Ancient pre-Columbian Peru, Bolivia and Mesoamerica

Irrigation agriculture is a transformational technology used to secure high food yields from undeveloped lands. Specific to ancient South America, the Chimú Empire occupied the north coast of Peru from the Chillon to the Lambeyeque Valleys (Figure 1.1.1) from800 to 1450 CE (Late Intermediate Period (LIP)) and carried canal reclamation far beyond modern limits by applying hydraulics concepts unknown to Western science until the beginning of the 20th century. The narrative that follows examines hydraulic engineering and water management developments and strategies during the many centuries of agricultural development in the Chimú heartland of the Moche River Basin. The story examines how Chimú engineers and planners managed to greatly expand the agricultural output of valleys under their control by employing advanced canal irrigation technologies and the economic and political circumstances under which large-scale reclamation projects took place. The following time period conventions are used in the discussion that follow: Preceramic and Formative Period (3000–1800 BCE) Initial Period (IP) 1800–900 BCE Early Horizon (EH) 900–200 BCE Early Intermediate Period (EIP) 200 BCE–600 CE Middle Horizon (MH) 600–1000 CE Late Intermediate Period (LIP) 1000–1476 CE Late Horizon (LH) 1476–1534 CE. Chimú political power and state development was concentrated in Peruvian north coast valleys. Each valley contained an intermittent river supplied by seasonal rainfall runoff/glacial melt water from the adjacent eastern highlands. Over millennia, silts carried by the rivers from highland sources formed gently sloping alluvial valleys with fertile desert soils suitable for agriculture. An arid environment tied the Chimú economy to intravalley irrigation networks supplied from these rivers; these systems were supplemented by massive intervalley canals of great length that transported water between river valleys, thus opening vast stretches of intervalley lands to farming. The Chimú accomplishments and achievements in desert environment agricultural technologies brought canal-based water management and irrigation technology to its zenith among ancient South American civilizations, with practically all coastal cultivatable intervalley and intravalley lands reachable by canals brought under cultivation.