Warragamba Dam wall to be raised to avoid catastrophic flood event


Three days before Warragamba Dam could spill due to severe storms, the Baird government has committed to raising its wall to prevent a potential flood disaster in western Sydney, four years after being advised to review the options.

As a looming east coast low raised the possibility that the dam could spill on Sunday, the government said it will commit $58 million towards raising the wall by 14 metres to avoid a catastrophe that could place 43,000 western Sydney residents at risk.

Construction, at an estimated cost of about $690 million, is expected to be complete within three to four years after a business case is signed off in 2019, subject to planning approvals.

http://www.smh.com.au/nsw/warragamba-dam-wall-to-be-raised-to-avoid-catastrophic...


Anyone still want to still deny human caused climate change ?

Belgarion wrote on Jun 17^th, 2016 at 9:28am:



It's about dangerous flooding due to increasing extremes from human caused climate change.

Warragamba Dam levels have exceeded 80 per cent for the first time in nearly 10 years.

The dam, 60 kilometres west of Sydney, is the city's primary water source. The Warragamba catchment area is 9000 square kilometres.

The last time the dam's levels rose above 80 per cent was June 2002, according to the Sydney Catchment Authority.

It was at its lowest in February 2007 when it fell to less than 33 per cent.
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In April 2005, when the dam was at little more than 40 per cent of its capacity, the environmentalist Tim Flannery said it might be in terminal decline. It had only two years' supply.

From January 2010 to 2011, dam levels increased from nearly 50 per cent to 76 per cent, as an unusually wet spring replenished supplies after the drought.

The last time Sydney dams were full was 1998.

Debbie Low, a spokeswoman for the Sydney Catchment Authority, says dam levels are typically affected by factors such as consistency of rainfall, soil moisture and evaporation caused by summer heat.

But they are also affected by political decisions and have political consequences.

Water had previously been transferred to Warragamba from the full Tallowa dam on the upper Shoalhaven River.

But the previous state Labor government cut off these transfers in 2008 and imposed a three-year moratorium. Excess water from Tallowa was instead diverted to surrounding rivers, which flowed into the sea. Transfers were resumed briefly in September but have since been cut off.

Had the transfers continued over this period, Warragamba would be close to full, according to projections obtained by the Herald.

The Greens say the government has manipulated Warragamba levels to keep them lower so the privatisation of the desalination plant at Kurnell is more attractive.

Now that Warragamba's levels are more than 80 per cent, the supply from the desalination plant has been reduced.

If Warragamba levels stay above 80 per cent for two years, the plant's supply will be cut off until levels reach 75 per cent again.

The government is trying to sell the Kurnell plant for an estimated $1.5 billion.

The Greens oppose the sale, arguing that the plant should be shut because its output is unnecessary and adds nearly $100 to the average water bill.

They point to Warragamba's rise above 80 per cent as further evidence it is not needed.

But the government has welcomed the rise of dam levels and says it will not affect the decision to privatise the desalination plant.

"This will have absolutely no impact on the long-term lease of the plant," the Minister for Finance and Services, Greg Pearce, said.

Read more: http://www.smh.com.au/environment/water-issues/dam-level-hits-10year-high-201112...

____ wrote on Jun 17^th, 2016 at 9:15am:


Tim Flannery a radical imam from the Climate change religion was preaching Warragamba dam would never be full again and warned there was only 2 years worth of water left in 2005.

The Climate change religion makes it up as they go along, can you get your story straight with this dam.
Quote:


We listened to the fearmongers on climate change and spent billions on desalination plants that are not used because they are not needed.

Belgarion wrote on Jun 17^th, 2016 at 9:28am:



It's about dangerous flooding due to increasing extremes from human caused climate change.

Wow - how much extra would that Warragamba catchment cover if it was raised fifty feet?  Anyone provided a map yet?

Apparently not only is 'global warming' causing the oceans to rise, but the dams as well.. buggar me!  We might see a flooded for good Lake Eyre yet.... open it up to the sea and install the GAIA Phase I..... we'll forcefully remove the Eyrian Mud Kipper and the Saltbush Striped Sloth to a better environment so they won't become extinct.

Put all those boat people to digging the canal from Port Pirie or whatever....

Sir Grappler Truth Teller OAM wrote on Jun 17^th, 2016 at 1:55pm:



A good contour map of the district would show how much extra land would be taken up by the 50 feet. 16 metrres

Laugh till you cry wrote on Jun 17^th, 2016 at 6:43pm:

Sir Grappler Truth Teller OAM wrote on Jun 17^th, 2016 at 1:55pm:


50 feet equals 15.24 metres. Close to 16 metres.

No evidence of what? Raising a dam wall 50 feet could raise the water behind the dam, up to a 50 foot (15.24m) higher contour line?   You really disagree with that statement?

A prudent man would take into account wave height which might mean the dam could not be filled to 15.24 metres and definitely not 16 metres.

As chief protagonist of a 15.24 metre erection, what would be the effect of an earthquake?

Laugh till you cry wrote on Jun 17^th, 2016 at 7:59pm:



Warragamba is now in an earthquake zone? DamN.

They would fill to the height of the spillway. That is how they are designed.

You don't get it. Waves!

I am awarding you an F in dam design.