Who gets to determine how the resources are allocated? Everyone does, thanks to their actions in the free market.

How does a libertarian allocate it? By respecting property rights, so the owner of said resource is the one who would decide how to allocate, based on the market.

Simply price? Yep, price and demand.

Who gets to handle the faucet? The owner/owners

Is anyone guaranteed water? No, well at least if we are seeing this thought a libertarian point of view, no, nothing can be guaranteed, anything can be earned.

Are you a libertarian? Have you read Ayn Rand?

Because I believe this is an interesting ideology and I have learn a ton from Ayn Rand.