The 1898 consolidation of all five boroughs as one unified City of New York brought the population from 2 million to 3.4 million people and intensified the need for more water. In 1905, the City established a Board of Water Supply to plan and build a new system of reservoirs and tunnels that would ensure access to clean water for the growing population.
The next year, the Board started planning the Catskill Aqueduct and installed a laboratory at 147 Varick Street to test equipment and building materials, and to analyze water and soil samples. The Board also hired a photographer to document this monumental project, and put the photo lab here to print and store thousands of images.