A hydroelectric power generation apparatus includes a hydroelectric power generation module, a supporting part, and a bar. The hydroelectric power generation module includes a rotary blade and a power generator that generates power by rotation of the rotary blade. The supporting part supports the hydroelectric power generation module. The supporting part can be installed at a water channel. The bar is connected to the supporting part to protrude from the supporting part. With one end of the bar closer to the supporting part or a portion of the supporting part serving as a center, the other end of the bar opposite to one end of the bar can be pivoted to switch a first state to a second state and vice versa.