Disastrous floods have been the portion of most of the provinces of New Zealand at some time or another. The cost in property and lives has been heavy, but the saddest fact of all is that many of the scars the country carries can be regarded almost in the light of self-inflicted wounds. The wholesale and frequently ill-considered denudation of natural forest and the unnecessary destruction of native bush, with a consequent interference with huge watersheds and nature's protective coverings, have led to widespread erosion.
Most of the larger rivers have their records of devastation, and for many years some of them have been a perennial menace. If the incidence of their destructive flooding has today been reduced, it can be attributed mainly to a vigorous better-late-than-never policy of river control and soil conservation which is beginning to have its first visible effects. The more troublesome rivers have exhibited an expensive persistency. The Waikato River in the north has created havoc along the whole of its great length and the Manawatu River, with its tributaries, has been no less active over a wide territory, both rural and urban. In the Wairarapa the Ruamahanga River has a long flooding history, and the Hutt Valley has suffered heavily from the river that traverses it. In the South Island, the Clarence, the Rakaia, the Rangitata, and the Waimakariri Rivers have often been a scourge to Canterbury, and in Otago the Taieri and Clutha Rivers have year after year caused serious damage on Taieri Plains and in the Balclutha and Inchclutha areas. In Southland the Mataura River enjoys a similar reputation.
In July-September 1863 a devastating combination of flood, snowstorm, and blizzard caused heavy loss of life among the mining population of Central Otago. In July 1863 a long and sustained fall of snow in the ranges produced grim living conditions in the area between Strath Taieri through the Maniototo County and its high country right up to the lakes. Then, without warning, warm and completely unseasonable rains precipitated a swift and continuing thaw. In a matter of days all the gold rivers—the Clutha (Molyneux), the Kawarau, the Shotover, the Arrow, the Manuherikia, the Bannockburn—and a score of fast-flowing mountain streams were in violent flood. The Clutha rose 20ft in a night; the Shotover was soon 35 ft above normal; and the Arrow, usually a slow-moving stream, engulfed Arrowtown. Tented miners on the river banks were caught unawares, and even on the terraces above the normal water level many escaped only with difficulty. Men watched helplessly while others were swept down the flood waters. On one Shotover beach eight tents, together with their occupants, disappeared. Many escaped with the loss of all they possessed, but others were less fortunate. Scattered communities from Queenstown to the Manuherikia suffered heavily. When the rivers subsided there was no reliable means of knowing how many lives had been lost, but thousands of miners had to start afresh without gear or goods.
Worse was to follow when snowstorms began early in August. Blizzards swept inland Otago from Outram on the Taieri Plains to the settlements at Lakes Wakatipu and Wanaka. It snowed almost daily throughout the whole of August 1863. Roads not only became impassable—they were impossible to find. In September, when the weather showed little signs of improving, the situation was critical everywhere. Snow continued throughout spring and into summer, and conditions did not return to normal until Christmas. Mining settlements and camps over an area of more than 800 square miles were isolated or engulfed by the snow, and each of the ranges had its quota of miners. But the Rock and Pillar, the Lammerlaws, the Raggedy, Rough Ridge, the Old Man, the Dunstan, and Hawkdun Ranges carried such a covering of snow that access was almost impossible. Late in September a police party was caught in the Kakanuis near Naseby. Frostbitten and in dire straits, most of its members reached safety but Sergeant Garvie, of Ranfurly, an old identity on the goldfields, lost his life. Late in October, when efforts were still being made to reach miners marooned at Campbell's Diggings—one of the new rush gullies, across the 6,000 ft Old Man Range—several bodies found on the frozen windswept tops were buried where they lay. Many stories could be told of individual courage and self-sacrifice in the rescue operations that continued unceasingly.
As well as the miners, runholders suffered heavily, experiencing severe hardships from isolation, exposure, and lack of food. Stock losses were heavy everywhere. The number of miners' bodies recovered was fewer than 20, but the numbers missing left the certainty of terrible tragedy. It was impossible to assess the total toll in lives, but the Otago Witness, in August and September 1863, counted over 100 fatalities in the floods and in the snowstorms that followed. Contemporary unofficial estimates give figures varying between 100 and 200, but the Warden's Court records place the ascertained deaths at 37. At the time, and in view of the constant movement among the mining population, it is certain that the fate of many was never determined.
In 1928, to mark the catastrophe, the Government erected a stone monument, between Teviot and Manuherikia—at Gorge Creek—in what today is a deserted gully. In 1863, however, it was known to the miners as Chamounix Creek, a bustling canvas town with stores, hotels, and grog shanties. At the time of the storms it was the centre of great mining activity. Several graves may still be seen in the gully and, on the bleak summit of the Old Man Range, there are cairns that mark the resting places of miners and rescuers alike.
Public and private properties worth many thousands of pounds were swept away and many towns were inundated in Central and South Otago in the great Clutha flood of 1878, which must rank as one of the worst visitations of its kind in the history of New Zealand.
A long severe winter had left an unusual depth of snow on the river's mountain watersheds; subsequently, hard frosts consolidated the snowfields which were over 100 ft deep in places. Spring came in cold and sharp and, as most settlers calculated, the frosts held the snows fast. Then, in September, warm north-westerly winds blew for several days, followed by 36 hours of continuous warm rains. The thaw set in swiftly and terribly. On 26 September 1878 the Clutha and all its tributaries rose ominously. By the end of the month every river and stream in the district was in flood, and these waters all flowed down to swell the Clutha. On 10 October a further 24–hour downpour of warm rains hastened the already rapid thaw, with the result that, for 200 miles, from the mountains to the coast, settlers and urban communities found themselves faced with annihilation. In unprecedented flood, the Clutha carried houses, bridges, timber, furniture, farm equipment, and livestock down to the sea. At Cromwell the flood waters reached 35–40 ft above normal, and nearly every town along the river's banks was inundated. Heavy bridges—costing thousands of pounds—at Clyde, Roxburgh, Beaumont, and Balclutha were swept away by the debris-laden waters. Communications throughout the Lake and Vincent counties were disrupted completely. At Queenstown, Lake Wakatipu rose to alarming levels as the snows from its encircling mountain ranges rapidly thawed. Parts of the town were under 6 ft of water, boats were used to traverse the streets, and a general evacuation was made. Clyde and Alexandra were flooded and the wide Manuherikia Valley resembled an inland sea. At Roxburgh and Millers Flat, houses were swept away and valuable mining claims disappeared. But the greatest sufferer was the wide fertile lowland farming country of South Otago which, with its centre, Balclutha—a thriving town—was completely overrun. Not only did the water spread deep throughout the town, but a fierce current raced along the streets wreaking havoc. The whole of the Clutha-Kaitangata area presented an unbroken expanse of swirling muddy water. Apart from damage to roads, bridges, buildings, and railway lines, the loss in farm livestock was enormous and its total was never accurately assessed. Many newly established settlers and settlements were ruined.
Loss of life was confined, fortunately, to one or two persons who were unlucky enough to be drowned while attempting to salvage possessions from their homesteads. The most lasting damage, however, occurred at Port Molyneux at the river's mouth. This port had already catered for a brisk coastal trade, but when the river gouged out a new channel it left the existing port installations high and dry, while a great sand bar blocking the entrance to the harbour appeared when the waters receded. To this day Port Molyneux remains a port only in name.
Phenomenal rain and cloudbursts have also been a frequent cause of damaging flooding and destruction. Here again the interference with natural conditions could be regarded as a contributory aspect of tragedy. One of the worst of these catastrophes occurred in Poverty Bay and Hawke's Bay in April 1938, when many thousands of acres of first-class farming land became a desolate waste as a result of what became known as the Esk Valley floods. The name given to the visitation suggests localised consequences which were in fact only a portion of the general effect. The whole provincial area from Napier in Hawke's Bay to Wairoa and Gisborne in Poverty Bay was deluged by torrential downpours which at their worst measured as much as 13 in. in 24 hours. Railway lines, road and telegraph communications, and bridges were swept away, in some cases right out to sea, and emergency measures on a national scale were necessary. A few days' rain wrecked a prosperous and fertile countryside and cost more than half a million pounds in public and private property.
Earlier in the year disaster occurred within the same area. On 18 February 1938 a cloudburst in the nearby hills overwhelmed a Ministry of Works construction camp at the tiny settlement of Kopuawhara, 35 miles north of Wairoa in Poverty Bay. Twenty-one persons, 20 men and one woman, were drowned in a brief night of terror when the usually harmless Kopuawhara Stream burst into mountainous, irresistible flood. There were four encampments in the locality accommodating hundreds of men, women, and children, but only one, No. 4 reserved for single men, lay in the direct path of the deluge. The floods rose late at night when the camps were asleep, and it was a miracle that the death roll was not a great deal higher. A special distinction attaches to the Kopuawhara casualty list in that no fewer than five of those who perished gave their lives in gallant but vain attempts to save others. Six months later, the Esk Valley floods having intervened, 1,000 acres of useful farming land were still under water in this area.
During Queen's Birthday weekend, 1963, Hawke's Bay experienced exceptionally heavy rain. In 24 hours in the Tangoio catchment area, 16 in. of rain fell, swept in by a strong south-easterly wind. The rivers rose suddenly and by early afternoon on 3 June all communications between Napier and Wairoa and Napier and Taupo ceased. At this time the traffic on these roads was particularly heavy and some hundreds of motorists were weatherbound. The Tangoio Valley was completely isolated and police, Army, and civil defence workers were unable to reach it for nearly two days. Until relief parties returned nothing was known of the fate of the 130 people living there. Although the Tangoio River had risen sufficiently to flood the settlements on the valley floor, the worst damage had occurred when the steep surrounding hillsides slipped bodily into the valley below. No people were killed, but farmers reported heavy losses among livestock.
by Bernard John Foster, M.A., Research Officer, Department of Internal Affairs, Wellington and Ronald Jones, Journalist and Script Writer, New Zealand Broadcasting Corporation, Wellington.