It is unlawful for any person or persons to lay out or cause to be established, laid out, graded, regraded or constructed any curb, street or sidewalk not in conformity to and in compliance with the permanent grades, or to cause to be established, laid out, graded, regraded or constructed any curb, street or sidewalk where the grade is not first established by the council as provided in this chapter, and any such curb, street or sidewalk established, laid out, graded, regraded or constructed not in conformity with the provisions of this chapter is a nuisance and shall be subject to removal and abatement by the city, and the cost of the abatement or change shall be assessed against the abutting property. (1957 code § 8.08.050.)