Joe Taranto's $2-billion scheme would redirect 400 megalitres of treated effluent from Sydney's North Head sewage treatment plant to the Upper Hunter, to be used for the region's industrial water needs - cooling power stations, irrigating crops and supplying mines.

With much of the Upper Hunter's water needs being met, the plan would free up water from Glenbawn Dam, near Scone, to be transferred to the Namoi Basin.

"Sydney is pumping about 1000 megalitres of grey water a day - it's criminal that we are throwing away all that water in to the ocean," Mr Taranto said.

"It's good water. It just needs a bit more treatment, but not much."

As part of Mr Taranto's scheme, water would travel from Sydney to Newcastle via a sub-sea pipeline utilising gravity-assisted technology - the Romans used the same principle to move water across mountains.

A two-metre diameter twin pipeline would enter the Hunter River at Ironbark Creek and then follow the powerline grid to Lake Liddell.

About 300 megalitres of water a day would be supplied to the Liddell and Bayswater power stations and the mining industry. As a result no water would be drawn from the Hunter River.

The remaining 100 megalitres would be used for irrigation throughout the Hunter.

Having met the needs of the Hunter, water from Glenbawn Dam could be transferred via two new reservoirs to Murrurundi.

MORE WATER PRESSURE STORIES

From there it can be sent on to Namoi Basin through a 14-kilometre tunnel, which would go through the Liverpool Range.

Mr Taranto is calling for a feasibility study to be conducted of his plan.

"All projects should be on the table and looked at," Mr Taranto said.

"A dam is only good if it rains, and where a dam is build, everyone else downstream is affected."

Recently, NSW Water Minister Melinda Pavey blasted her own department, claiming there are public servants who don't like dams. Ms Pavey vowed to change that attitude and said her new water department CEO was the first step.