Wednesday 1 March 2023

Floods, Weather and Global Warming

Some of you might have heard of the recent extreme weather events we’ve had in New Zealand, leading to huge damage, destruction and loss of life. I thought I’d give a bit of a background to this.

New Zealand is a ‘wet’ country, with a moderately high rainfall. We’ve also had a wet winter, wet spring, and wet summer, at least in the North Island. So the land was already at its limit. And then one day in January, Auckland got a downpour that was equivalent to an entire summer’s rainfall in a few hours. Mayhem ensued. The soil, and the city’s drainage systems, were simply unable to cope. Flooding, collapsed hillsides, roads wrecked, homes and backyards left uninhabitable. People died. Many still can’t return to their homes, and some will never be able to.

Then there was the more recent Cyclone Gabrielle which also wreaked havoc, especially along the North Island’s East Coast. Even more widespread damage, and the loss of more lives. Whole areas are destroyed. Hawkes Bay is normally prime horticultural land, producing many of NZ’s fruit and vegetables. The country around Gisborne, a bit further north, is also prime grape and corn growing land. Much of it is now metres deep in muddy silt. Crops are ruined, stock have died, houses wiped out. Big farmers cry on national TV when they look at what has happened to their land.

The most productive parts of the East Coast are the coastal river flats. And yes, there were stopbanks, but they either weren’t enough or they broke under pressure of the deluge. Roads and bridges in the area have also been destroyed, adding to the difficulty of clean up, repairs to viral services, and getting supplies in.

There’s also the problem of forestry ‘slash’. For those who don’t know the term, it’s the parts of trees that get trimmed off and left behind by the forestry companies. Because behind the river flats, much of the East Coast is steep hill country, and when the storms come, that slash gets washed down, destroying infrastructure, choking streams and riverbeds, piling up on farms and fouling normally beautiful beaches for tens of kilometres. This has been a problem for years, and the forestry companies are supposed to be cleaning up their act, but not much has changed it seems.

And then there’s that silt. What is it exactly? It’s the filtered loose soil, washed down from the hills by the rain, and left behind when the waters recede. Because what isn’t forestry up there is mainly sheep farms. And anyone who’s ever travelled through that country knows how bare and ‘bony’ the hills look. Barely a tree in sight, except for those forestry blocks. The once-dense native bush that used to clothe them and hold the soil in place has long been cleared. But the towns, orchards, farms and vineyards downstream are now paying the price. Long-term of course, this sediment raises stream and river levels, which will only lead to worse flooding..... And the wet weather isn’t done with us yet.

All of this has sparked talk about things like rebuilding roads to be more weatherproof or further inland or both, ‘managed retreat’ from coastal areas now under threat as sea levels rise and storms get worse and more frequent, building higher and better stopbanks, and replanting hillsides in native bush. The government has ordered an inquiry into the forestry industry. It’s also become obvious that improving/rebuilding city and town drainage systems is essential, especially in Auckland where much of the network is up to a hundred years old, and totally inadequate for modern times.

Now New Zealand is not a stranger to rebuilding after natural disasters, thanks to the Christchurch earthquake. Much of that city is still being rebuilt, and many people there are still traumatised. So we know something of how long it’s likely to take to rebuild not just a city but an entire region. The public and the government know it’s not going to be easy, and that the cost will be immense – and that’s without taking into account the effect on food prices, already skyrocketing post-Covid.

The human cost is likely to be high too. Stress and trauma take their toll, even for those not directly affected. I live in a part of my town that could possibly be flooded if the stopbanks give way in a storm. Every time it rains, I think ‘is this The One? Am I going to be flooded out? What should I pack, what should I take, where should I go, how can I get through this? What am I likely to lose?’ It’s always nerve-wracking. I used to think that a roof being blown off was the worst that a storm could do to me, but now…

Global warming affects us all. We are all vulnerable. Things have gotten very real, very fast. It’s been a wake-up call for us, but what happened here in New Zealand could happen anywhere. Even Australia, dry and often drought-stricken country that it is, has had its share of floods and destruction in recent years. No-one is safe. That’s the message to be taken away from this. No-one knows what’s going to happen. Always plan for the worst.

And know that global warming is going to affect you too, in some way and to some degree, sooner rather than later. It’s here folks, and it’s real.