Besides the obvious, water can be used in many ways to help keep your hair healthy. OK OK, these may be obvious to some, but I'm going to list them anyway.
1.) Cold Water Rinse- As your final rinse on wash or co-wash day, using cold water will help seal the cuticles giving you shiny and frizz free hair(well for some).
2.) Water Spritz- Helps to waken up the curls, soften your hair or make it more pliable to work with. It can also be used as a moisturizer before sealing with an oil or butter. ( I use distilled water for us)
3.) Get that last bit of product- Have you ever realized you ran out of shampoo or conditioner right before doing your hair? I know I'm not the only one who adds a little water then shake it up and use it until I restock. Well you can do the same thing!
4.) Product Mixes- Water is good base for most spritzes. Some mix with AVJ, glycerin, ACV, conditioner or even oils. Just be careful in terms of the mix breeding bacteria or going bad.(look up various preservatives)
Water is one of the best things for you. You should most definitely make sure you drink the suggested amount daily. I am very grateful that I have access to clean water and water in general. I would hope that those who have the same privilege, don't take it for granted.