Plan out and prepare for your needs before they come up. In becoming an Eagle Scout one of the most important things that has been branded into my brain is BE PREPARED. You should have a 3-tier approach to water planning.
First- Stored water
Second- Water filtration
Third- Water cleanliness
With these planned, you shouldn’t have to worry about water, which allows you to focus on other equally important tasks.
Just some of the reason you most definitely need water in all survival situations is for maintaining hydration,relieve fatigue,energize the muscles for better exercise,help you stay positive when you are hydrated,prevent headaches,maintain health weight,protect you immune system,Keep the digestive track well-flushed so that you can stay healthy.