Transport Scotland has revealed that the emergency repair of the bridge cost £10m. Meanwhile, it will also have to spend £11m in the longer term to replace the truss end links - where a hairline break occurred.
Bridge bosses had planned to undertake this work in 2011 - at a cost of £10m to £15m but the work was cancelled because of funding cuts.
Labour public services spokeswoman Jackie Baillie said that was “short-term thinking”.
But transport minister Derek Mackay said: “It should not be presumed that had the scheme in 2010 progressedthat the pins or truss end link members would have been replaced. It is oversimplifying the case.”