I had a conversation with Geoff Lawton and he said they never use well water is it could be contaminated. They only use collected rain water. They don't even filter it. So when Sepp says don't use water from your roof I'm not sure he has really listened to nature.
Sepp didn't say don't use water from your roof, he said "rainwater is not drinking water". He most certainly uses rainwater. Utilizing water off the roof for a garden is one of the recommendations he gave for a property we visited.
Rainwater is distilled water, pure H20. It hasn't yet come in contact with the earth body. This purifies and enriches the water. Rainwater can be used, but it is not drinking water because it hasn't yet been charged and filtered in the earth body; it lacks vital minerals and information that your body needs.
There are important reactions , geometry, and physics occurring when the acidic rainwater comes in contact with the basic earth. Also important phenomenon regarding to the structure of water, and how easily it can pass a cellular membrane. Too extensive to go into here but if you want more read some of Viktor Schauberger's works. The process of the water flowing through the earth body, where it can interact with soil and air, filters out the toxins that the rain collects from the atmosphere.
Well water (aquifer water as opposed to underground water veins) is not drinking water either because it is easily contaminated by agro-chemical farming. Pulling so much water out of the earth (from a place where it is meant to stay) makes a cavity that is then filled with penetrating water from the surface. This action leads to the salts and fertilizers being used in agro-chemical farming leaching into the aquifer. This probably has HUGE unknown ramifications.
In addition to lacking the minerals and charge the rainwater also collects whatever pesticides, fertilizers, pollution, exhaust fumes, aluminum oxides, and who knows what else out of the atmosphere. That's why the air is so lovely and fresh after a rain. If your rainwater is not interacting with the earth body, where these toxins are filtered out, then you are ingesting these toxins at relatively high rates.
This is why I think both Geoff Lawton and Sepp Holzer would both agree that spring water is the best drinking water. This is the big difference between the spring that we cased in Bozeman as opposed to the wells that were already on the property. The water that we made available was the best, cleanest, purified earth body water, as opposed to stagnant, yucky, agro-chemical well water.
I have a well, and due to my location out in the off-grid boonies, I am fortunate enough to be free from too much agribusiness. However my land is pretty arid, and we only get about 20 inches a year. I am developing my water catchment system currently -- should I be planning to drink my well water, or should I be collecting rainwater, then supplementing it with minerals? Without a spring, which is the better option? It seems the well...right now.
Photo Blog of our Off The Grid Permaculture Farmstead:http://mulchutopia.tumblr.com