22 June 2009

Cotter Dam enlargement moves ahead

| johnboy
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Andrew Barr has announced that he’s happy with the Environmental Impact Statement Assessment Report (EISAR) for the Cotter Dam expansion.

Now we just need to wait for the Commonwealth to agree.

ACTEW are breaking out the champagne.

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TP 3000 said :

While we are on the fires I have been told that Rural Fire Fighters were holding the fire back up near Bulls Head & had to just keep the fire back while SES crews went from Bulls Head through the mountains to Corin Dam to pick up the boat & crew that was forgetten about. They then came back to Canberra via Bulls Head. They then had to hold the fire back while NSW crews came around the fire to help. But they had 5 metre left to back burn & they weren’t allowed to burn that. Now that 5 metres could of stopped the fire coming from Bulls Head. I have also been told that NSW RFS Commission Phil Koperburg sent RFS crews from Sydney & surrounds, but they were rejected by the ACT ESA. But Phil Kopenburg made those crews wait at Golbourn as he knew something was going to happen.

Stick to the buses TP3000. Oh by the way were the people who told you this depot starters?

Back on topic people.

While we are on the fires I have been told that Rural Fire Fighters were holding the fire back up near Bulls Head & had to just keep the fire back while SES crews went from Bulls Head through the mountains to Corin Dam to pick up the boat & crew that was forgetten about. They then came back to Canberra via Bulls Head. They then had to hold the fire back while NSW crews came around the fire to help. But they had 5 metre left to back burn & they weren’t allowed to burn that. Now that 5 metres could of stopped the fire coming from Bulls Head. I have also been told that NSW RFS Commission Phil Koperburg sent RFS crews from Sydney & surrounds, but they were rejected by the ACT ESA. But Phil Kopenburg made those crews wait at Golbourn as he knew something was going to happen.

Granny said :

I went to a public presentation and consultation on the issue the other night, and, yes, they have learned lessons and they are still hoping to learn more from Victoria. I was really impressed with them.

I have had this hope before, too.

The problem of a disconnect between management and the people on the ground, some of whom have been fighting fires in the area for decades, doesn’t seem to ever go away.

The number of times I’ve heard stories (from interstate before any gets excited) from locals about knowing which way a bad fire would come from, or how to deal with it in a particular area when it does come, but being told by management to go away, or perhaps they’re told the prevention burn they’ve done for decades actually isn’t physically possible (ie – it’s agreed its needed, but ‘no one can get in there’)… These few words don’t do justice to the capacity for management to ignore their on-ground expertise in the lead-up to a crisis.

Inquiries air some of the issues, but then I have been told of the fire fighters being forbidden by management from giving evidence in reports and even to inquiries (well, perhaps if they were invited, but only management ever really give evidence in these situations). The recommendations get made. And then everything continues on to the next fire.

Sorry Granny.

Clown Killer8:03 am 23 Jun 09

Caf, section 5.2.3 simply details the innappropriate response. Many people on the ground, including some that I have fought fires with in NSW in the decadeleading up to 2003, were simply bewildered by the decisions made at the top between January the 8th through 10th. Rather than focus on what was a real and present danger they were witholding essential resources ‘in case’ something else happened.

Over 500 homes lost, four dead, our catchments incinerated. Its easy to be an armchair revisionist, but I think you do a disservice to the hard working people on the ground.

Jivrashia said :

“I wonder if access to Pryor’s Hut (and Mt. Ginini & Mt. Gingera) would be restricted due to this project?

I know that the alternative route is via Brindabella and Mt. Franklin Rd, but unfortunately I don’t own a 4WD to safely trek through these roads.

The Cotter Dam work is no were near this. You just go up the Corin Dam road and then walk up stockyard spur.

I went to a public presentation and consultation on the issue the other night, and, yes, they have learned lessons and they are still hoping to learn more from Victoria. I was really impressed with them.

Chop71: Doubt anyone from ACTEW will post – but check this document on the project from their site. The “Introduction and Background” section says:

As planned the new dam would submerge the existing dam which is on the Register of the
National Estate.

It also talks further on in the document about using the existing dam as a coffer dam during construction.

….and is there any chance people can use boats on the dam? There seems to be very little power boating areas available for ACT residents.

Can a person in the know from ACTEW please confirm if the old dam wall is staying? People here saying it’s 50m under the new wall height is fine, but is that assuming the dam is full?

They didn’t choose to do nothing – the following section 5.2.3 describes it:

On hearing Mr Ingram’s first report of the fire at 4.02pm, Mr Graham immediately directed units to the fire, as noted.

(and goes on into great detail).

They did later decide not to keep units out there during the night, which was a decision based on personnel safety. It’s easy to look back and see where things went wrong – often misunderstandings and incorrect information – but it’s easy to be an armchair General. I think it does a disservice to the emergency services people to imply that they just decided to let the place burn down.

From what I’ve been told those running the fires out at ESA Curtin HQ were worried & pulled troops in early (Friday morning). But the only sad thing was that (as far as I remember) Canberra had the cleanest water supply in Australia & possibly the world.

But if we didn’t have the fires then more work may of needed doing for dam prep work.

There back on topic.

This is getting really off topic, but Have any lessons really been learned?

The Melbourne fires seemed to have all the same issues

– warnings were coming after the fires went thru – tv bulletins were hours behind – phones were down due to congestion and poles down – ‘unprecedented conditions led to an unexpected firestorm (oops – just like the one in Canberra a few years earlier).

Clown Killer said :

This is getting off topic, but for the record I do know Chapter 5 and that’s exactly what I’m getting act. I think you’ll find that Sections 5.2.1 and 5.2.2 are littered with references to people expressing concern that the fires should be attacked aggressively to ensure that they were extinguished quickly – but not much was actually done to that effect. They could have chosen to do something and they decided not to.

Hindsite is a wonderful thing isn’t it? It is time we all accepted that shit happened, everyone (including the government) did the best they could at the time (although yes we now years later we know thing COULD have been done differently) and more importantly lessons for the future have been learnt.

I’d have thought that given we have the last flow restrictor in the MDB already (Yerrabi) another enhanced destructor of river health would be the last thing you would want to attach your name to.

The mind boggles. I’d love to see the environmental flow policy associated with this, assuming they have one. No spring flows means no or severely impacted fish recruitment. I doubt the turtles, water dragons etc will be too impressed either. And new lake syndrome should produce some superbly conditioned exotics (which you won’t be allowed to fish for) because we really need more spotty carp in our waterways.

What are they going to put in it? Maybe they are importing a few Navajo to do a rain dance, or perhaps engaging a few pubes appropriately coloured* and dressed in traditional attire will perform the ceremony.

But then again, something has to give the arborbleakum a drink now and a again.

*ala a certain stadiums grass during a certain bid for sporting events. Just not grass coloured. Canberra, home of the Red (Tape) Indians.

I wonder if access to Pryor’s Hut (and Mt. Ginini & Mt. Gingera) would be restricted due to this project?

I know that the alternative route is via Brindabella and Mt. Franklin Rd, but unfortunately I don’t own a 4WD to safely trek through these roads.

I can see the future headlines now: “Construction of dam expansion delayed due to rain.”

Don’t let the Government fool you into believing that we have water restrictions because there’s a drought. We have water restrictions becuase in January 2003 the ACT Government chose to let the catchmnt go up in smoke.

well, ck, bushfires do have a significant impact on the water cycle as, while mature trees take a little water from what rains there are and let the rest run into any catchment, re-growth following a fire means that saplings suck up a shirt load more water for some few years, meaning less into a catchment.

but we are actually still in a drought – i don’t think this is just about water restrictions, more about future proofing, as the predictions are for a drier climate with more incidence of fires (irrespective of how the last one was or wasn’t fought).

and granny, if we go watch the wall’s submersion i’ll bring the ginger beer!

I’m with caf and Thumper! I’d love to see it fill up, especially whilst eating chicken and champagne and stuff!

Clown Killer4:10 pm 22 Jun 09

This is getting off topic, but for the record I do know Chapter 5 and that’s exactly what I’m getting act. I think you’ll find that Sections 5.2.1 and 5.2.2 are littered with references to people expressing concern that the fires should be attacked aggressively to ensure that they were extinguished quickly – but not much was actually done to that effect. They could have chosen to do something and they decided not to.

I’m guessing you missed the outcomes of the Coroners investigations then.

I’ve looked at it, yeah (but I haven’t read it cover-to-cover), and I don’t think it supports your assertion. Have a read through Chapter 5.

Clown Killer said :

However, the regrowth in the affected areas, and there’s heaps, has now negateg any ill affect from run off so i don’t think that it is an issue.

My view, and I’m not saying it’s 100% right, is based on what I’ve been told by foresters familiar with the catchment and the species growning up there. Their view was one of 10-15 years before inflows per rain event get anything near the pre-fire state.

CK, your forresters are right. There will be a loss of yield from the catchment for as long as it takes to regenerate. Studies would indicate that initially run off would be higher and much dirtier and that as regowth picks up yield goes down, all things being equal. The choice of regeneration in the catchment also influences how rapidly yield will increase back to previous levels. Forrest takes longer than grass lands for instance.

What is unequal is rainfall. Sometime there is going to be above average rainfall for a year or too but not produce pre-fire level runoff but maybe 15%-25% less. Still lots of water.

Then the 78GL Cotter will fill not only from its 200 sq km catchment but also from overflow from the 100 sq. km Bendora
catchment.

Lets hope the dam is built before that happens. The dam will not only provide more storage, it will provide more water collecting ability.

Clown Killer1:11 pm 22 Jun 09

However, the regrowth in the affected areas, and there’s heaps, has now negateg any ill affect from run off so i don’t think that it is an issue.

My view, and I’m not saying it’s 100% right, is based on what I’ve been told by foresters familiar with the catchment and the species growning up there. Their view was one of 10-15 years before inflows per rain event get anything near the pre-fire state.

Clown Killer1:09 pm 22 Jun 09

Sure, they decided to leave the magic inaccessible-area bushfire evaporation machine in the garage!

I’m guessing you missed the outcomes of the Coroners investigations then.

Until the new dam fills, using the firebucket on a helicopter right near the dam wall when you have a massive expanse of water all at the same level would be borderline ridiculous.
And the bucket would have to be drawing water from 50m below the (future) surface of the new dam to make contact with the old dam wall.

Won’t be that exciting. All you will see is the water going over the top of the old dam, like it does a few times nearly every year, and filling the space between.

TP 3000 said :

I have been told that the ACT Labour Party are trying to have the dam completed AFTER an election. As they know that as soon as the Cotter dam is enlarged our dam capacity will go from 45% to 20%.

But caf, I would of thought that the old dam wall will be blown up, as it causes a hazard when we have another drought & when helicopters come in to fill their buckets, the buckets might catch on the old wall & bring the helicopter down. Or they may even temporarily empty Cotter (transfer the water to Googong) & remove the wall & empty Googong Dam (via transfer again) to make the new Cotter Dam look all full & pretty.

I think your figures are a bit off if you think we will go from 45% to 20% when the new dam is built. If anything i think the government would want it built before the election to show off their new infrastructure. And that helicopter must be pulling water from pretty deep if you think the bucket could get caught on the old dam.

TP 3000: Nah you can read the plans online – they’re going to leave the old wall in place. It shouldn’t present a hazard to anyone, since the top of it’ll be at least 50 metres under water.

“chose to let the catchment go up in smoke”? Sure, they decided to leave the magic inaccessible-area bushfire evaporation machine in the garage!

But caf, I would of thought that the old dam wall will be blown up
Nup, last plan I read was just to build a new one in front of it. Seems perfectly sensible to me.

as it causes a hazard when we have another drought
What kind of hazard exactly?

Hells_Bells7412:16 pm 22 Jun 09

Clown Killer said :

…water from where? not enough rain to fill it yet.

Oh there’s been mor than enough rain to fill the cotter dam many times in the last six years. It’s just that the new growth in the catchment sucks up the majority of the water and will continue to do so for possibly the next decade. Don’t let the Government fool you into believing that we have water restrictions because there’s a drought. We have water restrictions becuase in January 2003 the ACT Government chose to let the catchmnt go up in smoke.

Oh, it makes my day when I read someone not fooled (right or wrong). I suspect you are dead on the money.

I have been told that the ACT Labour Party are trying to have the dam completed AFTER an election. As they know that as soon as the Cotter dam is enlarged our dam capacity will go from 45% to 20%.

But caf, I would of thought that the old dam wall will be blown up, as it causes a hazard when we have another drought & when helicopters come in to fill their buckets, the buckets might catch on the old wall & bring the helicopter down. Or they may even temporarily empty Cotter (transfer the water to Googong) & remove the wall & empty Googong Dam (via transfer again) to make the new Cotter Dam look all full & pretty.

PeterH:
As caf says, the water doesn’t need to fill the dam to capacity, just overflow over the old wall for long enough to fill the new bit of space, and then a bit more.

According to the EIS the new 76m dam is being built 125m downstream, and the current wall is 26m high.

Anyone know the actual volume of the downstream component between old wall and new wall?

Interested people shouild be able to work out a guesstimated timeframe for inundating the old wall if you knew inflows, and data from how they intend to manage basic environmental outflows in the interim…
(ACTEW plan on a natural upstream catchment of between 69 – 73GL/pa inflow, environmental outflow from Cotter was ~=14GL/year (averaging 444L/second) in the last report I can find.)

Clown Killer12:01 pm 22 Jun 09

…water from where? not enough rain to fill it yet.

Oh there’s been mor than enough rain to fill the cotter dam many times in the last six years. It’s just that the new growth in the catchment sucks up the majority of the water and will continue to do so for possibly the next decade. Don’t let the Government fool you into believing that we have water restrictions because there’s a drought. We have water restrictions becuase in January 2003 the ACT Government chose to let the catchmnt go up in smoke.

It doesn’t need to fill to overtop the old dam – just has to fill the comparitively small space between the old dam and the new dam wall. The water will probably come from Corin.

caf said :

When it’s finished, I’m keen to go out there and watch as the old dam disappears beneath the water.

um, the water from where? not enough rain to fill it yet.

When it’s finished, I’m keen to go out there and watch as the old dam disappears beneath the water.

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