Some coastal suburbs in doubt


Concerns have been raised about the future of two coastal suburbs in Christchurch. Southshore and South New Brighton suffered heavily in the earthquakes of 2010 and 2011. But their recovery is being hampered by the sunken land that both sit on and its increased vulnerability to storms.

Perhaps the primary source of concern is how these communities will cope with rising sea levels, and increasingly volatile weather systems. New Brighton and South Shore have never been very high above sea level and occupy a narrow spit less than a kilometre wide, which has sand dunes on the coastal side and an estuarine environment on the other. And in recent years their vulnerability to the effects of flooding from storm surge have been shown.

Earthquakes are a second cause of concern. As a result of ground motion particularly on 04 September 2010 and 22 February 2011, land around the Avon-Heathcote estuary, the lower reaches of both rivers and the Brighton Spit slumped in some cases by up to 50 centimetres. Since then flooding can happen with brief rain or a large tide.

But there is a wider problem. Christchurch is not the only part of New Zealand with low lying housing. Coastal bays in Wellington, estuarine parts of Auckland and low lying land that might be protected by sea walls or sand dunes, but be at or close to sea level is also at risk. Good examples of the potential damage can be found in the winter storms of June 2013, and more recently Cyclones Fehi and Gita, which caused widespread storm damage along the West Coast and around Nelson

Whilst there are provisions in the Resource Management Act and statutory planning tools such as the Regional Coastal Policy Statements, councils have to trade off between environmental pressures and developmental pressures.

The last two years in New Zealand have been particularly stormy. During the summer of 2016-17, the Southern Oscillation Index was neutral, meaning weather came from all corners of the compass. For example a weather bomb – a rapidly deepening system of short duration, but quite intense in terms of rain and wind – passed over in January, dropping 300mm of rain in Arthurs Pass in a day in mid-January 2017. In June and July 2017 big southerly storms lashed Canterbury and large parts of the South Island’s east coast causing widespread flooding, and extensive coastal erosion. In February 2018, as mentioned earlier, two tropical cyclones passed over New Zealand just three weeks apart.

All of these storms caused millions of dollars in damage. In the case of Cyclones Fehi and Gita, they raised concerns about how coastal communities in less densely populated regions might fare in the long term. A low population region such as the West Coast does not have the financial resources to draw on from its ratepayer base that a region such as Canterbury or Auckland have. This makes coastal measures expensive, but have to be weighed up against moving and disrupting communities.

Even if the world went carbon neutral today, so much has been ejected that it would take several years or even decades for the effects of going carbon neutral to begin to be recognized. Even the 2ºC rise in temperature is limited to strictly that – some are saying even limiting global temperatures to a 1.5ºC rise might be too little too late – the subsequently increased volatility of our climate, going from intense droughts to severe rainstorm events; extreme cold to extreme heat would not be stoppable in our lifetime.

Another planning concern is the amount of sediment reaching the coast. Some parts of the world have a shortage of sand. This can at least in part be traced to rivers, which are the natural means of transport for sediment from the mountains to the sea, being dammed extensively. This thereby traps the sediment and little or no provision gets made for the need of long shore drift, which works the sediment along the coast enabling the replenishing of sand beaches after big storms. A failure to restore the balance somewhat would mean that coastal regions that are vulnerable would be more and more exposed to the sea, meaning properties would have to be abandoned.

Moving forward, one has to wonder what sort of future other coastal communities face. Maybe planners have a solution, but for the time being, councils and insurers alike are being faced with hard questions that no one really knows the answer to. And time might not be on their side.

Time for coastal planners to take climate change seriously


For the people trying to get away from Ex-Tropical Cyclone Fehi’s storm surge, it was all too real. For the people in small coastal towns along the West Coast watching the angry seas smashing what in some cases were the only roads in and out of their townships, the thoughts of being cut off must have been nerve wracking. As communities clean up and look to the future, it is time to ask just how good are the contingency plans for future storms, and whether planners have made adequate provision for such events.

Given that high intensity but relatively short duration storm events seem to be becoming a regular occurrence, how well prepared are we for the effects of climate change on the marine environment including how oceans contribute to storms? In January 2017, we had a “weather bomb” of highly damaging winds and substantial heavy rain in the Southern Alps; Cyclone Debbie, which caused widespread flooding in the Bay of Plenty; Cyclone Cook, which tracked quite quickly past New Zealand, without directly crossing the country. There was also several significant winter storms.

There were a number of facets of ex-Tropical Cyclone Fehi that I found concerning as someone who has studied natural hazards:

  1. Granted it was only a Category 1 Tropical Cyclone, Fehi’s relatively rapid evolution from a tropical depression in the Coral Sea to a
  2. Despite having lost its status as a Tropical Cyclone, the remnants of Fehi still managed to kick up 150km/h winds. It still managed to drop over 200mm of rain in a day and in some cases up to nearly 300mm
  3. The storm surge – granted it was exacerbated by king tides caused by a rare blue super moon – was punishing in many small settlements such as Ngakawau, Granity and Hector on the West Coast, north of Westport

It is true that councils have started planning for climate change on the coastal environment and the elevated risk posed by storms. Some communities are having to turn to their ratepayer base for more money to help fund expensive coastal works, such as sea walls and helping maintain existing natural features such as sand dunes.

Over the last 20 or so years I have been watching the tidal gauge charts at Lyttelton that have been appearing in The Press. 20 years ago, the lower end of the range was 0.1m and the top end of the range seemed to be consistently around 2.5 metres on king tides. Outside of that, the range could be as small as 0.5m-2.0m. Today in 2018, the range seems to be between 0.1m-2.7m. I am not necessarily suggesting this is due to changes in sea level – it could simply be that the tidal gauges today are better calibrated to detect more minute changes, and thus 0.1m-2.7m +/- all along.

This is important to know because hazard planners plan for the worst case scenario – and hope that reality is something a bit less severe. The worst case scenario would presumably be a storm – not necessarily a tropical cyclone, as a deep low pressure system with its origins in the Southern Ocean can cause much damage – with a surge, coinciding with king tides. Such a storm happened last week.

Moving forward, the damage caused by Fehi, aside from causing insurance companies and Civil Defence much grief, also kick up some serious planning issues. Are, for example, Regional Plans adequately tooled to deal with land zoning issues that may arise from coastal properties no longer being suitable for occupation? Does the New Zealand Coastal Policy Statement pay the due regard now needed to coastal hazards and climate change? And given Fehi could have been a stronger Cyclone, but mercifully was not, was what happened last week really a taste of the “worst case” scenario?

It is time to start asking and attempting to answer these questions.

 

The need for a Kermadec ocean sanctuary


I was disappointed to see in the Sunday Star Times today that New Zealand First have shown resistance to the idea of an ocean sanctuary. The comments in the Sunday Star Times, which allegedly caught the Green Party unawares, point to a potential hurdle in the future that the new Government will not be able to bypass.

New M.P. and former Labour M.P. Shane Jones, who is a potential cabinet member of the new Labour led minority Government, disclosed before the election that Sealord and Talleys were bankrolling his election campaign in Whangarei. Mr Jones who has extensive links to Iwi and backs customary fishing rights under the Treaty of Waitangi and fellow New Zealand First Members of Parliament have been described as close to the fishing industry.

Given the lack of regard shown for the marine environment around the world, there is a strong case for an ocean sanctuary around the Kermadec Islands. Which is why I was pleasantly surprised when the outgoing National Government in 2015 announced that New Zealand would commit to an ocean sanctuary covering the Kermadec Islands. It would not permit mining, oil extraction or fishing. The sanctuary would cover the oceans around islands such as Raoul and Curtiss Island.

This is also why I support the need for a blue water navy. Defence policy aside, New Zealand has a vast economic exclusion zone that is prone to being raided by illegals who have no legitimate business in New Zealand waters. The proposed ocean sanctuary covering the Kermadec Islands would not be exempt from the potential ravages of these raiders. A blue water navy with appropriate surveillance, backed by a strong judicial system would show raiders that if they conduct their illegal business in N.Z. waters, there will be a price to pay.

Despite the Green Party saying that they are confident that an appropriate outcome can be achieved, I have concerns about how any agreement will be passed into law, and whether it will be effective in protecting the marine ecosystem.

 

Ross Sea protection long overdue


It is not often that political news regarding the environment brings a grin to my face. However,  at the moment I am happy in the knowledge that a plan to make the Ross Sea a marine reserve is becoming reality, as a result of an agreement between New Zealand and the United States. After years of negotiations the 25 nations that control Antarctica’s fate, including New Zealand, have reached an agreement to turn a 1.6 million km² area into a marine reserve.

However many challenges still remain to be dealt with. The most important ones are:

  1. Enforcing the zone – will it be a joint operation by the nations that agreed to establish it, or will a few nations do most of the work?
  2. Will there be a clause that enables expansion of the reserve
  3. What happens to nations that are caught in breach of the marine reserve
  4. Is the range of marine life – both birds and mammals – that is to be granted protection diverse enough to ensure that the Ross Sea ecosystem is okay
  5. Correlating gas data with known marine currents to see how the Ross Sea ecosystem is performing

The negotiations have not always gone well. In past years, Russia and Ukraine have challenged the New Zealand/American initiative by refusing to support the reserve. Japan, a country well known for its whaling has often put up stubborn resistance to measures that would impede its ability to continue “whaling for scientific purposes”. China, whose vast and rapidly growing population have a huge ecological footprint, caused by decades of spectacular economic growth faces a challenge meeting near insatiable demand for fish.

It is perhaps also important for the U.S. to finish this agreement before the United States Presidential Election on 8 November – neither Donald Trump or Hillary Clinton have said anything about the sustainability of the worlds oceans. This is despite them being significant carbon sinks, whose whale population can take up 2 million tons and significant concern about the destructive effects of acidification.

But for now, let us celebrate the announcement of the Ross Sea Marine Reserve. It is a substantial victory for the seas and everything that live in them.

The problems with drilling for oil off Canterbury


The most recent attempt at offering a block off the Canterbury coast for drilling prospects, described as lunacy by the Deputy Mayor of Christchurch is not without its faults. And those faults are not just in the economic or environmental impact assessment of opening up the Kaikoura coast.

Anyone who did geology at a university or paid attention in high school geography will know that the South Island straddles the tectonic plate boundary between the Australian plate and the Pacific Plate. University level geology will also teach that four large faultlines running roughly parallel to each other, and aligned NE-SW enter the sea between Kaikoura and Picton. This is the transfer zone for seismic stress on the Alpine Fault, which is the tectonic plate boundary, as reflected in the high level of seismic activity experienced in this part of the country. The southern most is the Hope Fault which ruptured in 1888 in a magnitude 7.0-7.3 and ruptures every 120-140 years. The second is the Clarence Fault, which is not well known, but whose trace is visible from the air. A third is the Awatere Fault, which ruptured in 1848 in a magnitude 7.5 and felt across much of the country. The fourth is the Wairau Fault. All four are active faults.

Due to the proximity of these faults to the area that has been offered by the Government, a primary concern I have is that any drilling rig that does operate off the coast will have to be built to high standard of seismic engineering. If any product from the drilling rig is taken to a port, the onshore facilities will have a two fold hazard, because the Kaikoura coast is one of the most prone parts of the South Island coastline to tsunami with both near field and far field risks identified.

There are environmental risks that I am not convinced that the Government has taken into account, or plans to do so. The most obvious is an oil spill, either from the rig or ships or infrastructure associated with the rig. However low the risk of it actually happening might be, in a dynamic marine ecosystem, the consequences are substantial. Another is a fire caused by the loss of control of a bore that then goes rogue. Shutting down the bore would be just the start of the problem. Fighting the fire and stopping the contaminants from reaching the coast line. All of this requires a coast guard or other coastal agency with the means to respond in a timely and effective manner. The agencies exist, but how often they train for a spill and whether they have the equipment and personnel to respond is another question altogether.

The risks are also social. New Zealand is a nation that prides itself on being environmentally pure and ecologically responsible. Yes it is true that the world is not likely to be rid of the need for oil any time soon, and I am personally not opposed to drilling so much as I am that it gets done in a way that has community support. At this stage, there is no evidence to suggest any effort has been made to attain it. Kaikoura has an internationally acclaimed reputation for marine life and in particular whale watching, which draws in tens of millions of dollars per annum. Were there to be a spill or other disaster in which the marine environment is contaminated, the social cost – job losses and income aside – would be significant.

International companies want to come and invest in New Zealand. Exploration companies are no exception. I have no problem with them coming, as long as they are prepared to comply in full and without question with New Zealand environmental and occupational safety and health regulations. Not all of them are prepared to comply, as the United States found out when the well owned by a subsidiary of B.P. went rogue in 2010, so how will we know whether an exploration company will comply here?

I just hope the answer is not found out on the day we have a blue water emergency.