[Tagging] Drain vs ditch

[Markus]

Ciao Sergio,

On Thu, 31 Jan 2019 at 23:46, Sergio Manzi <smz at smz.it> wrote:
>
> My only marginal objection is for canal: why don't you ditch (pun intended...) the "used to carry useful water for transportation, hydro-power generation, irrigation or land drainage purposes" clause?
>
> Are there any other "Large man-made open flow (free flow vs pipe flow) waterways" that should not be considered canals?
>
> My concern is that somewhere in the world there could be a canal not built for any of those purposes and somebody could object to call it "a canal".

I would leave the canal uses (transportation, hydro-power generation,
irrigation or land drainage) for clarification – otherwise
waterway=canal were again mainly differentiated form
waterway=ditch/drain by size, which we wanted to avoid because it is
arbitrary. Possible other canal uses can still be added later.

> Also isn't "land drainage" potentially in contradiction with "useful water"?

Yes, you're right, *useful* should be removed.

Regards

Markus