Manning Clark House Forum Making Canberra Sustainable
Canberra, 17-18 October 2005

Water Futures for Canberra: Moving Towards Sustainability?

Paper by Professor Peter Cullen, AO, FTSE
Commissioner of the National Water Commission

Short Biography

Peter Cullen is a Commissioner of the National Water Commission, Chair of the Victorian Water Trust Advisory Council, a member of the Natural Heritage Trust Advisory Council and a Director of Land and Water Australia.

He was founding Chief Executive of the CRC for Freshwater Ecology at the University of Canberra. He is a Visiting Fellow at CSIRO Land and Water and was Adelaide’s Thinker in Residence during 2004.

Professor Cullen was appointed an Officer of the Order of Australia in 2004 for service to freshwater ecology, particularly in the areas of policy development, implementation and sustainability in relation to water and natural resource management, and to education.

Peter Cullen is one of the Wentworth Group of Concerned Scientists who seek to raise public awareness of natural resource issues facing Australia through their Blueprint for a Living Continent and their Blueprint for a National Water Plan. He is a leading commentator on land and water issues in the national media.

He is a graduate in Agricultural Science from the University of Melbourne, a Fellow of the Australian Academy of Technological Sciences and Engineering and a Member of the International Water Academy and the International Ecology Institute.

Introduction

Australians are all becoming concerned with running out of water as the recent drought has shown that many of our communities are vulnerable. There are increasing pressures for water to support irrigated agriculture, needed to feed and clothe us as well as provide jobs and export income, We are now appreciating that the environment itself needs a basic supply of water if it is to be maintained, and that in many systems such as the Murray-Darling in which we live, water has been a over-allocated at the cost of the environment and downstream users. Cities, like Canberra, are also growing, and demanding more water. Increasing demands from urban, agriculture and the environment, and yet climate change predictions indicate we have declining rainfall. We are entering the age of water scarcity, and this requires us to rethink the way we use and manage our water if we are to meet the growing demands.

Canberra has gone through an extensive period of planning for its future needs, and it is not my purpose to rehearse the various options that have been identified and well analysed by ACTEW and the ACT Government water planning group. ACTEW has presented its analysis to Government - Future water options — For the ACT in the 21st Century, ACTEW (2005) and there are an extensive series of documents available from the Think water, act water program of the ACT Government.

In 2003-4 ACTEW-AGL supplied about 49 GL of water to meet the needs of 357,000 people with water. Over the last 7 years this has ranged from 49-73 Gl/yr, obviously depending on weather conditions, water restrictions and other factors. In 2003-4 we each used, on average, 137 Kl/hd each year. This has ranged from 136 to 217 Kl/hd/yr. Residential customers take 65% of the water. The current usage of water in the ACT is 248 KL/residential property or about 88 Kl/hd and our commercial use is 36 Kl/hd.

Table 1 ACT Water Use 2003-4

Use	ML	% Use	No of properties	Usage/prop	Usage/hd
Bulk	4,051	8.2	Queanbeyan na
Residential	31,492	64.8	127,000	248 KL	88 Kl/hd
Commercial	12,739	26.3	9,000	1415 KL	36 Kl/hd
Other	298	0.6			0.8 Kl/hd
Total	48,580		136,000		137 Kl/hd

The ACT uses some 26.3% of supplied water to commercial users, which is higher that Adelaide (21%) or Sydney (19%). This is somewhat surprising since these other cities have a substantial heavy industry base that might have been expected to use more water than commercial users in the ACT.

Table 2 Residential Water Use, Kl per household

	National 2001	National	ACT 2000-1	ACT 2000-1	ACT 2003-4
	Total Use	% Used	Total Use	% Use
Kitchen	22.4 KL	8	15 KL	5
Laundry	36.4	13	30	10
Toilet	42	15	42	14
Bathroom	49.6	20	48	16
Outdoor Use	123.2	44	166	55
Total household	280		301		248 #

Table 2 shows the reduction in water usage during a drought period with restrictions on outdoor water use and heavy advertising to encourage people to use less water following the bushfires in the ACT catchments that reduced the water available to Canberra due to contamination.

Likely Future Demands for Water `

Various projections of likely future population have been made. The current water plan indicates a 36% increase in the population to 486,000 by 2030. With current use, during a period of restriction at 137 KL/hd/yr this would require 67 Gl of water each year.

We now know there are an increasing proportion of single person households in Australian cities, and these having an increased per capita water usage. These likely changes in housing patterns have not been built into the projections made here.

The ACT Water Strategy assumes that demand management measures (mainly pricing and public education) will be able to achieve a 12% reduction in per capita usage by 2013 and a 25% reduction by 2023.

These projections do not include the pressures from the surrounding towns to get access to water. Queanbeyan itself argues that its growth is constrained by lack of water, and towns such as Bungendore and Yass and even Goulburn are all facing severe water shortages and from time to time suggest they should be allowed to share the ACT water supply.

Table 3. Changing Demands for ACT Water, KL/hd

It is apparent that a community can markedly reduce its water use during a drought through widespread adherence to outdoor water restrictions, and the cessation of irrigation of extensive public open space. It is also apparent from the reduction in wastewater per head that water efficiency within the home has also improved.

The ACTEW water planning assumes a reduction in demand per head of 12% by 2013 and by 25% by 2023. The average water use has been 169 Kl/hd over the last 7 years, so a 12% reduction means we assume the usage will drop to an average of 149 Kl/hd/yr and a 25% reduction to 127 Kl/hd/yr.

Whether such reductions will be achieved once the community believes the current drought has broken is unclear. The community will expect a resumption of the watering of public open space that has been a significant contributor to the savings made in the last year or so.

It is difficult for an agency that is given various revenue targets by its owner, the government, to set about trying to reduce the sales of its product. It may mean the Government needs to put in place some clear financial benefits and sanctions to the ACTEW Board and management if it expects these targets to be achieved.

ACTEW, in its Future water options work, believes the ACT will need 70-73 GL/yr by 2023 and 77-88 GL by 2053 to have a secure water supply.

Bates et al (2003) provided CSIRO estimates as to the likely climate changes we face that will impact both on the supply of water and the demand. Global climate models indicate increases in mean annual temperature of 0.4 to 1.6 ° C by 2030 potential evaporation to increase as a result of increased temperature, mean annual rainfall will change by —9% to +2% by 2030 with decreases predominating in winter and spring and it is likely there will be increased frequency and intensity of extreme rainfalls. There is already weak evidence of a decline in rainfall over the ACT region over the last 40 years. Hydrologic modelling indicates a decrease in annual runoff in the ACT up to 20% in 2030, with the greatest decline likely in the Queanbeyan River.

The expected climate change with an increase in mean temperature and an increase in the frequency of hot periods will increase demand for water of from 1 to 14% by 2030.

With increasing demands for water, and likely climate change indicating we may have less rainfall and markedly less runoff, we need to consider all alternative approaches to meeting our needs.

In this context we need to appreciate that transporting water large distances is costly. Pipe costs are increasing rapidly, and energy costs may well double over the next 20 years. We use energy not only for pumping water, but for the treatment processes that are required if we seek to use recycled water.

We also need to appreciate that the demands of agriculture for water may be dependent on world trade issues and in particular free trade agreements with countries where labour costs are lower that ours. This may cause real impacts on the demands for water from labour intensive industries. We are also seeking to plan and build water infrastructure that has a life of around 100 years in a period of rapid technological advances in treatment technologies and in sensor and control systems.

Urban Australians expect Governments to supply them with adequate amounts of safe drinking water. They become angry with politicians when water restrictions are imposed. Many however do not seem keen to build more dams due the environmental costs of dams, and many are uncomfortable with the idea of using recycled water.

The current strategy of harvesting a further 12 GL from the Cotter system and pumping it to Googong dam is a cost effective way of augmenting ACT water supplies.

It is unfortunate that the Googong Dam was built in a rain shadow area, but the failure of State, territory and Federal Governments to manage the catchments has meant a proliferation of rural subdivision, and hence small dams in the catchment. Much of this water is now lost through evaporation.

Catchment management is critical to maintaining adequate water supplies to Canberra. If Canberra is to augment the Cotter dam and start drawing water from the Lower Cotter catchment it is inappropriate to have pine plantations in this area due to the ongoing risk of fire and prolonged catchment damage. Native forests recover quickly following fire.

There are further dam sites in the ACT and it would be rash to rule out the building of another dam sometime in the future. The prospects of enlarging the current Cotter dam, and building the proposed Tennent dam have been analysed in water planning. However, new dams are costly, since we have already built in the easier and hence cheaper sites. Not only is construction costly, but also we lose valuable lands that are inundated by a new dam, and this has implications for farming and nature conservation within the ACT.

The ACT is well placed to purchase water stored I n Snowy storages presently used by downstream irrigators. The National Water Initiative is moving to give irrigators a "property" right to their water licences, and these licenses can be bought and sold, separately from the land with which they used to be associated. The ACT can enter the water market and purchase water from these irrigators. The National Water Initiative specifically focuses on the need to open up the water market in the Murrumbidgee, where Murrimbidgee Irrigation Ltd rather than individual irrigators owns the water access entitlements, and the company has had a policy of not trading water out of its area. However NSW has agreed to remove such restrictions on trade.

This water could be piped to Canberra, or could be run down the Murrumbidgee River removed at a small diversion weir and treated before being supplied. This option has not been well considered in ACT planning due to uncertainty about the development of the national water market. In my view it is likely to be a most cost effective strategy for the ACT.

Canberra has led Australia in capturing stormwater, and holding it in urban lakes to provide recreation, aesthetic and nature conservation values. These lakes also provide major water pollution control benefits; ensuring urban runoff from Canberra has minimal impacts on downstream ecosystems or users. We make only limited use of this water for irrigating public open space, but these uses could be extended. One consequence might be a dropping of lake levels during dry periods that would have some impacts on present uses.

The Government has been providing a rebate for residents who install water tanks, and have now modified the scheme to require tanks to be plumbed for indoor water use for toilet flushing.

Water tanks provide a number of benefits. They trap water from summer rains that might not generate any runoff from a dry catchment. They slow down the first flush of storm water that is a cause of degradation of the health of urban streams. However, on a whole of life basis they provide relatively costly water compared to the mains supply, and there are concerns about the capacity of residents to manage them effectively to avoid health risks.

Canberra produces around 28 GL of treated wastewater from its sewage treatment works that is about 60% of the water we extract from the catchments, and downstream agricultural and urban communities recycle this water. We retain about 8% of this for local irrigation with recycled water.

The Government has set a target of 20% recycling by 2013. Often targets such as this drive perverse outcomes. The challenge for Canberra is to substitute recycled water for drinking water, not to expand irrigated agriculture in the ACT. Downstream farmers already recycle most of this treated effluent — all we may be achieving with expanding irrigation is transfer wealth from downstream communities to the ACT.

Technically we can now treat wastewater to such a degree that it can be returned directly to drinking water systems. There are many examples in Australia where the wastewater of one community becomes the drinking water of a downstream community, Indeed Sydney benefits from the wastewaters of Goulburn, Bowral and other towns in its catchments. In Singapore recycled water is returned directly to the supply storages, and Toowoomba and Goulburn are both cities that are now exploring this option in the face of severe water shortages.

Conventional housing is supplied with two pipe systems, one to supply drinking water and one to remove wastewater. We now have a number of communities where a third pipe system has been installed to supply recycled water to each house, which can be used for outdoor uses and for flushing toilets. Almost 70% of Canberra’s domestic water is used for these purposes so significant savings could be achieved.

However such a strategy requires expensive infrastructure to be built, and this is difficult in established suburbs, although it is easier in new greenfield developments. To prptect public health the water is treated to a high degree, and it may not cost much more to return it to drinking water standard and put it back in water supply storages. It is unlikely the Canberra community is ready for this, although it is important they start to become more educated about the benefits of recycled water.

There are opportunities for recycling also at the scale of office or apartment block where treatment facilities can be incorporated in the building and maintained by professional service companies. At Inkerman Street, St Kilda, a 236 unit housing development has incorporated recycling of domestic graywater (bathroom basins, baths and showers), from about half the units in four buildings using an activated-sludge (aeration) tank, with secondary filtration in a 400 square meter native wetland and sand filtration on the site. There is recycling of the combined gray/stormwater for sub-surface garden irrigation and toilet flushing across the entire development. An expansion in the use of small-scale plants in office or residential apartment blocks could underpin a new service industry required to successfully maintain and operate these plants with the necessary level of quality assurance (PMSEIC, 2003).

Many of our cities, including Canberra are designed around 19^th century ideas of water planning with a large sewage treatment work as far away from people at the downstream part of the catchment. Current thinking of water sensitive urban development requires state of the art stormwater management using swales and urban ponds widely used in Canberra, but also includes rainwater tanks and recycling for new developments.

Cost effective recycling suggests a greater number of smaller sewage treatment works distributed throughout the city, allowing recycled water to be supplied to downstream parks and gardens, and domestic users by gravity. There remain issues of appropriate water quality requirements so that treated water can be discharged to streams in winter and wet periods when it may not be required.

The water planning frameworks required under the National Water Initiative give communities the opportunity to look at their ongoing needs for water, and at the variety of ways these needs can be managed or met. There are a number of elements communities and Governments need to consider:

• Growth Trajectories — what are realistic population projections for the region and what wealth creating industries might be developed with a need for access to water
• Demand management — how can water demands be reduced by public education and pricing strategies.
• Opportunities to improved water use efficiency in delivery systems, residential areas through water sensitive urban developments, within dwellings, public open space and in irrigated agriculture.
• The likely future yield and its variability from existing water supply catchments in the light of predicted climate changes and the land uses that have been allowed in the catchments.
• Opportunities to purchase water from other license holders in the region. This is already happening where urban communities are purchasing water from irrigators.
• Alternative catchments where water can be harvested and stored for use, and the costs of such developments, including existing land uses that will be displaced or impacted.
• Opportunities to transfer water from other regions, given the costs of water transfers and the impacts and costs on existing uses.
• Opportunities to store and use urban stormwater using urban wetlands and ponds and perhaps aquifer storage and recovery.
• Opportunities to recycle treated effluents either through a third pipe system for non-drinking purposes or directly back into supply storages.

If this planning process is to be useful, the community need to be able to have a well informed debates about the alternative water futures open to them, consider a wide range of alternative ways of meeting their needs, and have rigorous triple bottom line assessment that ensures financial, social and environmental benefits including the energy costs of all alternatives.

The maturity of the community in having this debate, and the capacity of Government agencies to stimulate a well-informed debate is the key to a sustainable water future for the ACT.

ABS Water Account 2000-2001

ACT Government (2004) Think water act water.

ACTEW (2005) Future water options — For the ACT in the 21st Century. ACTEW Corporation.

Bryson C. Bates, Stephen P. Charles, Francis Chiew, Katherine Harle, Mark Howden, Mac Kirby, Murray Peel, Ramasamy Suppiah, Lionel Siriwardena, Neil R. Viney, and Penny H. Whetton.(2003) Climate change projections and the effects on water yield and water demand for the Australian Capital Territory. Consultancy for ACT Electricity and Water. CSIRO Land and Water

Prime Minister’s Science, Engineering and Innovation Council Report (2003) Recycling Water For Our Cities.. Australian Government

Water Services Association of Australia (2004) WSAAfacts 2004

Water Services Association of Australia (2005) Impact on Demographic Change and Urban Consolidation on Domestic Water Use, WSAA Occasional Paper No. 15 — June 2005

Water Services Association of Australia (2005) Testing the WaterUrban water in our growing cities: the risks, challenges, innovation and planning. WSAA Position Paper No. 01 October 2005.