It shall be unlawful for any person to continue a nonconforming use in any zone established by this title more than one year after the effective date of this title when such nonconforming use has been declared to constitute a nuisance or to be detrimental to public health, safety or welfare by a majority vote of the city council. The council shall have written notice served on the person last known to be the owner of the property on which such nonconforming use exists. The written notice shall order the nonconforming use to be discontinued within one year thereafter. If the owner of the property does not reside in the city at the time, the notice may be mailed to him by registered mail at his last known address. This section shall not be construed as limiting the right of the city or any person to abate a nuisance within the city under any existing laws or ordinances. (Ord. 64, 11-17-1971)