A device that controls the flow in a conduit, pipe, or tunnel without obstructing any portion of the waterway when in the fully open position. Structure or device for controlling the rate of flow into or from a canal or ditch. A movable, watertight barrier for the control of water in a waterway. See bear-trap gate, bulkhead gate, clam shell gate, coaster gate, crest gate, cylinder gate, drum gate, emergency gate, fixed-wheel gate, flap gate, flood gate, guard gate, high-pressure gate, jet-flow gate, outlet gate, paradox gate, radial gate, regulating gate, ring gate, ring- follower gate, ring seal gate, roller gate, skimmer gate, slide gate, sluice gate, stoney gate, tainter gate, tractor gate, vertical lift gate, or wicket gate.