Hi, Jeremy!
Refilling your water bottles is a snap when visiting Walt Disney World. There are plenty of water fountains you can use, with many located just outside of public restrooms. However, I rarely use the water fountains as I prefer to stop by any quick service counter location and request a free cup of ice water. The cast members will be happy to provide you will a refreshing ice water, yours for the asking.
When you get a cup of ice water from quick service locations, you can enjoy the water, drinking from the cup provided or refill your water bottles with it. If it is a super hot day, I refill a bottle to keep in my tote bag. If the temperatures are comfortable, I try to avoid a heavy bag so I just get additional cups of ice water as needed without carrying around a bottle.
The most important thing is that however you decide to get water, stay hydrated! The sun is hot and you will be doing a lot of walking, so drink that water!
Enjoy your vacation in
Walt Disney World!
Cathy