Cal. Gov. Code § 65915.2

If permitted by local ordinance, nothing in Section 65915 shall be construed to prohibit a city, county, or city and county from requiring an affordability period longer than 55 years for any units that qualified the applicant for the award of the density bonus developed in compliance with a local ordinance that requires, as a condition of the development of residential units, that the development include a certain percentage of units that are affordable to, and occupied by, low-income, lower income, very low income, or extremely low income households and that will be financed without low-income housing tax credits.