Permanent preservation areas reduce the exposure of sediments and nutrients in aquatic medium and improve the quality of water. The analysis of natural features and anthropic use in rivers' surroundings makes it possible detecting potential ecological unbalance. This study analyzed the potential and emerging environmental fragility in Permanent Preservation Areas (PPA). Environmental fragilities around drainage areas composing the sub-basin were assessed based on soil, relief, rainfall, land use/land cover (LULC) features. The degrees of emerging environmental fragility observed in the second-order stream were lower than those in first-order ones: 3.07 and 2.68, on average, respectively; and standard deviation of approximately 0.7 was recorded in each group. First-order streams are more closely associated with high slopes, and it increases their fragility. Then reduction of fragility levels around water springs due to conservationist practices will decrease material and energy transfer throughout network connections and rebalance the assessed aquatic ecosystem.