Hydrology and water resources management in ancient India

Abstract

Hydrologic knowledge in India has a historical footprint extending over several millenniums through the Harappan civilization (∼3000–1500 BCE) and the Vedic Period (∼1500–500 BCE). As in other ancient civilizations across the world, the need to manage water propelled the growth of hydrologic science in ancient India. Most of the ancient hydrologic knowledge, however, has remained hidden and unfamiliar to the world at large until the recent times. In this paper, we provide some fascinating glimpses into the hydrological, hydraulic, and related engineering knowledge that existed in ancient India, as discussed in contemporary literature and revealed by the recent explorations and findings. The Vedas, particularly, the Rigveda, Yajurveda, and Atharvaveda, have many references to the water cycle and associated processes, including water quality, hydraulic machines, hydro-structures, and nature-based solutions (NBS) for water management. The Harappan civilization epitomizes the level of development of water sciences in ancient India that includes construction of sophisticated hydraulic structures, wastewater disposal systems based on centralized and decentralized concepts, and methods for wastewater treatment. The Mauryan Empire (∼322–185 BCE) is credited as the first “hydraulic civilization” and is characterized by the construction of dams with spillways, reservoirs, and channels equipped with spillways (Pynes and Ahars); they also had an understanding of water balance, development of water pricing systems, measurement of rainfall, and knowledge of the various hydrological processes. As we investigate deeper into the references to hydrologic works in ancient Indian literature including the mythology, many fascinating dimensions of the Indian scientific contributions emerge. This review presents the various facets of water management, exploring disciplines such as history, archeology, hydrology and hydraulic engineering, and culture and covering the geographical area of the entire Indian subcontinent to the east of the Indus River. The review covers the period from the Mature Harappan Phase to the Vedic Period and the Mauryan Empire.