Fake. The Groom Lake Installation was discovered by Tony LeVier in 1952 and construction of the hangars, runway and main buildings ended in 1954.
its what it said! but hey you never know, maybe it was just a lake in the area of groom lake, who knows, but you said if it floods once in a while why
would there be fish in it from rainfall?? who knows!

Even if this lake was near Groom, the U.S. Government would have swized control of it.
That photo was taken in 1965, after a heavy rainfall left a few inches of water on the lakebed surface. If you look in the background, Area 51 hangars
5 and 6 are clearly visible as well as some of the EG&G radar facility.

But the amount of rain that would be needed to fill this huge lake bed would definately exceed the amount of annual rainfall that hits this region.
IMHO.