Since this probably isn't for competitive, you're probably want to post
here next time. Anyway, I have used Swampert to great success in the Emerald Frontier in various facilities. That Swampert definitely is inefficient though. Ice Beam is always superior to Ice Punch--the power difference is really noticeable. Ice Beam is necessary for KOing Dragon-types and slow Grass-types. Similarly, Waterfall is inferior to Surf in every situation except for a double battle I guess? Just use Surf though, simple. Lastly, Brick Break isn't adding anything to Swampert's moveset outside of breaking the rare Reflect/Light Screen. With STAB, Earthquake already has the damage output to make Brick Break not worth it, even against Normal-types.
The last moveslot can be tackled in various ways. There are definitely problem Pokemon for Swampert like Gyarados, Ludicolo, and really anything with a strong Grass move that is faster and/or capable of surviving Ice Beam. Double Team Venusaur, Sceptile, amd Meganium are definitely annoying in that regard. Gyarados is the Pokemon that poses the greatest offensive threat, so the Rock Slide tutor is definitely an option. It also gives you more PP to use against Zapdos (Pressure sucks) while destroying Articuno. Counter and Mirror Coat both have their uses, though I've never really found myself in a position where I was upset that I didn't have Counter. Rest is an option if you don't have a ChestoRest user on your team. My recommendation is Rock Slide but a lot can work.
Lastly, the EVs either need to focus on offense or defense. Swampert's great walling ability comes primarily from its typing, and it really does need a good chunk of EVs to wall things. However, I always preferred using an offensive EV spread to try to get more kills. I used this:
A Berry or Leftovers is the item of choice always.
Swampert @ Chesto Berry (use a Lum Berry if nothing else needs it)
Trait: Torrent
EVs: 96 HP / 200 Atk / 212 SAtk
Brave Nature (+Atk, -Spd)
- Earthquake
- Surf
- Ice Beam
- Endeavor (I was just lazy and didn't bother changing the move--use Rock Slide or Mirror Coat, as I said earlier)
The EVs are somewhat arbitrary but 259 SAtk really is superior to 206. The power it has is incredible. The defensive stats are 365 HP/216 Def/216 SDef, which was always plenty for me. Also, Swampert still outspeeds Donphan and Vileplume, even with a Brave Nature and no Speed EVs, lol. Either way, adjust them as you'd like, but the more Special Attack, the better. If you can't RNG breed for perfect IVs, losing the Attack is probably the best way to go--the SAtk is really important!
If it's just for the Elite Four, then your current build is fine. You really should still replace Waterfall with Surf though.