From Charles C. Mann’s fascinating book 1491: New Revelations of the Americas Before Columbus (p. 235, emphasis added):
Spread at its greatest extent over seven hundred miles of the coastline, Chimor was an ambitious state that grew maize and cotton by irrigating almost fifty thousand acres around the Moche River (all of modern Peru only reached that figure in 1960). A destructive El Niño episode about 1100 A.D. made irrigation impossible for a while. In response, the government forced gangs of captive laborers to build a fifty-three-mile, masonry-lined canal to channel water from the Chicama River, in the next valley to the north, to farmland in the Moche Valley. The canal was a flop: some parts ran uphill, apparently because of incompetent engineering, and the rest lost nine-tenths of its water to evaporation and seepage. Some archeologists believe that the canal was never meant to function. It was a PR exercise, they say, a Potemkin demonstration by the Chimor government that it was actively fighting El Niño.
Whenever I hear a politician or government official say: “This may not be an ideal solution, but we must do something about [you name it].” I think of the ancient Peruvians and their up-hill canal — and about ways to hide my wallet.