Sea Level Rise

The Hudson River is an extension of the Atlantic Ocean, a 150-mile-long estuary (tidal area where the river meets the sea) that stretches from the Narrows in New York Harbor to the Federal Dam at Troy. This means that any changes in water levels in the Atlantic and around the globe have a direct effect on sea level along the entire estuary.

Over the past century, sea level on the Hudson has risen at a higher rate than the global average— more precisely about 2.8 mm per year. From 2000 to 2025, the rate has accelerated, averaging 4.6 mm per year at The Battery tide gauge in Manhattan, one of the longest-operating gauges in the U.S.

The best data available indicates that we can expect the Hudson’s water levels to continue rising six feet or more by the end of this century, and perhaps that much again during the next century.

What’s at Stake?

Over 9,000 acres of riverfront lands lie within the expanding reach of daily high tides, threatening both the most critical river habitats and approximately 3,600 households and 6,900 people. Accompanying shifts of flood-prone areas will put approximately 6,400 more households and 12,200 people at greater risk from damaging storm surges and floodwaters. 

At the same time, the most critical habitats of the Hudson River ecosystem — the 13,000 acres of tidal wetlands and shallow water vegetation beds — will be increasingly stressed by rising water levels.

What We’re Doing

Scenic Hudson is working to advance long-range planning for sea level rise along the estuary — not only as a mission-driven organization, but also as a holder and steward of over 1,000 acres of protected lands along the river’s edge. Here are some helpful tools we have developed:

• Sea Level Rise Mapping: From 2013 to 2026, Scenic Hudson hosted an interactive map showing the estimated water depth for each increment of sea level rise to educate Hudson Valley residents about this threat. Although we have retired the online mapper, GIS users can download the data here. Other sea level rise mappers that are currently available online, as well as more information about how high water levels are likely to get, are listed below under Resources.
• Protecting the Pathways: An analysis and guide for preserving our tidal wetlands in the face of sea level rise.
• Hudson Valley Flood Resilience Network: A network of communities working to plan and implement sea level rise adaptations. Scenic Hudson is a founding partner.