Ps lived in D. D's sewage/stormwater system is over 100 years old. Two combined sewer/stormwater lines run under Ps' street. Originally, these pipes consisted of a 12-inch vitrified clay pipe on the western line and a parallel 15-inch vitrified clay pipe on the eastern line. In 1987, D conducted a video inspection of the pipes, which showed that the pipes were cracked, structurally unsound, and that they had significant root intrusion. D undertook a so-called slip-lining process that inserted polyethylene sleeves of lesser diameter through the clay pipes. It slip-lined the 12-inch clay pipe on the western line with a 9-inch polyethylene pipe, and it slip-lined the 15-inch clay pipe on the eastern line with a 12-inch polyethene pipe. In May 2014, D experienced an extremely intense rain and hail storm, accompanied by high winds; 1.3 inches of rain fell in just fifteen minutes. The total rainfall was 1.65 inches. The flow rate at the D's main sewer interceptor rose instantly from approximately 7 million gallons per day (MGD) to almost 70 MGD, and the storm caused 3 million gallons of combined wastewater (domestic sewage and stormwater) to overflow to receiving streams. That day, D's combined sewer/stormwater line also backed up into the basements of Ps' homes causing property damage. Ps sued D, claiming that it had been negligent in the design, construction, and/or maintenance and repair of D's public sewer lines.Ps also raised nuisance, trespass, and constitutional takings claims. Ps asserted that D had a duty to keep and maintain the lines in a reasonably safe and proper condition for the public's use and benefit. D moved for summary judgment. D produced evidence that it has had an excessive number of combined storm/sewer overflows due in part to the age of its infrastructure and that it has limited resources to address these issues. D also noted that the state and the federal governments imposed significant regulatory constraints on its actions and priorities, which was one of many factors that influenced D's decisions regarding the use of its limited funds. Ps' expert agreed that deciding the priority of projects was a matter of discretion and that such decisions involved the exercise of judgment and the weighing of technical merit and available resources. D maintained that it was entitled to summary judgment based on immunity and Ps' failure to establish causation for the negligence and nuisance claims. The court granted summary judgment to D concluding that Ps could not establish causation for purposes of their negligence claim. The trial court also rejected Ps' nuisance claim. As to trespass, the court found that Ps needed to show an intentional act and that there was no such allegation or evidence of that here. The court found that Ps failed to present sufficient evidence to support their takings claim. Ps appealed.