Without access to a town water supply, locals in the Bilambil Valley rely on water from the creek.
Mr O’Brien is concerned water extraction is affecting that supply.
"Lately, in the last few years, it’s stopping more and more constantly throughout the year."
Mr Karlos rejects that link.
"The water we’re taking out has no bearing on localised water, groundwater or creek water, which is what the farmers are using," he said.
"It’s not just the extraction of water, but concerns that this has become a lawless industry, an industry which pays no attention to their conditions of approval," TWA member Jeremy Tager said.
By limiting the number, size and hours of operation of water tankers, the Greens-led council has effectively halved the amount of water the Karlos operation is allowed to sell.
Larry Karlos is taking the council to the Land and Environment Court this week after it rejected his bid to run bigger tankers, which would allow him to sell his full 60-megalitre allocation.
‘Water quality one of the biggest issues in the world today’ Mr Tager said it was the Karlos operation which had a case to answer for what he alleged were breaches of its council approval.
He showed 7.30 photographs which allegedly showed tanker movements around the water filling station on the Karlos property on February 19 and 20.