I have heard of a device called a "Gravity Pump" that is supposedly capable of pumping water from a source such as a creek to a destination that is at a higher elevation such as a pond using no electricity or other fuels. What do you know on this?
Yes, there is a type of pump that does just what you’re describing, in fact there’s more than one. It sounds too good to be true, but you really can use water power to pump water.
Since you specifically ask about a gravity pump, it sounds like you’re describing the High-Lifter water pump. The company’s website has all the details about how this type of pump works, including diagrams. We don’t have a lot of information on how well the pump works, but it does come with a one-year warranty. The pump retails for about $900, and one online source is Advanced Energy Solutions.
Another pump that moves water to a higher elevation using only water power is the hydraulic ram pump. We’re much more familiar with this type of pump, but I think it’s also worth mentioning because it’s a bit cheaper, and there are lots of plans out there showing how to build your own.
Readers ask us about the ram pump pretty frequently, and we have a couple of good articles explaining the concept in our archive. Check out our 1973 article The Hydraulic Ram Pump for an overview, and Mother’s Hydraulic Ram Pump from 1979 for instructions on how to build your own. If you opt to buy a ram pump rather than building one you can expect to pay about $400 to $600 dollars depending on the size of the pump. One source is Lehman’s, which sells ram pumps and a good selection of other non-electric tools.
— Megan Phelps, senior associate editor