Except as hereinafter provided in this section, this chapter does not authorize any local agency to make any covenants, to perform any act, or to do anything which requires expending any funds other than revenues received or receivable from the enterprise and such other funds from any source as are legally available for such purpose and may be used by the local agency for such purpose without incurring indebtedness. Notwithstanding any other provision of this chapter, (a) a local agency may pledge, place a charge upon, contribute, or otherwise make available, as additional security for the payment of any bonds issued pursuant to this chapter for the purpose of providing funds for the acquisition, construction, improving or financing of public parking lots, garages, or other automotive parking facilities, any or all revenues or funds derived from any or all street parking meters then owned or controlled or thereafter acquired or controlled by such local agency; and (b) a local agency may also pledge, place a charge upon, or otherwise make available, as additional security for the payment of any bonds issued pursuant to this chapter any funds, including contributions, from any source which the local agency may legally apply to such purpose, excepting, however, any and all proceeds of taxation.