This would be a real headache if you had to do this every time you got heavy rain!

If they are a recent planting, yes I would move them to somewhere that doesn't get waterlogged. A raised bed would be ideal. They like a free drained site or their vigour and health can go downhill markedly if not.

If they have been in this spot for more than two seasons without problems I would leave them as the water logging must be a very temporary thing which they can of course cope with as most plants can. Week after week of flooding is different though.

A recent study I read about relating to how plants cope with flooding made surprisingly interesting reading. During the winter months when plants are dormant, many plants can cope quite well, even plants that are dry loving. It's during the start of their growing season when they can suffer most from saturated soil over a long period.

If you are on clay I would suggest that you dig a trench between the rows to include the outside. Fill the trench with old brick rubble, cover with a plastic strip, replace top soil. Any surplus can be put round the canes after putting a small layer of fresh straw. This is a practice which I used in Sussex on heavy Sussex clay, you may be in a low lying area. This method will serve you well for many years, it is also good for other soft fruit bushes.

Raspberries grow well in Scotland...which is not known for its droughts!!

But tend not to be on heavy soil :-)