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History.
History.
The Abbotsford Slip.
On the evening of August 8th, 1979, Streets that had been cracking for months were suddenly devastated by the earth moving. Weaknesses in the hillside came to a head with mud and rocks sliding down the hill like a slow-moving river. Houses folded like matchbooks. Thankfully there was no loss of life, though 200 people were displaced and 69 homes were lost.
By morning the extent of the slip could be seen. A gouge 75m wide and 30m deep had appeared where once houses stood, the trail of destruction left behind unprecedented. The first warnings that something was amiss started some 10 weeks earlier. Cracks on footpaths and roads, fractures in house walls and burst water pipes. The problems intensified, the residents wanted answers. Officials tried to stave off the problem by pouring gravel into the growing cracks, promising to investigate.
The ramifications of this were felt and seen over a 20 minute period on that fateful night, when the sound of houses, mud, rocks and trees, falling down the hillside were punctuated by the “ping” of live power cables snapping under the pressure. That no one was killed is a miracle.
Being a small community by modern standards, the spirit of unity helped pull those affected through. The loss of precious possessions was something everyone understood. They shared the heartbreak of sifting through the remains of their homes, trying to find items of sentimental value. It was mid-winter, snow and rain were still falling, it wasn’t an “ideal time” to become a refugee.
As the clear up continued, so an investigation was underway. “Unstable geology” was cited as the main cause, by the commission of inquiry that investigated the disaster. “The East Abbotsford slope had been potentially unstable for some thousands of years. The geological formations had a 6 degree to 10 degree down-dip slope which included thin beds of weak highly ‘plastic’ and silty clay, along which there was ‘little resistance to failure’.”(Source: The ODT, 7th Aug 1999)
The following year when the disaster was being discussed and the Green Island Council, praised for its handling of the incident, it was found that previous warnings about the unsuitability of the Abbotsford slip area for development had gone unheeded. In early 1951, a Mr O. J. McCabe, of the Ministry of Works had identified this part of Abbotsford as an area subject to erosion and marked it as unsuitable for housing development. He consulted a geology professor, W. N. Benson at the University of Otago who confirmed his findings.
Why then was it that houses were built there? It seems the report disappeared “without trace” in the 1950’s. Although the town plan was there, land identified as unstable was now zoned as residential. In 1940 Prof. Benson had completed his own analysis and warned in the strongest terms what his findings of the Abbotsford hillside had been and its instability. Also in the report he included an old map of the area and mention of slips that had occurred there as early as 1870, with another in 1925 and the largest in 1939.
Where the chaos was on that fateful night in 1979, grass covers the remains of the houses, torn down and thrown into this natural graveyard. Today the area where the slip settled is a sports field. Children play there in total bliss, mostly unaware of the events that led to this platform of land being formed.
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