A project that could potentially supplement the Lower Hunter's water supplies with billions of litres of water that has been trapped underground for thousands years is a step closer to being realised.
Hunter Water has been investigating the new water source deep under the Tomago Sandbeds in an ancient river known as the Hunter Palaeochannel in recent years.
It also indicated that water trapped inside the palaeochannel has not been exposed to the atmosphere for between 15,000 and 25,000 years.
Recent work has involved sinking three 273mm bores to depths of between 44 metres and 82 metres, well below the limits of the upper sandbeds.
Capacity testing revealed one of the bores was able to produce water at a rate of up to 50 litres per second or four million litres per day.
The third bore, which was completed last week, produced water at a rate of seven litres per second. The other bore did not produce water consistently.
"These results confirm we can tap into the palaeochannel aquifer, but more investigations and data analysis are needed," a Hunter Water spokesman said.
Hunter Water has been consulting with the Natural Resource Access Regulator and NSW Health to ensure water samples are tested and assessed thoroughly.
"To confirm how the palaeochannel aquifer recharges and its possible supply characteristics, Hunter Water will assess the data with industry experts and regulators to decide the best approach to further investigate how the source can sustainably be used to supply suitable quality water," the spokesman said.
"Although the process of investigating this option is low risk, Hunter Water is taking a careful, step-by-step approach to minimise any risk from drilling into this new and relatively unknown water source."
If successful the project could yield the first new drinking water supply for the Lower Hunter in more than 50 years.
This project has formed part of Hunter Water's draft Lower Hunter Water Security Plan, which is due for release in the early part of this year.
The plan contains a range of water security measures to improve the region's drought resilience as well as cater for population growth.
They include the establishment of a desalination plant at Belmont, a pipeline to connect the Glennies Creek and Lostock dams, increased water conservation and recycling initiatives plus continued leakage reduction across the network.
The United Nations has designated this year's World Water Day theme as "Groundwater: Making the Invisible Visible".
World Water Day is observed on 22 March to highlight the importance of fresh water and is used to advocate for the sustainable management of freshwater resources.
