By Iruni kalupahana, JadeTimes news
Development of the Sophisticated Hydraulic Civilization
The hydraulic civilization of the ancient Sri Lankans elaborated a relatively developed hydraulic system in the dry zone through cascading systems of tanks. These systems were very important in managing the water resources of the country, especially given the clear bimodality in rainfall amidst general aridity. The word "tank" is derived from the Portuguese word "tanque", meaning reservoir, but the local term "wewa" is still in common use. These tanks date back as early as the 3rd century BCE, and the construction of many of them is widely credited to the reigns of ancient Sri Lankan kings, such as King Mahasen, ruling from 274-301 CE and still celebrated as the "father of irrigation." During his reign, the chronicles of "Mahavamsa" credit him with the construction of some of the earliest large reservoirs, among them being the Minneriya Tank.
Design and Function of the Tank Cascade System
Cascade system of tanks consists of a cascade of interconnected tanks linked by micro catchments for storing, distributing, and using the water from ephemeral streams. Centuries old tank systems were indeed ingeniously planned to suit the erratic rainfall of the area. The catenary formation, bimodal rainfall distribution, and soils of different drainage characteristics these peculiar features of the landscape allowed the potential for development of tanks. These stone lined channels, in some instances, even connected the different tanks, enabling the efficient transfer of water from one to another, thereby providing an undisturbed water supply throughout the year. More importantly, the tanks were also serving an important ecological function by supporting diverse flora and fauna, including a wide range of aquatic species, birds, and mammals.
Traditional Village Life Around the Tanks
The tank itself was the very center of village life in the ancient dry zone, and houses were constructed at a relatively higher elevation near the tank bund. This developed an irrigation area along the valley while rain fed upland crops were grown on unirrigable slopes. The traditional tank village system consisted of tree belts around the tank to conserve water, upstream bunds, and water holes. These tanks were carefully maintained by villagers through traditional ways of raising earthen bunds and reinforcing those with stones, creating sluice gates that regulated the water flow, and planting vetiver grass to avoid soil erosion. It is this complex social organization that has ensured sustained utilization of water resources, developing a sense of community responsibility and stewardship over the centuries.
Legacy and Continued Relevance of the Hydraulic Civilization
Something for the present world came from that exceedingly odds facing old hydraulic civilization of Sri Lanka. The tank cascade system considered unique for its engineering precision with ecological balance continues to inspire modern water management practices. Many of the ancient tanks, which are still in use today, form vital sources of irrigation and water supply to rural communities. In fact, these ancient systems represented the apex of principles underlying sustainable water use, resource conservation, and community centered management something now considered visionary in contemporary environmental and agricultural planning. The resilience and ingenuity of Sri Lanka's hydraulic heritage continue to play a very pivotal role in shaping the country's sustainable development strategy, drawing from a proud history of innovation and adaptability.
Mastery of Hydraulic Engineering
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