http://en.wikipedia.org/wiki/California_Aqueduct
"Water flows through the aqueduct in a series of abrupt rises and gradual falls. The water flows down a long segment, built at a slight grade, and arrives at a pumping station powered by Path 66 or Path 15. The pumping station raises the water, where it again gradually flows downhill to the next station.
However, where there are substantial drops, the water's potential energy is recaptured by hydroelectric plants. The initial pumping station fed by the Sacramento River Delta raises the water 240 feet (73 m), while a series of pumps culminating at the Edmonston Pumping Plant raises the water 1,926 feet (600 m) to cross the Tehachapi Mountains. The Edmonston Pumping station requires so much power that several power lines off of Path 15 and Path 26 are needed to ensure proper operation of the pumps."
The part in bold is what I was referring to...from what I remember, the engineer that was talking about this {History Channel or TLC} said that the energy created by the falling water on the "downside" of the "hill" was sent back into the power grid. Since most grids are interconnected,
in essence the water does in fact aid itself.