The committee backed - in part - the recommendation of a report prepared by water manager Alistair Murray on the city landmark. The committee recommendation now goes to the full council.
The committee agreed to upgrade the water tower to 67% of national building standards to reduce safety risks. It was closed in 2012 after the Canterbury earthquakes because of the quake risk.
However, councillors said it was "too early'' to explore the site's tourism potential at this stage.
They did not approve Mr Murray's recommendation to have local service organisations run visits to the tower.
Mr Murray said the decision to strengthen the water tower was appropriate because of its "prime location''.
If it collapsed, it had "the potential to cause a lot of danger and possible loss of life outside the tower''.
The cost for the upgrade would be $1.3 million, and the report said the council had $1.4million in this year's budget for the work.
Chairman Lindsay Thomas raised concerns of a "budget blowout'' as the geotechnical investigation was not yet done.
Mr Murray said that was a "risk''.
He said the geotechnical investigation would be the first part of a detailed design, and its findings would be reported to the committee as soon as possible.
Councillors also raised concerns about the safety of visitors if they considered the tourism option, as including a lift for access was "not considered viable''.
Mayor Tim Shadbolt said having no lift would be "dangerous'' and a"contradiction'' within the council's rules.
Mr Murray said a management plan would be necessary, with supervision required while the tower was open and a limit of 50 people per visit.
