Does homeowners insurance cover re-drilling water wells that become dry?
No, Homeowners insurance is "Hazard Insurance" for losses to
your home from the specified covered perils detailed in your
policy.
Covered perils are typically losses resulting from Fire,
Lightning, Wind and Hail. Home insurance does not cover normal and
expected maintenance or repair expenses that are considered
incidental to home ownership.
It's no different than a clogged drain for example, If it's not
the result of a covered peril then it is not covered. Normal
Maintenance, Repairs or Home Updates are not hazard losses.