Cotter Dam expanders boned

johnboy 6 March 2012 64

cotter dam

The ABC brings word that ACTEW have told the 100 odd day workers on the Cotter Dam Expansion their services are no longer required. On top of that 120 permanents aren’t getting paid past Thursday:

ACTEW believes it could be three months before the clean up is finished and construction work restarts at the site.

The Cotter Dam expansion project was due to be finished in August, but is now expected to be completed by the end of the year.


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Chop71 Chop71 10:50 am 13 Mar 12

Sturmovik said :

dvaey said :

Paying the workers 1m per week for 3 months would work out to about 12mil.. when compared to the initial cost of 363mil, and a possible blowout upto 150mil, spending 12mil to retain your trained/skilled workforce doesnt seem like a stupid idea.

Its been reported that each day of down tools is costing them $250k, or over $22m for three months.

Intial cost was $120m, blownout to $363m, and now $500m?

and who will be paying this $500m? I guess the same ACT residents who pay the flood levy for the QLD and Vic Floods.

Sturmovik Sturmovik 9:26 am 13 Mar 12

dvaey said :

Paying the workers 1m per week for 3 months would work out to about 12mil.. when compared to the initial cost of 363mil, and a possible blowout upto 150mil, spending 12mil to retain your trained/skilled workforce doesnt seem like a stupid idea.

Its been reported that each day of down tools is costing them $250k, or over $22m for three months.

Intial cost was $120m, blownout to $363m, and now $500m?

dvaey dvaey 12:28 am 13 Mar 12

Paying the workers 1m per week for 3 months would work out to about 12mil.. when compared to the initial cost of 363mil, and a possible blowout upto 150mil, spending 12mil to retain your trained/skilled workforce doesnt seem like a stupid idea.

chewy14 chewy14 10:00 pm 12 Mar 12

Welkin,
A 1:100 year event doesn’t mean the biggest rainfall in 100 years, its the average recurrence.

Thumper Thumper 8:30 pm 12 Mar 12

Sturmovik said :

welkin31 said :

You can hear Mark Sullivan intervied by Ross Solly on the 7.30 Report last Friday;
http://www.abc.net.au/news/2012-03-11/cotter-dam/3882202
Questions about cost over-runs.
Solly tried to float the idea of a $500mill final cost, no luck at getting MS to agree with that.
MS ventures an interesting opinion that the aspects of water admin now included in ACTEWAGL could be all returned to ACTEW.

Henry82 said :

Sturmovik said :

My solution would have been to build the diversion pipes bigger to begin with. I imagine if they were twice as big water would have never overflowed past the old cotter dam and over the new one.

That’s the benefit on hindsight.

So on a tight budget, how much rain to you prepare for? a once in 20 year storm? 50 year storm? 200 year storm?

Plan for the worst, hope for the best…

Original budget was $120m, now $500m isnt out of the question.

So I guess my previous comment about the ACT not being very good at building things is correct?

welkin31 welkin31 6:00 pm 12 Mar 12

On the 2nd March at RiotACT – Mark Sullivan said the flood was a “…one in one hundred year event…”
Thar she blows! New Cotter Dam overspilled
http://the-riotact.com/thar-she-blows-new-cotter-dam-overspilled/66746
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 hundred year event so top marks to the engineers. Now we wait till tomorrows renewed assault.

Then in the Canberra Times Monday 5 March he is quoted – “We’ve had two 100-year floods in three days.”
http://www.canberratimes.com.au/act-news/jobs-to-be-cut-back-as-cotter-dam-work-stops-20120304-1ubep.html

I do not know what understanding of rainfall history ACTEW relies upon for these statements. I do know that in our relatively remote mountain regions rain data is patchy in time and space. But even with my meagre resources I can learn that in March 1950 BRINDABELLA STATION (070184) recorded 632mm – FAIRLIGHT STATION (070032 432mm and WEE JASPER STATE FOREST 73049 450mm.
So I am just not sure why anybody is talking about 100 year this or two by 100 year that.

Before leaving can I just roll this in from left field re the ACTEWAGL joint venture. I understand it was set in place by the last Liberal Govt.
I wonder why Labor left it standing ?
I am a bit at a loss to see how ACT consumers could gain by such an uncompetitive pairing.
Why would the ACT Govt owned ACTEW not want to retain the freedom to source electricity & gas from the most price competitive sources ?
With our recent supposedly competitive NEM – plus skyrocketing energy bills – I would have thought this is even more imperative.
So I ask, why not a D-I-V-O-R-C-E for ACTEW and AGL ?

Sandman Sandman 2:55 pm 12 Mar 12

JessP said :

Err when you are a Contractor you generally get paid a premium because you are not a permanent employee……that goes with the territory. Most contractors seem happy to make this choice – that is to take more money. They also have to accept the risk.

Suck it up. (And the water whilst you are at it).

Yep, just like a Farmer. Difference is that when a Farmer has a really good year he doesn’t go upgrading the boat, the house, the Clubsport or the Harley. He put’s it away knowing that next year he might have 90% of his crops wiped out by flood or the next 4 years might be in drought and he’ll barely scrape by.
No sympathy here for people who have overcapitalized or spent frivolously. Can’t expect to be paid for work you can’t do.

Skidbladnir Skidbladnir 2:14 pm 12 Mar 12

Henry82 said :

So on a tight budget, how much rain to you prepare for? a once in 20 year storm? 50 year storm? 200 year storm?

Independent probability is a funny thing that most people can’t grasp, and calling them “one in X year” events is quite unrepresentative and just leads to all kinds of trouble if people accept them as truth.
(EG: The regularly-mentioned “One in 100 year flood event” has a 64% chance of happening once or more in any 100 year period. You might get lucky and not have one, but if in the 99th straight year one hasn’t happened it’s not a certainty next year…)

Risks you’re talking about of an annual 5%, 2%, and 0.5% flood (one in 20, one in 50, and one in 200), correspond to a chance of happening once or more during any five year period of 22.6%, 9.6%, and 2.4% respectively.
(Assuming I remember my high school maths classes correctly…)

Sturmovik Sturmovik 1:47 pm 12 Mar 12

welkin31 said :

You can hear Mark Sullivan intervied by Ross Solly on the 7.30 Report last Friday;
http://www.abc.net.au/news/2012-03-11/cotter-dam/3882202
Questions about cost over-runs.
Solly tried to float the idea of a $500mill final cost, no luck at getting MS to agree with that.
MS ventures an interesting opinion that the aspects of water admin now included in ACTEWAGL could be all returned to ACTEW.

Henry82 said :

Sturmovik said :

My solution would have been to build the diversion pipes bigger to begin with. I imagine if they were twice as big water would have never overflowed past the old cotter dam and over the new one.

That’s the benefit on hindsight.

So on a tight budget, how much rain to you prepare for? a once in 20 year storm? 50 year storm? 200 year storm?

Plan for the worst, hope for the best…

Original budget was $120m, now $500m isnt out of the question.

welkin31 welkin31 1:36 pm 12 Mar 12

You can hear Mark Sullivan intervied by Ross Solly on the 7.30 Report last Friday;
http://www.abc.net.au/news/2012-03-11/cotter-dam/3882202
Questions about cost over-runs.
Solly tried to float the idea of a $500mill final cost, no luck at getting MS to agree with that.
MS ventures an interesting opinion that the aspects of water admin now included in ACTEWAGL could be all returned to ACTEW.

Henry82 Henry82 12:13 pm 12 Mar 12

Sturmovik said :

My solution would have been to build the diversion pipes bigger to begin with. I imagine if they were twice as big water would have never overflowed past the old cotter dam and over the new one.

That’s the benefit on hindsight.

So on a tight budget, how much rain to you prepare for? a once in 20 year storm? 50 year storm? 200 year storm?

Sturmovik Sturmovik 11:20 am 12 Mar 12

Thoroughly Smashed said :

dungfungus said :

Sturmovik said :

dungfungus said :

If Actew need to lower the level of the dam quicker why don’t they use syphons simply run over the top of the wall? This is a tried and proven method of moving water (emptying water beds, irrigating cotton etc.) and it uses no energy after priming. Pipes and hoses of any thickness can be used. The Greens would approve. Perhaps it is not hi-tech enough though so Actew will probably bring in expensive diesel pumps.

LOLs
You realise how big of a pipe you’d need? The dam already has two 2.5m diameter diversion pipes around the dam that was supposed to be big enough to flow excess water around the site.
Obviously they never planned for higher than average rainfall

I didn’t say one syphon; I said syphons and if 6 x 50cm metre pipes were installed as syphons the existing capacity of the diversion pipes would be incresed over 50% immediately. BTW, I didn’t hear what your solution was.

Two 2.5m dia pipes have a total cross-section of 9.8m²
Six 0.5m dia pipes have a total cross-section of 1.2m²

Whoops.

My solution would have been to build the diversion pipes bigger to begin with. I imagine if they were twice as big water would have never overflowed past the old cotter dam and over the new one.

Its amazing how soon people forget how much it can rain.

As for now, all they can do is wait for the water to drop, then dig out all the debris.

I think the Cotter dam project was already $250m overbudget, I wonder how far this will take it?

Thoroughly Smashed Thoroughly Smashed 11:10 am 12 Mar 12

dungfungus said :

Sturmovik said :

dungfungus said :

If Actew need to lower the level of the dam quicker why don’t they use syphons simply run over the top of the wall? This is a tried and proven method of moving water (emptying water beds, irrigating cotton etc.) and it uses no energy after priming. Pipes and hoses of any thickness can be used. The Greens would approve. Perhaps it is not hi-tech enough though so Actew will probably bring in expensive diesel pumps.

LOLs
You realise how big of a pipe you’d need? The dam already has two 2.5m diameter diversion pipes around the dam that was supposed to be big enough to flow excess water around the site.
Obviously they never planned for higher than average rainfall

I didn’t say one syphon; I said syphons and if 6 x 50cm metre pipes were installed as syphons the existing capacity of the diversion pipes would be incresed over 50% immediately. BTW, I didn’t hear what your solution was.

Two 2.5m dia pipes have a total cross-section of 9.8m²
Six 0.5m dia pipes have a total cross-section of 1.2m²

Whoops.

dpm dpm 10:27 am 12 Mar 12

I notice it has basically stopped overflowing now:
http://www.actew.com.au/Our%20Projects/Enlarged%20Cotter%20Dam/DamCam.aspx
Probably lots of cleaning up to do! I also notice the scaffold steps that were on the front wall are now missing, and presumably in the pond at the bottom.

It would be good to get some pics of the top deck to compare with some of the ‘before’ ones posted by Mark S on his twitter feed…
http://twitter.com/#!/Sullivan_ACTEW/status/175089298553581568/photo/1/large

Sturmovik Sturmovik 10:01 am 12 Mar 12

wildturkeycanoe said :

We should be being thanked by the city of Wagga Wagga for the Cotter Dam project. Imagine if all that extra water being held back at the moment ended up down the Murrumbidgeee river, how close it would have put the water over their levy bank. Thankfully Blowering Dam was also at a low level or its runoff would have certainly tipped the scales.
With the higher level of the dam and the nature of the shoreline, ie. an abundance of trees and debris, has anyone witnessed the type of material being washed over the wall and into the Cotter river? I can imagine it’d be like the Queanbeyan low level crossing in the last flood, or does it all get stuck at the top of the wall?

Apparently there is quite a bit of debris between the old cotter dam, and the half finished one.

dungfungus dungfungus 9:45 am 12 Mar 12

Sturmovik said :

dungfungus said :

If Actew need to lower the level of the dam quicker why don’t they use syphons simply run over the top of the wall? This is a tried and proven method of moving water (emptying water beds, irrigating cotton etc.) and it uses no energy after priming. Pipes and hoses of any thickness can be used. The Greens would approve. Perhaps it is not hi-tech enough though so Actew will probably bring in expensive diesel pumps.

LOLs
You realise how big of a pipe you’d need? The dam already has two 2.5m diameter diversion pipes around the dam that was supposed to be big enough to flow excess water around the site.
Obviously they never planned for higher than average rainfall

I didn’t say one syphon; I said syphons and if 6 x 50cm metre pipes were installed as syphons the existing capacity of the diversion pipes would be incresed over 50% immediately. BTW, I didn’t hear what your solution was.

wildturkeycanoe wildturkeycanoe 6:27 am 12 Mar 12

We should be being thanked by the city of Wagga Wagga for the Cotter Dam project. Imagine if all that extra water being held back at the moment ended up down the Murrumbidgeee river, how close it would have put the water over their levy bank. Thankfully Blowering Dam was also at a low level or its runoff would have certainly tipped the scales.
With the higher level of the dam and the nature of the shoreline, ie. an abundance of trees and debris, has anyone witnessed the type of material being washed over the wall and into the Cotter river? I can imagine it’d be like the Queanbeyan low level crossing in the last flood, or does it all get stuck at the top of the wall?

Sturmovik Sturmovik 11:03 pm 11 Mar 12

dungfungus said :

If Actew need to lower the level of the dam quicker why don’t they use syphons simply run over the top of the wall? This is a tried and proven method of moving water (emptying water beds, irrigating cotton etc.) and it uses no energy after priming. Pipes and hoses of any thickness can be used. The Greens would approve. Perhaps it is not hi-tech enough though so Actew will probably bring in expensive diesel pumps.

LOLs
You realise how big of a pipe you’d need? The dam already has two 2.5m diameter diversion pipes around the dam that was supposed to be big enough to flow excess water around the site.
Obviously they never planned for higher than average rainfall

Mr Evil Mr Evil 7:26 pm 11 Mar 12

Okay, if the GDE took seven years to finish, how long is this monster going to take???

Obviously, a lot of the more experienced contractors who have now lost their jobs are not going to sit at home (unpaid) waiting until the clean up has been completed, so no doubt they will not stay in the ACT, and find work elsewhere – so who takes their places once work on the Cotter Dam can commence again?

Pity they can’t all be called up for jury duty for the next three months – as that’d keep them on the books!

dungfungus dungfungus 6:45 pm 11 Mar 12

If Actew need to lower the level of the dam quicker why don’t they use syphons simply run over the top of the wall? This is a tried and proven method of moving water (emptying water beds, irrigating cotton etc.) and it uses no energy after priming. Pipes and hoses of any thickness can be used. The Greens would approve. Perhaps it is not hi-tech enough though so Actew will probably bring in expensive diesel pumps.

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