DCC: Natural Hazards

Abbotsford landslide 1979 (GNS Science, Dunedin) via ORCMass movement (landslide) hazard, Abbotsford 1979 (GNS Science, Dunedin)

Dunedin City Council – Media Release
Natural Hazards Approach Being Revised

This item was published on 10 Apr 2015

The Dunedin City Council is responding to community concerns and revising its planned approach to managing natural hazards such as landslides, flooding and sea level rise.

Following public feedback from consultation carried out from June to September last year, the planned approach now has greater provision for flexible case-by-case assessment. This would apply where the level of risk is more uncertain or variable. In areas where risk is lower, there would also be opportunities to manage risk through measures such as minimum floor levels.

A technical assessment of the risks posed by natural hazards was prepared by the Otago Regional Council. DCC staff used this to develop a proposed approach for managing land use and development in at-risk areas. This approach, or preferred option, sees natural hazards managed through a set of hazard overlay zones.

Rules attached to the hazard overlays set out what activities and development would be permitted, the standards for some types of development and what may be assessed on a case-by-case basis through resource consent. Under the original proposal, approximately 8600 of Dunedin’s about 46,600 houses in residential zones were affected in one way or another by the proposed overlay zones.

DCC City Development Policy Planner Sally Dicey says the preferred option is still to manage natural hazards through hazard overlay zones. However, following submissions from 184 individuals and organisations, a peer review of a flood risk assessment and discussions with experts in the natural hazards and risk management fields, a revised approach is being developed.

Feedback highlighted the difficulties in limiting development where there was uncertainty around assessments of natural hazard risk, due to limited data, variations in and changes to topography, and site specific factors.

“Allowing for more case-by-case assessment provides greater opportunities to take site specific factors into account. Where the risk from a natural hazard is lower, mitigation measures will be required. These are likely to include higher floor levels for houses or requiring homes to be relocatable.”
–Sally Dicey, City Development Policy Planner

Developed areas within dune systems have been removed from what was originally proposed to be the extreme hazard overlay. This is because there is a lack of information about how erosion might occur over the next 100 years along our coastline. These areas are likely to be the subject of future studies and may be included in mapped hazard areas in the future. A strict management approach has been limited to areas where there is a high degree of certainty about the risk from natural hazards. Prohibited areas are no longer proposed.

“This is a sensible and practical response to balancing the known risks we all face and the concerns of the community. Staff should be congratulated both for the thorough way they have researched and prepared these documents and for responding in this way to the matters raised at public meetings and in submissions.”
–Cr David Benson-Pope, Planning and Regulatory Committee

Ms Dicey says it’s important to remember the proposed changes mainly affect new development. In general, existing activities will carry on as usual.

Hazard overlay zones are proposed for floodplains, low-lying coastal communities and hills prone to landslides. This includes areas such as Brighton, Karitane, Macandrew Bay, Waikouaiti, Waitati and parts of the Taieri Plain.

The Dunedin City Council is preparing a new District Plan, the second generation District Plan (2GP). The ultimate goal of the Plan is the sustainable management of Dunedin’s natural and physical resources. Under the Resource Management Act, the DCC is responsible for managing land use to avoid or mitigate the effects of natural hazards. The DCC is also required to consider the effects of climate change and keep a record of natural hazards. The District Plan is scheduled to be publicly notified in September. The revised approach to natural hazards will be released as part of that consultation process. That will give people an opportunity to raise any remaining issues or concerns on the revised approach.

█ A report summarising the feedback received last year on the preferred approach to natural hazards is available at http://www.dunedin.govt.nz/2gp

Contact Sally Dicey, Policy Planner on 03 477 4000. DCC Link

Related Post and Comments:
10.12.13 ORC restructures directorates
30.7.12 ORC on hazard risks and land use controls
24.8.09 1. STS response – appeal. 2. Coastal protection – comments

Posted by Elizabeth Kerr

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14 Comments

Filed under #eqnz, Architecture, Business, Construction, DCC, Design, Economics, Geography, New Zealand, ORC, People, Politics, Project management, Property, Site, Town planning, Urban design, What stadium

14 responses to “DCC: Natural Hazards

  1. Elizabeth

    ### ODT Online Fri, 8 May 2015
    Up to 700 properties vulnerable
    By Chris Morris
    Up to 700 properties could be threatened if a major tsunami heads towards Dunedin’s coast. But, with up to 13 hours’ warning expected, Civil Defence staff have a plan that could have emergency services going door-to-door to move people out of harm’s way. Civil Defence emergency management officer Glenn Mitchell, of Dunedin, said one of the main tsunami threats facing the city came from faultlines off the west coast of South America.
    Read more

    ****

    Dunedin offers “subscription-based alerts through social media … the primary response to a tsunami threat in Dunedin continued to centre on disseminating information through print, online and broadcast media”.

    ### ODT Online Fri, 8 May 2015
    ‘Comprehensive’ warning plan for Dunedin
    By Chris Morris
    Dunedin is as ready as it can be to respond to the threat of an approaching tsunami, despite calls for greater use of technology to warn those in its path, Civil Defence authorities say. The assurance came from Civil Defence emergency management officer Glenn Mitchell, of Dunedin, as councils north and south of the city ramped up their own disaster response preparations.
    Read more

  2. Calvin Oaten

    I’ll wager Glenn Mitchell has shares in a substantial ‘worry beads’ manufacturing business. Otherwise he is talking up his job value hoping for a salary increase.

  3. Cars

    I’m shifting to Wanaka, caught between a tsunami and earthquakes.

    Chicken Little

  4. Cars

    Elizabeth, scaremongering has always been a tactic to control the masses. There was a Tsunami in the early 1900s and perhaps that in a strange way explains why Dunedinites preferred to live in Maori Hill rather than closer to the beach, and that seaside properties until the 1980s had no premium value built in. Auckland has 9 volcanoes, Wellington sits in area that could be best described as serial Russian roulette, Christchurch has had six or more significant earthquakes in its history.

    Will fear of some natural catastrophe cause all these areas to be abandoned? Can the DCC or any body mitigate the potential of any of these possible but rare natural and random events in our domain?

    The answer is no they cannot, because they do not know when or where.

    Far better they stick to their knitting. Fix the roads, repair the water supply system. Find a way to treat the sewage so that it does not poison the seabed, and get rid of the oversupply of traffic lights.

    Will they stick to their knitting?

    We all now know the futility of expecting that reasoned outcome.

  5. Richard

    Sea level rise is not a ruse to scare the masses. I will admit that i think there are plenty of those around, but a rapidly melting Greenland and the possibility of significant calving of glaciers leading to land ice melt in Antarctica is going to result in sea level rise anywhere between the conservative estimates of the IPCC and more radical projections of 6 metres or more no matter what the masses think of human invented anthropomorphic deities. In fact it has already risen quite significantly in Baltimore (a combination of sea rise and gulf stream movement) and Louisiana and Florida are losing land too. I wouldn’t be buying a house on the sea or in South Dunedin (some of which is below sea level I believe).

    • @Richard
      I would’t get too concerned about this matter. There has been a lot of scare tactics spread about regarding this matter. Nils Axel Morner is an acknowledged expert in this field and has conducted many observations throughout the world. OBSERVATIONS.
      This brief abstract ought to provide you with some relief from your anxiety.

      May 26, 2015 at 7:16 pm SEA LEVEL CHANGES PAST RECORDS AND FUTURE EXPECTATIONS
      by Nils-Axel Mörner

      ABSTRACT

      The history and development of our understanding of sea level changes is reviewed. Sea level research is multi-faceted and calls for integrated studies of a large number of parameters. Well established records indicate a post-LIA (Little Ice Age) (1850–1950) sea level rise of 11 cm. During the same period of time, the Earth’s rate of rotation experienced a slowing down (deceleration) equivalent to a sea level rise of about 10 cm. Sea level changes during the last 40-50 years are subjected to major controversies. The methodology applied and the views claimed by the IPCC are challenged. For the last 40-50 years strong observational facts indicate virtually stable sea level conditions. The Earth’s rate of rotation records a mean acceleration from 1972 to 2012, contradicting all claims of a rapid global sea level rise, and instead suggests stable, to slightly falling, sea levels. Best estimates for future sea level changes up to the year 2100 are in the range of +5 cm ±15 cm.

  6. Richard

    Douglas, you’re looking at a far too small a time-frame. Petroleum companies would go bust if they had geologists with such a small time-period focus.

    As you probably realize sea level has been about 70 metres higher (than now) in the past and up to about a 100 metres lower (than now) in the past (during ice ages when the water of the world gets held in ice in the higher latitudes). It was relatively stable for the last 10,000 years (which includes the 150 years you mention) but no longer is. There is a strong correlation between carbon in the atmosphere and air temperature and sea level. Past sea levels 10s of metres higher than now have been in atmosphere’s containing 280 ppm (parts per million). We’re currently at 400 ppm. Larger sea rise is coming, in fact it has already started. The only questions now are how fast and how much. They’re both questions that are strongly related to how long a changing warming climate can be denied. Deny for too long and the consequences will be grave.

    • JimmyJones

      Yes, Richard, the sky is falling. I guess that you are expecting floods, drought and pestilence in the near future. It looks like some of your facts are wrong:
      You say: “[sea-level] was relatively stable for the last 10,000 years but no longer is” – sea-level was increasing quite rapidly at the end of the last ice age and the rate of increase has been slowing ever since then (now about 1.6mm per year globally, 1.3mm in Dunedin). There is also no recent acceleration in sea-level rise and so no sign of any human influence on sea-level.
      You say that “There is a strong correlation between carbon in the atmosphere and air temperature and sea level”: The correlation between atmospheric carbon dioxide and temperature is only a positive correlation if you ignore the periods when it was a negative correlation or if you ignore the last 17 years of zero correlation. If there is a correlation, then it is so small that it is not discernible compared to the of natural climate influences.
      What do you mean by this? “Larger sea rise is coming, in fact it has already started”. At a rate of 1.3mm per year it will take 384 years for Dunedin’s sea-level to rise by 500mm. So no need to panic. In the last 17 years, which “changing warming climate” are you concerned about?

  7. Elizabeth

    Just to note. Please don’t bore the What if? readership with climate change to and fro. Look what happens at ODT Online – it dies every time the wrangle proceeds, the online editors repeatedly close the threads. Luckily, anyone reading this will be LONG DEAD before ‘it’ if ‘anything’ happens. Dust to frigging dust and a JM tear, for what, new life?

    Site Admin.

  8. Elizabeth

    Mick Strack questions whether there actually is security in property.

    ###ODT Online Mon, 6 Jul 2015
    Time to avoid hazardous areas
    By Mick Strack
    OPINION Home ownership has long been an aspiration for New Zealanders. It was, after all, one of the primary motivating factors of colonial settlers travelling from Europe to this land of new opportunities. […] Private property needs to be viewed from a broad perspective that recognises both the impermanence of some land and the huge social benefits associated with secure home ownership.
    Read more

    ● Dr Mick Strack is a senior lecturer in the University of Otago School of Surveying.

  9. Gurglars

    I’ve got a question for Dr Strack.

    Just how far should one move from the coast?

    Limestone at Fairlie, Kurow and similar inland towns suggest that movers would be smart to invest in a government sponsored horse and cart or bicycle, pack up and get a gypsy-like existence ever moving west, but horror of horrors, the west coast is only 200-odd km away and moving east!

    Perhaps we all move tomorrow to Treble Cone. That should be safe for a couple of weeks.

    Great to see that Chicken Little is alive and well and got a job at Otago U.
    (And coincidentally a house in Maori Hill)

  10. Richard

    Yes well Maori Hill is probably on average about 80-100 metres above sea level so it would seem to be a wise investment, only the complete melt of Antarctica (which has happened in the past) would possibly threaten his investment. For yourself Fairlie and Kurow are quite safe from sea level rise, but I’m not sure that it would be safe for a climate denier to buy there once the proverbial ‘shit starts to hit the fan’. They’re full of the masses so disdainly referred to above by one of your comrades (ooh aye) who may be a little ropeable by that stage. As for Treble Cone, well the lack of snow cover if we keep pumping carbon into the atmosphere at current rates might not go down well with a few. Good luck searching for a suitable place!

    • Gurglars

      Richard, I am far from a climate denier. I am a great believer in climate and weather. I’m however very cynical about the moves by the United Nations, nations and particularly town councils’ efforts
      A. To tax it
      B. To believe megalomaniacally that you and all the rest of the 10 billion human beings can change fluctuations that have been going on for above 50 million years.