The Sunken Gardens of the Peruvian Coast

Sunken gardens are a response to a situation in which ground water is near the surface of a desert but does not reach it. Since the 19th century this situation has generally been met in Peru by raising water from wells for canal irrigation. No mechanical means of raising water was known in ancient Peru, however, and sunken gardens provided the most economical solution to the problem. Ground water occurs near the surface on the Peruvian coast in some valleys where there is not enough water to maintain a river on the surface, and at the lower ends of better watered valleys where surplus irrigation water accumulates but does not reach the surface. The problem of salinization appears to have been more serious in sunken gardens than in irrigated fields. Since sunken gardens are effective only under rather rare combinations of circumstances, it seems unlikely that they played a major role in the development of Peruvian agriculture.