the actual HM the leader doesn't give to you, but it is located on a route near Sunyshore, home of the final gym leader, who allows you to use waterfall. this is for Pokemon diamond, pearl, and platinum.
Gym Leader Jasmine of Johto will give it to you. She is located at the shore in the northeast part of Sunyshore City.
After you beat the gym leader in sunyshore city,go to the top of the beach near the cave. Jasmine. She will give you HM 07 WATERFALL! :D
once you beat the last gym leader go out onto the beach at Sunnyshore City and a lady will give it to you.
In sunyshore city talk to the girl on the beach she will tell you to beat the gym leader, do it, then talk to her again and she will give it to you! Easy as that!
You can get the HM waterfall in Pokemon Diamond and Pearl by beating the 8th gym leader and talking to Jasmin by the little beach. She will give it to you.
After you defeat the gym leader of Sunny Shore City there will be a girl near the Shore named Jasmine she will give you the Hidden Move Waterfall . Hope I helped . Your welcome .
after beating the 8th gym leader go to the beach and the lady will give you the HM 7 waterfall
You must defeat the 8th gym leader in Sunyshore City. Then, go to the beach-like area to the very north of the city. Talk to Jazmine, a gym leader, and she will give it to you.
in sunyshore city, after you beat the gym leader,(no.8)talk to Jasmine(girl on the beach) shell give the HM 08. (Waterfall)
First u have 2 beat the gym leader, volkner. Then u go to that little beach north of the city and talk to jasmine and she will give u the hm for waterfall.
In sunyshore city after beating Volkner the gym leader and claiming your 8th and final badge, head north to the beach and you will find yourself in conversation with someone named Jasmine. She will give you HM07 waterfall.
You get waterfall once you've Defeated the Gym leader in SunshoreCity, After you have go to the northern beach and a girl will give it to you. Hope this helps.