OTT RLS & CBS Water Level Sensors Making a Difference in Harris County. Download the Case Study! The Harris County Flood Control District in Texas was created in 1937 in response to the devastating floods that struck Downtown Houston and Harris County between 1929 and 1935. Currently, the District's boundaries include 3.7 million people in 34 jurisdictions one of which is the City of Houston. In just one year Harris County endured two massive rainfall events with totals of 8-16 inches in 3 to 12 hours. A total of 9800 homes were flooded and 9 persons died. The District is using its "Flood Warning System" (FWS) to measure rainfall and water level amounts in real-time, to provide up-to-date flood information.