This is another interesting lake on mars. It appears that water seeps up through the ground, or that there is a deeper water table that is above the bottom of the lake and it feeds it.
I recall reading somewhere that a scientist was suggesting that the water on earth might have come from the millions of comets, which are made up mostly of water, that hit our planet over the millions of years.
If Mars lost its water, a long time ago, could it slowly be getting more from out there?
Again though, if this is water, one would expect some oxygen. So, then, why not some life around the edges of the water? Is there some kind of mineral in the soil that makes the water not usable for life?
As one looks at this photo it appears that the lake is in the shape of a reservoir and on the right is a damn, either natural or otherwise. It might be imagination, but it does seem this water is dammed. But why it appears natural is that on the right of the dam is more water. It is not dry.