I am trying to think about how many times I could flush a toilet in my house if I have to shut off the water to do a DIY project or if some disaster disrupts our water service.
Since atmospheric pressure can push water up to a height of 10 meters (33 feet) and my house is not that tall, it seems that the atmospheric pressure would push the water up and prevent me from using most of it. I think typically the only water in the system I could use would be the water that gets displaced with air bubbles going into a faucet or pipe as I draw water from it, and that only works for a body of water that is in contact with some air and is above that air, so the shape of your pipes determines how much water you can draw with that method.
To allow for more toilet flushes while the water is off, would it be possible to "shotgun" the plumbing system in the house, just like people shotgun beers? I am thinking I would turn on the highest component of the system (e.g. a shower on the 2nd story) in order to let air flow into the top of the system. Then I should be able to use a lot of the water from the pipes in order to flush toilets on the ground floor.
Would this plan work? Could it damage my plumbing?