Restoring and Preserving the Incan Cultural Wonder of Saqsaywaman

Locating Inca Terraces at Saqsaywaman to Restore the Original Drainage System and Protect the Great Walls

“…First, (i) terrace grades would direct runoff laterally away from the Great Walls and then along terrace paths. This conclusion is drawn from the studies of Gasparini and Margolies, who proposed that the site originally had terraces running concentrically around the hill and steadily rising in elevation ( Figure 8), a feature characteristic of other Inca sites [11]. Taking into account contours proposed by Gasparini and Margolies, flow directions were modeled ( Figure 9).…”

“…The INC has attempted to abate excess runoff in this section, and additional locations around the site, with the implementation of ad hoc drainage channels. However, these unsophisticated hydrologic systems were unable to properly control runoff [11]. The realization that uncontrolled runoff continued to pose a threat to the site motivated a complete evaluation of the runoff at Saqsaywaman.…”

“…This model leads to important conclusions about the intended drainage plans following completion; runoff is directed laterally to the east and west and then south along terraced paths [11]. [11] Assuming consistency among Inca architectural techniques, two additional conditions would be met by an Inca terracing system: (ii) runoff would be transported via base channels along terraces and (iii) runoff would only move from terrace to terrace through controlled drops. Tipon is an Inca site where there still exists a well-defined and functioning runoff management system that meets these conditions.…”

Using 3D Terrace Modeling to Preserve the Incan Site of Saqsaywaman

“…This dig uncovered important original Inca [16] This impervious surface had the unintended consequence of altering the natural infiltration and runoff patterns of the top section of the site, and caused a water slide of sorts to be directed perpendicular to the third wall. As previously mentioned, the construction of the third wall involved a single stone layer with a relatively impervious soil rock mixture backfill for strength and lacked drainage ports [6]. As this increase in water cannot effectively move through the impermeable backfill, instead it wedged itself between the backfill and the single layer of stones creating a hydrostatic pressure force gradient directed directly out into the wall (Figure 10).…”

“…The walls are composed of thousands of stones fitted together seamlessly without the use of mortar ( Figure 5). The largest of these stones weigh up to 200 tons, and many of the stones were transported from a quarry region 35 kilometers away from the site [6]. The three walls have very different properties even though they are relatively similar in outward appearance ( Figure 6).…”