Man has influenced the shape of the landscape most importantly through logging, mowing and afforestation.
Only a few decades ago, the majority of hills in the Notranjska Regional Park was bare because the steep slopes were used for grazing and the flatter ones were mown for grass. By gradual cessation of mowing and grazing in hilly areas, former meadows and pastures are becoming overgrown by forests, which is also the case in some areas at Lake Cerknica.
Man has also influenced the landscape of Lake Cerknica. The construction of a dam connecting the villages of Dolenje Jezero and Goričica, bridges at the village of Otok, construction of dams at the lake’s Vodonos and Rešeto sections, changes to the Stržen stream bed and interferences in several sinkholes have changed the landscape, but also influenced the pace of filling and draining of the lake.