THERE'S been much talk recently about the future growth potential for Bathurst with several correspondents offering creative solutions as to how our future water needs could be met.
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These include accessing Warragamba Dam via a pipeline (unlikely) or building a much larger dam (again very unlikely). More heroic still is the prospect of installing additional water distillation plants on the edge of the ocean and piping this water inland to Bathurst.
The sheer cost and the user pay principle will prevent that project from happening.
Some have suggested the possibility of finding significant new sources of underground water. For various reasons, none of these proposed solutions is likely to be viable.
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Chifley Dam is currently around 42 per cent full, and Winburndale around 92pc of capacity. However, the latter dam is only about six per cent of their combined capacity and, in practice, provides only a minor buffering impact from the present drought conditions.
Chifley Dam's effective capacity is considerably reduced by a silt load estimated to be 10-15pc of capacity. Given the dire situation of other regional dams in NSW, Bathurst Regional Council has been prudent in placing restrictions on the use of our town water in the face of some arguing for no restrictions.
However, dam levels are expected to fall to 38pc in October this year, triggering level four restrictions, with gardens being watered only by bucket, limited showering and the cessation of watering parks and ovals.
Dam levels are predicted to reach crisis levels in 2020 given the limited rainfall predicted over winter when Chifley Dam normally fills.
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Our current population is around 40,000 people who are reliant on these two dams. Imagine what the situation would be if our population were 80,000 or even 120,000, numbers that have been bandied about as to what Bathurst's future population might reach some time in the future.
So, is it time for Bathurstians to consider the question as to how many people can be securely accommodated in Bathurst?
Water is likely to be the most important limiting factor to Bathurst's future domestic and industrial growth. We could raise the current Chifley Dam wall by one or two metres, but that would also increase the net evaporation rate from the surface water.
Building another new and much larger dam at a great cost would run a real risk of never filling if the impacts of climate change on water supply continues.
Furthermore, it is not at all clear where a larger future dam could be built in the Bathurst area. Like Windamere Dam south of Mudgee, such a dam might become a stranded asset that never fills.
This could likely be a real scenario under predicted changes to rainfall patterns in the Bathurst area forecast by climate change modellers.
The current drought cannot necessarily be viewed as evidence of a changing climate since we have always had droughts in Australia. However, particular events do not define whether or not climate change is occurring; rather, we need to look at the whole data and determine the trends.
In spite of noisy climate change deniers, the trend towards a drier and more erratic climate is occurring, and that is likely to ensure much less rainfall in the future and increasing frequency of droughts in the Central Tablelands.
Of course, the current drought could break this year or in 2020 and could even prove to be the wettest year on record. Would we then continue with 'a business as usual' approach?
There are many significant actions which, as a community, we can take to minimise the impacts of climate change and the likely reduction in rainfall reliability.
These include water harvesting within the city boundaries, recycling sewage water, adding water tanks to every household, using irrigation water more efficiently, increasing the price of town and irrigation water, the creation of water-wise gardens, and switching from growing vegetables in open paddocks, to large climate-controlled glasshouses given over to hydroponics and or aquaculture.
Local farms could be made much more productive and more resilient in drought periods by firstly increasing soil carbon content, thereby being able to hold much more water, and secondly by restoring the once widespread swampy meadows that we drained to increase production that once drove mega-production across the pre-European landscape.
Soil carbon has dropped precipitously since 1815. Storing water underground, as nature once did, will also ensure that springs and creeks will likely flow for much longer than they do now under drought conditions. We have made an artform of drying out Australia.
A pipeline from Chifley Dam to Bathurst is an inevitability. Oberon Dam and the Fish River water supply is mostly committed to supplying water to the Blue Mountains towns, Oberon and its industries.
But in the final analysis, there is a finite number of people that can live in Bathurst and other regional cities, with or without climate change occurring, including Orange and Dubbo and their satellite towns and villages, while sustaining our current standard of living.
I'm not in a position to argue what a sustainable Bathurst population will be, but it is unlikely to be 120,000 and likely significantly much lower.
The same dilemma faces every village and city west of the Blue Mountains.
Farmers well understand the concept of carrying capacity. Bathurstians need to plan now for a future city with low to no growth and with a well-understood population ceiling.
To plan for a water deficient future will take us well outside of the three to four-year election cycle and the insistence that there must be continuous growth for a city to prosper.