La. R.S. 38:1522

The pledge shall be either by notarial act or by act under private signature, duly acknowledged, and a copy thereof shall be filed with the fiscal agent of the drainage district, and another copy shall be filed with the State Auditor. Upon filing, the pledgee shall be entitled to payment of the sums advanced upon the pledge, out of the revenues of the current year as collected, by preference and priority over all persons whatsoever, subject only to the legal rights of the holders of any bonds theretofore issued by the drainage district.