You live in an area that has been populated for many years, if I were you I would visit your local archieves and look through some of the old maps of your area going back as far as you can. Most villages are started on rivers or around lakes, some of these villages may not even be there anymore. It may be very dirty diving and there may be extra risks such as submeged trees, garbage and stollen cars, so make sure you are prepared for these things. And then the most important thing, get in the water and dive. The more you dive the more you will find. There may be artifacts all over the place just waiting to be recovered.
ZDD