The board of commissioners issuing such drainage certificates may by resolution empower and authorize its president and its secretary to negotiate and deliver such drainage certificates and collect the purchase price thereof and do any and all things necessary and incidental thereto, and the funds derived from the sale of the said certificates shall be expended solely in payment of the costs of the improvements herein authorized, and shall not be drawn upon for any other purpose whatsoever.
La. R.S. § 38:1674.8