California Code, Health and Safety Code - HSC § 50739

At the time the department makes a payment pursuant to Article 2 (commencing with Section 50745), 3 (commencing with Section 50755), or 4 (commencing with Section 50765) or contracts to make annuity fund payments in connection with a rental housing development, or both, a written agreement between the department and the agency, local finance entity, or local public entity shall be executed, designating the number of units within the rental housing development available to, or occupied by, very low income households, other lower income households, and other households. If the number of units occupied by very low income households or other lower income households in any housing development ever falls below the number agreed to by the department and agency, local finance entity, or local public entities, then units which become available for occupancy shall be made available on a priority basis to very low income households or other lower income households, as required, until the number of units so occupied equals at least the number specified in the agreement.

The department and the agency, local finance entity, or local public entity, may reduce the number of assisted units to less than 30 percent of a rental housing development only if necessary to maintain the development's fiscal integrity. Any reduction in the number of assisted units shall be reviewed annually to determine whether it is necessary to continue that reduction in the number of assisted units.