Section 39E. The land, water rights and other property taken or acquired under section thirty-nine B, and all works, buildings and other structures erected or constructed under sections thirty-nine C and thirty-nine D, shall be managed, improved and controlled by a board of water commissioners to be elected as provided by section sixty-nine A of chapter forty-one, or by its selectmen authorized to act as such, in such manner as they shall deem for the best interests of the town.