An hydraulic model study was carried out to estimate the discharge and downpull characteristics of the vertical lift control gates proposed for the Wreck Cove power project in the Cape Breton Highlands. The same gate geometry was selected with the two different upstream tunnel configurations of the Gisborne and McMillan reservoir–outlet structures. In the former, both free-surface and closed-conduit downstream conditions could occur in the prototype, whereas only closed-conduit flow would exist in the latter. In addition, the gate model was elastically suspended so that its susceptibility to flow-induced oscillations could be assessed. The entire test section was installed in a high-speed water tunnel for testing.The gate-bottom geometry was chosen on the basis of previously reported results with two-dimensional models. The three-dimensional features included in the present model (e.g., gate slots) did not yield downpull or vibration characteristics significantly different from the two-dimensional results. The advantages of the present gate configuration are discussed with respect to simpler but unsatisfactory systems.