Any violation of the provisions of this chapter by any person shall be unlawful and shall be referred to the City Attorney, who shall expeditiously prosecute all such violators. A violator shall, upon conviction, be subject to a forfeiture as provided in § 1-4 of the Code, together with the taxable costs of such action. 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.