A river flows through abundant trees under a blue sky and puffy clouds.
Delaware River The Delaware River flows through eastern Pennsylvania. ©: Nicholas A. Tonelli

Stories in Pennsylvania

Delaware River

Delivering clean and abundant water to wildlife and people living throughout the watershed.

Known to many for George Washington’s famous crossing, the Delaware River transcends history as a river of tremendous biological, economic and cultural significance. Originating from clear, cold headwater streams in the Catskill Mountains, it flows for more than 400 miles through the sweeping beauty of the Water Gap, beneath the bridge spans of Colonial-era river towns, and through the urban corridors of Trenton and Philadelphia before reaching the Delaware Bay and the Atlantic Ocean.

Along the way, the Delaware provides clean water utilized by industry, agriculture and nearly 20 million people, including residents of New York City and Philadelphia. Coastal communities rely on the river to support sport and commercial fishing for striped bass, shad and oysters. River towns draw revenue from the Delaware, including from anglers, kayakers and other tourists who visit to enjoy the area’s scenic beauty and array of outdoor recreational opportunities.

Sharing the river with people are wild sturgeon, eel and other wide-ranging freshwater species. On land, bobcat, bear and other mammals roam throughout this watershed that also contains an important segment of the Atlantic flyway, hosting more than 200 species of birds who spend part of their life cycle here. Downstream, the Delaware River estuary provides spawning grounds for horseshoe crabs and hosts one of the most critical stopover points for migrating shorebirds in the western hemisphere.

A colorful map reveals the path of a watershed.
Delaware River Basin The Delaware River originates from cool, clear headwater streams in the Catskill Mountains. © Delaware River Basin Commission

Mighty But Not Invincible

The Delaware River is an irreplaceable source of clean water, which is essential to all life. Historically, these waters were protected by forestlands located at its headwaters and throughout the watershed. However, increasing development has resulted in fewer, intact floodplain forests to slow the course of seasonal rains and absorb the impact of storms—leaving homes and businesses vulnerable to flooding and compromised water supplies.

Alterations in ways the water moves also place demands on the quality and security of this valuable resource. In spite of being the longest free flowing mainstem river east of the Mississippi, fish populations that include migratory shad, eel and sturgeon are at historic lows in the Basin due to a legacy of pollution, overfishing and the establishment of dams on the river’s tributaries.

Scenic lands located along the river have become coveted for development that sends nutrients and pollution into the river that provides drinking water to the cities of Philadelphia, Camden, Wilmington, Dover and other places downstream. Freshwater supplies are also threatened by increased salinity moving inland from the bay as a result of rising seas caused by climate change

Everyone’s River

Human demands for water are compromising the Delaware River’s ability to provide vital services to people and nature. In response, The Nature Conservancy is working with partners to implement strong science and innovative water management practices that will protect, manage and restore the lands and waters comprising the Basin.

These efforts go a long way in ensuring a healthy and functioning river that will support wildlife populations, including migratory fish, and provide opportunities for recreation and life-sustaining water for people and nature.