The pledge shall be either by notarial act or by an act under private signature, duly acknowledged. A copy of the act shall be filed with the state treasurer, another copy shall be filed with the state auditor, and a third copy shall be filed in the archives of the office of the levee district or levee and drainage district. Upon filing, the pledgee shall be entitled to payment of the sums advanced upon the pledge out of the revenues of the year or years so anticipated, as collected, by preference and priority over all persons, subject only to the legal rights of the holders of any bonds theretofore issued by the levee district or levee and drainage district.
La. R.S. § 38:512