Invercargill city councillors have approved a search for underground water sources, but are yet to approve the up to $750,000 such an exploration would cost.
A report, "Underground Water Supply Exploration for Emergency Alternative Source'', compiled by Land and Water Science was approved by the council's infrastructure and services committee meeting yesterday.
"There is a degree of uncertainty in the success in locating a suitable underground ... but committing to exploration of underground water is a considerably cheaper option than developing a source,'' the report said.
The cost to complete the project would be in the range of $400,000 to $750,000.
Cr Karen Arnold questioned if it was worth spending so much investigating something that might not have the expected results, but council water manager Alister Murray said staff were optimistic.
The report said a redirection of $100,000 from the council's water capital budget would be required for the first and second phases of the exploration while another $537,400 would be needed in the next financial year to complete the third and fourth phases (exploratory drilling and aquifer testing) in the next financial year.
The committee decided approval for the funding would have to come from the full council.
Invercargill has a single water supply, the Oreti River-Branxholme treatment plant.
Should it fail or become unserviceable the consequences could be evacuation of the city's entire population.
A report in 2017 warned the city could face claims from businesses forced to close, a government inquiry and widespread community discontent.
