The potential of small hydropower in Austria is a widely underestimated resource. The potential of extension in the region of small hydro power plants up to the year 2020 is estimated for 2 TWh, there from 0,7 TWh by optimization of already existing plants. The goal of this thesis is to show economical and technical possibilities, especially in upgrading of these already existing small hydro power plants. The thesis presents the options of power enhancement as an example of a - since 1937 in original condition working - small hydro power plant. Afterwards we check the results for plausibility, comparing it with the performance data of an also long existing, but already 2006 renewed small hydro power plant. The thesis includes also information about the technical fundamentals of small hydro power plants and will be a short compendium on the area of performance enhancing of small hydro power plants. The position of the discussed power plant is in a part of Styria where water power has been used for industrial applications for centuries. Therefore a short part of this work will show the historical dimensions.