Michael,
You are just days away from some water park fun!
Disney's Typhoon Lagoon Water Park is so much fun! I was just there a few months ago for the planDisney Podcast taping, and what an amazing place it is. You are sure to have a blast!
The bottom line is NO; you do not need a reservation to enter the Walt Disney World water parks. Many people have been confused by the new
theme park reservations system, thinking that it extends to the water parks, but it only applies to the four theme parks. So, you do not have to worry about that for your visit. I just went in to the ticket ordering system to confirm this, and the site said this;
At this time a park reservation is not required to visit a water park, however, reservation requirements are subject to change.
BONUS TIP
If you would like to plus up your water park visit, I strongly recommend you consider booking either a
Beachcomber Shack or make a
Typhoon Lagoon Umbrella 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 hideaway with incredible views of the wave pool, and an area for your family to connect and relax between activities. Just call (407) WDW-PLAY or (407) 939-7529 to make a reservation.
Write me back if you have any follow-up questions.
Have a Magical Vacation!Doug