Whenever the authority determines by resolution that it is necessary or desirable to obtain funds through the sale of bonds as provided for in this part to provide for the improvement of San Francisco Harbor and its facilities, including wharves, piers, seawalls, railroads, spurs, streets, and appurtenances to any of the foregoing, and personal or real property used in connection therewith, and any necessary dredging and filling in connection therewith by the authority, and to redeem bonds authorized prior to the enactment of this part and outstanding, the authority shall so certify to the committee. Funds so secured shall not exceed, in the aggregate, fifty million dollars ($50,000,000).