The fountain in Wellington's Oriental Bay has broken down and will be out of action for the next two months.
The Wellington City Council said it was organising a barge with a crane so staff and contractors could get out to the fountain to lift out the electric motor and pump.
It suspected an electrical short was to blame.
Council spokesperson Richard MacLean said the motor and pump would then be sent off for repairs and any other maintenance.
Mr MacLean said the pair were last removed for maintenance in 2009 and the mechanism required regular care, as electrical gear and seawater could be a problematic combination.
The Carter fountain was built in 1973.