Bushfires pose serious short- and long-term impacts to public drinking water quality. They can damage water supply infrastructure and water catchments, impeding the treatment processes that normally make our water safe to drink.
Several areas in New South Wales and Victoria have already been issued with warnings about the quality of their drinking water.
Here’s what we know about the short- and long-term risks.
Bushfires can damage or disrupt water supply infrastructure as they burn. And the risks can persist after the fires are out.
A loss of power, for example, disables important water treatment processes such as chlorine disinfection, needed to kill microorganisms and make our water safe to drink.
Drinking water for the towns of Eden and Boydtown on the NSW south coast has been affected in this way over recent days. Residents have been advised to boil their water before drinking it and using it for cooking, teeth brushing, and so on.
Other towns including Cobargo and Bermagui received similar warnings on New Year’s Eve.
In some cases, untreated water, straight from a river supply, may be fed directly into drinking water systems. Water treatment plants are bypassed completely, due to damage, power loss, or an inability to keep pace with high volumes of water required for firefighting.
We’ve seen this in a number of southern NSW towns this week including Batlow, Adelong, Tumbarumba, and the southern region of Eurobodalla Council, stretching from Moruya to Tilba. Residents of these areas have also been urged to boil their drinking water.
Untreated river water, or river water which has not been properly disinfected with chlorine, is usually not safe for drinking in Australia. Various types of bacteria, as well as the parasites giardia and cryptosporidium, could be in such water.
Animals including cattle, birds and kangaroos can excrete these microorganisms into river water. Septic tanks and sewage treatment plants may also discharge effluents into waterways, adding harmful microorganisms.
Human infection with these microorganisms can cause a range of illnesses, including gastrointestinal diseases with symptoms of diarrhoea and vomiting.
Bushfires can damage drinking water catchments, which can lead to longer term threats to drinking water. Drinking water catchments are typically forested areas, and so are vulnerable to bushfire damage.
Severe impacts to waterways may not occur until after intense rainfall. Heavy rain can wash ash and eroded soil from the fires into waterways, affecting drinking water supplies downstream.
For example, bushfire ash contains nutrients, such as nitrogen and phosphorous. Increased nutrient concentrations can stimulate the growth of cyanobacteria, commonly known as “blue-green algae”.
Cyanobacteria produce chemicals which may cause a range of water quality problems, including poor taste and odour. Some cyanobacteria can produce toxic chemicals, requiring very careful management to protect treated drinking water.
Many water treatment plants include filtration processes to filter small suspended particles from the water. But an increase in suspended particles, like that which we see after bushfires, would challenge most filtration plants. The suspended particles would be removed, but they would clog the filters, requiring them to be more frequently pulled from normal operation and cleaned.
This cleaning, or backwashing, is a normal part of the treatment process. But if more time must be spent backwashing, that’s less time the filters are working to produce drinking water. And if the rate of drinking water filtration is slowed and fails to keep pace with demand, authorities may place limitations on water use.
In order to reduce the risk of gastrointestinal and other illnesses, water suppliers and health departments may issue a boil water alert, as we’ve seen in the past week. Bringing water to a “rolling boil” can reliably kill most of the microorganisms of concern.
In cases where water may be contaminated with chemical substances rather than microorganisms, boiling is usually not effective. So where there’s a risk of chemical contamination, public health messages are usually “do not drink tap water”. This means bottled water only.
Impacts to catchments from bushfires and subsequent erosion can have long-lasting effects, potentially worsening untreated drinking water quality for many years, even decades.
Following these bushfires, many water treatment plant operators and catchment managers will need to adapt to changed conditions and brace for more extreme weather events in the future.
The “New Bradfield” scheme is more than an attempt to transcend environmental reality. It seeks to revive a pioneering spirit and a nation-building ethos supposedly stifled by the bureaucratic inertia of modern Australia.
This is not a new lament. Frustrated by bureaucracy, politicians in North Queensland have long criticised the slow pace of northern development.
In 1950, northern local governments blamed urban lethargy. One prominent mayor complained:
… these young people lack the pioneering spirit of their forebears, preferring leisure and pleasure to hardships and hard work.
These sentiments were inspired by an agrarian nostalgia that extolled toil and toughness. Stoic responses to the challenges of life on the land are part of the Australian legend.
With drought devastating rural and urban communities and a state election looming in Queensland in 2020, both sides of politics have proposed a “New Bradfield” scheme.
Civil engineer John Bradfield devised the original scheme in 1938. His plan would swamp inland Australia by reversing the flow of North Queensland’s rivers. Similar proposals go back to at least 1887, when geographer E.A. Leonard recommended the Herbert, Tully, Johnstone and Barron rivers be turned around to irrigate Australia’s “dead heart”.
These schemes have always been contested on both environmental and economic grounds. A compelling history of Bradfield’s proposal reveals many errors and miscalculations. But what the scheme lacked in substance it made up for in grandiose vision.
While less ambitious than the original plan, the “New Bradfield” scheme still engineers against the gradient of both history and nature. It would have irreversible consequences for Queensland’s environment, society and culture.
What’s more, the new scheme manifests much the same mindset as the old.
It’s an attitude that privileges the conquest of nature: in this case literally up-ending geography by turning east-flowing rivers westward. Its celebration of the human struggle against defiant nature reprises the pioneering ethos.
Like many pioneers, “New Bradfield” proposals disregard the interests and land-management practices of Indigenous people. The bushfires ravaging the eastern states show the folly of ignoring traditional ways of caring for country .
Overlooking native title realities can also cost governments and communities.
“New Bradfield” is promoted as “an asset owned by all Queenslanders for all Queenslanders”. But environmental destruction and disputes over water sales in the Murray-Darling Basin sound a warning.
Thus, northern Australia again sits amid a polarised debate about its utility to the nation. Such polarising contests diminish the likelihood of more viable projects being implemented.
Extravagant expectations of “untapped” northern resources have been proffered for nearly two centuries. Distant governments have fantasised the Australian tropics as a land of near-limitless potential. Northern communities have many times been disappointed by the results.
Today’s promises to “drought-proof” large areas of Queensland rely on similar images. “Drought-proofing” aims to keep people on the land but often defies economic and social reality.
The “New Bradfield” rhetoric echoes the inflated expectations of myriad disappointing northern development plans in the past. The Ord River project was touted as an agricultural wonder that would put hundreds of thousands of farmers into the Kimberley. Its success lies forever just over the horizon.
Much closer to the present proposal is the Burdekin Falls Dam. It sits in the lower reaches of the same river earmarked for the Hells Gates Dam that would feed the “New Bradfield” scheme. Damming Hells Gates has been advocated since at least the 1930s and has new supporters.
Back in the 1950s, damming the Burdekin was expected to generate hydro-electric power and irrigate vast swathes of farmland. After decades of political squabbling, the dam was completed in 1988. It does not generate hydro power. Although it irrigates some land downstream, the anticipated huge agricultural expansion never happened.
The Burdekin Falls Dam has helped the regional economy and could help to overcome the water shortages of the nearby city of Townsville. But it has not met the inflated expectations widely proffered decades earlier. The benefits that would flow from another dam further upstream are likely to be even more meagre.
Grandiose visions of northern development have a habit of failing. A “New Bradfield” scheme, animated by an old pioneering ethos, is unlikely to be different.
Drought-affected communities would derive more benefit from sober proposals that acknowledge the past, integrate Indigenous knowledge and incorporate agricultural innovation.
The Victorian government’s logging business is cutting native forests on steep slopes, in an apparent rule breach that threatens water supplies to Melbourne and rural communities.
Our research indicates that across vital water catchments in the Central Highlands of Victoria, state-owned VicForests is logging native forest on slopes steeper than is allowed under the code of practice. Logging also appears to be occurring in other areas supposedly excluded from harvesting.
Logging operations are prohibited from taking trees from slopes steeper than a certain gradient, because it can lead to soil damage which compromises water supplies. There are far better commercial alternatives to this apparent contravention of the rules, which must immediately cease.
Water catchments are areas where the landscape collects water. They are defined by natural features such as mountain ridgelines and valleys. Rain drains into rivers and streams, which supply water to reservoirs.
Forest cover protects the soil in water catchments by preventing erosion and other damage which can pollute water.
Areas that provide water for drinking, agriculture and irrigation are known in Victoria as special water supply catchments. Under the state’s Code of Forest Practice, logging in these catchments is prohibited on slopes steeper than 30 degrees (or 25 degrees in some catchments). VicForests claims it does not log trees on such slopes.
We analysed slopes across multiple special water supply catchments. We first examined the relationships between slope and logging disturbance using data from the Victorian government, Geoscience Australia, and the European Space Agency. To confirm the results, we visited multiple sites in the Upper Goulburn catchment, which supplies water to Eildon Reservoir, to measure the slopes ourselves.
We found logging in many areas steeper than 30 degrees. In larger catchments such as the Upper Goulburn, around 44% of logged areas contained slopes exceeding this gradient. In many instances, logged slopes were far steeper than 30 degrees and some breaches covered many hectares.
In the Thomson, Melbourne’s largest water supply catchment, 35% of logged areas contained slopes steeper than 30 degrees.
We also found areas that should have been formally excluded from logging but where the forest had been cut. Many of these exclusion zones were around steep slopes. In the Upper Goulburn catchment, nearly 80% of logged areas contained exclusion zones that should not have been cut.
Last week, VicForests rejected our allegations of slope breaches. VicForests claimed it was complying with a rule under which 10% of an area logged can exceed 30 degrees. This rule applies to general logging areas; our interpretation is this exemption does not apply to the special water supply catchments.
Forest on steep and rugged terrain is economically marginal for wood production because the trees are relatively short and widely spaced. Almost all timber from these areas is pulpwood for making paper.
So why are such areas being logged at the risk of compromising the water catchments that supplies Melbourne and regional Victoria?
We suspect pressure to log steep terrain is tied to the Victorian government’s legal obligation to provide large quantities of pulp logs for making paper until the year 2030 (coincidentally the year the government plans to phase out native forest logging).
This pressure is reflected in recent reductions in log yields. Some commentators have blamed efforts to protect the critically endangered Leadbeater’s possum for this trend. However, only 0.17% of the 1.82 million hectares of forest allocated to VicForests for logging has been taken out of production to protect this species.
In our view, other possibilities for declining yields are past over-cutting and bushfires. VicForests failed to take into account the effects of fire on its estimates of sustained timber yield – despite some of Victoria’s forests being some of the world’s most fire-prone environments.
Pulp logs sourced from native forests is not a commercial necessity; there are viable alternatives. Victorian hardwood plantations produced 3.9 million cubic metres of pulp logs last year. Most of this was exported.
If just some of these logs were processed in Victoria, it would be enough to replace the pulpwood logged from native forests several times over. Plantation wood is better for making paper than native forest logs, and processing the logs in Victoria would boost regional employment.
Degrading soil and water by logging steep terrain is not worth the short-term, marginal gain of meeting log supply commitments, especially when there are viable alternatives. The Victorian government must halt the widespread breaches of its own rules.
In a statement, VicForests said it “strongly rejects” the allegations raised by the authors.
In addition to the refutations included in this article, the company said:
Any concerns about its practices should be referred to the Office of the Conservation Regulator
VicForests does very little harvesting in catchments, where restrictions are in place
In the Thompson catchment, VicForests only harvests on average 150ha a year out of about 44,000ha in the catchment – which is 0.3%, or around 3 trees in 1000
VicForests only asks contractors to harvest on slopes if it complies with regulation.
David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University and Chris Taylor, Research Fellow, Fenner School of Environment and Society, Australian National University
As regional Australian towns face the prospect of running out of water, it’s time to ask why Australia does not make better use of recycled wastewater.
The technology to reliably and safely make clean, drinkable water from all sources, including sewage, has existed for at least a decade. Further, government policy has for a long time allowed for recycled water to ensure supply.
The greatest barrier to the widespread use of recycled wastewater is community acceptance. Research from around the world found the best way to overcome reluctance is to embrace education and rigorously ensure the highest quality water treatment.
Many people are happy to use recycled stormwater, while being reluctant to cook, drink or wash with recycled household wastewater. But there are technical, cost and supply issues with relying on stormwater to meet our country’s water needs. Stormwater has to be cleaned before it is used, the supply can be irregular as it is reliant upon rain, and it has to be stored somewhere for use.
On the other hand, household wastewater (which is what goes into the sewerage system from sinks, toilets, washing machines and so on) is a more consistent supply, with 80% or more of household water leaving as wastewater.
Furthermore, wastewater goes to treatment plants already, so there is a system of pipes to transport it and places which already treat it, including advanced treatment plants that can treat the water to be clean enough for a range of purposes. There are strong economic, environmental and practical arguments for investing more effort in reusing wastewater to meet our water supply needs.
This water can be used for households, industry, business and agriculture, greening public spaces, fighting fires, and topping up rivers or groundwater.
Technically, all water is recyled; indeed we are drinking the same water as the dinosaurs. Put very simply, water evaporates, forms clouds and falls as rain, and is either absorbed into the earth and captured underground or filtered through rock and goes back again into oceans and rivers.
When we capture and reuse water, we are not making more water, but speeding up the water cycle so we can reuse it more quickly.
We do already reuse wastewater in Australia, with many parts of regional Australia cleaning wastewater and releasing it into rivers. That water is then extracted for use by places downstream.
Despite this, there have been significant community objections to building new infrastructure to reuse wastewater for household use. In 2006, at the height of the Millennium drought, Toowoomba rejected the idea entirely.
However, since then a scheme has been successfully established in Perth. We must examine these issues again in light of the current drought, which sees a number of Australian regional centres facing the prospect of running out of water.
Despite initial reluctance, many places around the world have successfully introduced extensive wastewater recycling. Places such as Singapore, Essex, California, New Mexico, and Virginia widely use it.
Recent research from the Water Services Association of Australia, working with other research bodies, found several key lessons.
Firstly, the language we use is important. Phrases like “toilet to tap” are unhelpful as they don’t emphasise the extensive treatment processes involved.
The social media and news outlets can play an significant role here. In Orange County, California, wastewater was introduced through a slow process of building acceptance. Influential individuals were enlisted to explain and advocate for its uses.
Secondly, communities need time and knowledge, particularly about safety and risks. Regulators play an important role in reassuring communities. In San Diego, a demonstration plant gave many people the opportunity to see the treatment process, drink the water and participate in education.
We need to go beyond information to deep consultation and education, understanding where people are starting from and acknowledging that people
from different cultures and backgrounds may have different attitudes.
El Paso successfully introduced wastewater through strong engagement with the media and significant investment in community education, including explaining the water cycle.
Finally, quality of the water needs to be great and it needs to come from a trustworthy source. The more it happens, and people know that, the more likely they are to feel reassured.
It’s clear the public expect governments to plan and act to secure our future water supply. But we can’t just impose possibly distasteful solutions – instead, the whole community needs to be part of the conversation.
A report from The Australia Institute rejects government claims new dams are not being built, saying at least 20 to 30 large private dams have been constructed in the Murray-Darling basin in recent years.
While information on the number of private dams and the cost of their taxpayer subsidy is limited, the report says “it appears that just two of these dams cost taxpayers nearly $30 million”.
“Over $200 million was spent on dam-related projects [in the Murray-Darling Basin] according to official data, although not all of this will have been specifically on dams,” it says,
Maryanne Slattery, senior water researcher at the institute, said politicians don’t want to talk about these dams because “they do nothing for drought-stricken communities, the health of the river or struggling farmers”.
“These dams have been built on private land and are for the exclusive use of corporate agribusiness, such as Webster Limited,” she said.
“Politicians are reluctant to talk about why millions of taxpayer dollars have been spent subsidising dams that make the problems of the Murray Darling Basin worse”.
Water Minister David Littleproud has repeatedly berated the states for not building new dams. He said recently that of the 20 dams completed since 2003, 16 were in Tasmania.
“If NSW, Queensland and Victoria don’t start building dams, their water storage capacity will fall by more than 30% by 2030,” he said. “We put $1.3 billion on the table in through the national water infrastructure development fund in 2015 and have still had to drag most states kicking and screaming to build new dams.”
The report says new public dams would require public consultation, including with stakeholders who had environmental and economic concerns.
But private dams involved “minimal public consultation and can be approved and constructed based on environmental assessments commissioned from private consultants by dam proponents”.
The report looked at three dams in detail, on properties in the Murrumbidgee Valley owned by Webster Ltd – Glenmea, Bringagee and Kooba Station. The dams were funded out of the federal government’s $4 billion water efficiency program.
The report argues such dams are not the best way to save water. It points to the department of agriculture and water resources saying new dams can save water where they replace shallower ones (which have more evaporation), or where they collect recycled irrigation water.
“However, none of the three case-study dams in this report save water in this way. They are new dams, not replacing smaller, shallower dams. Water stored behind their approximately eight metre high walls would otherwise be stored in public headwater dams around 100 metres deep.”
These dams are designed to divert normal irrigation water and “supplementary water” – not to simply recycle irrigation water, the report says. Thus “they increase both evaporation and irrigation water use”.
Supplementary water is water that is surplus to consumptive needs. It is important environmentally and to downstream users, historically making up almost all the water flowing from the Murrumbidgee into the Murray, the report says.
“With major dams now targeting this water, the Murrumbidgee could be disconnected from the Murray in most years. This has implications for all NSW Basin water users, who are already grappling with how to meet downstream obligations within the Murray’s constraints and with no water coming down the Darling.”
The report says a Canadian pension fund had just been reported as “swooping” on Webster, “with specific mention of a property with one of these new dams”.
“The new dams that Australian taxpayers helped build appear to be highly valued by international investors,” the report says.
Our diets can have a big environmental impact. The greenhouse gas emissions involved in producing and transporting various foods has been well researched, but have you ever thought about the water-scarcity impacts of producing your favourite foods? The answers may surprise you.
In research recently published in the journal Nutrients, we looked at the water scarcity footprints of the diets of 9,341 adult Australians, involving more than 5,000 foods. We measured both the amount of water used to produce a food, and whether water was scarce or abundant at the location it was drawn from.
The food system accounts for around 70% of global freshwater use. This means a concerted effort to minimise the water used to produce our food – while ensuring our diets remained healthy – would have a big impact in Australia, the driest inhabited continent on Earth.
We found the average Australian’s diet had a water-scarcity footprint of 362 litres per day. It was slightly lower for women and lower for adults over 71 years of age.
A water-scarcity footprint consists of two elements: the litres of water used, multiplied by a weighting depending on whether water scarcity at the source is higher or lower than the global average.
Foods with some of the highest water-scarcity footprints were almonds (3,448 litres/kg), dried apricots (3,363 litres/kg) and breakfast cereal made from puffed rice (1,464 litres/kg).
In contrast, foods with some of the smallest water-scarcity footprint included wholemeal bread (11.3 litres/kg), oats (23.4 litres/kg), and soaked chickpeas (5.9 litres/kg).
It may surprise you that of the 9,000 diets studied, 25% of the water scarcity footprint came from discretionary foods and beverages such as cakes, biscuits, sugar-sweetened drinks and alcohol. They included a glass of wine (41 litres), a single serve of potato crisps (23 litres), and a small bar of milk chocolate (21 litres).
These foods don’t only add to our waistlines, but also our water-scarcity footprint. Previous studies have also shown these foods contribute around 30% of dietary greenhouse gas emissions in Australia.
The second highest food group in terms of contributing to water-scarcity was fruit, at 19%. This includes whole fruit and fresh (not sugar-sweetened) juices. It should be remembered that fruit is an essential part of a healthy diet, and generally Australians need to consume more fruit to meet recommendations.
Dairy products and alternatives (including non-dairy beverages made from soy, rice and nuts) came in third and bread and cereals ranked fourth.
The consumption of red meat – beef and lamb – contributed only 3.7% of the total dietary water-scarcity footprint. These results suggest that eating fresh meat is less important to water scarcity than most other food
groups, even cereals.
Not surprisingly, cutting out discretionary foods would be number one priority if you wanted to lower the water footprint of the food you eat, as well as the greenhouse gas emissions of production.
Over-consumption of discretionary foods is also closely linked to weight gain and obesity. Eating a variety of healthy foods, according to energy needs, is a helpful motto.
Aside from this, it is difficult to give recommendations that are relevant to consumers. We found that the variation in water-scarcity footprint of different foods within a food group was very high compared to the variation between food groups.
For example, a medium sized apple was found to contribute a water-scarcity footprint of three litres compared with more than 100 litres for a 250 ml glass of fresh orange juice. This reflects the relative use of irrigation water and the local water scarcity where these crops are grown. It also takes more fruit to produce juice than when fruit is consumed whole.
Two slices of wholegrain bread had a much lower water-scarcity footprint than a
cup of cooked rice (0.9 litres compared with 124 litres). Of the main protein sources, lamb had the lowest water-scarcity footprint per serve (5.5 litres). Lambs are rarely raised on irrigated pastures and when crops are used for feeding, these are similarly rarely irrigated.
Consumers generally lack the information they would need to choose core foods with a lower water-scarcity footprint. Added to this, diversity is an important principle of good nutrition and dissuading consumption of particular core foods could have adverse consequences for health.
Perhaps the best opportunities to reduce water scarcity impacts in the Australian food system lie in food production. There is often very large variation between producers in water scarcity footprint of the same farm commodity.
For example, a study of the water scarcity footprint of tomatoes grown for the Sydney market reported results ranging from 5.0 to 52.8 litres per kg. Variation in the water-scarcity footprint of milk produced in Victoria was reported to range from 0.7 to 262 litres. This mainly reflects differences in farming methods, with variation in the use of irrigation and also the local water scarcity level.
Water-scarcity footprint reductions could best be achieved through technological change, product reformulation and procurement strategies in agriculture and food industries.
This is the first study of its kind to report the water-scarcity footprint for a large number of individual self-selected diets.
This was no small task, given that 5,645 individual foods were identified. Many were processed foods which needed to be separated into their component ingredients.
It’s hard to say how these results compare to other countries as the same analysis has not been done elsewhere. The study did show a large variation in water-scarcity footprints within Australian diets, reflecting the diversity of our eating habits.
Water scarcity is just one important environmental aspects of food production and consumption. While we don’t suggest that dietary guidelines be amended based on water scarcity footprints, we hope this research will support more sustainable production and consumption of food.
The author originally disclosed that he undertakes research for Meat and Livestock Australia. His disclosure has been updated to specify that the above research is among the projects to which the MLA has contributed funding.