All curbs and gutters laid on any of the streets of the city, unless otherwise provided for by ordinance, shall be made of concrete and such curb and gutter shall be a combination concrete curb and gutter. Every such curb and gutter shall be laid under the direction of the permits and code management department, to conform to the grade established by the city engineer and according to such plans and specifications as may be adopted by the city. (Code 1953, § 18.31; Ord. No. G-90-50, § 1, 10-18-90)