ENVIRONMENTAL FRIENDLY SOLUTION TO COMBAT MASSIVE DEVELOPED VEGETATION IN NATURAL OR HYDROPOWER LAKES.

The Bistrita River was the first river harnessed for hydropower purposes in Romania, starting with 1960. Currently, on this river, 29 hydropower plants with different capacities are functioning, producing about 10% of the entire Romanian electric energy from hydro. Many of them were realized in series, in cascade. In the present paper, the area of Pangarati, Vaduri, Batca Doamnei, and Reconstructia hydropower lakes was analyzed. Of these, three are Nature Reservations, Nature 2000, RAMSAR sites. The lakes being realized in series, their clogging has appeared quite quickly, favoring the excess development of the aquatic vegetation. At the beginning of the paper, some local conditions are studied, based on the performed measurements for three years, being also analyzed the main species of appeared vegetation. Under these conditions, in the last two decades a systematic campaign of combat the excess developed vegetation has began. In the beginning, some methods that should have been completely banned in this area were applied, because these lakes are used also to supply water in many localities. Subsequently, other methods were tested, but without significant results. The paper briefly mentions these methods applied and tested previously. The purpose of the paper is to present an ecological method, with low cost, easy to implement, being tested in Lake Pangarati for three years. By this method, in places where it was placed, almost the total destruction of the existing vegetation is achieved, but also a reduction by over 40% of the vegetation developed in the following years, and with beneficial effects for the next lakes on the Bistrita River. Finally, some conclusions and references are also mentioned. [ABSTRACT FROM AUTHOR]