To be even fairerer, the body of water that gets pumped doesn't need to be dammed; if you have a steady enough river, you can suck the water right out of the side of it. Also, the basin isn't a prerequisite, you could build holding tanks at the top of a hill.

Hell, you could enclose the whole thing to control evaporation and use the same water over and over, no natural body of water necessary. Better yet, use a denser fluid to achieve the same result in a smaller space. You could probably fit the whole thing in a single building.