I have a very large deck that I want to power wash once a year (also house siding occasionally) and I don’t want to use my well-water because I’m afraid of running it dry. The decks are as much as 15 feet above ground. I’m installing a 500 gal. above-ground cistern to collect rain water to feed the pressure washer. What kind of a pump, and how much hp do I need, to move the water from ground level to the deck level 15 ft above? Can I run a short length of hose from the cistern to a pump that will sit on the ground beside the cistern, and then feed water from the pump up to the deck level and the pressure washer? I’d like to be able to store the pump indoors except when I need to get it out for the occasional wash, rather than a submersible pump. (I’m not sure why, it just seems simpler.) And if I do that, what kind of maintenance do I need to do if the pump has been inactive for months over winter?