canals, or navigations

above acanalcuts across adrainage also anavigationwhen aridge asslack basin building calledlevelsa canal canals cases contrast conveyance createreservoirsof current dams divideatop drainage engineered external flow generally have highestelevation humanmadechannels increase its itsvalleyin just known lengthen levels leverages locks low most ofdamsandlocksthat often orartificial ornavigations parallels part referred requiring reservoirs resources river series servicewater shares slack source speed staying stretches transportvehiclesin water waters waterways will works