[2022] Water transport issues, floating water....

I'll preface with the fact that I'm real new at this game.

I tried to move some water to my home to get some power set up. I dug from the edge of a mountain lake, and dug a tunnel to my home. However, the water is acting very awkward. The tunnel height came out in the middle of a wall, which was great, so I made an aqueduct-ish U-shape to a basin and a waterfall. I also did all this with mortared blocks, since I didn't know brick aqueducts didn't exist when I started this project.

The water was acting as expected for the most part, flowing through my tunnel, but when I made it step down to a waterfall, there was no water catching at the bottom. It just flowed in to whatever ground tile there was. I thought it was draining in to the dirt or something, so I surrounded every crack with mortared stone. No dice. When I tried to re-arrange things to try different things, I found that my water is now just floating in the air. It looked terrible, so I wrapped it up in mortared stone again and placed my water wheel. However, when I place the water wheel, the water that would normally be in the waterwheel disappears.... To make my wheel work, every time I start the server, I have to pile some dirt two or 3 tiles high underneath each column of the waterwheel. When I place a dirt tile and then remove it, water is in it's place. If I do this to all the spots where the water wheel removed the water, the new water gets the wheel spinning. It's pretty baffling.

All in all, it kind of looks terrible and I'm playing a solo server just for the fun of building a really nice home.

At this point, I'm going to probably just fill in the whole thing and start again with a new river from that lake. But the real question is, how do I do it properly?