The board shall not build any dam, sill or other restrictive structure of any kind which will reverse or otherwise materially affect the natural flow of Bayou Bartholomew; the board shall, however, be empowered to remove water from Bayou Bartholomew at any time when suitable water is available. The board shall not have authority to destroy or substantially diminish prior or vested water rights or uses.
La. R.S. § 38:2754