Hydro power plants operate their turbine to match the peaks in electricity demand. This leads to strongly unsteady flow regimes downstream of the power plants outlet into the river. From an ecological point of view, those sudden starting and stopping of turbines, called hydropeaking, are unacceptable. A more restrictive operating of the turbines is not economically practicable, therefore, to counteract these unfavourable effects of hydro power plants, two types of mitigation measures have been found to be effective; structural or morphological measures, i.e. resp. a compensation basin or modifications in the river morphology. The second is analysed in the work to assess the effect of various features inside a channel on hydropeaking rates. The tested case are then compared to a real channel reach with a groinfield. The most effective morphology for this purpose is found to be a groinfield.