Blinkered government fixates on decommissioning Victorian lake

Many people around Benalla in Victoria's north east, are opposed to the Victorian Government's plans to drain nearby Lake Mokoan and turn it into a supposedly attractive to tourists wetland.

The government argues that as it is shallow – when it is full its 365,000ML covers 8000ha - it loses on average 50,000ML a year to evaporation. As well, water that is fed down the Broken River, then the Goulburn River and later the Murray for irrigation, is far from clear and degrades the Broken River system in particular.

Victorian Water Minister John Thwaites said, “With the ongoing drought and challenges of climate change, we cannot sustain a water storage that loses 50,000ML a year.” He said that returning Lake Mokoan to a natural “world class” wetland “has enormous benefits for the environment” while protecting water user supplies.

The decommissioning will reduce the Broken valley's storage capacity from 400,000ML to 40,000ML, 10% of the existing. Opponents of the plan say it is the issue of surety of irrigation water supplies which they say will drop from 97% to 85% and the loss of protection against climate change and drought that concerns many.

Rehabilitation of the Mokoan wetland system is scheduled to start in 2009 and will save the government claims, 44,000ML of water annually. “These savings will be used for environmental flows in the Murray and Snowy Rivers,” it says.

But local Nationals MP Dr Bill Sykes said, “Currently Mokoan provides around 20,000ML for Broken system irrigators and 50,000 to 80,000ML for Goulburn/Murray irrigators and the environment. “DSE (the Department of Sustainability and Environment) and the Government only credit Mokoan with delivering 20,000ML per year.”

Sykes said irrigators and the community had provided money to offer an alternative solution to the Victorian government's flawed plan. It is based on the highly successful Barren Box Project near Griffith in southern NSW.

In that award winning project, as one observer put it, a previously “carp-infested shallow lake of dead trees” covering 3200ha, had been transformed by deepening part to retain water more efficiently and turning most of the rest into wetland. Murrumbidgee Irrigation Ltd and the local community were involved in the project.

Sykes said the earth excavated for the deeper Barren Box dam had been placed in a higher dam wall at a cost less than $2m a kilometre, according to Murrumbidgee Irrigation Ltd figures.

But the Victorian government is claiming that to do the same thing at Lake Mokoan as the irrigators want, would cost about $6m a kilometre. The department of Sustainability and the Environment, which is overseeing the decommissioning of the Lake, made a completely unsubstantiated claim that the alternative would cost $100m.

Sykes asked the Victorian parliament, “How can $6m a kilometre be justified? Is someone on the take or is this another example of of gross incompetence by the Bracks Government managing major projects using public money?”

Deputy Prime Minsiter and National party leader Mark Vaile supported Sykes in questioning the Victorian Government's costing for the alternative proposal. Also, he had doubts about security of irrigation water supplies under the proposed wet land regime.

In mid March Sykes put five questions in writing to Minister Thwaites covering issues including:

A request for an independent comparative assessment of the Government's decommissioning option and the irrigator's reconfiguration option;

Potential conflict of interests of the consultants being used by the Government to discredit the irrigator's proposal.

Sykes said, “The Minister can easily put this whole issue to rest by allowing the irrigators to work with Goulburn Murray Water engineers to thoroughly assess their reconfiguration proposal. The irrigators have agreed that if their proposal is shown to not deliver the required water savings at a reasonable cost, then they will back off [planning to emulate the Barren Box project].

“Conversely, if the irrigator's proposal stacks up, I would hope that the Minister would take it on as it would deliver a win/win/win situation for the Government, the local community and the environment.”

But so far the Government has denied access to water modeling and information needed to progress the project which has been in dispute for six years. Even freedom of information requests have been refused.

Murrumbidgee Irrigation Limited joined forces with Water for Rivers, a joint government enterprise which identifies water saving opportunities within the Murray-Darling system, to develop the Barren Box water saving project.

NSW Minister for Natural Resources Ian Macdonald said, “Not only will this work see significant water savings for the Murray and Snowy Rivers, it will also have local environmental benefits, including improving the water quality of the wetland area and water supply for downstream irrigators will not be affected.”

But it is a different matter in Victoria, Sykes says. “I suspect that the Victorian Government cannot honour it's commitments to maintain security of water supply to irrigators, deliver a world class wetland and ensure that Benalla and downstream residents are not flooded out, within a budget of less than $100m (if at all).

Irrigators, community propose sensible alternative

Benalla and Shepparton district irrigators and local community members in conjunction with Murrumbidgee Irrigation have pooled resources to develop an alternative plan for Lake Mokoan.

It involves two earth walls 11.8km in total length up to 6.5m high, enclosing an area from the centre of the lake towards the existing wall, that would be 5m deep and would hold 89,600ML. Before Lake Mokoan was built that area was known as the Winton Swamp.

After the dispute with DSE over $6m wall construction costs, spokesman for the group and local irrigator Wayne Spinks, said he had asked a local earthmoving contractor to examine their alternative proposal. They estimated the wall, with an internal sand filter and lined with geofabric and rock armour like the Barren Box Swamp storage, would cost about $1.75m a kilometre to build using excavators and dump trucks. Understandably, if scrapers were used, the cost would be significantly less.

Lake Mokoan's dispersible clay soils are similar to the wall material used at Barren Box, although the wall there cost less than $2m a km to build.

Spinks said his group originally budgeted on a cost of around $22m for the walls and water supply of lake diverters including 15% of that for contingencies. The 15% figure was used because that was relevant to Barren Box which came in early and under budget. Now the group, to match the Victorian Government, has boosted the contingency figure to 40% or $28.03m.

Offset measures already completed by the Victorian Government will be used by the group to boost savings for the environment as that money has already been spent and will cost another $20.1m. The total cost at $48.4m with 40% contingencies will still come in under the Government's decommissioning budget of $70m

Spinks and his associates in proposing what they call the Mokoan Wetlands Project, say that building a small but efficient, permanent wetland/storage in the bed of the decommissioned lake, maintains the current habitat for endangered species, such as the Latham Snipe and Murray Cod and removes the need to build expensive pipelines and purchase large amounts of water: 10,150 to 12,440ML.

“The significant purchase of water is not a true water saving and will only strip this community of wealth and future growth. An economic and social impact study must be completed to show the devastating effects on the region from the government's decommissioning,” the group says.

In a PowerPoint presentation it has made to support its case, the group says other advantages of the Mokoan alternative are:

A 97% reliable irrigation water supply that supports existing and future agriculture and industrial development;

Delivery of high security regulated flows around the Barmah Choke

Potential for economic growth in the region of $385m over 30 years;

Endangered species protection maintained and Tourism features enhanced with permanent and ephemeral wetlands.

Protection of Indigenous heritage sites under water

Maintained sporting amenities;

Reduced fire risk through permanent water availability;

Maintained local land values because of the retention of a large permanent lake.