Why do I have to pay for Alpine Lake water or sewer when I'm not at Alpine Lake?

 Neither part time nor full time homeowners are paying for water, per se. They are paying for their share of the cost of being connected to a water system that is expensive because the population density is low. Most of ALPUC's costs are fixed, not variable with the amount of water pumped.

Water is plentiful at Alpine Lake, unlike many other places in the world. But getting it to come out of spigots is expensive because Alpine Lake is a very low-density area, population-wise. Pumps, motors, billing, collections, taxes, main repairs and repair equipment, regulatory compliance, insurance, power, personnel and debt service all cost money. The fewer the number of customers, the bigger each customer's share of those total costs will be.