Considerations For Proving The Cause Of Flooding In Land Use Cases

Because of heavy rains this year, we've received a number of contacts from homeowners whose homes were flooded by excessive rainwater for the first time since they owned them. They want to make a claim for the flood damage that wasn't covered by insurance, or perhaps they had no flood insurance at all. The potential targets for their complaints vary -- the builder of their home for some sort of defect, their developer for not properly preparing the land, or a neighboring development for improper rainwater runoff or flood control measures.  

Pursuing a flood damage claim is not as simple as A-B-C. Just because flooding occurs after a rainfall doesn't mean that someone's automatically liable to the homeowner for damages. A connection between the defendant's wrongdoing ("causation") and the flooding must be established or the claim will fail. If challenged, that connection usually must be established by a qualified expert witness who can testify about how the defendant's conduct led to the home's flooding.

A defendant usually challenges causation in a flooding case in one or two ways. First, in land use cases the defendant usually argues that whatever it supposedly did wrong was not a cause of the flooding. Second, in any type of flooding case the defendant could argue that the rainfall event was so extreme that anything it did wrong didn't matter because nothing could've prevented the flooding since even the best precautions cannot guard against the most extreme events.

The first causation argument is the most common. It's almost always raised when a homeowner claims that a neighboring landowner or developer has improperly graded its land, improperly modified its land, or otherwise done something as a landowner or developer that's increased the risk of flooding on the homeowner's property. The difficulty is in establishing that the flooding was caused by that neighboring land use as opposed to someone else's land use.

The defendant, especially if it's a developer, can be expected to hire an expert to blame all the other surrounding land users, land uses, and land features, including the suing homeowner, for the flooding. Overcoming that argument will be extremely difficult, if not impossible, unless the homeowner has a qualified expert to testify and place the blame on the defendant. In fact, such cases often come down to a "battle of the experts," in which two qualified experts offer contrasting opinions on causation and the winner of the case is that party whose expert wins that battle.

The homeowner's expert will need to do some work to avoid having any opinions undercut. Calculations regarding water flow and depth may be necessary. The existence and size of culverts, ponds, and other land features and structures may have to be accounted for. Differences in elevation between the two parcels of land may be important. So may any changes that the suing homeowner has made to the land or its features, such as grading, adding or removing trees and other vegetation, and adding or removing fencing and structures. In the end, the expert will have to offer an opinion connecting the defendant's conduct to the homeowner's flooding or the claim will most likely fail. That'll require the expert to consider and rule out other possible causes of flooding that wouldn't be attributable to the defendant.

The second argument, that the rainfall was so extreme that nothing could've prevented flooding, is less common but may still need to be prepared for. This argument usually only arises when a tremendous amount of rain fell in a very short time period. The contention would be that with a certain amount of rain within a certain time period, flooding would occur regardless of anything the defendant did. Thus, to the extent that the defendant did anything wrong, it didn't matter because it can't be proved that the defendant's wrongdoing, as opposed to an act of nature (the extreme rainfall), was the cause of the homeowner's flooding. The homeowner's expert will have to analyze whether an extreme rainfall event occurred, such that the expert needs to be prepared to address whether it was the extreme rainfall, as opposed to the defendant's wrongdoing, that caused the flooding.