Your Christchurch accommodation is built in a city with a unique set of geographical landforms. The people who first settled Christchurch chose the site because of its easily-navigated rivers, its abundant flat land, its handy supply of stone and timber for building, and its good supply of fresh water.The fact that much of Christchurch is built in a swampy hollow was not a problem for the early settlers. So while you are out and about in the city, you can look around and still see evidence of the natural landforms upon which the city is built. Here are a few things to look out for.
Under The Volcano
The Port Hills which overlook the city are the western edge of Banks Peninsula. The Peninsula was formed when two volcanoes began erupting around twelve million years ago. The two volcanoes formed an island about fifty kilometres east of what was then the mainland of the South Island. The eruptions continued for millions of years and when they subsided, erosion began reducing them to less than half their original height. Then, around a million years ago, alluvial shingle eroded from the Southern Alps and washed down to the sea by rivers, filled in the shallow sea separating the volcanic island from the mainland and the Canterbury Plains were created. The harbours of Akaroa and Lyttleton are the drowned remains of the volcanoes’ craters. You can still see the burned rock and eroded basalt rock blasted from the volcanoes all those years ago. All you have to do is take a walk anywhere on the Port Hills.
The Shingle and the Swamp
Christchurch is built on a swamp. Long before humans occupied the area, this part of the Canterbury Plains was where several rivers, most importantly the Waimakariri River, entered shallow estuaries before empting into the sea. The slow moving water deposited sediments and the saturated ground formed an ideal habitat for many varieties of plant, such as flaxes and tussocks. As these died and decayed, they formed beds of peat which can be as deep as four metres beneath some parts of the city.
Around the western edges of Christchurch, the ground is composed of shingle, boulders and sand washed down from the Southern Alps over hundreds of thousands of years. These alluvial deposits are far more free-draining and during summer you can observe how much drier the landscape west of the city is compared to the heavy, swampy ground closer to the sea. The low-lying aspect of Christchurch, with the bulk of the Port Hills on one side and the slightly higher alluvial ground on the other, is the reason why the city can be a little smoky during winter. Cold air sinks down into the lowest parts of the city and is trapped there by a layer of warmer air above.
The Two Rivers
Christchurch’s two lovely rivers, the Heathcote and the Avon are what give the city its character. The similarity of the Avon to its namesake in England was not lost on the early settlers. Today, the willow-lined banks of the river, not to mention its boater-wearing punters, make the Avon one of the prettiest urban rivers in New Zealand as it curls gracefully through the city on its way to the Estuary. The Heathcote River, on the other hand, is a working river. The city’s founders used the Heathcote as a thoroughfare, taking boats and barges laden with produce up and down it’s deep, narrow channel. Today, the Heathcote is less well-known than the Avon, but it is still a rewarding river to explore.
Both the Avon River and the Heathcote River are spring-fed. They rise in leafy suburbs on the western edges of the city and their whole length is defined within the city limits. You can pass a pleasant afternoon discovering the curves and back-waters of these rivers. Along the way you can trace the evolution of the city which grew up along their banks. In many places you can find plaques, notice-boards and information panels detailing the historic life of places along the way.
The Harbour And The Estuary
The two landforms which have been most influential in the development of Christchurch are Lyttelton Harbour and the Avon-Heathcote Estuary. For pre-European Maori, the Avon-Heathcote Estuary, which they called Ihitai, was a valuable source of kai moana (sea food).
The estuary is the largest semi-enclosed estuary in Canterbury and is an internationally important habitat for migratory birds, most notably the thousands of Eastern Bar-tailed Godwits who make their annual pilgrimage from the Alaskan tundra to spend the summer months on the estuary.
On the far side of the Port Hills, Lyttelton was Canterbury’s first settlement. The long, narrow harbour was discovered by Captain Cook in 1770, although Maori had lived here for 700 years before then. For the first few years of the Canterbury settlement, Lyttelton was known as “The Gateway to Canterbury” for colonial settlers. Today, The Port of Lyttelton is one of New Zealand’s busiest ports.
The landscape of Christchurch is varied and interesting. All you have to do to experience it is wander abound the city. Happy exploring…