This article presents the use of geotextiles in the drainage, reinforcement, and protection works for the high slopes along the Danube-Black Sea Canal. The solution of using geotextiles applied directly to the surface of the slopes is presented. The tests carried out to verify the conditions of hydrodynamic stability, permeability, and drainage, conducted between 1985–1990, are described. The long-term performance of these geotextiles is also analyzed based on laboratory tests performed on samples currently taken from the site. Furthermore, the article highlights the technical, economic, and environmental efficiency of this solution compared to the use of traditional protective filters, with the following key advantages: increased labor productivity and reduced costs; a significant reduction in energy-intensive materials with a positive impact on the climate; and the near-perfect integration of these works into the natural environment.