Actions brought under this article have precedence over all actions, excepting criminal proceedings, election contests and hearings on injunctions, and in such actions evidence of the general reputation of a place is admissible for the purpose of proving the existence of a nuisance. If the complaint is filed by a citizen, it shall not be dismissed by the plaintiff or for want of prosecution except upon a sworn statement made by the complainant and his attorney, setting forth the reasons why the action should be dismissed, and the dismissal ordered by the court. In case of failure to prosecute any such action with reasonable diligence, or at the request of the plaintiff, the court, in its discretion, may substitute any other citizen consenting thereto for the plaintiff. If the action is brought by a citizen and the court finds there was no reasonable ground or cause therefor, the costs shall be taxed against such citizen.