhaven Water Supply Transfers and Environmental Flows Discussion Paper, which closed in October 2006.

Following the consultation period, the SCA and DNR developed a report for consideration by Government. The report took account of the findings of a broad range of scientific investigations, social, economic and cultural heritage assessments, and feedback from the community. It also put forward recommendations on possible water supply transfer route options, preferred operations for Tallowa Dam and new environmental flows, based on community feedback.

A total of 19 scientific, environmental and technical reports that examined the options for operational changes to the Shoalhaven Water Supply Transfer Scheme and new environmental flows, were on display from 28 August to 6 October 2006 in Kangaroo Valley, Nowra and Bowral.

In addition to the displays, the SCA undertook broader consultations to seek community views, values and feedback on the discussion paper. These activities included media releases, advertisements, a newsletter, website information, stakeholder briefings, meetings with the Shoalhaven Community Reference Group, community information sessions, as well as an email address and phone number for the community to contact with their comments and questions.

During the consultation period the SCA distributed:

2,876 copies of the discussion paper
2,486 ‘Have Your Say’ forms
509 compact discs containing the discussion paper and full set of reports.

In addition:

1,178 people visited the displays
the SCA’s website received 1,176 visits to the Shoalhaven Water Supply Transfers and Environmental Flows consultation page
85 people attended the community information sessions
889 people phoned the SCA for further information and/or to provide feedback
158 people emailed the shoalhaveninfo email address
a total of 132 submissions were received in response to the consultation.

The Shoalhaven Water Supply Transfers and Environmental Flows Discussion Paper, as well as the Knowledge Review and Investigations reports can be downloaded here:.

To order a CD of the full set of all the technical, environmental and scientific reports that were on public display during the consultation period, please email shoalhaveninfo@sca.nsw.gov.au or call 1300 722 468.

If you require a hard copy of one or more of the reports, please call 1300 722 468. Please note that some of the reports are extremely long (hundreds of pages) and the appendices for large reports will be provided on CD only.

When ordering a CD or the hard copies of reports, please provide your name and postal address, so your order can be mailed to you.

Minutes of the Shoalhaven Community Reference Group meetings are also available.

More information

For more information contact:

Shoalhaven Community Consultation
The Metropolitan Water Plan Team
Sydney Catchment Authority - 1300 722 468
or email shoalhaveninfo@sca.nsw.gov.au