Warning
27 April 2010 - 8:18am
Dam break flood risk may close track
The dammed Young River looking upstream towards the lake formed by the landslip at left. Photo by Matthew Haggart.
A 'code red' may be issued for the Young Valley-Gillespie Pass circuit track today, closing it to the public.
The Department of Conservation warning follows severe weather warnings issued by the MetService at the weekend.
A 2km-long dam formed by a landslip in the Young Valley in September 2007 could, when full, contain at least 17 million cu m of water.
An interagency management plan has been put in place to deal with issues that could threaten the stability of the landslip dam.
Under a large dam break, the present flood channels would not be able to contain the flow of water and people in the valley could be be harmed.
Trampers were being advised to keep out of the valley at the weekend, with warnings placed at Doc visitor centres and at track entrances.
The Otago Regional Council water information website shows the landslip dam's contents had risen from 579.2m above sea level on Friday to 581.2m by 4pm yesterday.
There had been 33mm of rain at Makarora since 4pm Saturday and it was still raining last night.
Wanaka Doc area manager Paul Hellebrekers said last night the situation would be reviewed first thing this morning, depending on the weather overnight and the rainfall that had been received.
The MetService website forecast prepared by John Crouch yesterday said several frontal bands, embedded within a strong moist north to northwesterly flow, were expected to bring periods of heavy rain to Westland and Fiordland through to at least tomorrow, with significant spillover into the headwaters of Otago and Canterbury lakes and rivers.
Up to 90mm was likely to spill over the main divide into the headwaters, with most of this rain occurring yesterday and today.
"This is a significant amount of rain for these areas, and will bring rapidly rising river and stream levels in Westland and Fiordland, and also to the rivers of Canterbury and Otago that feed from the Southern Alps.
"People within these areas, especially hunters and trampers in the mountains, and river-users elsewhere, are advised to take care over the next few days," the MetService said.
27 April 2010 - 11:00am
#2
Er, they're different things. Place a dictionary in front of yourself then consider the following:
An environmentalist says "save the Young!".
An environmental manager, in this case, says "hazard, risk, solution, outcome".
One is somewhat idealistic but admirable and necessary, the other is, as you more-or-less say, driven by anthropocentric considerations. If you don't like environmental management, go stand outside your regional council, with a placard.
28 April 2010 - 12:28pm
#3
not sure how the Young Landslide relates to any of what you are saying Jezer. The landslide is an entirely natural event. No manmade migitation has been put in place to remove the dam. The mitigation that has been put in place is to provide warning of downstream flooding should the dam break of it's own accord. There is no attempt in this case to change the course of nature but merely to prevent undue harm in the event of a flood occuring.
28 April 2010 - 12:54pm
#4
I guess my comment was more thinking out loud, as MM pointed out an environmental manager is not necessarily an environmentalist. If that dam bursts and sends a torrent down on the lowlands, rest assured someone will be blamed for not doing "something about it" - yet on the same hand we consider ourselves conservers of the environment - letting nature do what nature does. It's a conflict of interests. Damned if you do, damned if you don't... pun intended. But then again, I've never met an environmentalist so hard core he refuses to live in a house because the wood and iron was hacked out of the environment. I'm guess I'm searching for a balance in "environmentalism" because living isn't very practical without doing some form of "harm" to our environment, even if it's effect is short term. In fact maybe it's better to view "environmentalism" as "minimisation of negative effects." The greater good so to speak.
29 April 2010 - 12:21am
#5
If that dam bursts and sends a torrent down on the lowlands, rest assured someone will be blamed for not doing "something about it"
Maybe. Same thing with the Crater Lake on Ruapehu. One government minister (it might have been Nick Smith, but maybe I'm imagining that) was quoted saying that a few days' work with a bulldozer up there would be all that was needed to make the lahar risk disappear.
But that didn't happen. A warning system was put in place and when the lahar eventually happened, the system worked, nobody died.
I think it's not really about minimisation or the greater good, it's about saying that in a national park we're going to let natural processes take their course, and if there are downstream effects, we'll deal with them down there.
Isn't it funny how we talk about environmentalism and preserving the earth... and yet when a land slip causes a dangerous dam of water we talk about "Environmental Management." Makes we wonder what environmentalism is really about... letting the earth evolve as it has through floods, volcanos, winds, fire, earthquakes etc... or is it actually more about doing what we see as fit? With the stuff ups man has made in regards to introducing non natural species and the clearing of lands leading to erosion, you have to wonder if we shouldn't just let things take their course. Living things eventually heal themselves and restore the balance of their own accord. It would seem environmentalism is more about lessening the impact of the stupid mistakes we are still paying for or do not want to pay. So is enviromentalism really about the environment or is it about the environment from just our selfish point of view?