Hi, 

I am not suggesting we leave the landscape blank. The best would be to try get tailings pond officially rendered, otherwise we are tagging for the renderer, ie providing a tag to make sure the feature shows up on the map even if it is not an entirely correct tag, this is a big no no in OSM . OSM data is not only used to render the map and can be accessed by many data users in a number of ways. As an example if an organisation wanted to plot the position of all mine tailings dams they would have to filter the data for landfill sites and manually filter for tailings dams by reviewing the available imagery. If the tailings pond tag was used it would be a one step operation. I will contact the proposer of the tailings pond tag to see about rendering, elsewhere I have seen this could be a drawn out process but worth doing in the long run since, as you say, they are a significant feature all over Southern and Central Africa. In todays environmentally conscious world I am sure they are of considerable interest.

