Skip to content Skip to main navigation

Lifestyle

Part of the Canberra community
for over 30 years

Thar she blows! New Cotter Dam overspilled

By johnboy - 1 March 2012 76

The Cotter Dam Expansion Dam Cam is showing the worst case scenario of flood waters rising over the under-construction wall as the capacity of the river diversion is comprehensively overwhelmed.

Let’s hope the raging torrent doesn’t undermine the wall or this will become a disaster of 2003 bushfires proportion.

We certainly hope that doesn’t happen, but it’s not like this was meant to happen either.

UPDATE 01/03/12 09:10: Thanks to dpm for pointing us at the above video compression of the overspill

cotter dam overspill

[Photo by Androo]

UPDATE 02/03/12 8:18: And she’s still going very strong this morning:

cotter dam

UPDATE 02/03/12 09:31: This in from ACTEW supremo Mark Sullivan:

MarkS
2012/03/02 at 8:21 am

This morning observations are that the dam structure is sound. Heavy machinery has remained safe and cranes are fine. Have lost some forms and scaffolding and some light equipment. Biggest concern is the washing out of earthwork on the downstream side (looking at damcam it is on the left abutment or the right hand side looking at the dam). Possibly be a week before we get back on the dam and looks like a three week clean up. Flood is a one in one hunred year event so top marks to the engineers. Now we wait till tomorrows renewed assault.

What’s Your opinion?


Please login to post your comments, or connect with
76 Responses to
Thar she blows! New Cotter Dam overspilled
Filter
Showing only Website comments
Order
Newest to Oldest
Oldest to Newst
caf 1:27 pm 02 Mar 12

I think we should leave it like this and just build a few more viewing platforms. We could be Australia’s version of Niagra Falls – we’ll make a motza from the honeymooners!

Peekz 11:52 am 02 Mar 12

dpm said :

Thumper said :

We’re not very good at making things here in the ACT, are we…

Not sure what you mean exactly? 1) You can’t control the weather and 2) for something that was/is half-built when this rain ‘event’ hit (I love it how the media have embraced the new ‘event’ terminology!), there don’t seem to be any issues that have been caused by human error in the building process. Not sure what more they could have done here…..? 🙂

Surely this rain was factored in the to project schedule?

dpm 11:32 am 02 Mar 12

Thumper said :

We’re not very good at making things here in the ACT, are we…

Not sure what you mean exactly? 1) You can’t control the weather and 2) for something that was/is half-built when this rain ‘event’ hit (I love it how the media have embraced the new ‘event’ terminology!), there don’t seem to be any issues that have been caused by human error in the building process. Not sure what more they could have done here…..? 🙂

Thumper 11:26 am 02 Mar 12

Thoroughly Smashed said :

Thumper said :

We’re not very good at making things here in the ACT, are we…

It seems to be holding up…

I grant you that 🙂

Diggety 11:23 am 02 Mar 12

Skidbladnir said :

MarkS said :

Flood is a one in one hunred year event so top marks to the engineers.

*grumblegrumblegurmble*

Annual 1% non-dependant probability.
There is a sixty something percent chance of a 1% annual flood risk being realised once or more in a 100 year period.

You’re right of course Skid, but the “One in X years flood” is understood by most people; incorrectly, but nevertheless understood.

Thoroughly Smashed 11:08 am 02 Mar 12

Thumper said :

We’re not very good at making things here in the ACT, are we…

It seems to be holding up…

Peekz 11:02 am 02 Mar 12

As long as we don’t try to implode the dam in 50 years we should be fine 😉

Thumper 10:39 am 02 Mar 12

Thumper said :

We’re not very good at making things here in the ACT, are we…

Although I will admit that it is going to be seriously awesome when finished.

Thumper 10:36 am 02 Mar 12

We’re not very good at making things here in the ACT, are we…

Skidbladnir 10:28 am 02 Mar 12

However, top marks for communication go to ACTEW on this one.

Skidbladnir 10:23 am 02 Mar 12

MarkS said :

Flood is a one in one hunred year event so top marks to the engineers.

*grumblegrumblegurmble*

Annual 1% non-dependant probability.
There is a sixty something percent chance of a 1% annual flood risk being realised once or more in a 100 year period.

Peekz 10:03 am 02 Mar 12

thatsnotme said :

Hmmm, interesting. So Mr Evil = Funky Claude’s troll account??

No, Funky Claude just can’t quote properly.

davo101 9:25 am 02 Mar 12

caf said :

Interestingly the same thing happened during the construction of Googong Dam – http://www.engineer.org.au/images/4-11.jpg – and that’s a rock-fill dam.

I prefer this picture of Googong spilling. I like to wonder what was going through the minds of the engineers watching.

Deref 8:56 am 02 Mar 12

EvanJames said :

OpenYourMind said :

Let me just say how cool it is to have the local expert tell us how it is on RiotACT. Thanks MarkS

Seconded. Excellent work, great to see.

Thirded – thanks, Mark.

It must be disheartening to everyone working on dam. I bet it’s going to take a lot of work before they can get started again.

Great work, guys, thanks for your efforts.

MarkS 8:21 am 02 Mar 12

This morning observations are that the dam structure is sound. Heavy machinery has remained safe and cranes are fine. Have lost some forms and scaffolding and some light equipment. Biggest concern is the washing out of earthwork on the downstream side (looking at damcam it is on the left abutment or the right hand side looking at the dam). Possibly be a week before we get back on the dam and looks like a three week clean up. Flood is a one in one hunred year event so top marks to the engineers. Now we wait till tomorrows renewed assault.

thatsnotme 7:19 am 02 Mar 12

Hmmm, interesting. So Mr Evil = Funky Claude’s troll account??

buzz819 6:52 am 02 Mar 12

Mr Evil said :

rohbo said :

Mr Evil said :

A couple of questions.

Why were vehicles left parked on the topside of the dam when there had been pretty ample warning that NSW/ACT was going to receive a lot of rain in the next few days, and numerous flood warnings had been publicly issued?

If you know how to get some very heavy machinery off a 40m high wall i’m sure ACTEW would love to hear from you. Mark S from ACTEW said they got off everything they could with the cranes and the rest was too heavy so had to stay.

Umm, maybe the same way they got them up there in the first place?

Anyway, maybe I should have expressed myself better – the really heavy stuff isn’t the problem, as obviously if a 40 or 60 tonne object is going to be swept off the wall by the overflow, then I would suggest that there’d be bigger issues to worry about with the dam itself at that point. It’s some of the other smaller vehicles that appeared to be still on the dam in the photo that Mark submitted earlier this morning.

The point I was making is that we have had several days warning that the rainfall was going to be high, but some people seem to have been caught slightly ill-prepared by it all.

And as to my comments about objects seen floating down the river; yes, I understand that there will always be plenty of stuff that is washed down a river in flood, as witnessed on LBG last time we had a flood like this – but isn’t it a good idea to try and ensure that if at all possible that we don’t add to the debris pile unnecessarily?

I love arm chair critics, while you are sitting at your computer sipping your latte, photocopying stuff that no one really cares about, these guys are out slugging their guts putting together a remarkable structure that is built to contain 78 gigalitres of water, I can’t even fathom how much that is.

They have successfully built it in such away that the integrity is holding after a heavy onslaught of rain, no one is injured, they have done everything they can to make it safe – there and down stream and you think you could have done it better.

Good work Mr Evil. *sarcasm*

This time, good work to the construction workers up on the dam. *sincere*

Funky Claude 6:23 am 02 Mar 12

Funky Claude said :

The point I was making is that we have had several days warning that the rainfall was going to be high, but some people seem to have been caught slightly ill-prepared by it all.

And as to my comments about objects seen floating down the river; yes, I understand that there will always be plenty of stuff that is washed down a river in flood, as witnessed on LBG last time we had a flood like this – but isn’t it a good idea to try and ensure that if at all possible that we don’t add to the debris pile unnecessarily?

I would dear say that they had better access to forecasts and warnings than what you and I are privy to, and and as the equipment involved in the construction is worth thousands I doubt that they have adopt a reckless attitude to “add to the debris pile unnecessarily” as you suggest.

Not sure what has happened here, only the last sentence is mine. First two are quotes from Mr Evil

Devil_n_Disquiz 5:19 am 02 Mar 12

androo said :

I grabbed a short video of the overtopping shortly after it began. Sorry for the quality, using a flipcam but the audio gives you an idea of how loud it was.

You weren’t standing on a rock were you ? I came down and stood beside a couple who were filming. I was wearing bright yellow flouro shirt taking a few pics.

OzChick 12:29 am 02 Mar 12

Thanks for posting the time lapse videos. Amazing.

Do they always keep the lights on at night at this site?

Related Articles

CBR Tweets

Sign up to our newsletter

Top
Copyright © 2018 Riot ACT Holdings Pty Ltd. All rights reserved.
www.the-riotact.com | www.b2bmagazine.com.au | www.thisiscanberra.com

Search across the site