[Tagging] New description of waterway=pressurised

[marc marc]

Le 09.06.19 à 01:12, Richard a écrit :
> The water level drops a few inches and
> suddenly the "pipe" is no longer water filled

intermittent=yes/no

some industrial installations (I am thinking of an waterway between 
retention basins at the Grande-Dixence Dam, part of which is natural) 
have been under water since before I was born.
to say that this can no longer be a waterway=pressurised is to say that 
it should be divided into 2, a waterway=pressurised-in-a-mandmade-stuff 
and a waterway=pressurised-in-a-cave, this kind of micro-mapping
has its place in a subkey, not as a top-level value.