Protection of biodiversity

Protection of biodiversity

HEP continuously adjusts and improves its business activity with the requirements of protecting and maintaining biodiversity in line with legal regulations and with professional and scientific trends, which it applies in cooperation with scientific institutions and competent authorities.

Hydro power plants on the river Drava

There are three hydro power plants on the Drava River: Varaždin, Čakovec and Dubrava. All three hydro power plants are in the Regional Park Mura – Drava, because they have been recognized as important ornithological areas. A part of HPP Varaždin’s accumulation is on the territory of the Republic to Slovenia, which has proclaimed it an ornithological reserve – Reserve Ormož Lake. The accumulations of the Drava River have become winter homes and habitats of many protected bird species, as one of important winter homes of European waterfowl and a part of European ecological network NATURA 2000. In order to maintain a high level of biological and landscape diversity of wetlands and water habitats and as part of the solution to the problem of deposits, in the accumulation lake Varaždin an island was built for birds to nest. To finish this project, HEP cooperated with the State Institute for Nature Protection and Association BIOM. Alongside accumulations of HPP Varaždin and Dubrava there are watchtowers for bird watching.

In order to preserve the ichthyofauna, the Drava hydro power plants have been co-financing the restocking with trout, zander, pike and carp, which is carried out by sport angling societies of Međimurska and Varaždinska counties. In the left drainage canal of HPP Dubrava, there has been noticed a rare and endangered type of fish which is on the Croatian Red List of Freshwater Fish – mudminnow (Umbra krameri Walbaum).
In order to harmonize electricity generation and preserve all environmental constituents, measures are undertaken and regulations from the Natural Resource Management Plan are followed in the area of hydro power plants on the Drava. The most important activities are the following:
  • Regulation of water level and monitoring water quality in spawning areas, incubation and the early development of hatched eggs of fish and amphibians. Zoological institute of the Faculty of Science at the University of Zagreb offers professional help to HEP’s employees with these activities.
  • Revitalization of the old armlet of the Drava by removing perennial deposits and vegetation, which enabled the migration and spawning of fish in the old armlet of the Drava, but also nesting of water birds.
  • Removing invasive species as part of regular activities of preserving zebra mussel (Dreisseina polymorpha Pallas), and flowering plants – Canadian pondweed (Elodea Canadensis) and watermilfoil – Myriophyllum.
  • Late manual mowing of lawns and drainage of ditches in the area of hydro power plants on the Drava, for the purpose of preserving a critically endangered plant, German tamarisk (Myricaria germanica L. Desv.), which is on the Croatian Red List of Endangered plants and animals, and of orchids, the military orchid (Orchis Militaris L) and the early-spider orchid (Orchis sphegodes Mill.).
  • The control of activities near dams of HPP Čakovec and HPP Dubrava in order to preserve the otter (Lutra lutra L.)

Hydro power plants in Krka National Park

There are four hydro power plants on the Krka river: HPP Jaruga (built in 1903), HPP Miljacka (1906), HPP Grčić and small HPP Krčić. The two oldest hydro power plants Jaruga and Miljacka are located in the National Park Krka (proclaimed in 1985).
On all watercourses, on which are HEP’s hydro power plants, special attention is paid to achieving balance between environment protection and the use of water to generate energy, and such is the case in HPPs on the Krka river.
Krka National Park and hydro power plants on the Krka are a part of the European network NATURA 2000, which is also evidence that hydro power plants work in harmony with nature.

TE-TO Zagreb and ornithological reserve Savica

In the immediate vicinity of the combined heat and power plant Zagreb, there is an ornithological reserve, Savica Lake. The lake consists of 12 interconnected lakes, and in 1991 it was proclaimed an important ornithological reserve. It is looked after by sport angling society “Pešćenica”, the Croatian Ornithological Society, the City of Zagreb and TE-TO Zagreb. Savica is the only remaining wetland in Zagreb and its surroundings, and the proof of its biological value is a high number and variety of birds which dwell here.

This area is a mosaic of dense groves and open water areas rich in fish, insects and water vegetation, thus representing ideal feeding, resting and nesting grounds for birds. Ornithologists have recorded 180 bird species on Savica Lake, which is almost a half of the Croatian ornithofauna. Out of these 180 species, 18 are strictly protected on the international level.

Savica is an old armlet of the Sava River, which provided water to it until 1895. After a big flood in Zagreb, a dyke was built, so Savica was left without a natural water supply. After 1965 TE-TO Zagreb recharged Savica lake with clean cooling water (around 2,000 m3/h), which are taken from the river Sava and enable the development of flora and fauna.

The value of Savica Lake is seen in the education of young people about nature protection, which was recognized by the State Institute for Water Protection and the Croatian Ornithological Society, which organize bird watching on Savica Lake and their banding.

Protection of stork nests

In 2004 HEP signed an Agreement on cooperation when conducting protection measures for protected species of white stork (Ciconia ciconia L.).The employees of HEP Operator distribucijskog sustava make and put nest stands, in accordance with the guidelines of the Croatian Ornithological Society.
By conducting this measure at a low voltage distribution network the possibility of nest ignition, due to electric arc, as well as the death of storks, due to electric shock, are decreasing.

Protection of birds and small mammals from electric shock

Measures for the protection of birds and small mammals from electric shock and for the prevention of their death are carried out on the medium voltage overhead distribution network.

Bird banding

In all distribution areas of HEP Operator distribucijskog sustava d.o.o. birds are banded, in order to monitor their population. Bird banding is carried out by the Croatian Ornithological Society, and the distribution areas put necessary equipment (e.g. hydraulic baskets) at its disposal.