(a) The mixed-finance owner shall maintain an operating reserve account in an amount sufficient to cover the operating expenses of the development for at least a three-month period.

(b) Project income, project rental assistance, tenant rents, and tax credit equity may be used to fund the operating reserve account.

(c) Amounts derived from Section 202 or 811 (e.g., project income, project rental assistance, and tenant rents) in operating reserve accounts may only be used for the operating expenses of the 202 or 811 units.