the Moche valley, heartland of the empire. Problems such as irregular rainfall in
the adjacent highlands and the steady, albeit slow, rate of coastal uplift affected
irrigation. The latter led to a continuous downcutting of rivers, often stranding
the canal intakes. Such issues were ongoing problems for both the Chimú and
Incas.
The Incas conquered the Chimú during the latter part of the fifteenth century, if
not earlier, and installed Inca bureaucrats to administer these massive irrigation
systems. At the regional center of Farfán in the Jequetepeque valley, for instance,
local administrators retained positions of authority. Maintaining local irrigation
systems was one of their administrative tasks, along with others such as craft
production. As cotton was an important local crop—vital to textile production—
irrigation was critical.
In the highlands, the amount of irrigable land is more limited, so canals were
shorter, although some could still be quite long. Sources of water included
springs, rivers, and permanent snowfields above valleys. The irrigation systems
of the Incas in the Cuzco region were particularly impressive. Dozens of laborers
toiled to straighten the meander plain of the Urubamba River between Pisac and
Yucay, for example, increasing field systems on either side of the river, while
irrigation of the contour terraces above Pisac involved long canals that snaked
around hillsides. Tipón, a royal estate just south of Cuzco, has a sophisticated set
of irrigation features as well as beautiful fountains that suggest the movement of
water was more than just utilitarian.
Immediately prior to the Inca conquest, irrigation canals in the highlands
supported the fields of local communities. When the Incas conquered them,
however, the communities were required to provide the labor used to produce
agricultural surpluses. In order to maximize this production, irrigated terrace
systems were developed that augmented harvests (see Terracing).
Irrigation was thus critical to the success of the Inca Empire. In the Cuzco
region, it bolstered the agricultural surpluses that fed the city’s residents. On
royal estates, it supported the retainers and mit’a labor that made these royal
lands function. In the vast hinterland of the empire, irrigation supported the
agricultural surpluses required for state activities such as warfare and craft
production. It is evident that Inca specialists were well aware of the technology
that made such systems operate effectively. The fact that many of these systems
continue to function today is a tribute to their creators.
Further Reading