Sure to rise

SES, 20 July 2021

Our mid-winter birdwalk grapples with history repeating itself…

Our June Birdwalk came just a day or two after Canterbury’s “one-in-two hundred-year” flood, a nonsense description now that we have such rapid climate change. But it got me thinking about flooding in our river and the history of floods in Christchurch – situated, as we learned again, on one enormous flood plain. Besides, I had to think of something else because we walked our regular loop, upriver and down, and saw barely a bird.

The river level was high but contained, the water no longer discoloured or leaf-littered. Instead it was black and inscrutable, like the Scaups. If the Otakaro could talk, like the Whanganui River presumably can, having gained “legal person” status as a Maori natural resource, what would it say about the history it has flowed under bridges for?

Perhaps we could start with a photo of the Edmonds Band Rotunda published in The Herald two days earlier when the Otakaro was fully in flood. Thankfully for Birdwalk there are some Canada Geese in this picture! They might be colonists that have overpopulated the river but it is hard not to admire their dignified deportment. Quite English, like Thomas and Jane Edmonds, who built the band rotunda in 1929. It was a gift to Christchurch to celebrate their fifty years of business in the city selling ‘Sure to Rise’ baking powder.

Before the Deans from Scotland, our first European settlers, built in Riccarton in 1843 this land was swamp forest, no doubt resembling that last remnant we guard today and name Riccarton Bush. Tall kahikatea dominated the canopy under which the Otakaro would have meandered languidly amongst fern, toetoe, raupo and flax. It must have been home to so many more birds and fish.

When scouts for English settlers chose this swamp rather than Lyttelton Harbour for the new settlement they consigned all of us who would come later to a significant risk of flooding. Nevertheless the Avon River, arising not far away in Avonhead, is a very local river with a small catchment – unlike its bigger cousin to the north, the Waimakariri. It arises from the Southern Alps and links us, risk and benefit, to the tectonic uplift and mountain rainfall that characterises Te Wai Pounamu. Floods in the Waimakariri were more of a threat to the growing settlement of Christchurch.

In peelingbackhistory.co.nz I found this account:

On 4th February 1868, a severe storm hit Canterbury…

The first alarm for Christchurch was raised by a Fendall Town (Fendalton) resident who reported that the Waimakariri River had flooded and broken through its banks. This, in turn, sent a surge of water towards Christchurch via the Avon…

By nightfall, Market Place (Victoria Square) was knee deep in water, wrecking the businesses that called the place home. One man had to be rescued when he attempted to make his way through the flood. He fell into a hole that had been dug away by the water and almost drowned.

Throughout the night, cabbies drove people back and forth in their hansom cabs… For years, many remembered the cab’s lanterns flickering over the black eerie waters.

An Engineer who predicted that the Waimakariri would flood eventually was William Bray (his farm is now a suburb of Avonhead). His warnings were not taken seriously though. The following poem was written by Crosbie Ward of The Lyttelton Times.

——————————————————————————–

At Avonhead lives Mr Bray

Who every morning used to say,

‘I should not be much surprised today

If Christchurch city were swept away

By the rushing, crushing, flushing, gushing Waimakariri River’

He told his tale and showed his plan,

How the levels lay and the river ran.

The neighbours thought him a learned man,

But wished him further that Isfahan,

With his wearing, tearing, flaring, scaring Waimakariri River.

——————————————————————————–

On a happier but equally naïve day in 1978, a photo from The Press Archives shows a well-attended concert with local bands performing in the rotunda. Just one year later the Exxon oil company received a report from its scientists stating that burning fossil fuels would “cause dramatic environmental effects in the coming decades. The potential problem is great and urgent”. Exxon executives buried that report.

Note the building housing ‘Christchurch Drainage Board’ behind the rotunda, an older no-nonsense institution that helped us ‘swamp-dwellers’ come to terms with our chosen place. One of my Ophthalmologist mentors, the late and politically astute Roy Holmes, served on that body.

If the Otakaro really does have feelings, we must have hurt them when we felled the bank side kahikatea, drained the swamps, built weirs for punting, channelled the flow and bridged it for cars –this place that Hugh Wilson of Hinewai calls a ‘car-infested swamp’!

Perhaps the columns of the Edmonds Band Rotunda were a subliminal emblem of missing forest trunks that should support a shade-giving, carbon-sink canopy. And poplars planted along the banks at the accompanying Poplar Crescent were also a guilty nod to past grandeur, at the very time that the internal combustion engine became more popular than horse power.

And still the changes keep coming. In fact they are flooding in to this river’s natural history in front of our very eyes.

If the Otakaro really does have feelings, we must have hurt them when we felled the bank side kahikatea, drained the swamps, built weirs for punting, channelled the flow and bridged it for cars…

The recent earthquakes damaged the Band Rotunda requiring its demolition. Fortunately its 70-ton copper-sheathed dome was saved. It has only just been set back up on columns and the precinct restored to its ‘Sure-to-Rise’ glory. But more significantly, the earthquakes caused levels of land to drop around our river’s estuarine reaches, along with that liquefaction that eastern residents know now not to dismiss as empty words on LIMs. Much of that land is now red-zoned and more subject to inundation and the re-emergence of swamp.

And, returning to cause and effect of the recent flood, we would learn later from NIWA scientists that it was the hottest June on record, with temperatures 2° C above average. A study commissioned by the Christchurch City Council, combining actual records with computer modelling, would show that over the last decade sea level at Lyttelton Harbour has risen on average by 7mm per year!

That double whammy on relative levels, along with the greater frequency and intensity of weather events due to global heating, will increase flooding impacts on the river downstream from us. Perhaps it will even reach right up to our front doorstep where, like those businesses washed out in Market Place, we ply our wares: Best Eye Repairs.

AJS