Heavy rains are great news for Sydney’s dams, but they come with a big caveat


Ian Wright, Western Sydney University and Jason Reynolds, Western Sydney University

Throughout summer, Sydney’s water storage level fell alarmingly. Level 2 water restrictions were imposed and the New South Wales government prepared to double the capacity of its desalination plant.

But then it began to rain, and rain. Sydney water storages jumped from 41% in early February to 75% now – the highest of any capital city in Australia.

This is great news for the city, but it comes with a big caveat. Floodwaters will undoubtedly wash bushfire debris into reservoirs – possibly overwhelming water treatment systems. We must prepare now for that worst-case pollution scenario.

Reservoirs filled with rain

The water level of Sydney’s massive Lake Burragorang – the reservoir behind Warragamba Dam – rose by more than 11 meters this week. Warragamba supplies more than 80% of Sydney’s water.

Other Sydney water storages, including Nepean and Tallowa dams, are now at 100%.
WaterNSW report that 865,078 megalitres of extra water has been captured this week across all Greater Sydney’s dams.

This dwarfs the volume of water produced by Sydney’s desalination plant, which produces 250 megalitres a day when operating at full capacity. Even at this rate, it would take more than 3,400 days (or nine years) to match the volume of water to added to Sydney’s supply this week.

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The Warragamba Dam before the drought and after the recent heavy rains.

But then comes the pollution

Thankfully, the rain appears to have extinguished bushfires burning in the Warragamba catchment for months.

But the water will also pick up bushfire debris and wash it into dams.

Over the summer, bushfires burnt about 30% of Warragamba Dam’s massive 905,000 hectare water catchment, reducing protective ground cover vegetation. This increases the risk of soil erosion. Rain will wash ash and sediment loads into waterways – adding more nitrogen, phosphorous and organic carbon into water storages.




Read more:
Bushfires threaten drinking water safety. The consequences could last for decades


Waterways and ecosystems require nutrients like phosphorous and nitrogen, but excess nutrients aren’t a good thing. They bring contamination risks, such as the rapid growth of toxic blue-green algae.

Drinking water catchments will always have some degree of contamination and water treatment consistently provides high quality drinking water. But poor water quality after catchment floods is not without precedent.

We’ve seen this before

In August 1998, extreme wet weather and flooding rivers filled the drought-affected Warragamba Dam in just a few days.

This triggered the Cryptosporidium crisis, when the protozoan parasite and the pathogen Giardia were detected in Sydney’s water supplies. It triggered health warnings, and Sydneysiders were instructed to boil water before drinking it. This event did not involve a bushfire.




Read more:
Better boil ya billy: when Australian water goes bad


The Canberra bushfires in January 2003 triggered multiple water quality problems. Most of the region’s Cotter River catchments, which hold three dams, were burned. Intense thunderstorms in the months after the bushfire washed enormous loads of ash, soil and debris into catchment rivers and water reservoirs.

This led to turbidity (murkiness), as well as iron, manganese, nitrogen, phosphorus and carbon in reservoir waters. The inflow of organic material also depleted dissolved oxygen which triggered the release of metals from reservoir sediment. At times, water quality was so poor it couldn’t be treated and supplied to consumers.

The ACT Government was forced to impose water restrictions, and built a A$38 million water treatment plant.

Have we come far enough?

Technology in water treatment plants has developed over the past 20 years, and water supply systems operates according to Australian drinking water guidelines.

Unlike the 1998 Sydney water crisis, WaterNSW, Sydney Water and NSW Health now have advanced tests and procedures to detect and manage water quality problems.

In December last year, WaterNSW said it was aware of the risk bushfires posed to water supplies, and it had a number of measures at its disposal, including using booms and curtains to isolate affected flows.

However at the time, bushfire ash had already reportedly entered the Warragamba system.

The authors crossing the Coxs River during very low flow last September.
Author provided

Look to recycled water

Sydney’s water storages may have filled, but residents should not stop saving water. We recommend Level 2 water restrictions, which ban the use of garden hoses, be relaxed to Level 1 restrictions which ban most sprinklers and watering systems, and the hosing of hard surfaces.

While this measure is in place, longer term solutions can be explored. Expanding desalination is a popular but expensive option, however greater use of recycled wastewater is also needed.




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80% of household water goes to waste – we need to get it back


Highly treated recycled water including urban stormwater and even treated sewage should be purified and incorporated into the water supply. Singapore is a world leader and has proven the measure can gain community acceptance.

It’s too early to tell what impact the combination of bushfires and floods will have on water storages. But as extreme weather events increase in frequency and severity, all options should be on the table to shore up drinking water supplies.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University and Jason Reynolds, Senior Lecturer in Geochemistry, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bushfires threaten drinking water safety. The consequences could last for decades



Warnings about poor drinking water quality are in place in some areas affected by the bushfires.
From shutterstock.com

Stuart Khan, UNSW

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.




Read more:
How to monitor the bushfires raging across Australia


Short-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.




Read more:
Disaster recovery from Australia’s fires will be a marathon, not a sprint


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.




Read more:
What are parasites and how do they make us sick?


Long-term risks

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.

Boiling water will kill microorganisms, but not chemical substances.
From shutterstock.com

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.




Read more:
The bushfires are horrendous, but expect cyclones, floods and heatwaves too


Boiling water isn’t always enough

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.

Such “do not drink” alerts were issued this week following bushfire impacts to water treatment plants supplying the Victorian towns of Buchan and Omeo.




Read more:
How does poor air quality from bushfire smoke affect our health?


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 Conversation

Stuart Khan, Professor of Civil & Environmental Engineering, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘New Bradfield’: rerouting rivers to recapture a pioneering spirit


Waters from the Herbert River, which runs toward one of northern Australia’s richest agricultural districts, could be redirected under a Bradfield scheme.
Patrick White, Author provided

Patrick White, James Cook University and Russell McGregor, James Cook University

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.




Read more:
You can’t boost Australia’s north to 5 million people without a proper plan


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.

An idea with 19th-century origins

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”.

Blencoe Falls, on a tributary of the Herbert River, North Queensland, during the dry season.
Patrick White, Author provided

As the “dead heart” became the “Red Centre” in the 1930s, populist writers revived the dreams of big irrigation schemes.

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.

Water dreaming has been a powerful theme in Australian history. The desire to transform desert into farmland retains appeal and discredited schemes like Bradfield keep reappearing.




Read more:
The keys to unlock Northern Australia have already been cut


Contempt for nature and country

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.




Read more:
Remote Indigenous Australia’s ecological economies give us something to build on


Polarising debate neglects more viable projects

“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.

The Queensland Farmers Federation has cautiously welcomed the new scheme. Others have dismissed it as a “pipe dream”.

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.




Read more:
We can’t drought-proof Australia, and trying is a fool’s errand


Dam developments have an underwhelming record

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.

The proposed site for Hells Gates Dam is on Gugu Badhun country on the Burdekin River.
Dr Theresa Petray, Author provided

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.




Read more:
Damming northern Australia: we need to learn hard lessons from the south


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 Conversation

Patrick White, PhD Candidate in History and Politics, James Cook University and Russell McGregor, Adjunct Professor of History, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Researchers allege native logging breaches that threaten the water we drink



Researchers have uncovered what appears to be widespread logging of steep slopes in Victoria, which has the potential to damage critical water supplies.
Chris Taylor, Author provided

David Lindenmayer, Australian National University and Chris Taylor, Australian National University

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.

A steep slope recently logged measuring 33 degrees on site near Mount Matlock in the Upper Goulburn Catchment.
Chris Taylor

Logging on steep slopes matters

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.

Sobering evidence

Water in some affected catchments ends up in Melbourne’s drinking water supply.

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.

Recently logged areas near Mount Matlock in the Upper Goulburn Water Catchment. The top map shows where we detected slopes exceeding 30 degrees in logged areas (red). The bottom map shows areas designated by the Victorian government as exclusion zones (magenta).
DELWP 2019, ESA 2019, Gallant et al. 2011

Why is this happening?

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.

There are alternatives

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.The Conversation

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

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Dams are being built, but they are private: Australia Institute



A senior water researcher at the institute said politicians don’t want to talk about private dams because “they do nothing for drought-stricken communities”.
Shutterstock

Michelle Grattan, University of Canberra

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.The Conversation

Michelle Grattan, Professorial Fellow, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Three reasons why it’s a bad idea to ramp up Adelaide’s desalination plant


Sarah Ann Wheeler, University of Adelaide

Drought-affected farmers in New South Wales have called for South Australia to increase the use of its desalination plant to enable an increase in water allocations for other users along the Murray River.

The farmers’ argument is that if Adelaide in particular draws less water from the river more will be available for agriculture in NSW and Victoria.

The logic may sound appealing, but there are three good reasons why it’s not a good idea. Not only is desalination an incredibly expensive project, there are other strategies – like water pricing – that can more effectively reduce water demand.




Read more:
Is Australia’s current drought caused by climate change? It’s complicated


It’s also important to remember that the water flowing to South Australia is not “wasted” if it’s not diverted for industry. Stream flows are vital for keeping many ecosystems alive, and there are already serious concerns about current levels.

Adelaide doesn’t use that much water

First, Adelaide uses a very small amount of water from the River Murray. Over the past two decades, average diversions for metropolitan Adelaide and associated country areas have been just over 100 gigalitres (GL). This represents an average 1.25% of the water diversions in the Murray-Darling Basin.

SA in general (including irrigator use) has used an average 11% of water diversions over the past two decades. NSW has diverted 52% of surface water in the Murray-Darling Basin over the same period. Hence, the reality is that ramping up SA’s desal plant will have very little actual impact on NSW irrigators’ water allocations.

South Australia (the grey line) receives much less water from the Murray River than other states.
MDBA Water Audit Monitoring reports, CC BY

Desalination is expensive

Second, increasing desalination has heavy financial and environmental costs. The financial cost is why the plant has been run at only about 10% capacity (the minimum needed to maintain its working condition).

Previous economic analysis by consultants has suggested the desalination plant should only be used to increase water allocations to SA irrigators when temporary water market prices are above A$510 per megalitre (ML).

Given that temporary water prices are now trading around A$300/ML (albeit increasing due to increased water scarcity), we’re still a long way from a financial argument for turning to the desal plant, let alone considering the cost of its negative environmental impacts.




Read more:
Farmers experiencing drought-related stress need targeted support


Water is always variable

Third, we need to take into account the variable nature of Australia’s irrigation sector.

Farmers in NSW are complaining that they are on zero percentages of water allocations at the start of the water year (August 1). This sounds like a big problem. But it doesn’t mean the farmers will get no water from the river at all.

At the start of the season, water managers allot water in districts to irrigators every two weeks. Depending on the type of water entitlement owned, and given the current state of water conditions (e.g. storage, inflows, rainfall predictions), water managers will allocate a percentage of water to high security entitlements first, then general security, then low security. Only in high rainfall years will the low security group get any water. Most years they get none.

Since water was separated from land in the Murray-Darling Basin, this water is not tied to any particular use. Once allocated, irrigators can use their seasonal water for their crops, store it, sell it on the water market, or even choose to let it flow down the river.

It is not unusual for irrigators with low or general security entitlements to start the water year with low or no water allocated, especially in times of water scarcity. One reason is that these rights are traditionally associated with districts where farmers typically grow annual crops like rice and cotton. They have larger farms and more water rights – but also more flexibility about the amount they plant every year.

Low water allocations at the start of the water year act as a signal to these producers to think carefully about the amount of acreage to plant in the coming months. In addition, many NSW and Victorian farmers have access to carry-over water (unused stored water from the previous year).

The other option is the water market; irrigators can enter the water market to buy water. Current temporary water prices are still historically a lot lower than prices in the Millennium Drought, when temporary prices hit over A$1000/ML in many regions.

Finally, it is important to emphasise that water destined for urban use in SA is not “wasted water” for NSW and Victoria. It is still providing surface-water flows in the basin as it makes it way to SA.

Economic studies show that a healthy and sustainable river is worth millions of dollars in tourism and recreation, plus providing important cultural values, on which many small regional town economies are heavily dependent. And there is ongoing evidence that the Murray-Darling Basin is still far from being sustainable.




Read more:
The Murray Darling Basin Plan is not delivering – there’s no more time to waste


Unfortunately, many of the people who support more sustainable water reallocation for the environment are widely dispersed. They often do not have the lobbying power or the resources to engage successfully in policy debate.

The ConversationOf course, farmers need support. But the calls for more water to be allocated to irrigators will sound loudly as the drought continues, and it’s important to remember that there are other, less costly, options that also protect our environment.

Sarah Ann Wheeler, Professor in Water Economics, University of Adelaide

This article was originally published on The Conversation. Read the original article.

Sustainable shopping: tap water is best, but what bottle should you drink it from?



File 20180419 163991 13qaeez.jpg?ixlib=rb 1.1
The greenest option might be to get a disposable bottle but never dispose of it.
Shutterstock.com

Trevor Thornton, Deakin University and Simon Lockrey, RMIT University

Shopping can be confusing at the best of times, and trying to find environmentally friendly options makes it even more difficult. Our Sustainable Shopping series asks experts to provide easy eco-friendly guides to purchases big and small. Send us your suggestions for future articles here.


We have many options when it comes to how we drink water, given the large range of consumer products available, and Australia’s high standards of tap water.

But which option is the smartest choice from an environmental perspective?

According to the waste management hierarchy, the best option is one that avoids waste altogether. Recyclable options are less preferable, and landfill disposal the worst of all.

For water bottles, this suggests that keeping and reusing the same bottle is always best. It’s certainly preferable to single-use bottles, even if these are recyclable.




Read more:
Recycling can be confusing, but it’s getting simpler


Of course, it’s hardly revolutionary to point out that single-use plastic bottles are a bad way to drink water on environmental grounds. Ditching bottled water in favour of tap water is a very straightforward decision.

However, choosing what reusable bottle to drink it out of is a far more complex question. This requires us to consider the whole “life cycle” of the bottle.

Cycle of life

Life-cycle assessment is a method that aims to identify all of the potential environmental impacts of a product, from manufacture, to use, to disposal.

A 2012 Italian life-cycle study confirmed that reusable glass or plastic bottles are usually more eco-friendly than single-use PET plastic bottles.

However, it also found that heavy glass bottles have higher environmental impacts than single-use PET bottles if the distance to refill them was more than 150km.

Granted, you’re unlikely ever to find yourself more than 150km from the nearest drinking tap. But this highlights the importance of considering how a product will be used, as well as what it is made of.

What are the reusable options?

Metal bottles are among the most durable, but also require lots of resources to make.
Flickr CC

In 2011, we investigated and compared the life cycles of typical aluminium, steel and polypropylene plastic reusable bottles.

Steel and aluminium options shared the highest environmental impacts from materials and production, due to material and production intensity, combined with the higher mass of the metal bottles, for the same number of uses among the options. The polypropylene bottle performed the best.

Polypropylene bottles are also arguably better suited to our lifestyles. They are lighter and more flexible than glass or metal, making them easier to take to the gym, the office, or out and about.

The flip side of this, however, is that metal and glass bottles may be more robust and last longer, so their impacts may be diluted with prolonged use – as long as you don’t lose them or replace them too soon.

Health considerations are an important factor for many people too, especially in light of new research about the presence of plastic particles in drinking water.

Other considerations aside, is may even be best to simply buy a single-use PET plastic water bottle and then reuse it a bunch of times. They are lighter than most purpose-designed reusable bottles, but still long-lasting. And when they do come to the end of their useful life, they are more easily recycled than many other types of plastic.

Sure, you won’t look very aspirational, but depending on how many uses you get (as you approach the same number of uses as other options), you could be doing your bit for the environment.

Maintaining reusable options

There are a few things to bear in mind to ensure that reusable bottles produce as little waste as possible.

  1. Refill from the tap, as opposed to using water coolers or other bottled water that can come from many kilometres away, requiring packaging and distribution. Unsurprisingly, tap water has the lowest environmental impacts of all the options.

  2. Clean your bottle thoroughly, to keep it hygienic for longer and avoid having to replace grotty bottles. While cleaning does add to the environmental impact, this effect is minor in comparison to the material impacts of buying new bottles – as we have confirmed in the case of reusable coffee cups.




Read more:
Sustainable shopping: how to stop your bathers flooding the oceans with plastic


The verdict

To reduce your environmental impacts of a drink of water, reusing a bottle, whether a designer bottle or a single-use bottle you use time and again, makes the most sense from a life-cycle, waste and litter perspective.

The maintenance of your reusable container is also key, to make sure you get as many uses as you can out of it, even if you create minor additional environmental impacts to do so.

The ConversationUltimately, drinking directly from a tap or water fountain is an even better shout, if you have that option. Apart from the benefit of staying hydrated, you will reduce your impacts on our planet.

Trevor Thornton, Lecturer, School of Life and Environmental Sciences, Deakin University and Simon Lockrey, Research Fellow, RMIT University

This article was originally published on The Conversation. Read the original article.