65 Years of NYC Water

Editorial Note: this was written by Claude automatically when I asked it to visualize a CSV of NYC Water Usage. I made some edits to the copy.

New York City has about 1.1 million more residents than it did in 1980. It also uses roughly 500 million fewer gallons of water per day than it did back then.

The city’s population dipped through the 1970s and early ’80s bottoming out around 7.07 million in 1980. Since then it’s climbed almost every year, crossing 8 million by 2000 and peaking near 8.83 million in 2019, just before the pandemic knocked it back down. It’s been recovering since, sitting at roughly 8.48 million as of the most recent data.

Total water consumption tells the opposite story. It peaked at 1,512 million gallons per day (MGD) in 1979 and by the early 2010s consumption had fallen below 1,010 MGD. It’s stayed in a tight band around 1,000 MGD for the past decade.

NYC used about 213 gallons per person per day in 1979–1980. Today it’s around 118, nearly a 45% drop in individual water use.

A few forces explain most of the gap:

• Universal metering¹. Before the 1980s, most NYC buildings paid a flat water rate regardless of usage. The city rolled out metering broadly through the ’80s and ’90s, and suddenly using less water meant paying less — a direct incentive that hadn’t existed before.
• Low-flow fixtures². Federal plumbing standards from the early 1990s mandated low-flow toilets and showerheads in new construction and renovations, and NYC ran its own rebate programs on top of that to accelerate retrofits in older buildings.
• Leak detection and infrastructure repair³. The city invested heavily in finding and fixing leaks in both its distribution mains and building-side plumbing, cutting non-revenue water loss.

The 65-year trend is a rare case where a city got measurably more efficient even as it grew.

Data: NYC Open Data — Water Consumption in the City of New York⁴.