Hello, Jenny, and welcome back to planDisney! It's great to see a returning guest!
Jenny, I last stayed at
 Disney's Pop Century Resort with some of my planDisney besties and love the retro vibe of this entire property! From the decor inside
 Everything POP Shopping & Dining to the larger-than-life bowling pins as you walk through the resort. 
Now, Jenny, I like that you're planning ahead for August because staying hydrated during those steamy summer months is important for a Magical vacation. When I last stayed at Disney's Pop Century they did 
not have full cases of water available for purchase. They did have extra large bottles that were approximately 64 ounces in the packaged food section of the shopping area. Jenny, I'm often the Mom who is constantly encouraging my family to drink water, so I appreciate your conundrum. I have approached this in two ways in the past. We have either packed reusable water bottles and taken advantage of the free iced water at Quick-Service dining locations around the park or I have 
ordered cases of water (and other essentials) from a third-party grocery delivery service to be dropped off at our 
Disney Resort Hotel. 
Jenny, while likely not the information you were wishing for, I hope it helps in your planning process. Please come on back to planDisney with any additional questions. Best wishes for a crisp, cool, and refreshing vacation!
Lauren