[Tagging] Tidal inlets / creeks

[Malcolm Herring]

On 18/01/2011 12:44, charlie at cferrero.net wrote:
>
> It would be nice to be able to map the tidal waterways that run in
> between the mangroves and saltmarshes - particularly the manmade ones
> that have been explicitly cleared to allow marine vessels. Unfortunately
> I can't see any way of tagging a waterway that does not imply
> freshwater. Ideally we'd have a waterway=tidal_creek or something like
> that but this doesn't seem to be in use at all.
>
A way tagged natural=coastline should follow the local mean *high* water 
level so that all tidal areas will be on the wet side of the way. Any 
tidal areas (wetlands of all types, beaches, mud, etc) can be mapped as 
closed polygon ways that enclose areas above the local mean *low* water 
level. These areas will be rendered at the higher zoom levels. Navigable 
channels that exist between these areas will then have been left as 
non-tidal (i.e. always wet)
>
> Finally, is there a way of tagging saltwater lakes (i.e. lagoons)?
> natural=water, water=saltwater?
>
If the lagoon has a channel to the sea, then simply extend the coastline 
into them. If they are completely cut off, then your suggestion would be 
OK.