Before the decade of the 1960s, watershed modeling was primarily confined to modeling of individual components of the hydrologic cycle. This was principally due to limited computing capability and the availability of limited data. Since the advent of computers in the 1960s and the exponential growth of computing capability in the decades to follow, the watershed modeling started becoming more comprehensive. Since the groundbreaking development of Stanford watershed model by Crawford and Linsley in 1966, numerous watershed models have been developed. The development of more and more integrated and comprehensive models continues today. This study traces the evolution of watershed models before and during the computer era. Watershed models have not only become more comprehensive but have also been integrated into larger ecosystems and watershed planning and management models.
