Delaware River Basin
The Delaware River is the East Coast’s longest free-flowing river.
Flowing through New York’s Catskill mountains, Pennsylvania’s Poconos and the New Jersey Highlands, the Delaware River Basin provides high-quality drinking water to more than 17 million people including residents of New York City and Philadelphia.
Home to an incredible diversity of fish, wildlife and scenic vistas, the Delaware River Basin supports coastal communities with commercial fisheries and river towns with robust tourism revenue. Its floodplains reduce the impacts of floods on homes and businesses. Upriver, tributary streams are cold, clear and full of fish.
The Delaware River is renowned as the longest remaining un-dammed river east of the Mississippi. But these waters are not invincible - land conversion, stormwater pollution, and climate change threaten their health. The Nature Conservancy is working throughout the basin—in places like the Neversink River and the City of Philadelphia—to protect forests, floodplains and fish, while also working to make our cities more resilient.
With partners, TNC has identified lands that are important for maintaining clean water. In the headwaters of the Delaware River Basin, TNC is conserving forested lands, particularly those surrounding streams, lakes and rivers. In the Cherry Valley National Wildlife Refuge, along the Kittatinny Ridge and in the Poconos in Pennsylvania, our team of dedicated scientists and land protection professionals work with landowners, hunting and fishing clubs, and state agencies to protect and connect high-quality forests and floodplains.
The Conservancy is also advancing innovative restoration approaches that allow rivers to heal after centuries of development and degradation. Our river restoration projects showcase the benefits of reconnecting the Delaware River to its floodplain and re-introducing fallen trees and woody materials (removed from our rivers during the past centuries) back into our rivers and onto our floodplains. These approaches will help to improve water quality, manage river flows, and slow floodwaters, while restoring habitats that support healthy populations of fish and wildlife.
The Conservancy is also working in cities to reduce the impacts of stormwater on communities. For example, we are working with the Philadelphia Water Department to develop stormwater management solutions in two neighborhoods, transforming hard surfaces like pavement to absorb floodwaters and trap pollutants before reaching our streams and rivers.
Fish benefit too. In focusing on clean water, TNC is helping migratory fish, including American eel and ancient Atlantic sturgeon. The Delaware River once supported the largest population of Atlantic sturgeon in the United States; today, it supports less than one percent of the sturgeon’s historical spawning population. Now, a study led by TNC provides recommendations to help improve the sturgeon’s odds to not only survive, but to once again flourish.
Waterways and wildlife, forests, floodplains and fish—TNC is working on improving life throughout the Delaware River Basin.