Harnessing the Small Stream is a 75 year old reprint of an article in Popular Science Monthly, its old, but I imagine people knew a whole lot more about harnessing streams 75 years ago than they do today.
It shows the 4 basic types of small water power wheels, and where to situate the water wheels. It discusses dams, and how to measure water flow.
In my opinion, if you have to ability to harness hydroelectric power on the small scale, then it is in your best interest to do so. Even a small amount of usable water that runs 24/7/365 will provide an enormous amount of power over time. It can be expensive, especially if you contract it out, but over time that cost will be repaid many times over.
Of course, the key word is IF. Just because you have a stream does not mean it is suitable. You must have enough head and flow. Water builds potential energy as it drops from a height – and that energy increases the more water is moving at a time. The concepts in this PDF are not complicated, and neither are the suggestions, but it is not always intuitive. This book is a good starting point.Harnessing the Small Stream