Groundwater key to new Rous supply

Chris Dobney

Rous Water has ruled out some of the most controversial options in expanding the region’s water supply but, in an area of coal seam gas development, has thrown its weight behind groundwater extraction.

The county council – which supplies water to Ballina, Byron and Lismore LGAs and part of Richmond Valley – has taken the wraps off its future water strategy, which will go on public exhibition on Monday.

Rous Water chair, councillor Sue Meehan, said that while the region had sufficient water security in the short to medium term, the council had to plan ahead to maintain long-term water security.

The current supply from Rocky Creek Dam, Emigrant Creek Dam and the Wilsons River Source is expected to meet demand until 2024.

From that point on, the demand from new developments and the anticipated impact of climate change see a simultaneous reduction in supply and increase in demand, according to Rous’s modelling.

‘Forecasts show that, even with existing measures to reduce water use, demand will grow by 50 per cent over the next 50 years and changes to climate and rainfall patterns are likely to affect the reliability of our existing supplies,’ Cr Meehan said.

‘This strongly suggests that we need to act sooner rather than later to extend the life of our supplies and develop new water sources to ensure future water security.’

The strategy rules out the seemingly simplest solution – increasing the height of Rocky Creek Dam – as not cost effective and too environmentally damaging, situated as it is in the heart of Nightcap National Park.

Likewise, it has deemed desalination as too costly and unpopular to pursue.

Dunoon Dam

A possible additional dam at Dunoon has not been ruled out altogether.

But cost  ($160 million over 10 years) and environmental concerns have seen it mothballed in favour of water saving, water re-use and tapping groundwater sources.

‘Studies have showed that while the dam is technically viable to build, there are cultural heritage and ecological constraints as well as high upfront construction costs, which make other water sources more attractive,’ Cr Meehan said.

‘Rous Water will preserve the Dunoon dam proposal while other potential water sources are investigated.

Efficiency

Future water strategy manager Robert Cawley told Echonetdaily that even with the BASIX requirements placed on all new buildings, Rous would need to find additional household water savings just to stand still.

This would be a challenge, he said.

‘For example, retrofitting water tanks helps to reduce demand but even with the current level of subsidy many households have not taken it up.

‘Rous can’t afford to buy a water tank for every household but I agree that we need to take another good, hard look at tanks. How can we make them more attractive and affordable?’

He added that dual reticulation systems – such as have been successfully installed in some Ballina housing estates – while effective, are not within Rous’s power to require of developers.

Groundwater

Rous is already extracting groundwater from two sites: Alstonville and Woodburn. The council would look more closely at those and consider expanding them or moving them to more productive areas, Mr Cawley said.

But he acknowledged that the potential for CSG to interfere with aquifers was a serious concern.

‘The issue we face is the issue everyone faces,’ he said.

‘We need a system to protect our interests.’

But he wouldn’t be drawn on whether Rous would seek special state government recognition of the aquifers it plans to tap.

‘We think the [groundwater] resource is beneficial to the whole community. The CSG companies, the farmers and ourselves all want access to the water resource. We need a system of licensing and access,’ he said.

Mr Cawley said Rous would also look at tapping aquifers in areas of coastal sands where there were no known CSG deposits.

‘The other advantage of this is that much of the development is on the coast, so we would be tapping the source near where it is most likely to be used,’ he said.

‘Keeping them close to existing pipe networks would also help to keep costs down.’

He acknowledged this might require the building additional treatment plants but said it still remained a price-competitive option.

‘The cost to the consumer will remain paramount,’ he said.

‘The state government has made it clear this will remain a user-pays system.’

Re-use

Any discussions of water re-use invariably raise the old spectre of ‘toilet to tap’, which has been used to politically kill off such proposals in the past.

But Mr Cawley said a multiple treatment policy would address those concerns.

‘Rous’s number one priority is public health. The water coming out of a treatment plant is already above potable standard but it would not be simply pumped back into the pipes,’ he said.

Rather Rous would release the water well upstream of a water storage or treatment facility, such as Emigrant Creek Dam, where it would be blended with the natural water and add to environmental flows before being recaptured and retreated for drinking.

‘Another option would be to pump treated wastewater back into the aquifers,’ he said, ‘which would both address the issue of depletion and also add an extra level of filtration.’

To view the draft future water strategy and complete a consumer survey on the options, visit www.rouswater.nsw.gov.au.