La. Stat. tit. 33 § 3689.14
Said parishes are hereby authorized through their police juries to engage the services of an engineer and provide for his payment, which engineer shall prepare all plans and specifications as to grade, subgrade, drainage, manner and type of paving, surfacing, sidewalks, or other improvements, including the necessary curbing, guttering, aprons, headers and drains, providing that the police jury shall approve such plans and specifications by a proper resolution duly adopted. Such engineer so employed shall inspect the work as let in accordance with contracts hereunder and shall issue to the said contractor his estimates thereon from time to time as the said work progresses, which estimates may be paid by the parish either in full or by the retention of an amount not exceeding twenty (20%) per cent thereof as retained percentage. Upon final completion of the work the said engineer shall render a report to the police jury of the parish as to the completion of the work in a satisfactory manner, which report shall be duly certified to, and in addition thereto the said engineer shall do and perform any and all engineering duties required of him in R.S. 33:3689.1-33:3689.17. The police juries of the respective parishes are also hereby authorized to employ an attorney or firm of attorneys to handle all legal work in connection with such improvements herein authorized and provide for the payment of his or their fee.
La. R.S. § 33:3689.14