Abstract: A new hydraulic turbine assembly for deriving extra energy out of a conventional hydroelectric power generating system by incorporating a second turbine generator at the inlet from the reservoir. The inventive device includes a vertical water inlet pipe being extended into the water reservoir of a dam to deliver water to the conventional hydroelectric generating system. The vertical water inlet pipe has a water inlet point being positioned in the water reservoir to create an inlet free vortex formation. An outer housing tube having an inlet cone for collecting water from said inlet free vortex formation and an outlet draft in fluid communication with the vertical water inlet pipe to permit water to pass through the outer housing tube to the vertical water inlet pipe.