Any violation of the provisions of this chapter by any person shall be unlawful and shall be referred to the Municipal Attorney, who shall expeditiously prosecute all such violators. A violator shall, upon conviction, forfeit to the City up to $50 per day. Each day of continued violation shall constitute a separate offense. Every violation of this chapter is a public nuisance, and the creation may be enjoined and the maintenance may be abated by action at suit of the City, the state, or any citizen thereof pursuant to § 87.30, Wis. Stats.