Oren,

Leaving a faucet dripping is a common tactic in Northern climes to keep
the water in uninsulated pipes (or poorly insulated) from freezing. when
folks are asleep or away a dripping faucet keeps water circulating through
the pipes. Un circulated, uninsulated water may rapidly lose temperature and
freeze. Dripping faucets bring warmer water into the pipes which retards
freezing.

Dave M.