The Hydraulic Analysis and Simulation of the Inkamisana at Ollantaytambo, Peru

Over the course of two summers, a team of engineers and archaeologists from the University of Virginia, Wright Paleohydrological Institute and the National Institute of Culture in Peru studied Inca ruins at Ollantaytambo, Peru. The site, known as the Inkamisana, was used by the Inca for the worship of water and incorporates a flow network system for distributing water to sixteen different fountains. Water from the surrounding Patacancha watershed supplied water to the Inkamisana via a series of canals that run along the mountainside.
This report discusses the portion of the research that dealt with the hydraulic study of the fountains, drops, and channel structures that are part of the Inkamisana. There were three primary goals of this study:

1) Verify and update current plans of the site
2) Hydraulic analysis of the flow network
3) Simulation model of the flow network

The verification process included comparing the location and dimension of all fountains, channels, and drop structures to what were shown on previous plans. Correct flow paths of water throughout the site, especially at points of underground flow had to be documented. The hydraulic study consisted of an optimal flow analysis of flow behavior with respect to water supply. Flow parameters studied included ‘self-cleaning’ capability (sediment transport), scouring, jet behavior, and flow characterization (e.g. turbulent vs. laminar, super- vs. sub-critical). The simulation model incorporates varied inputs (e.g. source flow rate, valve behavior) to model behavior of the site under desired scenarios. The model also produces descriptive maps that relate these properties to their corresponding hydraulic elements.

This research project was the first hydraulic analysis completed of the Inkamisana. Ultimately it gives a comprehensive understanding of the hydraulics that govern one of the most magnificent fountain complexes in Peru. Knowledge and methods developed from this research can also be applied in the analysis of future studies of Inca ruins.