Abstract: A turbine system that can be releasably anchored in a flow of liquid, like a waterfall, and generate power from the flow includes a runner operable to receive some or all of the flow of liquid and rotate to generate power, a penstock operable to direct some or all of the flow toward the runner, and an intake operable to direct some or all of the flow into the penstock. The runner may be coupled to a generator to generate electric power. The penstock has a length that is adjustable to accommodate changes in the height of the liquid drop or waterfall, which may be desirable if the distance between the top and bottom of the drop fluctuates like an ocean's tide. The turbine system also includes a valve operable to modify the flow of the liquid flowing into the runner, and a control circuit operable to determine an amount of liquid entering the penstock and, in response to the determined amount, move the valve to increase or decrease the flow of liquid into the runner.