Icefall cave.
You get HM Waterfall at the end of Route 18 on the strip of grass in Pokemon Black.
You can get the Waterfall HM in Solar Cave (with key on any floor or without key on 20F, Look for a place with water in a square).
the girl at the very end of sunnyshore, she will give you the HM when you get the final gym badge
you have to have beaten the elite 4 and givenh celio on island one the ruby you go to island 4 and find hm 7 waterfall in waterfall cave
You can find Waterfall in the Dark Cave.
You can find the HM Waterfall in the Ice Path
you can find him in waterfall pond with HM dive or waterfall.
you will find waterfall on the 1st floor on ice path
you find it in the Ice Path
in the cave of origin
You can find it in the Dark Cave.
Icefall cave.
You get the HM waterfall in the same cave you get Kyogre
inside the cave of origin
You get HM Waterfall at the end of Route 18 on the strip of grass in Pokemon Black.
You can get the Waterfall HM in Solar Cave (with key on any floor or without key on 20F, Look for a place with water in a square).