A method and an apparatus for lifting a mass of water with a container from a larger body of water, in which method the container having at least one open opening is first located below the surface level of the larger body of water and the container is full of water, wherein the container is raised partially above the surface level of the water by elements attached to the container, and that the at least one open opening of the container is located below the surface level of the larger body of water during and after raising of the container thus lifting the mass of water located inside the raised portion of container above the surface level of the larger body of water.