The dimensions of the combined concrete curb and gutter shall be as follows:
Across the top of the curb, six (6) inches in width; back side of the curb from top to base, twelve (12) inches; the depth of the concrete in the gutter, five and one-half (5½) inches at the line of the curb; and six and one-half (6½) inches on the face of the gutter, fourteen (14) inches from the curb.