[Tagging] RFC proposed water property key 'ephemeral '

[Warin]

Hi,

Following from the discussion on "Seasonal, intermittent, and ephemeral 
water tags" I have created this proposal.


Hopefully the definition is tight enough that it excludes intermittent, 
seasonal and any other thing that is not ephemeral.

I have also included a guide on determination so that mappers can see 
how to determine if something is ephemeral.


So here it is ...

https://wiki.openstreetmap.org/wiki/Proposed_features/ephemeral


Is it clear? Do you understand it?


Would you use it? If so where?


Any thing else?