In order to survive, you must drink enough water each day to remain hydrated. Water you can collect and purify, but be aware that bleach does indeed have a limited shelf life.

You need a long term solution that will continue to provide water for all your needs (drinking, cooking, washing). Drinking water and water used for cooking won't keep long it usually will remain potable for 6 months, unless you use a preservative in it.

You can use water that's not safe enough to drink, but suitable for bathing, cleaning. Just make sure you store it separately from drinking water, also never use a drinking water container for ANYTHING other than "Drinking Water"!