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Author: Neville

  • Sea-rise planning in Gosford Council

    Sea level rise is an issue that is receiving spirited debate across all levels of the community, government and also the scientific community. Council does not have the expertise to analyse the complex issues associated with sea level rise and relies on State and Federal Governments to provide professional investigation, advice and direction on the projected sea level rise increases to assist in land use planning.

    The NSW State Government released the NSW Sea Level Rise Policy Statement in October 2009. This document states “The best national and international projections of sea level rise along the NSW coast are for 40 cm by 2050 and 90 cm by 2100”. Figures stated in the NSW Sea Level Rise Policy Statement are based on the best available scientific and specialist information and as such Council has adopted the planning level for sea level rise of 0.9m by the year 2100.

    While the NSW Sea Level Rise Policy Statement has not to date changed, the State Government has initiated a review. Council has been informed that the terms under which the review is being undertaken are as follows: “Current sea level rise benchmarks used to guide land use planning and infrastructure design in NSW are based on advice from both the Intergovernmental Panel on Climate Change (IPCC) and CSIRO. The NSW Government is committed to regularly reviewing these benchmarks to ensure that they are based on the most appropriate science.”

    The O’Farrell Government is concerned about the impacts of projected sea level rise on coastal erosion and flooding in coastal areas. To address these issues, a Ministerial Taskforce has been established to ensure that NSW has the best plans, legislation and other arrangements in place to deal with coastal risk. Establishing this Taskforce is an important step in ensuring that NSW has the best arrangements in place to manage coastal erosion and other coastal hazards, both now and into the future. The Taskforce will also review the application of sea level rise planning benchmarks and the adequacy of the science informing these benchmarks and will report to the NSW Cabinet.

    Council is responsible for planning for future development in Gosford, for managing the natural environment and for the wellbeing of current and future residents. Planning and development decisions taken now will be “on the ground” in 50 to 100 years. This places a duty of care on Council to plan for the future based on the best available information.

    The adopted rate for sea level rise allows Councillors, Council staff and the community to assess the potential risks associated with projected rise in sea level. It also enables Council to develop policies, carry out more detailed studies and make planning and development decisions that are suitable for the changing conditions.

    Background

    Gosford City Council recognises that sea level rise is a global problem that will impact locally on the NSW coastline and will require action by all levels of Government, including Council, and also the community. As a result, Council would like to ensure the community is informed of Council’s current sea level rise policy and related strategies, and what they mean for property owners. The following webpage outlines the potential impacts of sea level rise, state government policy, Council’s planning level & current strategic planning, and information for property owners.

    Vulnerability of the Gosford Local Government Area to Sea Level Rise

    Rising sea levels will bring significant change to Australia’s coastal zone in the coming decades. Many coastal environments such as estuaries, beaches, low lying floodplains, lagoons and wetlands are closely linked to sea level. There is a lack of knowledge in many cases as to how these environments will respond to sea level rise but the risk of tidal inundation / flooding of low lying areas and the potential beach loss must be considered in the Council decision making.

    The Australian Government’s Department of Climate Change released the report entitled
    Climate Change Risks to Australia’s Coast – A First Pass National Assessment, that brings together existing and new information to highlight the scale of the problem that Australia faces as a vulnerable coastal nation. The assessment provides an analysis of residential property at risk from inundation and erosion around the Australia coastline at the end of this century. This report identifies the Gosford Local Government Area as the third most vulnerable area in NSW to sea level rise.

    There are approximately 90kms of Brisbane Water foreshore, 50kms of Hawkesbury River foreshore, 14kms of beaches, 4 major coastal lagoons and numerous smaller waterways within the Gosford Local Government Area which are potentially affected by sea level rise.

    Due to the extensive length of foreshore, planning for sea level rise is and will be over the coming years very challenging and demanding for Council.

    Current Scientific Knowledge and Projections of Climate Change

    Australia’s two leading climate science agencies – the CSIRO and Bureau of Meteorology – have recently produced snapshot of the state of the climate to update Australians about how their climate has changed and what it means.

    The snapshot is sourced from peer reviewed data on temperature, rainfall, sea level, ocean acidification, and carbon dioxide and methane levels in the atmosphere. From this review, the CSIRO/BOM determined the following:

    • the rate of sea level rise increased during the 20th century,
    • sea surface temperatures around Australia have increased in the past 50 years,
    • trend over five decades of rainfall decreasing across much of southern and eastern Australia,
    • that all of Australia has experienced warming over the past 50 years,
    • the number of days with record hot temperatures has increased each decade over the past 50 years,
    • there have been fewer record cold days each decade.

    The key findings from the report are:

    • Australia will be hotter in coming decades
    • Much of Australia will be drier in coming decades
    • Climate change is real

    What Potential Impacts will Sea Level Rise have on Coastal and Foreshore Areas of Gosford?

    Recent experiences internationally have shown that in a changing climate, sea level rise is a real and growing threat to the present-day sustainability of our coasts and foreshore areas. Sea level rise is predicted to have significant impacts upon coastal areas. Some of the predicted future impacts of sea level rise include:

    • Increase in the areas affected by permanent tidal inundation
    • Increase in the intensity of regular and extreme tidal inundation/flood events. The Australian Government’s Department of Climate Change projects that with a mid-range sea level rise of 0.5 metres, inundation events that happen now every 10 years would happen about every 10 days
    • Increase in the risk of beach and dune erosion. Shoreline retreat can be 50 – 200 times the vertical sea level rise, depending on coastal geomorphology;
    • Changes to the coastal ecology and ecosystems. Terrestrial and aquatic plants and animals that rely on coastal habitats are likely to be adversely affected
    • Risk to built environment assets which could have consequences for the delivery of community and essential services

    Current State Government Policy & Guidelines with Respect to Sea Level Rise

    In October 2009, the NSW Government released the NSW Sea Level Rise Policy Statement to support adaptation to projected sea level rise impacts. The Policy Statement provides the following Sea Level Rise Planning Benchmarks for use in assessing the potential impacts of sea level rise in NSW:

    • increase of 0.4m by 2050 (relative to 1990 mean sea level)
    • increase of 0.9m by 2100 (relative to 1990 mean sea level)

    The SLR planning benchmarks can be used for purposes such as:

    • incorporating the projected impacts of sea level rise on predicted flood risks and coastal hazards;
    • designing and upgrading of public and private assets in low-lying coastal areas where appropriate, taking into account the design life of the asset and the projected sea level rise over this period;
    • assessing the influence of sea level rise on new development considering the impact of sea level rise on coastal and estuarine habitats and culturally significant sites and identifying areas at most risk from sea level rise,
    • assessing the impact of changed salinity levels in estuaries, including implications for access to fresh water.

    The primary purpose of the benchmarks is to provide guidance supporting consistent considerations of sea level rise impacts, within applicable decision-making frameworks. This includes strategic planning and development assessment under the Environmental Planning & Assessment Act 1979, along with infrastructure planning and renewal.

    The use of these benchmarks is required when undertaking coastal and flood hazard assessments and studies in accordance with the NSW Coastline Management and Floodplain Development Manuals. It is already a statutory requirement that the preparation of Local Environmental Plans gives effect to and must be consistent with these manuals.

    For more information about how these sea level rise planning benchmarks have been determined, refer to the Technical Note: Derivation of the NSW Government’s Sea Level Planning Benchmarks

    In addition in October 2009, the above NSW Department of Planning released the Draft NSW Coastal Planning Guideline: Adapting to Sea Level Rise to provide guidance on how sea level rise and its associated impacts are to be considered in land use planning and development assessment in coastal NSW.

    In conjunction with the release of the Department of Planning draft Guideline, the Department of Environment, Climate Change and Water (DECCW) have prepared the following two draft guidelines to assist Councils incorporate the sea level rise planning benchmarks in coastal hazard studies and flood studies:

    Gosford Council’s current adopted Sea Level Rise Planning Level

    In recognition of the State Government policies/guidelines and Council’s duty of care in respect to future planning in the Gosford local government area, Council placed the sea level rise planning level of 0.9m on public exhibition between 12 August 2009 and 18 September 2009.

    The public exhibition included the publication of sea level rise maps that were produced to provide an initial indication of areas that may be potentially impacted by increases in sea level of up to 90cm above various scenarios as listed below:

    • average tidal inundation
    • king tide inundation
    • 1% Annual Exceedence Probability (AEP) flood inundation
    • Ocean storm surge inundation

    The purpose of the consultation activities was to exhibit and inform the public. Council was seeking to share information about sea level rise so the public would gain knowledge and become acquainted with the facts as they were understood by Council at the time. The consideration of a planning level for sea level rise and the exhibition of sea level rise mapping was an initial step that will assist this Council to work with its community through this complex and multi-faceted problem.

    Following the public exhibition, Council reviewed the submissions and at the meeting held on the 1st December 2009, Council resolved the following:

    1. Council adopt 0.9m as its sea level rise planning level for the year 2100 with an assumed linear increase from 1990 levels as the basis for Council staff to proceed with risk assessment, policy development, and strategic planning decisions.
    2. The sea level rise planning level is used in all relevant strategic processes and Council commit to reviewing all relevant strategic documents to incorporate the adopted sea level rise planning level to enable management options for development controls to be developed.
    3. The sea level rise planning level is used in all relevant asset management and capital works project planning processes to enable proper consideration of potential sea level impacts in all relevant decisions.
    4. A notation be placed on planning certificates pursuant to s149(5) of the Environmental Planning & Assessment Act 1979 that the land is within the 0.9m sea level rise extent as identified on the most relevant map held by Council.
    5. The sea level rise planning level be reviewed upon the adoption of new information or policy by State Government and the process of this review involve engagement activities with the community.
    6. The measures already in place to address coastal risk and flood risk continue to be applied and are reviewed upon the adoption of new information or policy by State Government.
    7. Council write to the Director General of the Department of Planning requesting the formulation of a Severe Physical Hazard zone for inclusion in the standard template.

    In response to Resolution D, Council identified all the properties found to be affected by projected Sea Level Rise up to 0.9m above the 1% estuary and storm surge flood events. In 2010 a s149 (5) Planning Certificate message was then applied to each of these identified properties and a letter sent to each property owner advising of Council’s resolution and the application of the encoding. However due to the lack of consistency and clear direction from the State Government Council at its meeting held on the 3rd July 2012, resolved that:

    1. Council remove the S.149(5) Planning Certificate message that relates to sea level rise until such time as the NSW State Government Legislate/Regulates that all Local Government Councils in NSW give a clear direction to all property owners who are affected by this event.
    2. Council write to our Local State Members seeking their support in the State Government providing a clear direction on a consistent approach across the state regarding sea level rise and s149 (5) Planning Certificate messages or that they repeal the Legislation.

    In accordance with resolution A Council in July 2012 then removed all the s149 (5) planning certificate messages relating to sea level rise from each of the previously identified properties.

    In accordance with resolution B letters were sent to Local State members of parliament seeking their support in the State Government providing a clear direction on a consistent approach across the state regarding sea level rise and s149 (5) Planning Certificate messages or that they repeal the Legislation.

    At the meeting held on the 4 September 2012, Council resolved the following:

    1. That sea level rise mapping on Council’s website be presented in a single series of maps across vulnerable areas based on king tide levels and 20cm, 55cm and 90cm increments.

    In accordance with resolution B the sea level rise mapping has now been simplified to one map only.

    Identification of Properties Potentially Affected by Sea Level Rise

    The adoption of a sea level rise planning level has the possibility of affecting the future use and development potential of certain land in the vicinity of the coast and estuaries. Until specific strategic plans that relate to an area have been completed (such as floodplain, coastal and estuary risk management studies) it is currently difficult to determine with certainty what specific mitigation/development controls can be applied to affected land within the area.

    Gosford Council’s Current Strategic Planning and Actions in relation to Sea Level Rise

    Planning for an uncertain future, where the trends of the past cannot be relied upon, is an emerging issue for Council. In undertaking this complex planning, Council will be, in many instances, “breaking new ground”.

    Planning for sea level rise and more broadly climate change is, and will be over the coming years, very challenging and demanding for Council. This Council has a relatively strong tradition in planning for hazards such as coastal erosion and flooding through the development of coastal management plans, estuary management plans and floodplain risk management plans. These have provided our community with information and guidance regarding local flooding and coastal erosion issues that already exist. In many cases these plans have accurately predicted hazards and subsequently have alleviated risk to life and damage to property.

    As the changes to climate manifest themselves over time, it is likely the extent of hazards such as these will change, and this planning tradition will assist with meeting the challenges we will face. To enable this to happen it is important that climate change parameters such as a sea level rise planning level be adopted to ensure it is imbedded into these strategic processes.

    It is equally important that a sea level rise planning level is a consideration in all asset management and capital works project planning.
    The process for doing this is best described in the flowchart below:

    Our Sea Level Planning Process

    Coastal Management Planning Process

    Figure 1 – the sea level planning process

    Public Participation

    Public participation in deciding on how the impacts from sea level rise are to be managed will follow at a later stage, when strategies are being developed. Council is currently undertaking the following strategic plans that could potentially determine development controls and strategies for particulars areas:

    • Brisbane Water Foreshore Floodplain Risk Management Plan
    • Erina Creek Floodplain Risk Management Plans
    • Narara Creek Floodplain Risk Management Plans
    • Gosford Open Coast and Broken Bay beaches coastal processes and hazard re-assessment.
    • Coastal Lagoons Management Studies
    • Brisbane Water Estuary Management Plan
    • Lower Hawkesbury Estuary Management Plan

    As further resources become available further strategic plans will be undertaken on other areas potentially affected by sea level rise.

    Local residents are encouraged to become involved with these studies via community consultation forums such as public meetings, workshops, community surveys and other initiatives. The community consultation forums will be advertised in the local papers and on Council’s website.

    Forums will provide residents the opportunity to have their say and help shape the adaptation management options that could include development controls and engineered structural controls.

    Engagement with community networks and interested groups will be essential as this Council adapts and responds with the aim of becoming more resilient to the impacts of climate change. This will be an ongoing process and as new information from State Agencies is received by Council, it will continue to be shared with the community.

    Useful Links

    View the following resources for further information:

  • Sleep-out to aid Vinnies. Malcolm Turnbull

    Dear Neville,

    The mark of a great society is the way it treats the neediest and most vulnerable.

    Next month, I will be joining St Vinnies in their annual CEO sleepout – business and political leaders used to warm beds will be sleeping outdoors on a chilly winter night to raise money for the homeless.

    The campaign will raise badly needed funds so St Vinnies can continue the important work they do in helping the homeless break the cycle of despair by offering them short term crisis accommodation, counselling and opportunities for education and training.

    Last year the sleepout raised $5.3 million, of which just over $36,000 was raised in support of my sleepout. So I am hoping to outdo that figure this year!

    PLEASE DONATE TO ST VINNIES HERE.

    The money raised last year funded important programs around the country including:
    • $146,000 for literacy and numeracy programs for homeless people at the Ozanam Learning Centre in Sydney.
    •  $310,000 for outreach services, including counselling and material aid packages.
    • $230,000 for 9 crisis accommodation places for women escaping domestic violence.
    • $210,000 in funding of 30 previously unfunded crisis accommodation beds at Matthew Talbot Hostel in Woolloomooloo.
    Yours sincerely,

  • Green groups attack government resistance to EU climate change goals

    Green groups attack government resistance to EU climate change goals

    Campaigners and industry experts criticise government plan to block new EU-wide renewable energy targets

    Ed Davey

    Energy and climate change secretary Ed Davey is to oppose new EU goals on renewable energy within electricity generation. Photograph: Gareth Fuller/PA

    Green campaigners and industry experts have hit out at the government’s plans to block new EU-wide renewable energy targets, which they say are essential to cutting greenhouse gas emissions and creating a green economy.

    Ed Davey, the energy and climate secretary, is to set out on Monday the UK’s position on energy and climate change targets within Europe. He will oppose any new goals on increasing the share of renewable energy in electricity generation, but will argue for climate change goals that would be tougher than any yet agreed in an international forum.

    Targets of generating 20% of the EU’s energy from renewable sources by 2020 have been credited with spurring huge growth in the sector, which accounts for tens of thousands of jobs in the UK, with more in the supply chain and wider economy.

    Wind turbine manufacturers are deciding whether to build factories that will entail tens of billions of pounds of investment, but have been holding off because of uncertainty over the coalition’s support for such development. Industry experts said these potential investors were likely to be further spooked by the government’s announcement.

    Robert Norris, of Renewable UK, which represents the green power industry, said: “If the government does not send the right signals, then major international companies deciding where to build their big wind turbine factories will go elsewhere. We can’t afford to let this opportunity slip through our fingers. It’s absolutely vital to set targets on emissions and renewables for 2030 as soon as possible. The wind industry urgently needs long-term clarity to attract the billions of pounds of investment to build the massive next round of offshore projects that will create tens of thousands of jobs.”

    Ruth Davis, political adviser at Greenpeace UK, said: “The UK has some of the best renewable energy resources in Europe, and a renewables industry with huge potential for growth. An EU target would create a new market for that industry, and in doing so attract vital investment into our economy. In opposing a renewables target, not for the first time the irrational prejudices of the Tory right seem to have trumped the interests of working people in Britain.”

    But a CBI spokeswoman said a renewables or low-carbon energy target was not needed, as long as the EU was forcing industry to pay for carbon emissions. However, the EU’s carbon price has plunged to record lows, with little chance of picking up before the end of the decade.

    Davey wants the EU to agree a target of cutting carbon by 40%, compared with 1990 levels, by 2030, and to go for a 50% cut if other countries agreed similar goals. The EU is on track for most of the emissions cuts that would entail, partly as a result of its pursuit of renewable energy, and the UK already has targets for cutting carbon to 2027, which would in themselves produce the cuts needed to meet an EU target of halving carbon by 2030.

    Davey’s decision to push for a new target on emissions but not on renewables, was seen as a compromise that allowed the Lib Dem secretary to declare a strong emissions target, but also as a victory for George Osborne.

    The chancellor has opposed any firm new targets on renewable energy beyond 2020, when the target of generating 20% of energy from renewable sources, such as sun and wind, runs out. The renewables industry and other low carbon green industries are one of the few areas of the UK economy that have shown clear growth during the financial crisis and recession.

  • Peak Oil: It’s Dead — Again?

    Peak Oil: It’s Dead — Again?

    Personal Finance newsletter

    Show do not change

    I’m confused.

    “The IEA says Peak Oil is Dead. That’s Bad News for Climate Policy,” blares a Time magazine headline.

    But there’s just one problem.

    The International Energy Agency (IEA) has said no such thing.

    “New oil sources, many of them unlocked by new technology—the Canadian oil sands, tight oil in North Dakota and Texas, ultra-deep water oil in the Atlantic—has helped keep the supply of oil growing, even as greater efficiency measures and other social shifts have helped blunt demand in rich countries like the U.S. Oil isn’t likely to be cheap—a barrel of Brent crude is $102 – and getting it out of the ground isn’t going to get any easier. But it’s increasingly likely that we will have more than enough oil in the future to keep the global economy growing and stave off any Mel Gibson-esque apocalypses,” says Time magazine.

    “Indeed, a new assessment released yesterday by the International Energy Agency (IEA) predicts that the surge of supply from North America—most of it from new unconventional sources—will transform the global supply of oil and help ease tight markets. Between now and 2018, the IEA projects that global oil production capacity will grow by 8.4 million barrels a day—significantly faster than demand. Oil isn’t likely to peak any time soon.”

    The only thing this article does well is confuse what peak oil really is.

    As we’ve reported, peak oil refers to the flow rates. It refers to the fact that the “easy to get to” oil is gone. It’s the “hard to reach” expensive oil that we now have to go after. Hydraulic fracturing – like I said – is more expensive than traditional drilling techniques.

    Even my old friend – and former colleague, Chris Nelder will tell you this.

    There has always been a lot of confusion about this point. Peak oil was never about “running out of oil.” The only people who characterized it that way either didn’t know what they were talking about or were trying to confuse the issue. Peak oil has always referred to the production rate of oil — it’s about finding the point where that production rate peaks.

    It’d be nice if Time actually checked its facts before running with these bogus stories hell-bent on confusing reality.

    While Time magazine circulates inaccuracies, we’ve been profiting from peak oil.

     by

  • Sea Level rise : Drowning in numbers

    Sea level rise: Drowning in numbers

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    We urgently need to know how far and how fast the sea will rise, but the latest attempt to put figures on it is dangerously misleading

    IMAGINE your job is to protect London from surging seas. In one way it is easy: unlike most coastal cities, London has a formidable flood defence system in the form of the Thames Barrier, capable of protecting it from all but the highest storm surges.

    But as the seas rise, the risk of the barrier being breached will increase steadily. With a 1-metre rise in local sea level, London will get flooded every 10 years. So when do you start building new flood defences, and how high do you make them?

    The stakes are enormous. Building new defences will cost tens of billions and involve decades of planning and controversy before construction even begins. Get it wrong, and storm surges could kill thousands and displace millions. So all around the world, planners are clamouring to know how fast the seas will rise as the planet warms.

    Until recently, scientists could not give them any reliable numbers. There were no computer models capable of simulating the melting of the world’s ice sheets and glaciers.

    The 2007 report of the Intergovernmental Panel on Climate Change (IPCC) handled this uncertainty really badly. It acknowledged that we don’t know how fast all the ice will melt, but then gave some numbers anyway – between 18 and 59 centimetres of sea level rise by 2100 – based on highly dubious assumptions such as glaciers continuing to flow at the same rate and the Antarctic ice sheet growing larger. The numbers also assumed a maximum warming of 5.4 °C, even though the report’s highest projection was 6.4 °C. Unsurprisingly, many people wrongly took 59 cm of sea level rise to be the worst case.

    Now we have some more numbers. A European-funded project called ice2sea has developed computer models of glaciers and ice sheets. Earlier this month it announced that melting ice would contribute between 4 and 37 cm to global sea level by 2100. Adding this to the other causes of sea level rise – the main one being the expansion of the oceans as they warm – gives figures of between 16 and 69 cm by 2100.

    Some media reports focused on the fact that this is less than some other recent estimates of at least a metre. “Seas will rise no more than 69 centimetres by 2100,” proclaimed this magazine.

    Others focused on the fact that even this relatively small rise could have devastating consequences. “Floods could overwhelm Thames Barrier by end of century,” declared The Guardian in London.

    How much trust can we put in these numbers, though? The whole point of the ice2sea programme was to “reduce the uncertainty”, but its numbers come with some rather large caveats.

    For starters, the modellers didn’t have the computing power to look at a range of scenarios for how much carbon dioxide we will pump into the atmosphere. Instead, they looked at just one – a “mid-range” scenario predicted by the 2007 report to lead to warming of around 3 °C.

    Yet actual emissions today are much closer to the worst-case scenario, which some recent studies predict could lead to warming of 6 °C or more. And far from falling, annual global emissions are rising ever faster. With hundreds more coal-fired power stations being built and new sources of fossil fuels like tar sands being exploited, there is good reason to think emissions will continue to soar for many decades to come.

    What’s more, to account for the fact that warming will not be uniform across the globe, the modellers had to produce regional projections of warming, snowfall and so on to feed into the ice models. But regional projections are highly unreliable, with different models often producing wildly varying results. The prime example is the Arctic, where the sea ice is disappearing much faster than anyone expected.

    To understand why regional climate predictions are so much less reliable than global ones, think of the heat entering the atmosphere and oceans as water pouring into a bath. Predicting the average level of the bath is much easier that predicting the height of the waves sloshing around.

    So the climate information being fed into these latest ice models could be way off the mark.

    And even if it isn’t, how do we know the models are right? Well, say the researchers, they can reproduce some of the observed responses to the actual 0.5 °C warming of the past few decades, such as the retreat of glaciers. But that doesn’t prove they can predict the response to future warming of 3 or 6 °C. There are similar issues with global climate models.

    This kind of research is vital. But when such a limited study is presented as the “best estimate” available, the danger is that it will be misinterpreted in the same way as the 2007 IPCC report. Its numbers do not encompass the worst-case scenario – far from it. They don’t even represent the most likely scenario. The narrow range implies a degree of certainty that simply doesn’t exist. Nobody should be basing life-and-death decisions such as how to protect Londoners on these numbers.

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  • If the tide is high, our sewerage systems won’t hold on

    24 May 2013, 3.19pm EST

    If the tide is high, our sewerage systems won’t hold on

    Sea levels are rising and the world’s vast coastal settlements face many damaging changes. One of the most difficult and expensive challenges is the risk to the safe and effective operation of our sewerage systems. We give our sewerage system little thought, but life in modern cities would be dangerous…

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    Increased coastal population growth and rising water levels could lead to damaged sewerage systems and water contamination. Flickr/autowitch

    Sea levels are rising and the world’s vast coastal settlements face many damaging changes. One of the most difficult and expensive challenges is the risk to the safe and effective operation of our sewerage systems.

    We give our sewerage system little thought, but life in modern cities would be dangerous and unhealthy without a reliable and sound sewerage system. This may be a “weak point” in our public health defences if we do not respond to the threat of climate change effects.

    Infrastructure down the drain

    Gravity is the best friend of the conventional urban sewerage system. When we flush our toilet or pull the plug out from the bath, gravity drains the wastewater away from us. For many people, that’s the last time we think about our wastewater.

    Sewerage infrastructure (mostly small, medium and large pipes or “sewers”) is built on or under ground at lower levels than your house. This is often along streams, rivers and the coast line.

    Predicted sea level rises will make the difficult job of building and maintaining the sewerage system even harder. There is speculation about the timing, extent and nature of sea level rise, but the most authoritative predictions are between 15 and 80cm by the end of the century.

    Sea level rises, associated tidal events and storm surges may enter the sewerage system along coasts and estuaries. Australia’s coastal developments are getting bigger and bigger, which means increasing amounts of wastewater. This is accelerating the scale of the problem and cost of the solution.

    Sydney Water has assessed exposure of its drainage and sewerage system and identified the lowest lying assets, many of them very close to sea level. Sydney’s situation holds true for many sewage treatment and water treatment plants in Australia. Relocation of such facilities may be of enormous cost.

    What are the risks of climate change effects?

    Rising sea levels could cause water to flow back into the sewerage system and stop wastewater flowing out. This could lead to “overflows” of untreated sewage getting into our waterways or other locations of public health risk. Saline sea-water may corrode the infrastructure – such as pipes, steel reinforcing, and electrical pumping and control equipment – not designed to deal with it.

    Extreme weather events may cause dramatic damage to systems. In the US, Cyclone Sandy created enormous sewage pollution from storm surges and coastal flooding. The system was swamped and damage was caused to sewers, pumps and treatment plants. The cost of repairs to New York’s sewage treatment plants is estimated at US$2 Billion.

    Other US cities have recognised their vulnerability. Three major sewage treatment plants in Florida, due to their very low elevation, may be engulfed by rising sea levels in five decades according to a recent investigation.

    In 1998 Australia got a stark reminder that untreated sewage wastes and estuarine waters can have devastating effects on human health. A period of wet weather and high holiday populations caused sewage contamination of oysters in Wallis Lakes in NSW. This caused an outbreak of 467 cases of hepatitis A through the rich oyster leases in this coastal estuary. Much of the sewage system in the area relied on on-site sewage disposal or boats that discharged untreated sewage waste.

    Are there solutions?

    Identifying the key sewerage infrastructure that is at risk of damage from sea level rise and tidal or storm surge events is very important.

    As sections of the sewerage infrastructure approach the end of their design life they can be rebuilt at higher elevations or relocated further from exposed coastal locations, if this is possible. Corrosion from salt water intrusion may accelerate the need to replace damaged assets.

    We also need urban planning to consider the difficulties of low altitude coastal developments. These have been constructed with impressive ocean views in mind, but without a thought for the sewerage engineers who have to get the wastewater away in an efficient and safe manner.

    I have seen hundreds of locations where the sewerage system blocks or malfunctions and the resulting impact is unpleasant and unhealthy for people and the natural environment. On a very large scale, the situation can be disastrous.