A few thoughts:

The cost of drilling a well, even a shallow one, is substantial. It's much, much cheaper to stockpile municipal water for emergency use.

Ask about permits! In many municipalities, you can't just plunk in a new water well where you please. They may be restricted or banned for a number of reasons, everything from stability of the land area to water rights in dry areas.

Wells can't just sit: they need maintenance. A well that is static -- not pumped regularly -- can become non-potable due to bacterial growth.