Created in 1927.  Flood of 1916 worst on Santa Ana River.  Maximum flood discharge of 45,000 second-feet.  Flood of 1938 devastated orchards and cities across the alluvial plain of the Santa Ana River.  Development of the county would have been impossible without the facilities of the Orange County Flood Control District.

The Orange County Flood Control District was designated as an Orange County Historical Civil Engineering Landmark in 2001.  The plaque is located at the George Osborne Building, Santa Ana, CA

See image below for the Atchison Topeka & Santa Fe Railroad bridge (only connection between Orange & LA Counties) during the flood of 1916.