Board of Water Supply. City Water Tunnel No. 1. Geological test borings on corner of Hester Street and Ludlow Street. Sheds housing drill rigs, like this one, popped up on the Lower East Side in 1910 to collect core samples of rock from hundreds of feet under the busy sidewalks. These geological investigations were essential in planning the path of City Water Tunnel No. 1. March 21, 1910.