Ryan,
Thanks for asking your question to planDisney!
I was just visiting
Disney's Typhoon Lagoon Water Park last month, and I had a great time. I am sure you will too!
The Theme Park Reservation program using the
Disney Park Pass System is just for the four theme parks. You do not have to make a park reservation for a water park.
BONUS TIP #1
If you would like to plus up your water park visit, I strongly recommend you consider booking one of the reserved spaces. At Typhoon Lagoon you can book either a
Beachcomber Shack or a
Typhoon Lagoon Umbrellas reservation. In both cases you get a "home base" where you can keep your belongings and give your family a place to meet up. In the case of the Beachcomber shacks, you also get a nice, secluded place with incredible views of the wave pool for your family to connect and relax between activities. Just call (407) WDW-PLAY or (407) 939-7529 to make a reservation.
BONUS TIP #2If you end up visiting
Disney's Blizzard Beach Water Park, they have
Polar Patios and
Lodge Umbrellas. These can be reserved the same way as their counterparts in Typhoon Lagoon.
Write me back if you have any follow-up questions.
Have a Magical Vacation!
Doug