Fixing cities’ water crises could send our climate targets down the gurgler



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Water treatment plants can’t afford not to think about electricity too.
CSIRO/Wikimedia Commons, CC BY-SA

Peter Fisher, RMIT University

Two cities on opposing continents, Santiago
and Cape Town, have been brought to their knees by events at opposing ends of the climate spectrum: flood and drought.

The taps ran dry for Santiago’s 5 million inhabitants in early 2017, due to contamination of supplies by a massive rainfall event. And now Cape Town is heading towards “day zero” on May 11, after which residents will have to collect their drinking water from distribution points.




Read more:
Cape Town is almost out of water. Could Australian cities suffer the same fate?


It’s probably little comfort that Santiago and Cape Town aren’t alone. Many other cities around the world are grappling with impending water crises, including in Australia, where Perth and Melbourne both risk running short.

In many of these places governments have tried to hedge their bets by turning to increasingly expensive and energy-ravenous ways to ensure supply, such as desalination plants and bulk water transfers. These two elements have come together in Victoria with the pumping of desalinated water 150km from a treatment plant at Wonthaggi, on the coast, to the Cardinia Reservoir, which is 167m above sea level.

But while providing clean water is a non-negotiable necessity, these strategies also risk delivering a blowout in greenhouse emissions.

Water pressure

Climate change puts many new pressures on water quality. Besides the effects of floods and droughts, temperature increases can boost evaporation and promote the growth of toxic algae, while catchments can be contaminated by bushfires.

Canberra experienced a situation similar to Santiago in 2003, when a bushfire burned through 98% of the Cotter catchment, and then heavy rain a few months later washed huge amounts of contamination into the Bendora Dam. The ACT government had to commission a A$40 million membrane bioreactor treatment plant to restore water quality.

At the height of the Millennium Drought, household water savings and restrictions lowered volumes in sewers (by up to 40% in Brisbane, for example). The resulting increase in salt concentrations put extra pressure on wastewater treatment and reclamation..

The energy needed to pump, treat, distribute and heat water – and then to convey, pump, reclaim or discharge it as effluent, and to move biosolids – is often overlooked. Many blueprints for zero-carbon cities underplay or neglect entirely the carbon footprint of water supply and sewage treatment.

Some analyses only consider the energy footprint of domestic water heating, rather than the water sector as a whole – which is rather like trying to calculate the carbon footprint of the livestock industry by only looking at cooking.

Yet the growing challenge of delivering a reliable and safe water supply means that energy use is growing. The United States, for example, experienced a 39% increase in electricity usage for drinking water supply and treatment, and a 74% increase for wastewater treatment over the period 1996-2013, in spite of improvements in energy efficiency.

As climate change puts yet more pressure on water infrastructure, responses such as desalination plants and long-distance piping threaten to add even more to this energy burden. The water industry will increasingly be both a contributor to and a casualty of climate change.

How much energy individual utilities are actually using, either in Australia or worldwide, will vary widely according to the source of supply – such as rivers, groundwater or mountain dams – and whether gravity feeds are possible for freshwater and sewage (Melbourne shapes up well here, for example, whereas the Gold Coast doesn’t), as well as factors such as the level of treatment, and whether or not measures such as desalination or bulk transfers are in place.

All of this increases the water sector’s reliance on the electricity sector, which as we know has a pressing need to reduce its greenhouse emissions.

Desalination plants: great for providing water, not so great for saving electricity.
Moondyne/Wikimedia Commons, CC BY-SA

One option would be for water facilities to take themselves at least partly “off-grid”, by installing large amounts of solar panels, onsite wind turbines, or Tesla-style batteries (a few plants also harness biogas). Treatment plants are not exactly bereft of flat surfaces – such as roofs, grounds or even ponds – an opportunity seized upon by South Australian Water.

But this is a large undertaking, and the alternative – waiting for the grid itself to become largely based on renewables – will take a long time.

A 2012 study found large variations in pump efficiency between water facilities in different local authorities across Australia. Clearly there is untapped scope for collaboration and knowledge-sharing in our water sector, as is done in Spain and Germany, where water utilities have integrated with municipal waste services, and in the United States, where the water and power sectors have gone into partnership in many places.

The developing world

Climate change and population growth are seriously affecting cities in middle-band and developing countries, and the overall outlook is grim. Many places, such as Mexico City, already have serious water contamination problems. Indeed, in developing nations these problems are worsened by existing water quality issues. Only one-third of wastewater is treated to secondary standard in Asia, less than half of that in Latin America and the Caribbean, and a minute amount in Africa.

The transfer of know-how to these places is critical to reaching clean energy transitions. Nations making the energy transition – especially China, the world’s largest greenhouse emitter – need to take just as much care to ensure they avoid a carbon blowout as they transition to clean water too.

Just as in the electricity sector, carbon pricing can potentially provide a valuable incentive for utilities to improve their environmental performance. If utilities were monitored on the amount of electricity used per kilolitre of water processed, and then rewarded (or penalised) accordingly, it would encourage the entire sector to up its game, from water supply all the way through to sewage treatment.




Read more:
This is what Australia’s growing cities need to do to avoid running dry


Water is a must for city-dwellers – a fact that Cape Town’s officials are now nervously contemplating. It would be helpful for the industry to participate in the strategic planning and land-use debates that affect its energy budgets, and for its emissions (and emissions reductions) to be measured accurately.

In this way the water industry can become an influential participant in decarbonising our cities, rather than just a passive player.


The ConversationThis article is based on a journal article (in press) co-authored by David Smith, former water quality manager for South East Water, Melbourne.

Peter Fisher, Adjunct Professor, Global, Urban and Social Studies, RMIT University

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

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King tides and rising seas are predictable, and we’re not doing enough about it


Mark Gibbs, Queensland University of Technology

Recent king tides have again caused significant damage to coastal assets in Australia and New Zealand. This time the combination of large tides and coastal storms damaged properties on Torres Strait islands and in Nelson and other coastal areas of New Zealand. It is increasingly recognised worldwide that, despite many coastal adaptation plans being developed, the implementation of these plans is lagging.

King tides occur several times a year when the Moon is slightly closer to the Earth (so they’re sometimes called perigean spring tides). This means king tides are predictable, as are rising sea levels. The combination, along with sporadic storm events, will lead to increasing flooding of our coastal cities.




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Higher sea levels, whether creeping (associated with anthropogenic climate change) or transient (episodic storm events), have impacts on both private and public property and assets. What is now mostly nuisance flooding will become more problematic, and the ever-increasing global damage bill from disaster will continue to mount.

According to the global re-insurer Munich Re, losses from natural disasters in 2017 totalled US$330 billion, the second highest on record. Almost half of these losses (41%) were uninsured.

Who’s responsible for adaptation plans?

In keeping with the theory that risk is best managed by those closest to the risk, local government in Australia is the level of government best suited to managing such local risks. In response to the increasing threat from rising sea levels, many local government councils around Australia have developed coastal climate adaptation plans.

Federal and state governments clearly also have roles to play in managing coastal inundation. The federal government is often the insurer of last resort, especially for public infrastructure.


Read more: Coastal communities, including 24 federal seats at risk, demand action on climate threats

Read more: Coastal law shift from property rights to climate adaptation is a landmark reform


In Queensland, the state government has implemented the successful QCoast2100 program. This is helping local governments to develop adaptation plans all along the state’s coastline.

It is increasingly recognised that many of the plans developed in the past contain overcomplicated analyses of oversimplified adaptation options. Instead, we need less complicated ways of determining the most suitable adaptation option and assessments that consider more tailored and considered options, which will then be more readily implementable.

What are the options?

Coastal climate adaptation options tend to fall into one of three categories:

  • retreat – relocate assets and structures inland or to higher ground
  • protect – mostly by building engineered seawalls, although green infrastructure can also be implemented
  • accommodate – live with the hazard but reduce the vulnerability of structures and assets.

Retreat makes intuitive sense: relocating assets out of harm’s way reduces their vulnerability. However, this approach has proved politically problematic, especially for private buildings.

Most communities are familiar with seawalls and other forms of coastal protection. Others fundamentally disagree with the principle of hard coastal protection measures.




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The third adaptation option, accommodating sea-level rise, is becoming the most popular approach in many nations, including the low-lying Netherlands. However, this approach is probably the least understood in Australia and rarely appears as the preferred option in Australian coastal adaptation plans.

This option includes making existing structures less vulnerable. This might involve relocating electrical and air-conditioning services and switchboards higher in existing buildings. Over time, vulnerable sites can be repurposed with less vulnerable land uses and structures.

This is different from pre-emptively evicting and relocating entire communities from vulnerable locations – the retreat option. The retreat option is most easily implemented immediately after major flooding that has led to significant damage.

Plans must consider the politics

Early coastal adaptation plans commonly advocated mass pre-emptive coastal retreat, but local government often ended up shelving or rejecting such recommendations. Instead, councils simply commissioned the construction of small local seawalls in areas at risk of erosion.

More developed and recent coastal adaptation plans consider finer spatial scales. What they still often don’t do is consider more sophisticated and politically informed adaptation options and approaches.

Hence adaptation planning is still often best characterised as the “plan and forget” approach. These plans typically lack monitoring and evaluation and a realistic implementation strategy.

The ConversationIncreased flooding of our coastline is inevitable and happening. Therefore, adaptation planning needs to consider more nuanced options that are likely to be more politically palatable and implementable.

Mark Gibbs, Director, Knowledge to Innovation; Chair, Green Cross Australia, Queensland University of Technology

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

Hidden depths: why groundwater is our most important water source



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Deep dive: water flows from a bore in Birdsville, Queensland.
Lobster1/Wikimedia Commons, CC BY-SA

Emma Kathryn White, University of Melbourne

Vivid scenes of worried Cape Town residents clutching empty water vessels in long snaking queues are ricocheting around the globe. Everyone is asking, “How did this happen?” Or, more precisely, “Can it happen in my city?” The importance of effective water management has been shoved, blinking, into the limelight.

In Australia we’re watching somewhat nervously, grateful to have been spared the same fate – for now, at least. Experts tell us that the key is “water divestment” – that is, don’t put all your eggs in one basket (or, perhaps more appropriately, don’t get all your water from the same tap).

Perth is held up as a shining example of Australia’s success in water divestment. The city now relies partly on desalination and crucially gets almost 70% of its supply from groundwater.




Read more:
The world’s biggest source of freshwater is beneath your feet


Groundwater, the great salvation of parched cities and agricultural development, is the world’s largest freshwater resource. The volume of fresh water in all the world’s lakes, rivers and swamps adds up to less than 1% of that of fresh groundwater – like putting a perfume bottle next to a ten-litre bucket.

What’s more, because it’s underground, it is buffered somewhat from a fickle climate and often used to maintain or supplement supply during times of drought.

Yet caution is required when developing groundwater. Sinking wells everywhere, Beverley Hillbillies style, is unwise. Instead, robust groundwater management is required – defining clearly what we want to achieve and what are we prepared to lose to get it.

Despite the common perception of its abundance, groundwater is not inexhaustible. Its management is fraught with minefields greater and more enigmatic than those of surface waters. It is, after all, much easier to spot when a reservoir is about to run dry than a subterranean aquifer.

Subsidence can be surprisingly rapid, as in the case of this example in California’s San Joaquin Valley.
USGS

Only when aquifer depletion is already quite advanced do we begin to see the tell-tale signs at the surface: metres and metres of subsidence, huge cracks in roads, and dried-up wetlands clogged with dead trees and dried-out bird carcasses.

For the most part, however, groundwater remains out of sight, hidden beneath many metres of soil and rock. We only remember it is there when something goes wrong, such as a drought, at which point people begin raving about groundwater, location, yield, salinity, stygofauna – wait, what?

Actually hardly anyone cares about stygofauna; most people have never heard of these tiny subterranean creatures, and you will certainly never see one as a state emblem. Mound springs? What are they? Clearly being underground has left groundwater with an image problem.

There was much media coverage of water theft from the Murray River, with broadcast journalists reporting breathlessly from tinnies, and dramatic footage of huge pumps sucking swirling brown water from a sluggish river. Film of groundwater pumps sedately slurping water is much harder to get, because bores tend to be on private property, often hidden inside little tin shacks and kind of boring, really.

Groundwater just doesn’t capture the public imagination. Great reservoirs and rivers are evocative of wilderness and adventure; they almost make you want to build a little raft and float lazily away, Huck Finn style. But the thing is, groundwater feeds many great rivers, supplying base-flow, so when we suck water out of wells, in many instances we may as well be sucking out of rivers.

Despite this connectivity, in many regions groundwater and surface water are managed separately. This is akin to treating to your left hand as a separate entity to your right. Regulation of groundwater lags behind that of surface water and, in many parts of the world including the United States, China, India and Australia, groundwater is overexploited and pumped prolifically, leading to severe social and environmental impacts.

Mound springs support unique and endemic ecosystems and bubbling clear cold water, a welcome sight for dusty travellers. And as for the aforementioned stygofauna, well, what could be cooler than a blind cave eel?




Read more:
Squeezed by gravity: how tides affect the groundwater under our feet


Groundwater will become increasingly important as a water source as we grapple with growing cities and burgeoning populations, not to mention climate change, which is projected to reduce rainfall across eastern Australia.

It is crucial that we ensure our groundwater management is effective and robust in the face of drought. It is no longer enough just to write management plans; we must put them to the test by running our groundwater models through a range of future climate and management frequency scenarios. We need increased investment in groundwater management planning, and for management to be conducted in conjunction with surface water management.

The ConversationWith many cities’ water supplies drying up before our eyes, we also need to remember to think about the water we cannot see.

Emma Kathryn White, PhD Candidate, Infrastructure Engineering, University of Melbourne

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