It is provided to embody as a modularly constructed system, a water wheel for power generation via generators with transversely extending water blades as hinged or folding blades. In this regard it is provided to arrange the water blades over a truss framework. The truss framework for each water blade is formed by a transversely extending prism-like arrangement of plural connected struts as transverse supports, whereby these are connected at node points by longitudinal rods, and at least one strut of the transverse supports is connected with the wheel rim. In that regard, a longitudinal rod located at the top and arranged over the transverse supports is embodied for the rotatable support of a pivotably received water blade via a mounting receiver and a longitudinal rod is allocated as a counter support for the water blade in its working position. Simultaneously this longitudinal rod serves for limiting a pivoting motion of the neighboring water blade in the turbulent region.