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5 Wari Hydraulic Works in the Lucre Basin
- University of Iowa Press
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5 WariHydraulicWorks intheLucreBasin alfredovalenciazegarra The principal hydraulic works of the Lucre Basin (canals, reservoirs, aqueducts , and so forth; see fig. 5.1) are associated with the site of Pikillacta itself as well as with the vast terraces and cultivable fields of the basin, which reveals that the agricultural production that supported the valley economically was controlled administratively from Pikillacta during the Middle Horizon. The hydrographical network is comprised of the Lucre River (fig. 5.1, Río Lucre), which is formed by the streams called Chelke (R. Chelque) and Colcaique (R. Colcaique), and the lagoons of Pumaorqo and Muyna. The river is fed by more than fifteen springs, of which four—Parojan, Pacramayu , Cusara, and Llutuqasamayo—run permanently at a rate of 87 liters per second, with periodic increases in this volume during the rainy season. A part of this flow of water was captured by the residents of Pikillacta and led through two canals to their agricultural fields on the south and east sides of the Lucre Basin (see fig. 5.1 and chapter 2, fig. 2.3), as well as to the main center of Pikillacta by means of a magnificently conceived and executed hydraulic system. The annual rainfall average in Lucre is 619.95 millimeters per year. Sufficient water for irrigation during the Middle Horizon was made possible only by means of hydraulic technology. Although there is well-defined seasonality , with the year divided into distinct wet and dry seasons, there is not enough rainfall to permit the growing of maize without supplementary water provided by artificial irrigation. In the planting season (August to September), rain is scarce and the water deficit was made up with artificial irrigation. When the plants were in full growth (December to January) and the rainfall abundant, artificial irrigation was reduced. Nearing harvest season (May to June), water was again used for irrigation as necessary. All of the canals have their intakes in the headwaters of the Lucre River and the Chelke stream (R. Chelque), whose waters come from the springs mentioned above. They are built of stone and follow the level curves of the [3.236.55.137] Project MUSE (2024-03-29 03:19 GMT) 5.1. The hydraulic system of the Lucre Basin. 88 | valencia western hills of the basin along a gentle slope, where they provide water for human consumption and agricultural needs. The entire system was conceived and calculated in advance of the construction of Pikillacta so as to provide sufficient flow at the correct speed in order to deliver the required water without damaging the hydraulic works. The system consists of the following canals, each of varying length: Canal LengthinMeters A(Pikillactaupper) 16,000 B(Pikillactalower) 11,200 C(Amarupata) 3,825 D(Huascar) 3,110 E(Mamaqollapata) 8,489 F(Lircay) 2,500 G(Rayallacta) 3,000 Total 48,124 The total extension of the entire canal system in the entire Lucre Basin and the adjacent alluvial fan of Rayallacta is more than 48 kilometers . This calculation is the minimum, since it does not take into account other canals that have been observed but remain to be studied. These include Canal H of Choquepukio (fig. 2.3, Chokepukio), Canal G of Rayallacta (see discussion below); the extension of Canal E to the front of the town of Oropeza (fig. 5.1, Orepesa), and other smaller extension canals that apparently are fed off both margins of the Lucre River, from its confluence with the Chelke stream down to the lagoons in the basin bottom. Canal A The study of Canal A, was conducted by means of three excavation campaigns I carried out in Pikillacta, under the patronage of Gordon McEwan and Kenneth Wright. The first campaign , in October of 1990, encompassed the urban center of Pikillacta, part of its interior canal, and Canal B. The second campaign, in June 1995, followed Canal A from the interior of Pikillacta through the aqueduct of Rumiqolqa (figs. 5.1 and 2.3) to the tunnel of Urpituyoc. The third campaign, in September 1995, followed the canal from the tunnel to the aqueduct of Combayoc (fig. 5.1; fig. 2.3, Combayoq). In total, sixty 1-meter squares were excavated along a 5.22-kilometer extension of the canal. Canal A terminates in the central part of Pikillacta. It has 16,000 meters of total length from its intake on...