The New Zealand Transport Agency (NZTA) expected to start construction on the State Highway 83 bridges during the next financial year, subject to funding.
If that happened, the new bridges could be carrying traffic before the beginning of 2014.
Mr Joyce, as a result of inquiries by Waitaki MP Jacqui Dean, said the agency was making good progress on the project.
It was consulting all necessary parties and preparing information to support the necessary statutory applications.
Mrs Dean said Mr Joyce's reply had come in response to her requests to have work started on the replacement as soon as possible, prompted by concerns raised by upper Waitaki residents and transport operators over the 100-year-old wooden-piled bridges' safety after recent floods.
"We now know preliminary work on the project has started and the minister himself is maintaining an interest," she said.
"That the work could be completed before 2014 is also good news."
In a move to allay any immediate safety concerns with the present bridges, the agency said they were structurally sound and it fully expected to maintain them in that condition until the replacements had been built.
If there were emergency events, special arrangements would be made so personal and light vehicles could cross under supervision.
Fire tenders would also be made available on each side, Mr Joyce said.
