One is subject to liability for a private nuisance, but only if, his conduct is a legal cause of an invasion of another's interest in the private use and enjoyment of land, and the invasion is either (a) intentional and unreasonable, or (b) unintentional and otherwise actionable under the rules controlling liability for negligent or reckless conduct, or for abnormally dangerous conditions or activities.
Plaintiff property owner sued defendant neighbors for diverting surface water from their property onto the property owner's property. The trial court found that the neighbors did not act unreasonably, but the Wisconsin Court of Appeals summarily reversed. The neighbors appealed. The lower court determined that the neighbors' landfill project effectively blocked the normal flow of surface waters as the flow existed prior to the landfill project and was a legal cause of the property owner's serious water problems. The neighbors argued on appeal that the lower court did not consider the social utility of the development project, which it should have done, failed to consider whether the property owner mitigated its damages, and that comparative fault principles should have been applied to apportion the liability of each party. The court affirmed the order of the court of appeals, which remanded the matter to the trial court with instructions to award the property owner damages in the stated amount and to address the punitive damages and attorney fees issues raised by the property owner which were not initially addressed by the trial court.
Are defendant's liable for damage to plaintiff's property?
The court held that the property owner sustained serious harm as a result of the intentional invasion of surface waters caused by the neighbors' development project and that the invasion of surface water caused by the neighbors' conduct was unreasonable. The court further held that an analysis of unreasonable conduct did not necessitate an express consideration of the social utility of a defendant's conduct; that the property owner was entitled to an unreduced award of damages; and that comparative fault principles were inapplicable to this case.