The problems with the quality of water in closed tanks have been known for years. The improvement of water quality parameters in the lake increases its possible uses. Nowadays there are many methods of recultivation of water reservoirs. Choosing the suitable one is conditioned by the interaction of various factors that cause gradual degradation of lakes, as well as the recultivation costs and the type of tank. The article presents the practical application of the AHP method in solving multicriterial problems of recultivation of water reservoirs. This method makes it possible to take into account many aspects of the problem and find their solutions both on the basis of measurable parameters and expert evaluations.