Hydrology Expert Reviews Property Damage Dispute

This case stems from a drainage dispute between neighbors in California. The plaintiff claimed that the neighbor’s poor property drainage caused water intrusion that led to flooding in the plaintiff’s basement. In the year leading up to the complaint, there were record rainfalls in the parties’ county of residence. Because the events correlated with significant rain events in the area, the defendant neighbor argued that her house was not built to sustain that much rainfall and that the damage was not due to how her property drained off. A hydrology expert was sought to access and aggregate rainfall data to demonstrate how much rainfall there occurred in the area during the particular dates in question.

Question(s) For Expert Witness

1. How would you go about accumulating data regarding the amount of rainfall on particular days in specific locations?

Expert Witness Response E-074950

To determine the amount of rainfall on particular days in specific locations, you would first gather data from two different types of sources. One is official weather observing sites and the other is cooperative weather observing stations. These cooperative weather observing stations are not so-called 24-hour weather stations. They usually create data once a day. There are typically anywhere from 6-12 observation sites between the two different sources. You then order the doppler radar images covering the entire area, zoomed into the location involved in the case. You then correlate these radar images with the actual observed data. I have estimated rainfall for a specific location over a specific period of time many times, as this is my occupation. I have worked on over 1,000 cases and most of these cases involve some form of precipitation, should it be rain or snow. I obtain blue ribbon certified data which is well regarded in court.