Tenterfield council finds water, but how much?

The new bore on the archery grounds will undergo draw-down testing starting Monday to assess its replenishment rate. The goal is a dam which is never allowed to drop beneath a designated level.

The new bore on the archery grounds will undergo draw-down testing starting Monday to assess its replenishment rate. The goal is a dam which is never allowed to drop beneath a designated level.

Bore drillers have found what appears to be a gusher at the archery grounds in the quest to supplement the town water supply, but council chief executive Terry Dodds urged caution until the results of draw-down tests are in.

Mr Dodds said drilling into the underground water reservoir is like bursting a bubble, initially releasing good water pressure but it's the replenishment rate which will determine the value of the bore.

He said the rate usually drops 20-50 per cent so the bore could produce eight litres a second at best or down to five at worst, but the 72-hour draw-down tests will determine the figure. The tests should begin next week once infrastructure is in place. Mr Dodds said the water pumped out will not be wasted.

READ ALSO:

The drillers have moved onto a location west of the New England Highway on a road reserve near the southerly 80kmph zone. There, true to the hydrogeologist's predictions, they've struck a sand bar at 40 metres, indicating that the current hill formed over a preexisting river many hundreds if not thousands of years ago.

Given their proximity to Tenterfield Dam, 'fingerprint' tests will be done on water from both new bores to ensure their supply is coming from sources other than the dam itself.

Mr Dodds said test bore licences on the new water sources have now been sorted out, with an application made by council to extend its Water Access Licence to account for the bore water supplementing the dam supply.

He said if everything goes perfectly to plan -- and that's a big 'if' -- the new bore water could be flowing into the dam by December 23.

"But one day late and we'll probably miss the traditional Christmas holiday period, and historically that's the start of the hottest months and the greatest loss to evaporation."

The dam remains at 32 per cent, thanks to the donated Rural Aid desalination plant reducing losses in the order of 35,000-40,000 litres of water a day. Adherence to Level 4.5 restriction remains critical as once the dam level drops to around 20 per cent the water quality changes, creating major issues for the old water treatment plant.

"It's 4.5 until we're over this," Mr Dodds said.

Longer term, the new bores will be integrated into council's Integrated Catchment Water Management Plan to maintain the dam supply at a level yet to be determined, so that it never drops below that level. Mr Dodds said all the government water bodies are 'in violent agreement' of the plan to secure supply long term, and are working together really well towards that goal.

"We can't afford to not learn from this. We'll have secure water and a new filtration plant and reap the social, environmental and economic benefits, if it all works out."