In a water wheel with an integrated electrical generator, a ring element for forming a rotor is rigidly concentrically connected with the water wheel. The ring element is assembled of modular individual segments with inserted permanent magnets. At least one corresponding partial ring as a stator is allocated to the rotor, whereby each partial ring carries electrical coils in correlation to the permanent magnets of the ring element of the rotor. The partial rings of the stator are stationarily mounted by holding elements on support struts of the water wheel.