Yes, you are absolutely allowed to bring your own food and non-alcoholic beverages into both Typhoon Lagoon and Blizzard Beach. This is a fantastic way for families to save money on vacation. You can bring a cooler, provided it is small enough to be carried by one person (or on a small wheeled frame) and does not contain any glass containers or loose ice. Disney requires that any cooling be done with re-freezable ice packs to prevent messy spills and drainage issues in the seating areas. Prohibited items also include dry ice and, of course, any alcoholic beverages, which must be purchased on-site. Many guests pack sandwiches, fruit, and bottled water to avoid the premium prices of the snack stands. There are plenty of picnic tables and shaded seating areas throughout the water parks where you can enjoy your meal. This policy is significantly more relaxed than many other regional water parks, making Disney's parks very family-friendly for those on a budget or with specific dietary needs that might not be met by standard theme park fare.