id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
18854	Validation for stream and river direction	Geimas5	team	"Because of an ongoing import of N50 data, we have in Norway a huge amount of lakes and ponds with the elevation specified. Because of this, it would be very useful to have a validation in JOSM for the direction of streams and rivers based on this elevation information.

This can, of course be made very complicated to cover every case, but even a simple validation of the cases:
* (ele:200)<----(ele:100)
* (ele:200)<----(node)<---(ele:100)
* <----(node)---->(node)<----

Would help a lot.

From experience, it would avoid a lot of false positives if 1-2 meters of ""wrong direction"" was allowed. 

This means that while:
* (ele:200)<----(ele:100)
would result in an error:
* (ele:101)<----(ele:100)
would not.

It would also be natural to assume natural=coastline was at ele:0.

"	enhancement	new	normal		Core validator	tested		mapcss waterway stream river direction