Pipeline benefits missed

I READ with interest a recent opinion piece in the Daily Liberal by Ian Kiernan AO in regards to the Macquarie River to Orange Pipeline Project.

Put simply, those opposed to the pipeline project overstate the impacts on the river and understate the benefits to Orange.

The Macquarie Pipeline Project, if approved, would guarantee the Orange water supply for the next 50 years while impacts on the river are minimal.

The critical eye Mr Kiernan has brought to waste management and litter in Australia can be respected. However, his assessment of the pipeline project can not be viewed in the same light.

Mr Kiernan claims the Macquarie Pipeline is "monstrous", an act of "lunacy" and councils such as Orange should be looking to "new practices" and "emerging technologies".

Let's deal with the last claims first. Orange City Council has been a leader in water conservation. During the recent drought, water consumption fell to approximately 140 litres per person per day, which was among the lowest in the state.

The residents of Orange have embraced water savings. Through council-funded projects such as "Water Tight", homes were audited and retrofitted free of charge with more efficient water devices. And even with a return to better conditions. consumption last week was 158 litres per person per day.

Orange City Council delivered Australia's first large-scale potable stormwater harvesting scheme. The award-winning Blackmans Swamp Stormwater Harvest Scheme has been followed up by the Ploughmans Creek Scheme and will be templates for similar schemes across the country. The principles of stormwater harvesting are also being proposed for the Macquarie project, where water is harvested away from periods of low flow. Dams are topped and kept at safe levels so Orange is not victim to extreme events.

Orange City Council continues to diversify its water supply, which now includes the existing dams, stormwater harvesting and groundwater, with no over reliance on any one source. Yet even with this diversity, Orange does not have the level of water security enjoyed by riverbank cities such as Dubbo or Bathurst.

The recent rain has been good. But the probability of a rainfall-based system failing in Orange has not changed. Until we deliver extra water sources and we have improved security, residents and employers will still be hostage to the next dry spell and we don't know when that might be.

It's surprised many to learn that Orange's dams would have remained at more than 50 per cent if the Macquarie Pipeline was available through the recent drought.

This was one of the major findings during the development of the Environmental Assessment for the project.

While some people believe there had been little or no flows in the Macquarie River for much of the last decade, the actual data tells a very different story. And what that data reveals is that even when the region was in drought the Macquarie Pipeline would have delivered water security to the city with minimal impact on the river.

Orange's dams were at their worst in 2010 when they fell to less than 23 per cent. If we had the pipeline working, the dams would have been at more than 60 per cent that year. All this when the modelled annual average extraction between 2000 and 2010 was 1.5 per cent of flows in the river.

On average, 300,000 megalitres a year flows past the proposed offtake point. The pipeline's long term average annual extraction is 1665 megalitres or 0.54 per cent of flows.

Orange City Council has set the trigger point for when pumping can begin at when 34 megalitres/day is flowing in the river, to ensure it doesn't impact on low flows. According to NSW Office of Water parameters, low-flows in the Macquarie are those below 22 megalitres a day. There are flows above 22 megalitres a day 80 per cent of the time.

On a day when the 34 megalitre trigger is reached and 12 megalitres is extracted, the water level in the river at the off-take point would fall by 19 millilitres. This scenario is the greatest impact the project will have on the river and across 118 years modeling this scenario only occurred on 40 days. For 50 per cent of the time, river flows exceed 110 megalitres a day. During most extraction periods, the level in the river at the off take point will fall by less than 10 millilitres.

The latest assessment also found that the downstream impact of the Macquarie Pipeline would be negligible. For example the pipeline operations would equate to 0.16 per cent reduction of inflows into Burrendong Dam.

If Orange City Council can not demonstrate the impacts on the river can be minimised then NSW Government consent will rightly be a challenge.


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