I want to know the answer to the following question:
After the water purification plant at the Croton Watershed is built, how much more water will be added to the city's supply each day?
All the background I'm provided with is that "As a result of the watershed's integrity and undisturbed natural water filtration system, New York is one of only four major cities in the United States the majority of whose drinking water is pure enough not to require purification by water treatment plants.". Is that enough to answer the question?