The Bayou D'Arbonne Lake Watershed District is hereby created out of Bayou D'Arbonne, Bayou Corney (Little and Big), Bayou Little D'Arbonne, Bayou Middle Fork, and the watershed of each of the said streams, situated in the parishes of Lincoln and Union and more particularly defined as follows:
Lincoln Parish: All of Lincoln Parish lying and being situated East of the Range line dividing Ranges 3 and 4 West.
Union Parish: All of Union Parish lying and being situated west of Bayou De'Loutre.
La. R.S. § 38:2551