If you water heater tank is leaking it needs to be replaced, you cannot repair the tank. Please do not try to use duct tape or epoxy to temporarily repair the tank. Call a licensed Arizona plumber to have it replaced immediately and save yourself from thousands of dollars’ worth of flood damage. Also if you notice rust on the bottom and it's not leaking, yet... you just might want to call a plumber to replace your water heater. Estimated life of a water heater in Arizona is 6 - 8 years for electric and 10 - 12 for gas. Keep in mind there are different factors which could increase or decrease longevity.