A.   Base: A city base is fixed and established at the south quarter corner of section 6, township 47 north, range 3, west Boise Meridian, said point also being the 291/2 mile corner of the new north boundary of the Coeur d'Alene Indian reservation. All official grades and elevations fixed and established on any of the streets and avenues and sidewalks of the city shall be with reference to and computed from the city base as fixed and established in this subsection. (1983 Code § 12.04.150)
   B.   Grade Lines: All grades and lines shall be established and approved by the city council in accordance with ordinances establishing the grade lines of the various streets and curbs. (1983 Code § 12.04.160)