Opening the floodgates

December 13, 2008
When floodwaters threatened Takaka on Monday a fortnight ago, some may have assumed this would bring to an end the arguing over the need for measures to protect the township. But it has only heightened feelings. Geoff Collett reports. -------------------- It's Monday, so it must be raining. On Takaka Hill, it's coming down in sheets. On the radio, there's yet another heavy rain warning for the region to greet the start of a new week.
The only bright spot - from an entirely self-serving point of view - is the thought that just maybe, there could be the prospect of a first-hand look at the flood hazard that we keep hearing the Takaka township is in mortal danger of.
Fat chance. Off the hill, the sky withdraws into a leaden, brooding presence, threatening but not delivering another deluge.
Not like two Mondays earlier, when it bucketed down like it hadn't for years. The level of the Takaka River shot up, and it broke its banks and poured across paddocks and backyards, across the state highway and down the main street, through a few shops. As isn't unknown in these parts, it stopped in the nick of time. Disaster was averted. The next morning, the sun came out again.
If you're one of those who likes to personify nature, you could regard it as a warning shot, for the timing was rather exquisite. Just that weekend, a group of locals had met to organise some resistance to the Tasman District Council's master plan for addressing the flood question. The tussle over what to do - whether the council's idea of banning new homes from being built on flood-prone land, or the "let's have none of this nonsense from over the hill" approach of the more vocal agitators - looked set to drive the whole argument into a mire of confusion and dispute.
Then the rain came and offered a sharp reminder that this little town, much of it built across the river's floodplain, really does tempt nature's nasty side. Just maybe it shouldn't be dithering about keeping itself dry?
1983 has been a year lots of people have been talking about since that Monday a couple of weeks back - July 10, 1983, actually, the date of the Big One, when the township truly was inundated in what is officially regarded today as a 50-year flood.
It was the aftermath of that disaster that gave Paul Sangster his understanding of what can go on around the place when the rain comes down in its full fury. He worked in insurance then, and spent six weeks after the '83 flood visiting houses all over the place listening to stories - "where the water came from, how the water was, what happened with it".
"Then I started saying, 'There must be a way of trying to control the amount of water'."
The council of the day proposed building stopbanks at a cost of many millions. The locals voted the idea down, reckoned it was overkill. Sangster reckons council staff then got the pip and have stymied initiatives to tame the river since.
There's no avoiding Sangster in the argument about Takaka and its flood risk. The former Tasman district councillor is an affable but bluntly-spoken salt-of-the-earth sort, certainly not the stereotype most outsiders would conjure up when thoughts turn to the hippie haven of Takaka, but deeply immersed in the community and plugged into the township's "other" half - the farmers and business owners, old-school residents, those who believe firmly in the township doing things its way without undue interference from over the hill. He has emerged as the spokesman for the informal group fighting the council's proposal to ban new houses being built on the floodplain.
Today, Sangster has offered to play tour guide to the visiting reporter. Whatever one makes of his numerous opinions and theories on what has happened, and what should happen, it is hard to deny that he knows his town, and he's studied the way the river behaves during floods to the full extent of his layman's energy and enthusiasm. There's an unavoidable undercurrent of disdain for the way the council has been treating Takaka, and for Golden Bay's two current councillors and community board.
One of those councillors, Stuart Borlase, gives every impression that he's a little over hearing about Sangster's views. Nevertheless, Sangster won't pass up this opportunity to air them once again.
His tour takes in riverbeds, bridges, banks, streams, swales, the backs of buildings, culverts, road cambers, fences, building sites, shops, main streets and back roads. The common theme is of a council run from Richmond that just doesn't understand how things work in Takaka.
Sangster starts at a remarkably non-noteworthy spot on the main highway on the southern outskirts of town, Bridgers Hollow. He explains that its importance lies in an ancient man-made roadside embankment, the remnants of a 19th-century railway line built between the fledgling township and East Takaka.
While it is low and barely noticeable to an unwitting passerby, Sangster says it serves to trap floodwaters pouring from the river and across the highway, then sends them in the direction of the town centre.
At Bridgers Hollow, a small outlet through the old embankment, underneath a rather ugly footbridge on the roadside walkway, is the only place where floodwaters can escape if the township is not to be inundated. On occasions like the other week, it was quickly overwhelmed and Commercial St was soon underwater.
The welter of commentary and local knowledge that Sangster offers up can also quickly overwhelm, frankly, but in essence, he pinpoints two or three crucial elements.
First is the township's existing stopbank, if you can call it that. As with so much about such issues, there is a long and involved back story to this bank - again, out of all proportion to its appearance.
Back in the 1940s or '50s, the local authorities built a long stone wall across farmland alongside the river where it flows past the township, to help keep the water at bay. The wall fell into disrepair and was no match for the flood of 1983.
Since then, the owner of much of the land it is built on, Duncan McKenzie, has taken it upon himself to use the wall as the foundation for a home-built stopbank. He offered the land along the wall's length as a dumping ground for unwanted material from roadworks and the like - an offer apparently enthusiastically accepted by the council and various contractors - then used his earthmoving machinery to gradually build it up and over the old wall into a low, gently sloping rise.
It's not much more than a metre high but is, Sangster and McKenzie argue, an effective way of funnelling the floodwaters away from the township and on to neighbouring farmland, where they reason it is a far lesser risk to life or limb.
Unfortunately, a couple of problems present themselves with this somewhat ingenious approach - done, Sangster points out, out of the goodness of McKenzie's heart.
Firstly, the neighbouring farm owner is unhappy about water being directed on to his paddocks and doesn't like Sangster's proffered solution, of continuing the stopbank across his property to keep the river even further at bay.
Secondly, the council is no longer benign about this do-it- yourself approach. Last year, it ordered McKenzie to stop adding to the stopbank and to lower it by 30cm, and warned him that he risked prosecution. He had little choice, but called Sangster for advice. "Unreal" is Sangster's verdict. He reckons McKenzie deserves a handsome cash reward, not threats. If the bank wasn't there, the flooding the other week would have been much more damaging, he promises.
The council, for its part, cites the risk of the bank diverting water on to land earmarked for subdivision. Beyond that, its engineering manager, Peter Thomson, doesn't want to venture an opinion on the merits of the bank. He will concede that it probably did hold back some water in the recent flood, but he's dubious about its ability to handle a bigger event.
Borlase reasons that whatever good the bank does, it isn't up to the standard the council would expect, and he can't see the council wanting to get involved in extending it or otherwise endorsing it. Then again, he concedes that the council risked looking bloody-minded in the way it went after McKenzie. He was against the farmer being forced to lower the earthworks.
Sangster and Co's other principal beef lies around the council's management of the Takaka River bed. With veteran Takaka publican Graham Drummond, of the Junction Hotel, he continues the river tour, pointing out the gravel beaches and islands that have built up in the bed, and the enormous areas of gravel banks that were torn away and washed out to sea two weeks ago.
The council has almost stopped gravel extraction from the river in the past 15 years, and the buildup has reduced the bed's flood capacity, they argue. The council has failed to tackle works that would address bottlenecks in the river, where it narrows significantly (such as under the Waikoropupu bridge) and the flood capacity is further compromised.
Thomson isn't buying into the gravel debate. He will only observe that "in my experience on these issues, there's often a lot of opinion based on conjecture rather than information".
The problem is, there's not all that much hard data to back up anybody's opinion. Thomson says the council has done no recent studies on building a properly engineered stopbank. While some, including Borlase, suggest that the cost of such work would run to $10 million or more, Thomson cannot verify that figure. Nor has the council investigated the questions around gravel accumulating in the river.
It is keen to better understand and study the way the river and its floodwaters behaved in the latest flood, but will need to find funding if that is to happen properly.
Anyway, the council has another strategy - to change the planning rules for Takaka, to ban further building on the floodplain full stop and direct new houses to land such as around Park Ave, an emerging subdivision back towards East Takaka.
Sangster will be among those leading the fight against that proposal to the Environment Court. The suggestion that the township could one day be largely moved off the floodplain is crazy stuff, he says, out of all proportion to the real risk. Putting on his old insurance man's hat, he points out that in the latest flood, only three shops were flooded - and that was the first property damage in 25 years. It's a slight risk, he says, and can be made even slighter with a bit of common sense, a bit of tweaking of the way the river is managed.
Borlase holds firm. "Somebody said to me this morning, 'It's only one in 25 years. If you've got to pull up a little bit of carpet in 25 years, what's wrong with that?'. Yeah - if we can be sure that the '83 flood is the biggest one we're going to get, I could live with that. But who knows if there's going to be a (100-year flood), with twice as much water coming down the main street? There would possibly be a loss of life. There would certainly be devastation to a lot of properties."
His principal argument is that, like it or not, the council has a duty of care under the law to its residents and cannot let them build in harm's way. If it lets the building continue and there is a devastating flood, "people will be taking us to court right, left and centre, and deservedly so".
The back and forth has all the appearances of going on, if not quite forever, then certainly well into the future. Although, of course, there is always the prospect that nature will have the final say.