Hydraulic Engineering and Water Management Strategies ofAncient Societies

Societies of widely different social, economic, political, religious, and technical innovation characteristics in opposing world hemispheres developed urban and rural population centres with water and agricultural systems to maintain stable economies and expanding populations. Despite vast historical, cultural, and world view differences between these societies, one common thread united them: the necessity for mastery of engineering skills to provide water for cities and agricultural systems. Although it may be thought that the technical basis to support water engineering practice is accompanied with pre-scientific concepts, many recent discoveries reveal the contrary: sophistication in the concept, design, and execution of water supply and distribution systems indicating knowledge of hydraulic principles beyond the scant hydraulics literature that survived the centuries. In the absence of ancient treatises on hydraulics practices, archaeological analysis of hydraulics works coupled with modern analysis methods provides a way to understand their technological accomplishments through ‘reverse engineering’ methodologies involving computer modelling techniques. Thus computer methodologies play a role to uncover the design intent, functionality, and operation of ancient water systems to provide insight into ancient engineering practices and their theoretical/empirical basis. In South American archaeology, the large variation in ecological conditions and landscape barriers provided the stage for the rise of civilizations and largely determined their agricultural practices. As an example, the Chimú civilization (800–1480 CE) occupied Peruvian coastal regions extending 500 km from the southern Chillon Valley to the northern Lambeyeque Valley. The desert coastal zone extends only a few kilometres inland from the Pacific Ocean before being bounded by the Cordillera Negra mountain chain. Agriculture was possible in coastal alluvial valleys through networks of canal systems originating from intermittent seasonal rivers. The temperature near the equator is near constant throughout the year while coastal rainfall averages about 2mm/year; occasional massive El Niño events which can deposit up to 150cm of rainfall in a few days occasionally break this pattern and cause extensive flooding and Weld erosion. Clearly, hydraulic practices related to the control of limited (and sometime excessive) water resources were vital for survival. Defensive measures to protect fill aqueduct structures against excessive El Niño rainfall and flooding events are expected to appear in the technology base as flood control was vital to sustainability.