Industries continued to thrive, with grist, paper, saw and clothing mills operating in the area. Between 1890 and 1910, the Croton and Muscoot rivers were flooded to create the New York City reservoir system thereby changing the local landscape considerably. In the 1920s small lake communities began to spring up as vacation havens for summer visitors and farmers’ guests. These lake communities became larger and firmly established, eventually evolving from seasonal to year-round neighborhoods now known as Lake Lincolndale, Lake Purdys and Lake Shenorock. Following World War II, the rural countryside of Somers continued attracting "weekenders", many from New York City who became more mobile because of the proliferation of automobile travel. The construction of Interstate 684 in the mid-1970s facilitated a resurgence of residential and commercial development in Somers for the next 20 years. Somers grew most rapidly during the 1980s and 1990s, after IBM and PepsiCo built large corporate facilities within it.