An emergency bag is a bag that has everything you need to push through an immediate and drastic change of plans. Situations like natural or man-made disasters can cut you off from things you take for granted: grocery stores, running water, shelter, cellular coverage. When this happens, you need a bag that you keep close to you at all times and ideally weighs less than sixty pounds. A good estimate for bag size is something capable of holding at the minimum of 35 liters and ideally 55 liters. This is a bag that you should take with you in your car because it may be the bag that weathers you through the storm.
11.5 L water bottle (minimum)
At the minimum, you should have the equivalent of 1.5 to 2.0 liters of clean, potable water on your person at all times. There’s the “8 x 8” rule that gets thrown around a lot in popular medicine. Eight glasses of eight ounces of fluid a day is definitely a good place to start but depending upon the climate you’re in, the conditions you’re facing, and your own personal metabolism, you could easily need a lot more. Two Nalgene or Sigg 1.0 L bottles is ideal. It’s a quick visual reference to let you know you likely have at least one day of clean water.