Guillermo Umana

Macquarie University

ENVG267

Snowy River Environmental Flows Report 2012

Table of Contents

1. Introduction

2. Findings

2.1 . Natural and Current Total Flow Volumes

2.2 Seasonal Variability in Flows

2.3 Flood event Frequencies

3. Discussion

4. Recommendations

5. References

Executive Summary

It is clear now, after 10 years of environmental flows down Jindabyne dam, that the

progress in regaining environmental stability in the Snowy River has been little. This report

draws on previous monitoring reports from different sources, including the Snowy River

Scientific Committee, The Snowy Water Inquiry and Snowy River Alliance, to compare the

pre and post Hydroelectric Scheme environmental state of the Snowy River with its current

state. It can be argued that the main reasons for lack of environmental flow target-meeting

are droughts and the water entitlements payed by the government such as the Mowamba

Borrowing account. This report concludes that droughts and environmental variability will

continue as the effects of climate change become stronger in South-Western Australia, so

they should not be an excuse not to release adequate environmental flows into the Snowy

River. Political will should be enhanced by further transparency in the monitoring and

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increasing role of the now inactive Snowy Scientific Committee. The government should

repay all borrowings as soon as possible and make sure that future flows mimic seasonal

flows in a more adequate way. Today sedimentation continues to be a problem, as well as

invasive vegetation and poor habitat for native species. It is recommended that a new

Snowy Inquiry takes place to create new targets that better reflect the current situation of

the river and the effects of climate change.

1. Introduction

The Snowy Mountains Scheme diverts the water of 12 rivers and 71 creeks in the Snowy

Mountain region to generate hydro-electric power and provide water for irrigation of lands

to the West of the Snowy River (Smith, 2000). The economic and social importance of the

Scheme contrasts with the environmental degradation that diverting the waters generate.

Since the begging of the Scheme’s operations, 99% of the Snowy River’s natural flow below

Jindabyne Dam has been diverted, producing sedimentation, poor habitat quality for native

species and lack of water mixing among other problems (Smith, 2000).

Map 1. Illustrative Map of the Lake Jindabyne Area (Australian Geographic, 2011)

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In 1997 with the Snowy Hydro Corporation Act, the governments of New South Wales,

Victoria and the Commonwealth created the Snowy River Inquiry, a project to gather

community and expert opinions about the future of the Snowy River. The Inquiry provided

the government with a series of composite options to generate a positive impact on the

Snowy River. In 2002, a historic agreement between NSW, Victoria and the Commonwealth

was signed to return 21% of the Snowy’s natural flow by 2012 (ADE, 2010). This meant that

by 2012, more than 120 GL of water should have been flow down the Snowy (Snowy

Scientific Committee, 2008). In reality the flows did not surpass 38Gl a year between 2005

and 2009.

Map 1 (above) shows the Snowy River at Jindabyne Dam, which is the dam that was chosen

in 2002 to release the environmental flow. The map also shows the Mowamba River, which

provided the Snowy with environmental flows for a period of time from 2002 to 2005. These

flows had to be re-payed to Snowy Hydro Ltd by the government(s) through the Mowamba

Borrowing Account, which meant that after 2006, the environmental flows to the Snowy

were reduced to allocate the water to other Snowy Hydro commitments (ADE, 2010). This

reduction was also reinforced by the droughts that occurred during the first decade of the

21st century. Anyhow, La Niña events during 2010-2011 have meant that more water is

being allocated to the environmental flows in recent years.

This report argues that the environmental flow scheme should avoid being dependant on

climate change to deliver appropriate flows to the river. A review of the current procedures

should be made to adapt the flows to a less climate-dependant scheme. Also, monitoring

transparency and political will should be enhanced to make the environmental flows

become a regular activity, with constant improvements.

2. Findings

2.1 Natural and Current Total Flow Volumes

The Snowy Water Scheme requires that at least 2,088 GL of water are diverted to the

Murray and Murrumbidgee systems each year, from which more than half comes from the

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Snowy catchment (Smith, 2000). Table A provides information on natural and actual flows of

the Murray, Murrumbidgee and Snowy and the amount of households dependant on those

rivers.

Table A. Key Statistics for the three main Snowy River Scheme River (Smith, 2000: 9)

It is clear from the table that percentage of difference between the natural flow of the

Snowy and its current flow is much greater than the one for the other 2 rivers. Although

tributary rivers provide the Snowy with extra water below Jindabyne, the flow at its mouth

is half of what it would be at natural flow.

On the other hand the number of households benefited directly by the Murray and

Murrumbidgee is more than 6 times the one for the Snowy River. Smith (2000) points out

that the irrigated lands of the Murrumbidgee and Murray support agricultural production

over $750 million a year with water from the Scheme. The Scheme also produces 38% of

Australia’s hydroelectric power (Erskine, 1999A). The economic importance of the water

diversion is obvious, but the importance to recuperate the Snowy River is also evident. Both

interests can be met more accurately if Climate Change and transparency are enhanced, as

argued below.

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2.2 Seasonal variability in Flows

The reduction of flows in the Snowy River cannot be seen as a simple reduction of water

volume. The impact on native species, water variability, flow duration and frequency of

floods are some of the recorded effects of the 30 years of constant flows at 1% of the

natural levels (Erskine, 1999A). Figure 1 (below) shows a comparison of the flows of the

Snowy River below Jindabyne Dam and Dalgety. Both comparisons not only show a massive

reduction of flows but also a complete lack of seasonality, which is essential for the health

of native species, the movement of sediments downstream and water mixing. Degradation

of the river environment downstream of Jindabyne is in a great extent caused by the lack of

seasonality.

Figure 1. Changes in mean monthly discharge pre-and-post-SMHS (Erskine et al., 1991A: 9)

It can be argued that stronger peak flow events are needed. Although environmental flows

since 2002 have aimed to input seasonal variation, the effects have been minimal. Since

2010, peak flows have been increased in days and volume (as shown in the discussion

below) but furthering peak flows in spring are needed to fully clear the sedimentation

problems, especially at the mouth of the river and provide native species with regular

seasonal changes.

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2.3. Flood Event Frequencies

Figure 2. Pre-and post- Jindabyne Dam annual flow volumes at Dalgety (Rose & Bevitt,

2003: 14)

Figure 2 (above) shows the impact of the Scheme in flood variability and baseline flows in

the Snowy River. While the average flows prior to 1966 were above 1000000 ML a year, the

average flows from 1966 to 1995 were well below 200000 ML a year. Most importantly, the

variability of floods was very high prior to the scheme, with peak years reaching 25000000

ML. During the operation of the scheme, the Snowy has not seen annual flows above

500000 ML.

The environmental flows up to now have not been able to fully address the sedimentation

and poor river habitats generated by low flows. Even after the first environmental flows in

2002, the mouth of the river has been having entrance closures (see Picture 1). For example

on 31st of December 2006, the entrance closed, and was manually opened on 4th of March

2007, only to close again on the 9th of April (Wheeler et al, 2009). A factor that has made

environmental flows ineffective is a reduction of snow melting in the snowy mountains

because of less snow precipitation. Lower volumes from the tributaries of the Snowy mean

weaker discharges to the ocean. Floods with a peak discharge size at least four times greater

than the mean annual flood are important in mobilising sediment (Rose & bevitt, 2003). An

adjustment of the environmental flows is needed to address the impacts of less and less

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snow in the Snowy Mountains and less and less water from tributaries to support

environmental flows.

Picture 1. Google earth View of the end of the Snowy River

(https://maps.google.com.au/maps?

q=marlo&ll=37.799069,148.554811&spn=0.035538,0.084543&hnear=Marlo+Victoria&gl=au&t=h&z=14)

3. Discussion

The reality of the environmental flow program is that the targets created in 2002 will not be

met. Figure 3 shows the comparison between real and target GL of water per year released

to the Snowy River. It is possible to see that between 2004 and 2005 and between 2007 and

2008 the droughts forced a decrease of the flow down the river to levels similar to 1998-

1999 ones.

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Figure 3. Comparison of Target (SWIOID 2002) versus Actual Volumes in the Snowy River,

GS 222026 (Dalgety) (Snowy Scientific Committee, 2008: 6)

According to the Department of Primary Industries, the reasons for the unavailability to

meet the targets are: The repayment of the initial releases to the Snowy River which are

part of the Mowamba Borrowing Account and the drought conditions since 2002.

According to the report by the Snowy Scientific Committee (2009), Snowy Hydro Ltd had

followed the requirements of the Water Consultation Liaison Committee with no input of

the SSC. The lack of target-meeting since 2002 has been accompanied by a lack of

transparency in the monitoring. In May 2011 the Committee’s first three-year term expired

and to date (Oct 2011) it has still not been re-established (Snowy Alliance, 2011).

Consequently there has been no Snowy Scientific Committee to oversight the October 2011

big spring releases or prepare release recommendations for the 2012-13 Water year to the

Snowy, which must be completed by January (Snowy Water Alliance, 2011).

Wheeler (2009) explains a significant reduction in rainfall and snowfall have been recorded

since 1950, and the trend will continue, which makes it evident that meeting targets for

environmental flows will become harder each year. Variability in climate will increase as

well, with years of high rainfall such as 2011-2012 and years of very little rainfall such as

2008.

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Table B shows the peak flow rates of 2010, 2011, 2012. It can be seen that the amount of

water released for the peak flows for 2011 and 2012 are much higher than the one in 2010.

La Niña events during 2010-2011 mean less pressure to divert water to the Murray and

Murrumbidgee. On the other hand, El Niño events are expected for the coming years, and

the way the Scheme will cope with the possible droughts will define future environmental

flows.

Table B. Peak flow Rates for 2010, 2011 and the expected values for 2012 (Department of

Primary Industries, 2012)

Inconsistency in the flows is not an effective way to maintain the river channel in the long

run, so alternative ways of maintaining the downstream areas of the Snowy without being

affected by climate change variability should be generated. Due to high rainfall and

significant inflows into Lake Jindabyne in early 2012, a total of 80 GLs of water was released

into the Snowy River system below Jindabyne Dam. This is a positive event, but what will be

of the environmental flows during the possible El Niño events of 2012-2013?

4. Recommendations

There must be a re-evaluation of the environmental flow scheme and a new set of more

transparent targets that take into account the realities of Climate Change. In 2009 the

Snowy Scientific committee recommended that a persistent but variable base flow

throughout the year; with a peak flow of 870 ML d-1, lasting 1-2 days released in January;

and again in February would minimise the likelihood of poor water quality in pools and

consequent stress on in-stream fauna. The future of the Snowy River environmental flows

depends on the ability of the government in partnership with Snowy Hydro to use the water

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in the most efficient way. It has been seen that climate change will make it harder and

harder to avoid the pressures that the agricultural lands around the Murray and

Murrumbidgee will generate on the Snowy. Reduction of the water diverted to these areas

will be a task that will involve new agricultural technologies, relocation of households away

from these vulnerable areas and more controls over agricultural use of water in these areas.

The complex nature of the Scheme makes it difficult to make recommendations that avoid

complex regional strategies. As for the next 10 years, the governments of NSW, Victoria and

Australia should show more transparency in the functioning of the environmental flows and

the Independent Snowy Scientific Committee must be immediately be re-established to

ensure transparency of procedures (Snowy River Alliance, 2011). The Mowamba Borrowing

Account should be reviewed. It is clear that extra cuts on the environmental flows down

Jindabyne to repay borrowings will make the existing flows inefficient to combat

sedimentation and loss of habitat. A new Snowy Water Inquiry could be a possibility to find

other ways of compensating Snowy Hydro ltd for the water that will be put into the

environmental flows, without having to reduce the flows to the levels seen in 2004-2008.

5. References

Australian Department of the Environment, (2010), Snowy River Environmental Flows, <

http://www.youtube.com/watch?v=jcDHc63Aehw>, accessed 4 September 2012.

Australian Geographic, (2011), Snowy River Map, BYAG CARTOGRAPHY, MAY-19-2011,

<http://www.australiangeographic.com.au/journal/snowy-river-map.htm>, accessed 4

September 2012.

Climate Change In Australia, (2012), ‘Regional climate change projections TECHNICAL

REPORT’, Chapter 5,

<http://www.climatechangeinaustralia.gov.au/documents/resources/TR_Web_Ch5i.pdf>,

accessed 4 September 2012.

Department of the Environment, (2012), ‘Rising river alert Snowy River below Jindabyne

Dam’, Media Release, 23 August 2012.

Department of Primary Industries, (2012), ‘Office of Water Website’, <

http://www.water.nsw.gov.au/Water-management/Water-recovery/Snowy-Initiative/

Snowy-initiative/default.aspx>, accessed 4 September 2012.

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Erskine, W.D., Terrazzolo, N. and Warner, R.F, (1999A), ‘River rehabilitation from the

hydrogeomorphic impacts of a large hydro-electric power project: Snowy River, Australia.’

Regulated Rivers: Research and Management, 15: 3-24.

Erskine, W.D., Turner, L.M., Terrazzolo, N. and Warner, R.F, (1999B), ‘Recovery of the Snowy

River: politics and rehabilitation’. Australian Geographical Studies, 37(3): 330-36.

Rose, T. A. and Bevitt, R., (2003), ‘Snowy River Benchmarking and Environmental Flow

Response Monitoring Project: Summary Progress Report on available data from 1999—

2001’, Environment Australia. DIPNR, Cooma NSW,

<http://www.environment.gov.au/water/publications/environmental/rivers/nrhp/

snowy.html>, accessed 4 September 2012.

Smith, S, (2000), ‘The Future of the Snowy River’, Briefing Paper 2/2000, NSW Parliamentary

research Service,

<

http://www.parliament.nsw.gov.au/prod/parlment/publications.nsf/0/30970BFB572FC564C

A256ECF000707D3/$File/02-00.pdf>, accessed 5 September 2012,.

Snowy Scientific Committee, (2008), ‘Adequacy of environmental flows to the Snowy River

Report SSC_1’, Snowy Scientific Committee for the Water Administration Ministerial

Corporation, Canberra, October 2008.

Snowy River Alliance, (2011) ‘Fact Sheet 2011’,

<http://www.snowyriveralliance.com.au/facts.html>, accessed 4 September 2012.

Snowy Scientific Committee (2009), ‘Environmental Releases from Jindabyne Dam:

Recommendations for 2009-2010’. Report SSC_2. Prepared for the NSW Water

Administration Ministerial Corporation. Canberra. June 2009.

Wheeler P; Nguyen T; Peterson J; Gordon-Brown L (2009), ‘Morphological Change at the

Snowy River Ocean Entrance, Victoria, Australia (1851-2008)’, Monash University, Australia,

Online Publication Date: 01 March 2009

Wolfenden, B, Brooks A, Williams, S, (2008), ‘Snowy Flow Response Monitoring and

Modelling The potential drift-barrier effect of Mowamba Weir’, Office of water, NSW,

Australia.

Snowy Water Inquiry, (1998), ‘Final Report: submitted to the governments of NSW and

Victoria’, Snowy Water Inquiry, Sydney,

<

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http://www.parliament.nsw.gov.au/prod/PARLMENT/Committee.nsf/0/93FF46746ED75CFB

CA2571A3001A7>, accessed 4 September, 2012.

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