Neighborhoods in New York City receive their drinking water from reservoirs of the Croton System, Catskill System and Delaware System, or often a combination of all three. The Water Distribution Map below shows which system is currently supplying water to various parts of the city. The map is a graphical representation that does not delineate exact boundaries between the distribution of one water source or another.
For more information about New York City drinking water, visit Drinking Water.
Water from the Catskill and Delaware Systems, located west of the Hudson River, and the Croton System, located east of the Hudson River, can taste different to some of our customers. This is largely because of differences in the geology, soil conditions, and naturally occurring minerals in the watersheds that surround their reservoirs. On rare occasions, extreme weather events and seasonal changes in the reservoirs can make the difference in taste more pronounced. These changes are temporary and they do not signify a problem with the safety of your drinking water.
How do we know? Our scientists test the City’s tap water hundreds of times each day, 365 days a year. They collect samples from the reservoirs, aqueducts, treatment facilities, and 1,000 street-side sampling stations throughout the five boroughs to ensure the tap water is safe, clean and healthy.
Operational decisions about the City’s water supply—including the proportion of water from the three systems—are often made on an hour-to-hour basis. We encourage customers to call 311 or file a report online if they notice a difference in the taste or smell of their water. This helps our engineers and scientists track trends and adjust the waterworks so that we can continue to provide the high-quality water that New Yorkers expect.
To learn about some common reasons for observing changes in your drinking water, please visit Drinking Water FAQs. For more information about how we measure water quality, visit Drinking Water Supply and Quality Report.