(A) The base, or datum plane, for the city shall be sea level datum as established by the United States Geological Survey being a level plane 601.32 feet below the line on a copper marker of the United States Geological Survey bench mark on the south entrance to the Adams County Courthouse.
(B) The grades of all streets between the point at which the grade has been heretofore or may be hereafter specifically fixed and established and the elevation above the datum plane specifically fixed shall be a straight line drawn from one fixed point to the nearest fixed point, unless the Director of Utilities and Engineering deems it expedient to make use of a vertical curve instead of the straight line above specified.
(1980 Code, § 13.903)