Yep in the days before refrigeration, a springhouse was the closest thing to it. Small little structure built over shallow basin that the water would constantly flow in and out of. You'd stick the milk jugs and similar things in the water to keep them cool. It would also keep the air inside considerably cooler than outside, so other foods would get hung and stored in there.
That 3/4"(?) galvanized(?) pipe with the coupling is the one that confuses me, wondering what that was and if it was coming or going?
That whole thing could be a godsend for irrigation / growing purposes. That's my lament, the place I want to grow things is at the top of the hill and my well is at the bottom.