/diy/ - Do It Yourself

I have pic related on my property. The leaf covered mess at the end of the concrete walkway is a drainage box for the pond, to prevent overflow and flooding (I can clean it more regularly once the setup is in place, at the moment the only concern there is free flow of water). I decided just for fun, I want to put one or multiple water wheels in there to catch and spin with the water coming down, and use that energy to charge 12dc batteries.

So what I understand so far of this process is:
>water spins wheel
>?wire terminals on wheel? send power to voltage regulator
>regulator charges batteries
>batteries power devices

I know I'm missing at least one step here. I'm looking to get a full list of parts I would need, and a better understanding of how I would put it all together. I'd also like to know what you all think would be the amount of power I'd get from this setup.

The likely permanent location for the regulator, batteries, and any other equipment would probably be in the rafters of that pavillion on the island. I realize it would be an absolute bitch to get the wires there, at the moment I'm thinking of getting special underwater rated cable for it, but that's something I can figure out on my own. Once I have it there, I can use it for LED lighting strips, security cameras, radio, etc. power draw is the only limit

so what's your advice?