Saturday, March 8, 2014

Land Had "Very High Natural Values"

Land had 'very high natural values'
By Mark Price, on Saturday 8 March 2014
Otago Daily Times

 Thirty years ago, the Labour government of the day sent groups of scientists off on a mission. They were asked to find the parts of the landscape that still reflected the way New Zealand was before people began making changes. One of the Recommended Areas for Protection (RAPs) they came up with was a 590ha area of land above the Clutha River at South Hawea Flat, near Wanaka. Last month that RAP went under the plough. Mark Price reports.

On the road between Luggate and Hawea Flat  your eye is drawn west to the majestic snow-capped mountains of Mt Aspiring National Park.

The flat land in the foreground barely registers.

But this land - 590ha of half-cultivated dry grass and tussock along Kane Rd - has suddenly become a battleground between conservationists and farmers.

Two months ago, a digger began dragging kanuka, scrub and the odd pine tree into heaps.

Two weeks ago, a tractor towing a chunky set of discs started turning over the topsoil.

By the time the Royal Forest and Bird Protection Society obtained an Environment Court enforcement order on Monday, the agricultural contractor had already left the field.

However, the order means the farmer cannot seed, water or fertilise the land until the matter has been settled in court.

Conservationists know the land in question as South Hawea Flat, Lindis RAP (A12) - RAP standing for Recommended Area for Protection.

Correspondence between Forest and Bird and the Queenstown Lakes District Council over the farmer's cultivation has focused on the rarity of the land's native plants.

But the man who helped establish Lindis RAP (A12) and other RAPs in the Upper Clutha emphasises there is more to the issue.

Now retired from the Department of Conservation and living in Gisborne, Dr Chris Ward told the Otago Daily Times last week Lindis RAP (A12) was recommended for protection 30 years ago because it represented a landscape that was in danger of disappearing entirely.

''The essence of the value of places like this is not simply the rare species.

''It's actually about having the whole system of the landform and the ecological and geological history of the land and the soils and the vegetation that goes with the whole system.

''It reflects a large proportion of the character of the Upper Clutha.''

Dr Ward said when they started looking for places still in their native state, they already had ''very little to start with''.

''The whole context was to identify the best of what remained and then seek its protection rather than see everything degraded to minuscule remnants. These areas - whatever their degree of modification - they still had very high natural values.''

Dr Ward said Lindis RAP (A12) combined the high terrace of Hawea Flat and the drop-off to a set of low terraces leading to the Clutha River.

''The whole point of it was that it was very much undeveloped in the pastoral sense and had large amounts of its indigenous character - though obviously highly modified through grazing and fire.''

The report he helped produce noted the area's ''excellent terrace sequence''.

''The total extent of the RAP, although considerable, is little more than 1% of the original extent of terrace landforms dominated by fescue tussockland and shrubland in the Upper Clutha, and barely sufficient to give an adequate visual impression of the earlier landscape.''

While its vegetation had been ''strongly modified'' by grazing and fire, the report described what remained as ''substantially native communities''.

The report suggested the reasons the land had not been developed further were because the soils were ''among the poorest of the flatlands'' and irrigation water was relatively inaccessible.

Reflecting on the many RAPs he helped identify in the 1980s, Dr Ward said there had been ''more grief than satisfaction'' over how they had fared.

While some had been formally protected, many had not.

''It's the old problem that every success in conservation is temporary and every loss is permanent.''

''When an area is protected, or a decision is made not to destroy something, it can be seen as a victory or a gain for conservation. But it's always temporary because these things can be reversed.

Dr Ward said the cultivation of Lindis RAP (A12) was another of the losses in a world system with a bias against conservation.

''What's left of the natural scheme of things is always being whittled away, and every generation seems to take another chunk of it.

''I'm sure there will be people who will say there was an awful lot of this [Upper Clutha land]. But if every generation takes 60% of what's remaining and leaves 40%, thinking that's being generous, then that becomes two-thirds of five-eighths of [not much].''

Revealing his geological background, Dr Ward said a ''key part'' of the value of an area like Lindis RAP (A12) was its soil.

''The discs turning over the soil have already done irreversible damage. You can't undo that.

''The actual soil profile ... is a reflection of the geological and human history up until now.

''Getting to the guts of natural character is recognising that an undisturbed soil is a key part.''

RAPs were a product of the Protected Natural Areas Programme (PNAP) that began in 1983.

The programme was intended to protect native landscape features and provide the government with a basis for negotiation with landowners about formal protection.

It was controversial at the time, with some landowners refusing survey parties access, believing they could lose the parts of their properties identified as RAPs.

Philip Woollaston, associate minister for the environment (1987-88) and minister of conservation (1989-90) told the ODT the surveying ''tapered off'' after the 1980s, for economic reasons.

''It was never formally abandoned but just withered on the branch because of cost-cutting.''
Some RAPs got protection via the tenure review process, and by other means, but Lindis RAP (A12) was not one of those.

A report done for the QLDC in February last year by ecologist Rebecca Lawrence did, however, recommend part of the RAP be ''taken forward'' for further consideration as ''significant indigenous vegetation and fauna habitat''.

That would put Lindis RAP (A12) in the district plan and would require the landowner to gain resource consent before carrying out the type of work that has now been done.


Protected areas Recommended Areas of Protection (RAPs):
The land known as South Hawea Flat, Lindis RAP (A12) is one of 19 RAPs in section 4 of a 1980s document called the Lindis, Pisa and Dunstan Ecological Districts Survey Report for Protected Natural Areas.

The others are:
Double Peak, Chain Hills, Dip Creek (two), Morven Hills, Grandview Creek, Hospital Creek, Lagoon Creek, East Camp Creek, West Camp Creek, Long Gully, Long Gully Terrace, Upper Smiths Creek, North Lindis Pass, Mid Breast Creek, Grandview Tops, West Chain Hills, Lindis Crossing.
The report also lists RAPs in the Pisa and Dunstan areas.

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Clyde Dam Highly Problematic

Since the filling of the Dunstan reservoir behind the Clyde dam was completed in 1993, the Clyde dam controversy has faded in the minds of most New Zealanders. But the woes of the last 'think big' project have not gone away. Despite extensive and costly mitigation measures, issues remain regarding gorge instability, faultlines, and reservoir sediment build-up.

The Cairmuir-Dunstan Fault cuts across the gorge just above the dam, and the River Channel Fault disects the dam and the powerhouse. The discovery of the River Channel Fault came as a surprise to dam workers, who uncovered the micro-fractured rock running in a wide band along the riverbed. Obviously, fissured rock is not suitable for dam foundations. The first solution was to pump vast amounts of slurry concrete into the fault, but concerns mounted over the extent and depth of the faultline, and the likely futility of 'dental' concrete.

Finally, experts were called in to determine the extent of the fault issue. It was calculated that the River Channel Fault was 12-15km deep. This lead to a dam re-design in 1982 (during which a sluice channel was omitted leading to later modifications that reduced the dam's MW output by one-third). Subsequent investigations carried out by a team of some 40 geologists revealed serious instability issues throughout the gorge. The result was an incredibly expensive gorge stabilization programme, costing $936 million dollars (2005 value), resulting in the total cost of the project blowing-out to $1.4-1.8 billion dollars. The exact cost is unavailable or unknown, suggesting the true cost could be even higher.

There was considerable doubt over whether or not the dam would be safe, but in the end the government of the day, under Prime Minister Robert Muldoon, refused to admit that the project had been botched, and it was finished, complete with a controversial 'slip-joint' to accommodate earthquakes up to, supposedly, 7 on the Richter Scale.

The 'slip-joint' was hailed as an engineering achievement, but one of New Zealand's most respected geo-technical scientists at the time, Gerald Lensen, insisted that it was designed incorrectly, because the River Channel Fault is 'tensional' (pulling apart) and not 'lateral' (slipping sideways). Needless to say, this fact has been kept quiet ever since.

Now, according to GNS scientists, the 'big one' is overdue along the Alpine Fault (bigger than the 7.8 Fiordland quake in July 2009). Meantime, the 6,500 measuring and monitoring stations quietly observe the landslide movements, reduced but not stopped, and visible silting up continues in the Kawarau Arm at an alarming rate estimated to be 1.46 million cubic metres per year, building up the reservoir bed profile by an estimated 1.85m annually.

The Decline of Large Hydro

In the 21st century, energy that is "renewable" is defined as energy from a source that is both naturally replenishing and environmentally safe and sustainable. The term “new” renewable energy has also been used to define the latest wave of renewable technologies that are truly environmentally sustainable.

By such standards, hydropower over 10 MW is no longer considered renewable because the negative impacts of large hydropower outweigh the so-called renewable benefits, which have inherent limitations.

In New Zealand, we are told that to maintain our present society and standard of living we need a minimum increase in power availability of 2.5% per annum (peak power), with 170 MW of new generation added each year. Based on this figure, we would need the equivalent of one Luggate dam (86 MW) every 6 months, or one Tuapeka dam (350 MW) every 25 months, or another Clyde dam (432 MW) every 29 months. Clearly, this is not a credible long-term solution.

World-wide, large hydropower declined in the 1990s because of mounting opposition that culminated in the World Commission on Dams report (2000), which acknowledged that large dams do not meet best practice guidelines in the water and energy sector. The global recession spurred more large dam projects, especially in developing countries, but the tide has turned and large hydro is again in decline as new renewable technologies sweep the world.

The intrinsic problems associated with large dams have long been glossed over. Hydroelectricity is often falsely promoted as cheap and reliable. While the operating costs of hydroelectric dams can be relatively low, their construction costs are extremely high, running into the billions of dollars for major projects. They are also prone to cost overruns. The WCD (World Commission on Dams, 2000) found that on average dams cost 56% more than forecast. And 55% of the hydroelectric projects studied by the WCD generated less power than planners promised.

New Zealand's Clyde dam is an obvious example of disastrous cost overruns. According to the public record, the 1982 winning bid from the joint venture of W. Williamson & Co. of Christchurch and Ed. Zublin AG of Stuttgart, was $102.6 million. Ten years later when the dam began producing power, the cost had climbed to $1.4 – 1.8 billion. Conversely, the planned generation of 612 MW had fallen to an actual capacity of 432 MW.

Typically, construction and mitigation costs are under-estimated, long-term costs are ignored, the value of the proposed dam and mitigation measures are inflated, while the value of the current and potential benefits from the existing environment are under-reported.

The proponents of large dams also invariably claim that large hydropower is "green" energy. However, the carbon footprint of a large-scale hydro project is anything but "green". A comparative study at the University of Auckland found that large hydro has a full-life carbon footprint that is 2.5 times larger than that of tidal energy.

A similar comparative study in the U.K. found that in terms of grams of CO2 equivalent per kWh of electricity generated, large hydro in the U.K. comes in with a carbon footprint 2 to 6 times larger than that of wind power. Specifically, large hydro has been measured at 10-30gCO2eq/kWh while wind has been measured at only 4.64gCO2eq/kWh, the lowest except for nuclear (Carbon Footprint of Electricity Generation, 2006).

It is easy to understand why large dams rate so poorly. For example, the Clyde dam contains 1 million cubic metres of concrete, equivalent to about 3 million tonnes. Manufacturing one tonne of cement requires 4.7 million BTU’s of energy, which is the amount contained in about 170 litres of oil or 190 kilograms of coal. Obviously, this combined with emissions from machinery involved in earthworks for foundations, roading, terrain forming, landslide mitigation, and through the loss of river corridor carbon sink forests or vegetation, adds up to an enormous carbon footprint.

There are over 54,000 large dams in the world, some 5,000 of which are over 50 years old. The typical design-life of such dams is 80 years, and an increasing number of old dams are being classified as high risk. It is a telling fact that more dams are being decommissioned than built in the U.S., but dam owners typically avoid decommissioning issues and try to evade the considerable costs associated with dam removal and river restoration. This scenario points to a looming dam safety crisis.

In the past, the benefits of large dams were viewed as outweighing their obvious short and long-term environmental impacts. That has changed.

Large hydropower once represented the epitome of 20th Century technology and a passport to prosperity, projecting a misguided belief that Nature could be controlled without consequences. In the 21st Century, we face a new reality, for which 20th Century energy solutions are unacceptable.

Roxburgh Dam Decommissioning?

The Roxburgh dam was commissioned in 1956, and it is New Zealand's oldest concrete gravity dam. Such dams have a design lifespan of 80-100 years, but the actual lifespan of a dam depends on the rate at which its reservoir fills with sediment. Assessing the remaining life of a dam and reservoir is complex, but reservoir flooding events indicate that time is running out.

When other issues are added to the picture, questions must be asked.

The Roxburgh dam - like the Clyde dam, has faultine and landslide issues that are potentially catastrophic (something which has been kept quiet). However, when the Roxburgh dam was built, there was minimal geotechnical investigation and mitigation undertaken, despite obvious evidence of major landslides in the Roxburgh Gorge, notably at Island Basin.

But reservoir sedimentation is the most problematic issue. In fact, within 15 years of the dam's commissioning, the dam's two low level sluice gates were inoperable, and since then the silt burden has filled much of the Roxburgh reservoir reaching back to Alexandra. In 1995, ECNZ estimated that 1.5 million cubic metres of silt had entered the Roxburgh reservoir every year before the Clyde dam was built, and that a total 50 million cubic metres of silt had accumulated in the reservoir, raising the bed profile 'considerably'. Attempts to 'flush' the silt have had little effect, and have not reversed this process. This is probably because of the 'Gates of the Gorge,' a narrow bottleneck just below Alexandra.

As a result, Alexandra has become flood-prone, and has installed flood defence walls along the river. But even these will not be high enough to prevent future flooding, because the riverbed will gradually keep rising. It was thought that by building the Clyde dam that this sedimentation problem would be largely solved, but some silt still gets through to continue choking the reservoir and river, and the Manuherikia River still contributes silt when it is high.

Efforts continue to "buy time" for the Roxburgh dam. More "flushing" will only move some of the sediment load further toward the dam. (Flushing has failed to remove sediment wherever it has been tried, including on the Colorado.) Physically removing millions of cubic metres of sediment is not practicable because of the costs involved. An interim measure is to remove some sediment from the Manuherikia confluence, and also from the Galloway area, but this does not address the major constriction at the 'Gates of the Gorge.'

The most desperate strategy is to raise the operating level of the Roxburgh reservoir, and this was done in 2009 when a rise of .6m was consented. While this allows water to reach the dam more easily, it also increases the risks associated with flooding events, both at Alexandra and the dam. In the life cycle of a dam, this is the "Russian roulette phase."

The dam owners and the Crown must face up to the fact that the Roxburgh dam and reservoir will not last forever, and that enormous risks are imposed on communities in the meantime. A feasibility study is needed to determine the most effective decommissioning and de-silting methodology. Where such dam removal projects have been undertaken overseas, the costs as a proportion of construction, range from 35% to 150%.

However, since there has been no provision for the ultimate decommissioning of the Roxburgh dam (typical of the hydropower industry), there is something of a head-in-the-sediment policy on this issue.

Questions should be asked, including the most difficult question of all ... when the time comes to decommission the dam, who will pay?
© Clutha River Guardian 2009-2015