1. - 4-way Sillcock Key (aka 4-way water key)
2. Rig basic trip-wire warning devices with party poppers and fishing line or twine.Used to open handleless outside sillcock faucets on commercial buildings, government buildings, etc.
Fits 4 most common size sillcocks.
Costs about $5 - $10 at hardware stores, Loews, Amazon.
Even with power off and no water pressure you should still be able to get clean water from a multi story building until the pipes run dry.
Not very loud but enough to provide an early warning at night for an overnight camp site.
Make sure you can get a string or line tied to to the pull cord before you need them. On some you might need to glue a small loop or use a piece of duct tape.
Great Ideas,
Thanks.