Elland Bridge in Elland partially collapsed in the early hours of Tuesday after significant flooding in the area.
A barge was wedged against the grade II listed bridge and several others were left stranded on the towpath after high water receded.
Councillor Tim Swift said the crossing would not reopen until December at the earliest.
A temporary footbridge has been installed over the canal near the the bridge. Road diversions are also in place.
Calderdale Council said it had been having regular discussions with the Canal and River Trust (CRT), which owns the bridge.
Cllr Swift said: "We have requested CRT make an immediate start to designing a replacement for Elland Bridge.
"Unfortunately this will be a major project and initial estimates are that a new bridge would not be in operation until at least December 2016."
Other bridges in Yorkshire suffered serious damage during the recent floods, including Tadcaster Bridge in Tadcaster.
A damaged road bridge in Calderdale is beyond repair and will need to be replaced, the council leader has said.