Any development, any building or structure constructed, moved or structurally altered, or any use established after the effective date of this chapter in violation of the provisions of this chapter by any person, firm, association or corporation (including building contractors or their agents) shall be deemed a violation. The Land Conservation and Zoning Administrator or the County Zoning Department shall refer violations to the District Attorney or Corporation Counsel, who shall expeditiously prosecute violations. Any person, firm, association or corporation who or which violates or refuses to comply with any of the provisions of this chapter shall be subject to a forfeiture as provided in Chapter 290 of the County Code, together with the taxable cost of action. Each day which the violation exists shall constitute a separate offense. Every violation of this chapter is a public nuisance and the creation thereof may be enjoined and the maintenance thereof may be abated pursuant to § 59.69(11), Wis. Stats.
Any property owner asserting as a defense to a charge of violating this chapter that the alleged violation has been in place more than 10 years before enforcement action was initiated has the burden of proving that:
A. 
The building or structure that is in violation has been in place more than 10 years before enforcement action was initiated.
B. 
The building or structure (and its use, if the use is nonconforming) has remained essentially unchanged for at least 10 years.
C. 
The use of the building or structure has been active and continual for 10 years or more. If use was discontinued for more than 12 months, that use shall not be considered active and continual.