Hydropeaking is a major issue for storage hydropower plants. Hydropeaking can affect negatively the aquatic environment along river streams. For several hydropower plants studies which analyse measures to reduce the surge effect are currently under preparation. A common technical measure is to construct a compensation basin downstream of the powerhouse. The selection of an adequate compensation basin volume is a compromise taking several aspects, such as construction costs, environmental impacts of the compensation basin during construction and operation as well as reduction of hydro peaking, into account. The determination of the required storage volume is based on different environmental factors. The main factors are surge ratio, discharge gradient, released maximum discharge and released minimum discharge. However, the selection of these factors is complex and normally not a straightforward process. As for each river these factors can have a different environmental affect several cases have to be analysed. In addition the operational parameters of a hydropower plant, such as peaking hours and peaking discharge, can be varied. This can lead to numerous simulation runs. The simulation – including checking and quality control – of hundreds of cases and a sensitive analysis is time consuming. Design of experiments (DOE) provides a set of methods, which allows an identification of the factors with a significant influence on the storage volume. In addition by deriving a simple model, such as linear model, first estimations can be prepared. DOE is a promising set of methods which could reduce the significantly the required work regarding simulation runs.