2008: RDMD (Resources and Development Management Department) name change to OC Public Works
2004: RDMD (Resources and Development Management Department) formed by merger of PFRD and PDSD.
The agency headquarters building at 300 N. Flower St. in Santa Ana is one of two Hutton Towers constructed in 1993. The building is named for EMA founding director and engineering pioneer Herbert George Osborne, known as the "father of the Santa Ana River Flood Control Project" for his many significant contributions to planning, public works, and building projects. Osborne began his County career in 1950 as a civil engineer in the Orange County Flood Control District, and held a number of leadership positions before retiring in 1980.
1997: EMA and GSA combine to form three new departments including PRFD, PDSD and Housing.
PFRD (Public Facilities and Resources Department)
Harbors, Beaches and Parks
Engineering & Permit Services
Internal Services (added a couple years later)
Watershed (added a couple years later)
PDSD (Planning and Development Services Department)
Building and Safety
1992/1993: Housing Department added to EMA
1991: Agricultural Commissioner added to EMA
1976: GSA (General Services Agency) formed by a split of Public Facilities from EMA.
1974: EMA (Environmental Management Agency) formed and included the following groups: