build a water wheel and install a pump on it---plus your homebuilt alt...
If you've got water with a significant flow and head, but the high end is below (even FAR below) your house, use a hydraulic ram. You can build one out of a few plumbing parts, rubber from an old tractor tire or inner tube, steel strap, some nuts and bolts, and a little welding. Essentially no maintainence and even easier and cheaper to build than a water mill or wheel.
You can share the headwater pickup/cleanup and tailwater return facility between the ram and a mill/generator, but you'll need to run a separate pipe for each ("ram pipe" for the ram, "penstock" for the mill) from the inlet to the device. The ram wants to be low so use a wheel design that wants to be low, too, and you can put 'em in the same facility. Of course you can dig a trench for both at one shot. (The ram wants a long straight pipe, the mill is less picky though straight helps.)
A ram is like a transformer for water, taking in a relatively large amount of water at a low pressure and delivering a smaller amount at higher pressure, dumping the excess water at a low point. You adjust it for the amount of water it takes in, and it self-adjusts for the pressure-flow tradeoff at the output (with some feedback into the input adjustment so that's not quite pure). At low output flows it can generate a hysterical pressure and pump a dribble of water up a mountain.
(Actually it's an EXACT analogy of a switching power supply with a fixed on-time, configured for voltage-boost. Inductor -> ram pipe full of water. Capacitor ->a ir trapped in the "pressure dome" - a foot or so of pipe capped on top and a "sniffter hole" to insure it always has air. Diode -> one-way valve. Switching transistor & driving oscilator -> spring-loaded "clack" valve.)
I was just rereading an old home-power book from the hippie/comune/whole-earth-catalog era that has an excelent home-brewable design. If anybody's interested I'll dig it out and post the reference, and maybe a text description of the design.
The copyright would be expired by now if it weren't for Disney's lobbiests, but thanks to them it's not. So I can't just post it, illos and all, without getting permission. But the design should be unemcumbered - at least for home-brewers.
If you build one, run a penstock pipe for a mill/genny at the same time and cap it. That way if you want to put in a mill later you don't have to dig up the scenery again.