Had a look but I dont think this had been done yet. Basically collects water when raining, could be made into 2 types, a portable one you can place down anywhere (like all the camping equipment) and a larger one for settlements perhaps? Minimal items required to build like Wood/Steel, Leather/Plastic and a bucket or something. Could either collect dirty or purified water after x hours of rain. Yield possibly dependent on light or heavy rain. I might be able to write the scripts and stuff for this, it's just I have zero experience making models. http://www.primalsurvivor.net/wp-content/uploads/2015/09/collecting-rainwater-with-plastic-tarp-tent.jpg