The Osada Recreation Area on the left bank of Brno Valley Dam (Czech Republic) represents a location that is extremely affected by the abrasion process due to a combination of adverse factors (fetch related to the dominant wind speed and direction over the water surface causing wave motion, the geological structure and morphology of banks, boat traffic). Our research focused on confirming the hypothesis that properly designed low-cost biotechnical structures can contribute to the active stabilization of a bank under special protection status. The hypothesis was verified by the method of wave train analysis (to prove wave height reduction) and spectral analysis (to prove wave energy dissipation due to breaking) of synchronized data collection of wave motion. The records of water surface motion were taken with the aid of electronic devices on the windward and leeward sides of the structure specifically assembled for the purposes of our research. Comparing the results of both sensors proved the effect of the stabilizing structure (double willow wattling) consisting in wave height and peak spectral energy density reduction. The leeward values decreased to approximately half the windward values due to the process of waves passing through the structure and energy dissipation.