Proponents of cityhood for Saddleback Valley have begun applying for incorporation through the Orange County Local Agency Formation Commission (Lafco), the panel that recommends approval or denial of such proposals to the Board of Supervisors.
The proposed city would include the areas of El Toro, Lake Forest, Nellie Gail Ranch, Laguna Hills, Aegean Hills and Portola Hills.
Mission Viejo residents voted to incorporate in November.
The Saddleback application is being sponsored by the Santa Ana Mountains County Water District, which voted last week, 4-0, to support the incorporation effort.
Under state law, any public agency that would be affected by incorporation, such as a sewer or water district, is entitled to sponsor a cityhood application.