The Department of Forests and Waters¹ is hereby authorized to dredge and remove flood waste, deposits, flood water obstructions, gravel, bars and debris from any river or stream or part thereof; to restore or rectify flood damaged or destroyed stream channels, wholly or partly within, or forming part of the boundary of this Commonwealth, except the tidal waters of the Delaware River and of its navigable tributaries; to construct and maintain dams, lakes and other works and improvements, as in the judgment of the department may be necessary to impound flood waters and conserve the water supply of the Commonwealth; and to provide additional recreational areas; and to construct and maintain flood forecasting and warning systems.