La. Roads, Bridges and Ferries § 48:887
Any parish, in addition to the revenues which may be received from the sale of bridge revenue bonds and from the collection of tolls and other bridge revenues derived under the provisions of this Sub-part, may accept from any federal agency, any state or state agency, or any municipality or municipal agency, or other political subdivision, grants or advances, for or in the aid of construction or acquisition of any bridge or the payment of any bonds issued under this Sub-part.
The parish may also accept contributions and advances from any source of money, property, or other things of value to be held, used, and applied only for the purpose for which the grants, advances and contributions may be made, and the parish may contract for the repayment or return of such grants, advances and contributions.
La. Roads, Bridges and Ferries § 48:887