In determining the amount of bonded indebtedness to be incurred, the board may include all costs and estimated costs incidental to or connected with the acquisition, construction or financing of the works or property set forth in the report required by Section 74800, and all engineering, inspection, legal and fiscal agent’s fees, costs of the bond election and of the issuance of the bonds, and bond interest estimated to accrue during the construction period and for a period of not to exceed 12 months after completion of construction.