Big Size River improvements

[Hauzmanus]

What I am suggesting is the following:

We cant get river depth from OSM, but it could be improved upon via generation.

OSM Marks big rivers like the Danube with the River Area feature type. During generation of water bodies on the map, the program could decrease the height of the river area by 15-20 meters, and select a height at which it will fill the river. After the selection, ARM has the 80x80M pond object, which it could use to fill up the river.

I've done this manually on my Vác map, where quite a large portion of the map has a River going through it. I was quite successful at doing this to replace the river on the map. Maybe you could add this as a method to solving rivers?

[jetelain]

Hi, it could have a common solution with #92.
The problem is not only to "punch" the terrain, it have to remain a slope from the source of the waterway/river.
I've not yet found an efficient way to compute the height-map of the "river polygon" according to the waterway slope (which is already computed).