There were also extra operating costs for increased water testing, additional electricity to pump water further and ongoing chlorination.
Some councillors queried whether the money should be spent on existing bores, when the future might see the need to drill completely new bore sites.
"Even if it was more expensive shouldn't we also investigate pulling out of all the current bores and putting them somewhere else such as near Miracle Water?' asked councillor Bayden Barber.
Mayor Lawrence Yule said this was also being considered.
Councillor Simon Nixon queried whether it was wise to be going ahead with approving the funding when the results of the Havelock North Water Inquiry were not yet known.
Mr McLeod said the funding was a signal in the annual plan that more work was needed than had previously been budgeted for.
"We need to make provision in the annual plan, and consult with the community, and we also need to do further detailed work as well as hear what the inquiry has to say."
In terms of consultation, it was agreed that the matter was of high community interest and that it should form a separate consultation document in the draft annual plan.
The plan was to hold a number of community meetings as part of that consultation, a major factor of which was also to debate whether or not to continue with chlorination.