My son and I took a walk through the Paekakariki Domain this afternoon, which provides a good vantage point from which to view the Paekakariki hills [click here to view map].
These hills rise steeply from the eastern side of the State Highway, creating a dominant backdrop to the town of Paekakariki. Rugged and raw, rather than picturesque, with their wind-gnarled scrub and angular contours, I have always found them alluring.
The hills are formed from “greywacke”, made up of hard sandstone and siltstone (argillite). The hills are likely to have been the result of uplift from the Pukerua fault which runs north-south from Cook Strait along Pukerua Bay. Like many landforms of greywacke, the hills and cliffs from Pukerua Bay to Paekakariki are very sheer, as greywacke tends to fracture very easily under stress. This means that it probably wasn’t the best idea to site both a railway line [completed in 1886] and a state highway [built 1939] directly under them, particularly once their vegetation cover, which provides a degree of stability, was destroyed. However, despite their instability, the forest was cleared on these hills, as was the case throughout New Zealand, to allow for farming. Owing to their topography and limited fertility, it is unlikely that these sheer hills have ever been suitable for anything other than low intensity sheep farming [note one sheep in photo above, on left].
The first known event causing part of the hillside to sheer away was the 1855 Wairarapa Earthquake, which is thought to have created a gully from the top of the hill across from the Paekarakiki railway station. This gully was later quarried, possibly not helping the situation. Other gullies have been created by subsequent heavy rainfall events, including in recent years, causing erosion.
Erosion damage is clearly evident when driving up Paekakariki Hill, where erosion barriers made from old tyres can be seen. Farmers are increasingly allowing indigenous scrub to regenerate in the gullies, which will over time provide the best protection against slips.
Gazing at the sheep specks on the side of these sheer hills, I found myself musing whether a more appropriate name for Paekakariki might today be Pae-hipi (“perch of the sheep”), rather than “perch of the kakariki”, though I hope that the day the will come when the bush around Paekakariki will once again reverberate with their chatter.
See also: Paekakariki: perch of the green parrot
Photo top: Paekakariki hills from Paekakariki Domain. Middle: this shot is of the hills to the right of the beginning of the Paekakariki Hill Road, showing regenerating scrub in one gully. Bottom: this is a close-up of vegetation in the top shot. (Photos: C. Knight).
A great background story in two senses of “background.” I have for years wondered about the sanity of those who decided to clear those hills. Did they not know what the consequences would be? Or did they just not care? Was it because they were mostly from the UK, a country not directly affected by volcanic activity or earthquakes?