Does a stream have a "river" of humid air above and around it?

Factual Questions
1

This apartment, and my last one, are both near natural water features. My old place was next door to my former high school, just across from where there is a pond and an artesian well that feeds into it. My present place is next to what appears to be a tiny rivulet that runs mostly underneath streets and sidewalks. The asphalt over it subsides constantly, the city comes and patches it with more asphalt, then it settles again. The new apartment, and my old high school are both at the bottom of large hills, which was once explained as part of the mechanism by which artesian wells occur. There’s a layer of bedrock more or less at the bottom of the hill and around it; so all the water in the hill, from rain, garden run-off, or what have you, collects at the level of this bedrock and bubbles to the surface in the form of a spring. I wouldn’t be at all surprised if the rivulet that runs by my new building is associated with a spring at the base of the hill, although its all covered now with buildings and pavement so I can’t tell for sure. This is in the Palms area of L.A., so in its state of nature the stream must have eventually found its way down to what is now known as Ballona Creek, but in early times was the Los Angeles River before that changed course, sometime in the eighteen-hundreds.

Both apartments seem to be unusually humid, also. Is it possible that the air all around this tiny wash is naturally humid, as part of the normal hydrography of such a geographical feature?

2

Damp soil especially with higher features around it causes the area above it to be more humid. Valleys maintain a micro climate different from areas above the valley walls. Rivers often have a fog bank that fills the lower areas near the river, and the fog ends there.

3

I agree with HD. I came in to say “you can see this on foggy days”.

4

Now that you mention it, we often get condensation on the windows. Also, the ground, for a good fifteen yards on either side of this tiny river never does get completely dry. Where you normally would expect to see sidewalk, they’ve left it unpaved, and it always seems to be muddy.

The leaves of a handsome banana tree can be seen just beyond my second floor balcony rail. The statue is Kuan Lin, Goddess of Peace (or maybe Tiny Link Sausages). Of course I’ve seen banana plants around here before, but never one this lush. This leads me to suspect the plant is taking advantage of the naturally occurring extra moisture in the soil.