Water is an issue for the nation (one of the driest continents on Earth), as well as for Townsville, a large regional city in the dry tropics. The choices we make about water security underpin cost of living pressures, liveability and the ability of the city to grow and support jobs and industry.
Water is a simple supply and demand relationship. We can’t expect an unlimited supply and we can’t expect to have unrestrained demand.
We need a reasonable balance.
On the supply side - Townsville has an excellent water supply system, with highly treated and very safe water sourced from the Ross, Paluma and Burdekin dams.
While the Ross is our main supply dam, it is highly variable, with a limited catchment and low rainfall. The Paluma dam is situated in the wet tropics and is much more reliable, but can only supply 30 ML per day. The Burdekin dam is a huge system, with over 1 000 000 ML per year of water allocations, some of which is not committed. Townsville has 120 000 ML of allocation from the Burdekin.
In 2014, the Department of Energy and Water Supply (DEWS) undertook an assessment of Townsville’s water security. It found that at current consumption levels of 60 000 ML per year, we would have to be on Level 4 water restriction on average once every 160 years. It’s almost certain that we will have level 4 water restrictions this year (and perhaps next year). But that doesn’t mean we have a chronic water shortage problem.
It should be noted that the DEWS report used historical data in its modelling and did not consider the impacts of climate change on rainfall and catchment flows. However CSIRO have found that climate change is not likely to result in significant changes to rainfall patterns in North Queensland.
It is however worth considering that with population and economic growth we would expect to see demand grow to around 75,000 ML/a by 2026 (if current usage patterns remain the same). Even with that level of consumption, DEWS found that we would have to impose Level 4 water restrictions only once every 100 years.
Nevertheless, people are concerned about the city’s water supply, so it is worth some discussion now.
There have been a number of supply side solutions floated: Haughton pipeline duplication ($250M), Hells Gate Dam ($2-3B), Desalination (over $5B), but all these proposals have logistical challenges (and costs) as well as significant environmental impacts.
This begs the question… What about the demand side?
Townsville discharges 40 ML per day of treated water into the sea. There is an opportunity for reuse of this water, either in a third pipe system for irrigation or returned to the Ross Dam for additional treatment as part of the potable water supply. Reuse of treated wastewater directly into the water supply dam is not only safe, but common in many parts of the world, including Europe.
Many of us have travelled to places like London, drunk the water without hesitation, without ‘taste’ issues and without any ill-effects. The time will come when water management of this kind will be common in Australian cities, but until then there are other water saving options.
The reuse of treated wastewater for irrigation (whether for food production or for maintaining public facilities like sporting fields) is already common place in Australia and is a viable solution for Townsville. It will come at an additional infrastructure cost, but a much smaller cost than the supply side solutions. It will also be more reliable as it will not depend on rainfall
Alternatively, we can maintain our water demand to 60 000 ML/a and these works wills not be required. If we are factoring in population growth, to reduce our total city demand means we need to reduce our per capita consumption by 20%. If, as some are predicting, Townsville grows to 300,000 these reductions would need to be around 50%. The good news is both targets are achievable.
The average Townsville household uses 1,700 litres of water per day, while in Brisbane, Sydney and Melbourne households use around 210 to 285 litres per day. More than 70% of Townsville's water supply is currently being used on residential lawns and gardens
This needs to be addressed by applying targeted and effective price signals on usage, but also through a range of strategies that give us more benefit per drop of water (more efficient showers and toilets, better grey water reuse systems, less thirsty gardens or less wasteful gardeners)
It is time to have a healthy discussion about Townville’s water use. People need to understand their options along with the pros and cons of every choice. They need to know what are the most cost-effective and responsible courses of action, but they are being badly let down by the media and the major parties. But through forums like this blog the Greens are happy to lead the conversation.
The Greens propose policies which are economically, socially and environmentally responsible. And our approach to a sustainable water supply for Townsville is consistent with this approach.
The same can’t be said for the current election campaign, with the haphazard, expensive and unsustainable solutions being proposed by the major parties and their unfunded and poorly researched proposals.
by Wendy Tubman
The Townsville Greens will publish blogs considered to be of merit. The opinions expressed are those of the Author.