Pub. Resources Code, § 21071

“Urbanized area” means either of the following:

(a) An incorporated city that meets either of the following criteria:

(1) Has a population of at least 100,000 persons.

(2) Has a population of less than 100,000 persons if the population of that city and not more than two contiguous incorporated cities combined equals at least 100,000 persons.

(b) An unincorporated area that satisfies the criteria in both paragraph (1) and (2) of the following criteria:

(1) Is either of the following:

(A) Completely surrounded by one or more incorporated cities, and both of the following criteria are met:

(i) The population of the unincorporated area and the population of the surrounding incorporated city or cities equals not less than 100,000 persons.

(ii) The population density of the unincorporated area at least equals the population density of the surrounding city or cities.

(B) Located within an urban growth boundary and has an existing residential population of at least 5,000 persons per square mile. For purposes of this subparagraph, an “urban growth boundary” means a provision of a locally adopted general plan that allows urban uses on one side of the boundary and prohibits urban uses on the other side.

(2) The board of supervisors with jurisdiction over the unincorporated area has previously taken both of the following actions:

(A) Issued a finding that the general plan, zoning ordinance, and related policies and programs applicable to the unincorporated area are consistent with principles that encourage compact development in a manner that does both of the following:

(i) Promotes efficient transportation systems, economic growth, affordable housing, energy efficiency, and an appropriate balance of jobs and housing.

(ii) Protects the environment, open space, and agricultural areas.

(B) Submitted a draft finding to the Office of Planning and Research at least 30 days prior to issuing a final finding, and allowed the office 30 days to submit comments on the draft findings to the board of supervisors.