No person shall obstruct a fire hydrant. Fire
hydrants shall have a three-foot clear radius measured from the center
of the stem of the top of the hydrant. No foliage, fencing or other
objects may obstruct the clear area. No person may landscape to change
the grade around the base of a hydrant so as to preclude the use of
a four-inch cap. The four-inch cap shall be clear for six inches from
the bottom of the cap to grade level.