So we know that plastic water bottles are not good for the environment, but drinking water is best for us. There are options though, reusing bottles that you already have is one, buying a water bottle, preferably a non plastic one. There are many metal ones you can buy instead.
If you are out and about and do want water then buy one in a glass bottle, glass can be recycled over and over, so much better for the environment.
There’s a company called Belu that not only sells in glass bottles, but also donates money to WaterAid, to help provide clean water to developing countries. However you may not find them in your local supermarket or general store, but they do sell in bulk at wholesalers.