Without prejudice to any other functions assigned or transferred to them by or under this Act, it shall be the duty of each river authority, as from the second appointed day, to take all such action as they may from time to time consider necessary or expedient, or as they may be directed to take by virtue of this Act, for the purpose of conserving, re-distributing or otherwise augmenting water resources in their area, of securing the proper use of water resources in their area, or of transferring any such resources to the area of another river authority.