queensland lies about dam levels

[jeff f]

was talking to a friend of my fathers who works for sunwater

and he told me that the government is lying about the dam levels

they are saying the current combined levels are 58/60%

this man who works at wivenhoe told me that the true current levels are way higher

sommerset 98% and releasing water into wivenhoe wich is over 70% and the island has gone under

north pine at 75% stockyard creek is full and so is kurwongbah

ads up to 88%combined total

[chris_stewart14]

HA! True? Conspiracy theory... Maybe they want a buffer because once it hits 60% the drought is officially over.. I doubt this means open slather on yard hosing and free rein on water like ten years ago but I for one definately plan to start taking longer showers

[nadders]

yeah but imagine how many people who aren't too smart will be thinking to themselves if the dams are 88% full they dont need to watch their water use anymore, it makes sense to be as conservative as possible on the figures as far as this goes.

not saying that lying is necessarily a good thing but there are circumstances where it helps lol

[Mack_attack]

hey jeff, your comined total is assuming that all dams have equal capacity

[efc]

not sure if wivenhoe is near 70%

[jeff f]

Mack_attack wrote:

hey jeff, your comined total is assuming that all dams have equal capacity

no it doesn't its just working on percentage of a total

each dams percentage full is added together(443) then the total is divided by 5 dams

[shortie]

jeff f wrote:

Mack_attack wrote:

hey jeff, your comined total is assuming that all dams have equal capacity

no it doesn't its just working on percentage of a total

each dams percentage full is added together(443) then the total is divided by 5 dams

see jeff a uni education isnt everything hey. lol

Do your calc again Jeff

[wesfish]

of course they will lie , to try and justify spending all that money on the pipeline...i believe they emptied the dams to get their drought which was needed to start the pipeline, peter beattie wanted it something like ten years ago and was told no way unless the dam levels were critical , i know in 98 the big w was full and they let it out for 5-6 years to get the drought... just my thought

[Mack_attack]

jeff f wrote:

Mack_attack wrote:

hey jeff, your comined total is assuming that all dams have equal capacity

no it doesn't its just working on percentage of a total

each dams percentage full is added together(443) then the total is divided by 5 dams

you'd be right if it were simply an average of totals themselves but since each are percentage of a different capacity the equation above will not not give a combined total eg.

from SEQ:

W = 43.96%, S = 97.15%, N = 71.8%

according to your calc (W+S+N)/3 = 70.996%

but since each is a percentage of a different total real calc should be

((WxC) + (SxC)+ (NxC))/ combined C)= 58.85% where C is capacity

[fishingnut]

great thread btw, adding on pipe lines i have been told that a pipe has been completed pumping water from borumba into npd. and they have already done some trail runs pumping water in :ohmy:

[wallyfly]

mack_attack is correct. You can play with numbers 'til the cows come home but there can only be one correct answer and in this case it's 58.85%. Suggest you check the details on the weather sub.. the lakes bris for a full explanation.

[rayke1938]

They are still only quoting on the capacity of 3 dams what about Hinze ,Leslie Harrison, and all the other dams under SEQ water controll after all they now have the ability to transfer water from them all.

Another fact is that Wivenhoe is primarly a flood control dam and is not supposed to be allowed to fill over 75% capacity so that it can absorm a major event and prevent flooding of Brisbane so the figure for wivenhoes capacity should be quoted as a percentage of the 75% mark not the 100% mark which they are currently doing for media purposes. So the 70 figure that the sunwater bloke would be the accurate figure.

Cheers

Ray

[fishingnut]

wallyfly wrote:

mack_attack is correct. You can play with numbers 'til the cows come home but there can only be one correct answer and in this case it's 58.85%. Suggest you check the details on the weather sub.. the lakes bris for a full explanation.

of coarse hes right! way too smart to be wrong :blink:

[thatkellychic]

Mack_attack wrote:

you'd be right if it were simply an average of totals themselves but since each are percentage of a different capacity the equation above will not not give a combined total eg.

from SEQ:

W = 43.96%, S = 97.15%, N = 71.8%

according to your calc (W+S+N)/3 = 70.996%

but since each is a percentage of a different total real calc should be

((WxC) + (SxC)+ (NxC))/ combined C)= 58.85% where C is capacity

..... and you're a student?? what on earth are you studying???

[Mack_attack]

civil engineering

[thatkellychic]

i should have guessed. hehe.

[tomca]

I remember when Wivenhoe was built, the press release claimed it is full at 60% and the top 40% is used as a buffer so we don't have a 1974 type flood again.

Imagine the outrage when the dam is under 80% and they open the floodgates. I hope political pressure doesn't allow another flood because they were too scared to let some of the water out.

[noname]

call me what ever, but i always thought 100 percent was full, no matter what, so my question how does a dam become 125 percent full?

[jeff f]

i dont know i'm just going on what the fella that works there in the office told me

[chris_stewart14]

Does anyone know at what level they let the gates go? North Pine especially? Is it 100 or not that high?

[tomca]

as far as I know, NPD is purely water storage and if it reaches the spillway its full. Wivenhoe was primarily built for flood mitigation.

[efc]

why there isnt a pipeline up the range to toowoomba is beyond me.

it should have been number one on the list

[Swagger]

Some interesting theories there and could have a good amount of truth to it, seems to make sense. I'd say the government would dister the truth a little to avoid people overusing water to help maintain the water levels over a longer period of time, in case of such events reoccurring.

[tugger]

i'll just add that we're all glad to see this rain and the dams full again the pipe lines will gaurd us again from a huge population in sth east qld running out of water .what would we do then if 2 million people run out of water

[dhess]

I think you guys got it a bit wrong.

According to wikipedia:
/>http://en.wikipedia.org/wiki/Wivenhoe_dam

Wivenhoe's storage capacity is 1165000 ML.

Flood storage capacity is given as 1450000 ML.

So about 25% in flood storage available once its full.

The dam levels given by SEQ Water and the media are based on the capacity being 1165000 ML. So no misinformation and nothing funny happening.

/>http://oldsite.seqwater.com.au/content/standard.asp?name=DamOperationsandMaintenance

[Terry H]

dhess, if that was the case, that some people are getting their figures wrong, then that would make the 'supposed real' figure lower than what it truly is.

What Mack_attack is showing is correct, you really cannot take a straight average for the total capacity of our 3 main dams. The reason you can't do it that way is because of the different storage capacities. It would be like saying if you have one dam (a coffee mug) at 100%, and another dam (your bathtube) at 25%, then add those two together (100+25 = 125 / 2 = 62.5) and you get 62.5% storage capacity. Clearly a coffe mug is not going to make any difference in your total capacity compared to the bathtube, and you're real storage capacity is more like 25.1%

So yes, you really need to take the weighted average like what Mack_Attack has shown.

DAM - Current Volume - MAX Volume

North Pine Dam 154508 214960 71.88%

Somerset Dam 369024 379850 97.15%

Wivenhoe Dam 512231 1165240 43.96%

Combined (North Pine, Somerset, Wivenhoe) 1035763 1760050 58.85%

SEQ Water's website shows all SEQ Water dams levels: http://seqwater.com.au/newsite/index.php?option=com_damlevels&Itemid=8

Why don't the media show other dams? Well probably because Brisbane, for the most part, is fed by NPD, Somerset and Wivenhoe. Sure there is a pipeline between Hinze and Wivenhoe, but we're not actively sourcing water from Hinze. Besides, it's only a contingency plan to transfer water between dams when we need it, just like the recycled water.

Why would they lie about it? How can they lie about it? Go to the old SEQ Water site: http://oldsite.seqwater.com.au/content/standard.asp?name=DamOperationsandMaintenance

There you can see the water level at MAX storage capacity and the CURRENT storage capacity. Go see the water level for yourself, do these figures look right? yes.

What's with all the conspiracy stories

noname wrote:

call me what ever, but i always thought 100 percent was full, no matter what, so my question how does a dam become 125 percent full?

Dhess covered it

Somerset and Wivenhoe Dams each have space above their designated Full Supply Level, which is normally empty. This ‘space’ can be used to temporarily store floodwaters, when required.

/>http://oldsite.seqwater.com.au/content/standard.asp?name=FloodOperations

so 100% is their designated full supply level, 125% would be using that extra temporary flood mitigation level.

[mick fillet]

didnt they raise the wall of bigW and a second spill way with a cause way linking up to the brisbane river was built? pretty sure thats what i look at when i drive along the wall. maybe the percentages of bigW are taken on its new capacity levels

[EMP]

Terry's explanation on Mack's numbers is totally 100% correct.

To get the average "present actual content" (if there's such a thing) of 3 different containers (in this case the dams), what you do is add the full capacity all up (let this be A), get the total actual contents of all 3 containers (let this be and then divide B by A. Finally, move two decimal places to the right to get a percentage figure.

Nerds. :laugh: :laugh: :laugh:

EMP

PS I like Jeff's interesting post; it's very intriguing........

[Terry H]

Sorry EMP, I changed my comparison to something more extreme to help show the need for weighted average

Don't blame me, we just use weighted averages at work sometimes :ohmy:

[benno573]

they should be leaving as much water as possible in somerset. it is a much smaller and deeper dam with a far lower evaporation rate than wivenhoe.

just a quick one - when they raised the wall of awoonga many moons ago... gladstone was on water restrictions with the dam at 52%... which was the equivalent of 90% before they raised the wall!

i don't really care if they are understating the capacity or whatever they are doing if indeed they are doing it. just tell me when i can wash my bloody boat again!

and can we please stop with the maths stuff... i deal with it all day at work and i don't want to see more of it at home!

[Terry H]

benno573 wrote:

and can we please stop with the maths stuff... i deal with it all day at work and i don't want to see more of it at home!

But I want to be one of those that are "number one in numbers!"

[EMP]

It's very intriguing as to what a 100%NPD would look like........:ohmy: :ohmy: :ohmy:

Maybe I could plant a worm setup along Dayboro Rd. :laugh: :laugh: :laugh:

EMP

[EMP]

Does anyone see the homepage now? Or maybe it's just me...

My latest post is showing up partly on the homepage... I swear I didn't break the site... :(

EMP

Ne'r mind, it's fixed now. Yey!

[dhess]

TerryH wrote:

dhess, if that was the case, that some people are getting their figures wrong, then that would make the 'supposed real' figure lower than what it truly is.

..........

I was not disputing the fact that weighted averages are the correct way of calculating total levels in storage. I was referring to people being mistaken in the belief that reported levels are being given as a percentage of flood storage capacity not water storage capacity.

I am not a dumb dumb you know!

[StevenM]

The combined total just went down a bit.

I did a full flush

[EMP]

StevenM wrote:

The combined total just went down a bit.

I did a full flush

:laugh: :laugh: :laugh:

EMP

[fishingnut]

man does my brain hurt after reading that!!!!

ATTACK OF THE NERDS look out :laugh: :laugh: :laugh:

[werewolf]

dhess wrote:

Wivenhoe's storage capacity is 1165000 ML.

Flood storage capacity is given as 1450000 ML.

So about 25% in flood storage available once its full.

I'd just like to clarify that the the flood storage is 125%, ie the same "full" capacity again, plus some! :woohoo: This is a vast capacity for flood mitigation!

[Terry H]

dhess wrote:

TerryH wrote:

dhess, if that was the case, that some people are getting their figures wrong, then that would make the 'supposed real' figure lower than what it truly is.

..........

I was not disputing the fact that weighted averages are the correct way of calculating total levels in storage. I was referring to people being mistaken in the belief that reported levels are being given as a percentage of flood storage capacity not water storage capacity.

I am not a dumb dumb you know!

Sorry dhess, I know you weren't disputing weighted average. The line you quoted from me, and the paragraph under that were two different things I were talking about :laugh:

I just read all the posts again, and now I don't even know where the hell I was going with regards to my comment to you. My point was that SEQWater gives out a % based on the supply level, this is easy to see given the figures out. So the only mistake someone could make, is to then calculate it based on flood storage capacity, which would then result in a lower figure than what is really happening. How I came up with this point, I have no idea. For some reason I thought you'd mentioned someone has got their figures wrong, or something. :laugh:

Sorry :laugh: I'm tired. Might go to bed now instead

What you said is right dhess.

What I said was right.. just part of it was plucked out of no where and irrelevent to the discussion it seems :laugh:

[rayke1938]

Big thanks to Terry and D hess for clearing up some misapprehensions that I held but if all of SEQ are going to be under the same water restrictions and SEQ water has the capacity to move water around then all the capacity of all their dams should be counted and then averaged out.

Cheers

Ray