A special tool is required to remove the lock from a water meter. These tools are known as barrel lock keys and are not available to the general public.
Generally, the only individuals who may open water meter locks are authorized employees working for a water utility company. In many areas, tampering with water meters is a crime that can result in serious penalties. In Missouri, one can be found guilty of tampering in the second degree if a utility offers evidence that a water meter has been bypassed or modified to measure usage inaccurately. In Ohio, evidence of meter tampering is used to show that a person intended to commit the crime of theft.