To reach the lake you take the road leading to Cusco, you can se the lake at the right hand side after a few minutes (before the bridge). You can stop at the gas station "Fama" and walk the 50 meters down to the shore.
I visited the lake in the afternoon, and the pictures have the blue light that you often have here at Altiplano.
White-tufted Grebe with a fish
Silvery GrebesTiticaca Grebes, one at a nest?