The hydroelectric plant was built with the least amount of pollution. The observation of hydroelectric power plants from an economic-ecological aspect depends on the morphological and topographical locations and the level of technological development. There are three types of hydropower plants: run-of-river, storage and reversible. Run-of-river hydropower plants are those whose upstream storage can be emptied in less than two hours of operation at rated power, or such storage does not exist at all. In HPP Miljacka, kinetic energy is directly used to start the turbine. It is one of the oldest active hydroelectric power plants in the world, which operated as an experimental power plant from 1902 to 1906. The hydropower plant was built by hand, on the Krka river basin and has a constant flow. It is located in the area of the National Park and is "hidden" by four waterfalls: Brljan, Manojlovac, Rošnjak and Miljacka. Thanks to its plant-geographical position, the area of the Krka River has a large number of strictly protected endemic plant species and subspecies, including as many as ten stony endemics, which are found only within the borders of the Republic of Croatia. In the caves in the area of the Miljacka waterfall, the manfish lives, which is endemic to the Dinarides and an endangered species. Therefore, there is little impact on the environment, the water does not change its natural flow and there are no floods. It represents an important energy, industrial and cultural heritage, and in 2018 it was inducted into the Hydro Hall of Fame. It is interesting to mention that the technician Josip Franzotti was fascinated by the power plant and did not leave it, even though he lived only four kilometers from the power plant.