We have (involuntarily) found out how the outside rainwater draining works in the northern germany refuge. There is a drainage sump as well as a ring drainage around the house and two cisterns in the garden that serve as a reservoir and have an overflow pipe in case they’re filled to a certain level. These cisterns can of course be used for watering the garden using a submergible pump, as they’re filled with free rainwater. Here’s what I came up with as an idea to make use of this reservoir. It’s a post combining the electrical wiring of the two pumps and an outlet for watering:

This is as much as I can do for now, since I need an electrician to wire the thing up correctly. We’ll see how (and if at all) this works this summer 🙂