What are you trying to prevent? It would be beyond the capacity of almost anyone to alter a meter to achieve a consistently higher consumption reading. That would take some extreme technical know how at a minimum. Meters are built to be pretty much tamper proof and the meters used at parks are no exception.
It is possible that park misreads the meter (easy to check, read it yourself) or they may also have additional things running off your meter (even easier to check, unplug your rig and see if the meter continues to run). Now if what you are trying to do is see your usage at any given time, that is a different story.
