Some parts of California make this easier by calling the county by the name of the biggest city. This makes local geographical references easier for non local audiences. Eg. The desalination project in Carlsbad -> San Diego County -> California -> United States. Even though Carlsbad isn't the city of San Diego, CNN might report that a desalination project is in progress in San Diego, and still be relatively accurate.

It seems that people do this in conversation by default already, even if the legal boundaries don't conveniently match with what they mean.