We own about 20 acres up here. Probably enough to build a pond. We have a stream that turns into a fast running brook that goes down to the lower part of our property I don’t know if it would be deep enough though. When there is a lot of water it’s probably only a few inches deep but, it sure moves fast. It dries up at the end of summer/fall.
If you really want to put yourself in the position of being more self-sufficient in the case of society totally breaking down, scrap the idea of solar electric generation. Instead, put together some type of wood-fired steam engine electric generating system. (Of course, somebody will need to get a boiler operator’s license for your own good. It will show you have enough knowledge to keep from blowing yourself up.)
With your access to inexpensive batteries, you’re in a better position than most people to also store some of the electricity you’d generate.