(a) 
Within the districts established by this article or amendments hereto, there exist lots, structures, uses of land and structures, and characteristics of use which were lawful before this article was enacted, amended or otherwise made applicable to such lots, structures or uses, but which do not conform to the regulations of the district in which it is located. It is the intent of this division to permit such nonconforming uses to continue, under regulations herein contained, until the same are removed, but not to encourage their survival.
(b) 
It is further the intent of this division that nonconforming uses shall not be enlarged upon, expanded or extended, nor be used as grounds for adding other structures or uses prohibited elsewhere in the same district.
(c) 
Nonconforming uses are hereby declared to be incompatible with the permitted uses in the districts involved.
(2005 Code, sec. 17.12.01)
Except as herein provided, no nonconforming use of land or buildings nor any nonconforming structure shall be enlarged, changed, altered or repaired except in conformity with the regulations contained in this division.
(2005 Code, sec. 17.12.02)
Any use or structure which does not conform with the regulations of the zoning district in which it is located shall be deemed a nonconforming use when it possesses any of the following characteristics.
(1) 
Such use or structure was in existence and lawfully operating on November 12, 1973, and has since been in regular and continuous use.
(2) 
Such use or structure is a lawful and conforming use at the time of the adoption of any amendment to this article but by such amendment is placed in a district wherein such use is not otherwise permitted.
(3) 
Such use or structure was in existence at the time of annexation to the city and has since been in regular and continuous use.
(2005 Code, sec. 17.12.03)
(a) 
A nonconforming use is a lawful use of land, although such does not conform to the provisions hereof, and may be continued; but if said nonconforming use is discontinued, any future use of said premises shall be in conformity with the provisions of this article.
(b) 
A legal nonconforming use, when discontinued or abandoned, shall not be resumed. Discontinuance or abandonment shall be defined as follows:
(1) 
When land used for a legal nonconforming use shall cease to be used in such manner for a period of one (1) month.
(2) 
When a building or other structure designed or used for a nonconforming use shall cease to be used in such manner for a period of six (6) months.
(c) 
Abandonment of a nonconforming use shall be determined by the intent of the user or owner to discontinue a nonconforming operation and the actual act of discontinuance, as the facts are found to be by the board of adjustment.
(2005 Code, sec. 17.12.04)
(a) 
A nonconforming use of a building may be changed to another nonconforming use of the same or more restrictive classification, after approval by the board of adjustment; provided, that when a nonconforming use is changed to a conforming use of a higher or more restrictive classification, it shall not later be reverted to the former, less restrictive classification.
(b) 
No nonconforming use shall be changed to another nonconforming use which requires more off-street parking spaces or off-street loading space than the original nonconforming use unless additional off-street parking and loading space is provided so as to comply with the requirements of division 9 of this article.
(2005 Code, sec. 17.12.05)
Nothing in this division shall be taken to prevent restoration of a building destroyed to the extent of not more than fifty percent (50%) of its reasonable value by fire, explosion, or other casualty or act of God, or a public enemy, nor the continued occupancy or use of such building or part thereof which existed at the time of such partial destruction.
(2005 Code, sec. 17.12.06)
The right to operate a nonconforming use shall cease and such use shall be terminated under any of the following circumstances:
(1) 
When such use is abandoned, as hereinabove provided.
(2) 
When any provision of this or any other ordinance of the city is violated with respect to a nonconforming use.
(3) 
When a nonconforming use is changed to a conforming use by rezoning.
(4) 
When the structure in which a nonconforming use is housed, operated or maintained is damaged to the extent of more than fifty percent (50%) of its value, as provided in section 14.02.536 hereof.
(5) 
When the right to maintain or operate a nonconforming use has been terminated by the board as provided in division 15 of this article.
(2005 Code, sec. 17.12.07)
The operator, owner, or occupant of any nonconforming use of land or buildings shall, within six (6) months after the date of this amendment (of [if] nonconforming on such date) or within six (6) months after having been rendered nonconforming by any subsequent amendment hereto, register such nonconforming [use] by obtaining from the zoning enforcement authority of the city a certificate of occupancy bearing the designation “Nonconforming,” even though a previous certificate of occupancy may have been issued. Such certificate (nonconforming) shall be considered as evidence of the legal existence of a nonconforming use, as contrasted with an illegal use or violation of this article. The enforcement authority shall maintain a register of all certificates of occupancy issued for nonconforming uses and shall, on written request and payment of fee, issue a duplicate certificate to anyone having a proprietary interest in the property in question. A nonconforming structure need not be registered.
(2005 Code, sec. 17.12.08)