You will need it during your adventure, but it's not really worth it. It's rarely used in-game, and it's not worth teaching it Waterfall as a move to know forever. I'd recommend just getting an HM slave.
Here are some Pokemon that can be your new slave. :3
If you mean in battle though, it's takes mediocre damage. So it could be something to consider, but my option is you should not learn it.
Hope I helped. :)