Off the grid and icky plumbing

I didn't know that about off-the-grid plumbing in sims, but I do know that in real-life, a privy hole, as someone suggested, is always dirty since it's just a hole in the ground with a seat over it and you can only clean the seat. So, I was thinking of a more hybrid solution either way. You don't need electricity to connect to city sewage, much less have modern plumbing, but you do need a water source and, unless you are having a drought, a rain barrel would work great if it were big enough.

I was building a traditional style Philippine home based on YouTube instructions from Simpolcheeks and she mentioned that, while new home mostly just have showers, the older one had rain barrels and a scoop that one used in a bathtub. Ancient Romans, on the other hand, would use an impluvium placed in the center of their atriums which led the collected water through filters into a reservoir that could then be pumped out when needed. Combing these two ideas, I ran a reservoir/rain barrel all the way through the house from roof to cellar and attached a water heater to its cellar level wall, assuming all plumbing in the house could attach to the reservoir. I doubt very much that it will work in the sims except as regular plumbing, but I'm pretty sure it would work in real life... if only rain barrels were legal in my state. *SIGH*