New York City's municipal water draws primarily from the Catskill and Delaware watershed systems upstate — a genuinely soft, low-mineral supply that's been prized for brewing (and for coffee and cooking generally) since well into the 19th century, when the city's German immigrant brewers found the local water well suited to the lager tradition they brought with them.
Soft water behind a real 19th-century lager brewing boom
The figures for New York City's water: calcium 8 ppm, magnesium 3 ppm, sodium 5 ppm, sulfate 4 ppm, chloride 15 ppm, bicarbonate 12 ppm. That's genuinely soft by any standard on this site, closer to Portland's or Denver's low-mineral profiles than to any of the harder historic European sources. New York had a substantial brewing industry through the 19th and early 20th centuries, concentrated particularly in Manhattan and Brooklyn, much of it built around German immigrant brewers producing lager styles suited to exactly this kind of soft, clean water — a genuine parallel to how Pilsen's soft water suited the pale lager tradition that developed there around the same broad era.
What survived Prohibition, and what didn't
Prohibition (1920-1933) devastated New York's brewing industry the same way it devastated brewing nationwide, and the city's once-substantial 19th-century lager brewing scene never fully returned to its earlier scale or diversity in the decades immediately following repeal — a pattern that mirrors the same post-Prohibition consolidation that pushed American Lager toward large-scale industrial adjunct brewing nationally. The water itself never changed; what changed was the number and scale of breweries drawing on it, a reminder that water chemistry alone doesn't guarantee a brewing tradition survives economic and regulatory disruption.
Using this profile
Because this water starts soft and low in most minerals, it's a flexible base for building toward a wide range of target profiles with brewing salts, similar in practical terms to Denver's or Portland's water — gypsum or calcium chloride additions land close to their expected effect without a strong existing mineral background to account for; PeriodicDeck is a useful reference for the underlying chemistry of the ions involved before making those additions yourself. This reading is a general reference rather than a live feed of the current supply — confirm your own New York City tap water before brewing.