I spent 20 months of my life traveling around Europe and Asia and I found the sources to fill up my camper's water tank mostly using OSM data! It works very wel

I spent 20 months of my life traveling around Europe and Asia and I found the sources to fill up my camper's water tank mostly using OSM data! It works very well in most areas. I used the the app Maps.me for that (which by the way I would not recommend anymore). Maps.me's internal search function is not intuitive but I found out the right key words to get to drinking water sources. To your list I would add the search for springs. Especially in mountainous areas you often find usable springs (sometimes pipes coming out of a wall) with drinking water.