RESIDENTS across the Tweed are being urged to limit their water use to help minimise the amount of salt water from entering the shire’s reticulation system.
It comes after tides up to 380mm higher than predicted pushed salt water into Bray Park Weir on Monday night, triggering Council to enforce immediate water restrictions as a precaution.
Attempts to release a large volume of water from Clarrie Hall Dam yesterday to flush the salt water from the Bray Park Weir pool had little success, said Manager of Water and Wastewater Anthony Burnham.
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“The wave that went down the river yesterday evening prevented further salt water getting into the weir from another higher-than-predicted tide overnight,” Mr Burnham said.
“But the salt levels in the Bray Park Water Treatment Plant are higher than yesterday and more residents will have salty water in their taps today”
Tuesday’s release refreshed the top strata of water in the weir but the heavier salt water sank to the bottom.
Mr Burnhamd said it was important that residents worked with council and limited their use of water to help minimise the amount of salt water being sucked into the system.
“Our tests have confirmed that the water being drawn into the Bray Park Treatment Plant is saltier than the water we tested yesterday morning,” he said.
“Basically all the salty water drawn in will have to be released via household taps so the less drawn in, the quicker this situation can be resolved.
“We have closed the deeper baffles where the water intake occurs to limit the draw of salt water from the lower water stratum within the weir pond and are only drawing from the top strata, which was refreshed by yesterday’s release from the dam.
“Today we will begin a continual release from the dam of 50 megalitres a day to maintain that refresh as we bring in a dredge to draw the salty water from the bottom and pump it out directly over the weir wall.
“However, the salty water already within the reticulation system is going to spread beyond Murwillumbah today and over the coming days.”
According to the Australian Drinking Guidelines, the salt levels are not harmful to human health, however, residents are being told to use bottled water for drinking if the taste is too unpalatable.
The water at Uki and Tyalgum is not affected and no restrictions apply in those villages.
Mr Burnham said the extremely high tides responsible for the contamination were brought on by the stunning solar eclipse in the northern hemisphere.
“Since Saturday, all the high tides have been greater than predicted but the last of these occurred overnight,” he said.
“While the spectacular solar eclipse in the northern hemisphere played a major role in Monday night’s overtopping, the fact is that with the effects of climate change and rising sea levels these events are going to become more frequent and of higher intensity.
“This current incident brings into clear focus the need to raise the wall of the weir and Council will be working hard to get the approvals and licences in place to get this important project off the drawing board and into construction.”