It floods fairly frequently, but it also dries out quite quickly,
Ha ha ha. You were joking, right?
I live right next to this one. The problem is not that it floods; the problem is that it takes ages to drain low enough to be usable again.
The winter before last I was taking an alternate route on the bike for 2-3 months due to flooding. Last winter it was fine through the whole winter as far as I remember. This winter looks like I will be taking the road route for 3-4 months.
From Swavesey, you can take the Fen Drayton / Fenstanton diversion. Low road (from Fenstanton to St Ives) floods also, but that dries out quickly.
If you're going all the way from Cambridge to St Ives, consider the new cycleway alongside the new A14 & old A14 (now A1307) then Low road into St Ives. It's all fairly good apart from the shitty connection at Girton, which has two options to choose from but both are rubbish. It isn't as nice as the busway, but that's mostly a reflection of how good the busway is.