Catchment-wide questions about proposed Wyangala Dam expansion

Wyangala Dam: true costs questioned across catchment

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Sue and David Webster at the base of Wyangala Dam wall. They fear raising the wall will destroy some of the most valuable country on land that has been farmed by the family for five generations. Photo: Daniel Pedersen

Sue and David Webster at the base of Wyangala Dam wall. They fear raising the wall will destroy some of the most valuable country on land that has been farmed by the family for five generations. Photo: Daniel Pedersen

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Above and below Wyangala Dam, the true cost of raising the wall by 10 metres remains an unknown.

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THE prospect of raising the Wyangala Dam wall has left Reids Flat farmers David and Sue Webster frustrated and deeply worried about the future of a property farmed by five generations of the family.

The property stands to lose 500 hectares of prime river flats currently used for cropping.

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The Websters, who witnessed the 1971 extension of the wall, which was first built in 1936, reckon the dam will have to be limited to about 30 per cent capacity for the duration of the build.

And with that comes not only reduced water allocations for irrigators, but compromised flood mitigation capacity, they say.

The wall dwarfs utility buildings near its base. Much of the existing park would likely be buried to extend the wall.

The wall dwarfs utility buildings near its base. Much of the existing park would likely be buried to extend the wall.

The Department of Planning, Industry and Environment acknowledges, "as with all major infrastructure projects, there will be many challenges during construction".

"The level of Wyangala Dam storage during some stages of the wall-raising project is potentially one of these challenges," a department spokesperson said.

"Specialists teams are undertaking work to find the best solution to these challenges in close consultation with all water users."

The spokesman said planned state government dam enlargements would increase the amount of storage "at both Wyangala and Dungowan creating a triple bottom-line benefit to all water users".

Wyanagala Dam wall is enormous. An engineer's report lodged with the government last week suggested raising it by 10 metres would add another 40 per cent bulk to it.

Wyanagala Dam wall is enormous. An engineer's report lodged with the government last week suggested raising it by 10 metres would add another 40 per cent bulk to it.

Standing at the base of the dam wall Mrs Webster said of her son John's export lamb operation: "we did the right thing, we went through a succession plan and looked at what we've left them, a can of worms".

Mr Webster said a senior Nationals MP late last year dismissed his concerns and described the project as a "done deal".

After such a standoff, Mr Webster said he would never vote for the Nationals again.

"That is just politics from the National Party, the Nats don't really represent country people anymore, they just represent themselves."

There is a growing chorus of discontent across the Lachlan River catchment about possibly raising the Wyangala Dam wall.

Above the existing dam, Upper Lachlan NSW Farmers branch chairman Robyn Alders says landholders are deeply concerned.

Dr Alders - who currently runs 571 ewes and lambs and 120 wethers on the 200-hectare Toledo on the Fullerton Road - said the manner in which the Wyangala project was shaping up promised no positive return on investment.

Some of the river redgums that will be inundated are enormous.

Some of the river redgums that will be inundated are enormous.

The immediate concern among Upper Lachlan farmers is that if Wyangala ever filled, one significant rainfall event on the back of that would result in the loss of superb grazing land, killing pastures and ancient river red gums.

"And once trees like that die, there's no return for trees of that age."

Dr Alders said there needed to be a cohesive, catchment-wide approach to soil health to address both loss of topsoil and siltation.

"National water security is incredibly important," said Dr Alders, "and the agricultural sector is incredibly important".

She said more efficient use of the dam's current capacity would better serve all water users and such a large amount of money could be better spent supporting transition to more efficient water use.

"There are water-use efficiency technologies available and they are being used in the United States, Israel and the European Union, but those countries support their farmers," she said.

Dr Alders said one of the major issues the government had so far been silent on was siltation.

Mr Webster said already below Cowra there was a sand 'slug' 150 kilometres long in the Lachlan.

"You can see trees growing in the river," he said.

Dr Alders said that suggested there were already major siltation problems caused by the dam in its existing state.

She said sustainable management of siltation had been recognised as a 'significant threat' to the longevity, usefulness and sustainable operations of dams by the World Bank.

It is not only above the dam that farmers are concerned.

The years needed to construct a new wall and the consequent reduced capacity at Wyangala Dam would cast downstream irrigators into a new millenium drought, says Booligal irrigator Gordon Turner.

There would be no general security water available in that time and Water NSW would have difficulty delivering even high-security allocations, he said.

"It's a terrible investment for the taxpayer."

Mr Turner also said reduced flooding or spill events would effectively threaten internationally significant wetlands, the Great Cumbung Swamp and the Booligal Wetlands.

Monitoring Straw-neck Ibis nests at the Booligal Wetlands, along the Lachlan River. Photo: Dr Jennifer Spencer, DPIE

Monitoring Straw-neck Ibis nests at the Booligal Wetlands, along the Lachlan River. Photo: Dr Jennifer Spencer, DPIE

Australia has signed agreements with Japan, China and South Korea to protect migratory birds that use territory in both countries - they include both wetlands.

"We don't think the public would think it a benefit to destroy the breeding opportunities of millions of Australia's water birds and damage hundreds of thousands of hectares of nationally significant wetlands and flood plains," he said.

Mr Turner said after 40 years of Nationals this year he flicked his renewal form in the bin on Australia Day.

Bev Smiles says the costs to the whole of the Lachlan River system must be considered.

Bev Smiles says the costs to the whole of the Lachlan River system must be considered.

Inland Rivers Network president Bev Smiles says the entire system would be severely disrupted by raising the dam wall.

She insists there are significant water-saving measures that are more cost-effective to be had by maintaining existing infrastructure.

"The Jemalong Irrigation system is a case in point. Similar water savings and improved yield could be had repairing Jemalong," she said.

Ms Smiles said the amount of conveyance water currently needed to deliver orders made within the scheme would match an enlarged Wyangala's yield.

She questioned why such possibilities were not included in the Regional Water Strategy.

"It seems there's an attitude that regional water strategies involve building dams."

Wyangala Dam releasing water during the flooding of 2016.

Wyangala Dam releasing water during the flooding of 2016.

Ms Smiles said a larger dam would take more water out of the system and that meant less flows downstream.

"The true cost to both economy and environment of less natural flows downstream is enormous, for instance losing wetlands, how is that assessed as a cost?"

Ms Smiles said it was yet to be seen whether the business case for the dam fully assessed whole-of-system costs.

"The business case must be released as a public document because an uknown amount of public money would be needed for the project," she said.

Asked what effect raising the dam wall would have on the Murray Darling Basin Plan, an MDBA spokesperson said: "the Basin Plan sets out sustainable diversion limits (SDL) for each valley in the Murray-Darling Basin".

"SDLs are how much water on average can be used in the Basin by towns, communities, industry and farmers. State governments are still required to keep within the SDL set by the Basin Plan," the spokesperson said.

"Through water resource plans, the MDBA is required to assess the impact of any proposed changes (including new or expanded dams) to state water management.

"This is to ensure there is no net reduction in the protection of planned environmental water as agreed to by Basin states through the Basin Plan."

MDBA chief executive Phillip Glyde was clearer at federal senate estimates on October 25 last year when asked by Senator Sarah Hanson-Young how SDL limits would be maintained should Wyangala be expanded and more water stored in it.

Mr Glyde said: "The proponent of the dam that you're talking about (Water NSW) would be the entity that would have to acquire that water from within the market".

A DPIE spokesperson, when asked if the department might be forced into the water market, replied: "no".

"The allowable take of water will be constrained by the sustainable diversion limit for the Lachlan established in the Basin Plan and embedded in the NSW water sharing plan."

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