The most visible consequences of coal-mining in the
Šaleška dolina Valley are the submergence of the ground and formation of
submerged lakes. The Velenje, Družmir and Škale lakes together extend over more
than 2 km2 and comprise a volume of 50 million m3. Lake
Družmir is over 85 m deep and thus the deepest lake in Slovenia. The Šoštanj
Thermal Power Plant has been supporting research connected with the quality of
water in lakes and in the Paka River as well as various studies dealing with
flora and fauna of lakes, flowing waters and lakeside areas. A great deal of
research in the field of environment was carried out by the researchers from the Institute for
Ecological Research ERICo Velenje for TEŠ.
A secondary living environment – biotope, which contributed to a larger
diversity of plant and animal species, has been formed by the lakes. Supplement habitats providing extremely variegated
and diverse life conditions have been formed in a relatively small area: from
extremely dry ruderal living environments, meadows and forest edge to water
environments - marshy lands, streams, small lakes and pools. Thus over 220
species of birds, among them also representatives of less common and even rare
species, have been sited in this area: the Red Knot, Little Egret and the Black
Stork. Twenty-seven different species of dragonflies, around 40 % of all living
species in Slovenia, were recorded in the surroundings of water bodies. These
included the Red-veined Darter Dragonfly (Sympetrum fonscolombei), which is
classified as a vulnerable species and the Spotted Darter (Sympetrum
depressiusculum), which is a critically endangered species in Slovenia. The
water environment and lush flora create a suitable living environment for
amphibians. Four species of frogs were spotted in this area in 2002: the
European Tree Frog (Hyla arborea), the Edible Frog (Rana esculenta), the Marsh
Frog (Rana ridibunda), the Common Toad (Bufo bufo) and the Alpine Triton
(Tritus alpestris). All species of amphibians except for the Fire Salamander
are listed in the Red List of Endangered Amphibians in Slovenia.