The Canterbury Nor’wester
In a windy land, the most notorious gale is the Canterbury nor’wester. Born in the heart of the mountains, it accelerates down the great valleys east of the Main Divide and roars out across the plains. Distinctive lenticular clouds, as seen here above the Ben Ohau Range, are regular companions of the wind.
I had spent my childhood growing up on a sheep run at the mouth of the Rakaia Gorge, and was paying a nostalgic return visit to the area 60 years later. Within the protective bubble of our modern car, we could hear the engine labouring and feel the buffeting of the wind outside as we toiled our way up the road to the Lake Coleridge power station in the face of an old-man nor’wester roaring down the gorge. The sky up ahead, above the headwaters of the Rakaia and Mathias Rivers, looked bleak, with clouds spilling heavily over the mountains and beginning to obliterate them in a screen of grey mist. In the wide riverbed below, columns of dust were swirling across the shingle, and the trees in the shelter belts were tossing violently and leaning heavily in the wind.
My mind kept re-running childhood memories of our old Ford truck rocking violently as it ground its way in second gear up this same road to Lake Coleridge village. I was forcibly reminded that as a child I had been told that the Rakaia Gorge was the windiest place in New Zealand, possibly in the world. Now the scepticism that had come with adulthood was being dented. Perhaps those childhood recollections hadn’t been exaggerated by the passage of time after all.
Without a doubt the seemingly ever-present nor’wester is one of the more abiding memories of the weather during my childhood. The constant singing of the telephone wires; hillsides alive with the endless movement of tussocks rippling in the wind; the relentless sighing of the pines that surrounded the homestead; the excitement of awaking to see the lawn littered with small branches snapped from the trees during the night. Powerful memories, and not without foundation.
How appropriate is the name Windwhistle, given to the tiny settlement where the wind sweeps from the gorge onto the Canterbury Plains. The place is still no more than a crossroads with a small shop (once McHugh’s blacksmith’s) and the little school where I began my education. Back then the school consisted of a single corrugated-iron-clad classroom in a rarely mown paddock, sheltered by a growing pine plantation. Now it has two classrooms and a neatly mown playing field much more snugly protected by mature plantings.
Doubtless there are many places in New Zealand where the locals would dispute the claim that the Rakaia Gorge is the windiest place in New Zealand, but nobody could dispute the distinctiveness of the nor’wester and the powerful effect it has on both environment and people.
Everyone who has lived in Canterbury will be familiar with the nor’west “arch” that regularly appears over the Southern Alps, signalling the imminent arrival of a weather system from the west. Streaky clouds stretch across the mountains, leaving a gap of clear, light sky against which the ranges are clearly outlined. High-country people know that the arch is the likely precursor of strong winds roaring down the long, wide valleys of the Waimakariri, Rakaia and Rangitata Rivers, and of heavy rain in their upper reaches. Cantabrians know that it is also the signal for the arrival of the infamous nor’wester on the plains—a strong, hot, dry wind that makes conditions unpleasant all the way to the coast.
Is the Rakaia the home of the old-man nor’wester, as I have been led to believe? Wind is funnelled down each of the big rivers, but the Waimakariri and Rangitata are obstructed by front ranges before they reach the plains. In contrast, the Rakaia Gorge acts as a mighty funnel for the nor’wester immediately before it hits the flat.
A typical nor’wester sequence begins most commonly in the spring, with the gradual appearance of cloud behind the main ranges of the Southern Alps. This may build up over a period of several days. Eventually the headwaters of the rivers on the eastern side become obscured by a dense mass of grey cloud, and rain squalls move quickly down the wide valleys of the Rakaia and its large tributaries, the Mathias and Wilberforce. Heavy rain falls in the mountains and is frequently borne down the valleys by increasingly strong winds as far as Mt Algidus Station, near where the Wilberforce meets the Rakaia.
By Lake Coleridge village the rain has generally ceased, and the wind, funnelled by the steep-sided Rakaia valley, has become a gale. As it sweeps across the wide shingle flats it whips up huge dust clouds, which at times almost obscure Mt Hutt, to the south of the river.
To the north, the wind builds up in a similar fashion down the Wilberforce. The steep-sided lump of Mt Oakden, near the head of Lake Coleridge, parts this wind, the southern flow augmenting that along the Rakaia. The northern blasts directly down the lake, churning up waves as much as a metre high. It continues on over the irregular moraine hills and terraces on the northern side of the Rakaia, into the High Peak valley, over the Malvern Hills and onto the Canterbury Plains.
The main thrust of the nor’wester reaches a climax near the Rakaia Gorge bridge, and is at full force as it bursts out onto the plains. In the most severe storms, peak gusts of 160 kph and sustained winds of around 115 kph have been recorded.
Not only is the nor’wester ferociously strong, it is also hot and extremely dry, and can last for as long as four or five days. Given its combination of destructive force, swirling dust and dry heat, it is no wonder it has a reputation for driving people crazy. It is claimed that during a prolonged nor’west cycle both the suicide rate and domestic violence increase.
Although nor’west conditions tend to peak in spring, they recur regularly throughout the summer. Eventually, however, the weather cycle moves on and is typically replaced by south-easterly winds, which bring cooler and, often, wetter conditions—sweet relief from the nor’wester’s merciless aggravation.
The writings of the earliest pioneers in Canterbury reveal the enormous impression the nor’wester made on them, and the problems it caused. The most vehement descriptions tend to come from explorers and settlers in the Rakaia Gorge area. Nobody has described the horrors of an old-man nor’wester more vividly than the inimitable Lady Barker who, for a few years, helped her husband establish a sheep run named Broomielaw—now known as Steventon—in the Malvern Hills. In Station Amusements in New Zealand she wrote:
For a week past, a furious north-westerly gale had been blowing down the gorges of the Rakaia and the Selwyn, as if it had come out of a funnel, and sweeping across the great shelterless plains with irresistible force. We had been close prisoners to the house all those days, dreading to open a door to go out for wood or water lest a terrific blast should rush in and whip the light shingle roof off.
The yellow tussocks were bending all one way, perfectly flat to the ground, and the shingle on the gravel walk outside rattled like hail against the low latticed windows. The uproar from the gale was indescribable, and the little fragile house swayed and shook as the furious gusts hurled themselves against it. Inside its shelter, the pictures were blowing out from the walls, until I expected them to be shaken off their hooks even in those walls which had plank walls lined with papered canvas; whilst in the kitchen, store room, etc. whose sides were made of cob, the dust blew in fine clouds from the pulverised walls, penetrating even the dairy, and settling half an inch thick on my precious cream. At last, when our skin felt like tightly-drawn parchment and our ears and eyes had long been filled with powdered earth, the wind dropped at sunset as suddenly as it had risen five days before.
This all sounds too bad to be true. Was Lady Barker exaggerating? I don’t think so. Many other settlers in the area were also well-educated people who kept diaries or wrote reminiscences. They all describe their experiences of the nor’wester in similar vein. One of the more graphic accounts was by “shagroon” Mark Stoddart—“shagroon” being how the rather superior Canterbury “Pilgrims,” who were the original immigrants from the Canterbury Association, referred to a squatter who came to Canterbury from Australia. Stoddart arrived in Christchurch in 1851 and explored the Rakaia valley that year as far as Lake Coleridge. He then took up 20,000 acres (8090 ha) of land, known as Terrace Downs, on the northern side of the Rakaia just downstream from Windwhistle and open to the full force of the nor’wester as it emerged from the Rakaia Gorge. In 1851 he recorded: This beautiful spot, however, has peculiar drawbacks of its own—the nor’-west winds, the curse of New Zealand, pour thro’ this embrasure of the mountains with a force which must be witnessed to be believed and converts the avenue-like bed of the river into the most howling scene of desolation—horsemen are blown out of the saddle, sheep drift before it miles upon miles, cultivation is uprooted and the soil carried bodily away.
Stoddart was himself so carried away by the wind that he was moved to write “The Shagroon’s Lament,” which includes the following stanzas:
Among the dreary mountains, far up above the gorge,
There lives a potent demon, ever working at his forge;
A worker at the winds is he, a flatulent old buffer,
And he sends his manufactures down that man and beast may suffer.
I’ve witnessed all the winds that blow, from Land’s End to Barbadoes—
Typhoons, pamperos, hurricanes eke terrible tornadoes.
All these but gentle zephyrs are, which pleasantly go by ye
To the howling, bellowing, horrid gusts which sweep down the Rakaia.
The little cloud now sailing down is foreman at the bellows.
At Mt. Hutt’s base he’ll take his place to overlook his fellows,
There’s Gust and Puff, and Shriek and Howl, and demons without number;
And they’re coming now, with dusky brow, to waken summer’s slumber.
The Prince of the Air is roused from his lair,
And howls in his bullying might:
The gravel and dust are now mixed with the gust,
And the demons shriek out with delight.
The gardens—my joy—my leisure employ!
Where are now thy flowers of thy trees?
They are blackened and bruised and most awfully used,
With cabbages, carrots and peas.
Oh! Squatters beware of the Powers of the Air,
When you come with your cattle or sheep;
For New Zealand’s a spot just loosed out of pot.
And the wind there is never asleep.
It comes from the south with a burst in its mouth,
Bringing snow, sleet or drizzling rain:
Or it changes to West, and does its behest,
With a blast twice as furious again.
The best of good fellows can’t stand the strong bellows,
That are ever at work on this shore:
So stick where you are, it is better by far,
Than come here and be heard of no more.
T.H.Potts has another who recorded his impressions of the ferocious wind, commenting in his diary:
29 April 1855: A day not soon to be forgotten. Last night the wind increased with strong gusts, and towards midnight raged with a violence that was perfectly astounding. Our roof soon felt the effects of the storm, the walls rocked, windows blown out, and we had to pass the whole night in barricading the doors, whilst the rain poured in torrents through the open roof, damaging most of our effects. At dawn we got ready for a start to Rockwood (next to Terrace Downs) for shelter, as our own dilapidated cottage was untenable. Mr Phillips and Seal came as we were about to start, and we all returned with them. Great numbers of trees were uprooted, our fences very much injured, some rails were blown from the posts to an incredible distance. The stable roof blown down, and much other damage we suffered from this terrible tempest. On our arrival at Rockwood, the ravages of the storm were most conspicuous in the multitudes of fallen trees that were lying in heaps on every side.
A short time later Potts and two friends explored the upper Rakaia valley. They followed a tributary Lake Stream—which led them behind the Mt Hutt Range to the Lake Heron basin. Potts recorded their setting up camp:
Harry [Phillips] went duck shooting, Leach and T.H.P. [Potts] cooking. Leach gave an alarm and T.H.P. ran to see what was the matter. The grass was on fire. We endeavored to put it out, but in vain. The wind was too strong.
We untied our horses, threw our swags on them, and ran into the riverbed waving everything but a waistcoat. We camped in the riverbed but could get no wood to spread our blankets with. The weather looked bad—very bad, but we were so pleased at finding this plain…that we were happy enough.
If Stoddart’s pen was inspired by the nor’wester in full blow, it was equally moved by its sudden cessation. On the northern side of the lower Rakaia Gorge is a hill I used to know as Fighting Hill, supposedly because it sits at a point where the nor’wester meets and tussles with the south-easterlies from the plains that eventually succeed it. Stoddart described the meeting of the two air masses in this area:
… the most beautiful phenomenon of the reaction of aerial currents. After two or three days of continual tempest, without the slightest change in the appearance of the sky which is of pale blue with black snake-like clouds undulating but stationary, a small white vapour may be observed coursing along the base of the mountains coming up from the south like an express train, throwing itself into the teeth of the north-west blast, enlarging, splitting into wreaths and fragments, whirling into most fantastic shapes—gathering again and charging the embrasure; the battle generally lasts about a quarter of an hour, the tornado is stamped out—the victorious cloud rolls up the mountainside and vanishes and the delicious calm of a summer evening reigns over the whole landscape.
The writings of the early pioneers put my recollections in the shade, and there is no doubt that the spring nor’westers caused much more havoc to those living in the area than they do today. Sealed roads have had an ameliorating effect, but the key change has been the planting of shelter belts.
The building of the Lake Coleridge power station provides a prime illustration of the effect of the shelter belts. In 1911, construction began on a bare, open, tussock-covered terrace exposed to the full force of the nor’wester. In her book Lake Coleridge: The People, the Power, the Politics, Rosemary Britten describes the conditions thus:
Early settlers wrote of dust blowing in clouds down the river bed making it look as though the river were on fire, with thick smoke rising from it. When the builders of the power station began work near the river their days were a battle against the wind. Dust and gravel was blown so forcibly against the unprotected building that men could hardly make themselves heard and it was often impossible to carry on … people told of having to crawl on hands and knees because they couldn’t stand against the wind. A three year old son of Mr Kissel, the first engineer, was caught up by the wind and flattened against a wire fence, unhurt but quite unable to move.
Tree-planting for shelter was begun at once, and within five years the benefits were starting to be felt. Extensive planting continued, such that by 1930 over 150,000 seedlings had been put in the ground—mainly various species of pine. These converted Lake Coleridge village into a sheltered haven, and today’s large plantations and arboretum are testament to the vision of the power-station builders.
Further down the valley, beyond the Dry Acheron Stream, numerous shelter belts have been planted across the river terraces, and although they have a distinct lean down the valley, the nor’wester is no longer so feared by the farmers out on the plains. In fact so effective have the trees been in providing shelter that a high-quality golf course—named, like Stoddart’s property, Terrace Downs—has been created on the terrace directly above the Rakaia Gorge bridge, on the northern side of the river—directly in the wind’s path.
Of course, not all nor’westerly weather patterns are as unpleasant ordestructive as those described. In fact most cause no more than a day or two of mild discomfort—perhaps some drying off of pasture or garden and a desire for a long cold drink and access to a swimming pool. But every few years come gales both memorable and disastrous.
Unforgettable is one that took place in August 1975. In sustained winds of well over 100 kph, trees and power poles were toppled, cutting off power and phone links and blocking roads and railway lines over a wide area. Numerous plantations across the plains were blown flat, and much of the Balmoral pine forest was destroyed.
More recently, in October 1988, a nor’west gale following a period of drought blew thousands of tonnes of topsoil from the Canterbury Plains farmland out to sea. Large areas of crops were laid waste by windburn and the sandblasting effect of wind-borne dust. Buildings lost their roofs and several power pylons were demolished.
Any description of a nor’wester is incomplete without mention of the flooding that tends to come with it. Although on the plains the wind is hot and dry, the heavy rain that accompanies it in the headwaters of the Rakaia and its tributaries swells the rivers. Particularly in spring, when the wind causes rapid snow melt, the rivers tend to flood dramatically, often rising very fast. In a big flood, they become a swirling yellow-brown torrent, their narrower stretches a concentrated surge. These floods have a significant effect on the water supply to the Lake Coleridge power station, frequently depositing debris that blocks the diversion channel which carries water from the Harper River into the lake.
Most affected by the flooding, however, are the people who work at Mt Algidus and Manuka Point Stations, for the only road access to these properties is via dangerous, shifting fords across the Rakaia. At times they can be cut off from the rest of the world for weeks. The problems the river can cause are well documented by Mona Anderson, who lived at Mt Algidus Station for over 30 years and wrote several books describing life there. In one of these, A River Rules My Life, she gives a graphic description of her return to the station after her first time away:
Our return trip next day was most unpleasant. Jim was waiting for us in a howling nor’-west gale. ‘You won’t be able to see for dust in the riverbed,’ he told us.
He was right. The silt and fine riverbed shingle hit us in the face. I kept my eyes shut tightly, but my ears and hair seemed to be full of dust, and when I ran my tongue round my mouth I could feel grit on my teeth. We had not been home long before the rain came pelting down, and in the morning for the first time I saw the river in all its might. It was a roaring muddy-brown torrent. Waves caused by the main body of water hitting a submerged bank were leaping six feet into the air. On the surging surface of the water floated sticks and logs, and now and then a whole great tree was carried past, its branches arching slowly into the air and under again as it turned in the grip of the flood. No wonder Ron had refused when I asked for one more day in town.
Although humans have managed partly to tame the nor’westers that tear through the Rakaia Gorge, the winds remain a dominant factor in the lives of the people of the area. Even a relatively mild nor’wester can be an unforgettable experience, as I can attest myself.
As a university student I regularly worked in my Christmas holidays as a shed hand on Ryton Station, on the shores of Lake Coleridge, at shearing time. On one occasion I was given a week or two’s work as a tractor driver, and found myself on a caterpillar tractor charged with harrowing and sowing turnips in a paddock on the terraces above the Lake Coleridge powerhouse road. It took only a few minutes’ driving downwind to find myself completely grey, with dust coating my clothes and in my mouth, ears, nose and hair. My eyes were circles of white behind dust-covered goggles, and a plume of dust stretched hundreds of metres ahead of me—precious topsoil heading towards the Canterbury Plains. The experience left me with a comprehensive memory of the feel, sight, sound and even taste of a Rakaia Gorge nor’wester.
A real wind.