In the seemingly never-ending battle with Giant Salvinia, LDWF has scheduled a drawdown of Lake Bistineau, located in Webster, Bossier, and Bienville parishes, to begin in just a couple of weeks. When Exactly Will LDWF Begin To Drawdown Lake Bistineau? Despite these extensive control efforts, the rapid expansion of giant salvinia warrants the need for a drawdown at this time. Why Does LDWF Continue To Drawdown Lake Bistineau Every Year? In addition to herbicide applications, LDWF staff have released over 37,000 giant salvinia weevils into portions of the lake difficult to access with spray equipment.