The message
from "Sue & Bob Hobden" contains these words:

Friends have just moved into a house (12 miles W. of London) where the front
garden which is actually across on the other side of the road is liable to
flooding from a small stream that runs past it at the end(offshoot of the
R.Thames). Indeed, this winter it was under up to 4ft of water for a couple
of weeks. A real bog garden.

Whilst I can think of a few plants that may survive and flourish, Iris
siberica, I.laevigata, Zantedeshia atheopica, and some other "marginals"
have you any other plant suggestions.

I'm not sure if any land plants will survive being totally underwater
for a couple of weeks :-(

Digging planting holes will loosen soil, which may lead to serious
erosion during a flood; apart from losing part of the garden this can
undermine walls, fences etc and may not be covered by their household
insurance. They may need to take specialist advice about protectng and
stabilising the soil surface.

Janet.