Hi! I've reverted some changed to former basins. As I explained at https://www.openstreetmap.org/changeset/151908744 , it's better to keep ways and areas separate if each of them can provide some information. So, I restored barrier=retaining_wall to the lines (because you can't cross those lines if you try to walk across); and I restored landuse=brownfield to the areas (because that's what those areas are at present; historic tags are good, but tags that describe present condition are better). Also, I restored  was:natural and was:water instead of disused:natural & water, because... uhm... natural objects can't really get disused ;) That prefix is for man-made amenities.