[Tagging] tagging floodplain

[Warin]

Hi,

There is a draft to tag floodplains using the key natural.


http://wiki.openstreetmap.org/wiki/Proposed_features/floodplain


My thinking is that this would lead to conflicts with other 'natural' 
tags .. like natural=scrub than may be applied to the same area.


So .. what would be the best key to use for this feature/value?

I am thinking that as it is associated with a waterway (it must start to 
flood from somewhere and that is usually a waterway) that the key 
waterway should be used. It would have rendering similar to a lake - but 
'intermittent' so dashed lines rather than a solid colour.


Thoughts?


{There is presently flooding in some areas of Australia, why my thoughts 
have turned to this. All too soon it will turn to bushfires}