It is unlawful and an offense for any person to disturb, interfere with, open, operate, close, turn on, turn off, attach any pipe or hose to, or connect anything with any fire hydrant, or any stopvalve or stopcock belonging to the city. However, this section shall not apply to any member of the fire department when in the lawful discharge of his duties as such, or to any person endeavoring to prevent or put out any fire in any lawful manner. (2000 Code § 17-110)