The Delaware River Estuary

Delaware Estuary Map

Estuaries are places where a river meets the sea or ocean. At the Delaware Estuary, the freshwater of the Delaware River mixes with the salt water of the Atlantic Ocean to form a unique habitat for fish, birds, and other wildlife.

Estuaries are among the most productive habitats on Earth. They host more wildlife births than any other ecosystem and are vital spawning, nursery, and feeding grounds for fish, shellfish, and birds. They also support amphibians, reptiles, and mammals. Estuaries are critical to the health of coastal environments, as well as to the human habitats they support by providing drinking water, industrial water, fisheries, transportation corridors, and recreation. Estuaries are lined with vital wetlands that filter sediments and pollutants from the land and serve as buffers that protect from flooding and erosion.

The Delaware River is the longest undammed river on the East Coast of the United States. Originating in New York’s Catskill Mountains, the East and West branches of the Delaware River unite in Hancock, NY to form the main stem of the river. The river flows 375 miles from the Catskills to the Atlantic Ocean. Its watershed encompasses 12,765 square miles in four different states—New York, New Jersey, Pennsylvania, and Delaware—and is home to nearly six million people. Additionally, the Delaware River sustains thousands of species of wildlife.

The Delaware Estuary, which includes the Delaware Bay and the tidal reach of the Delaware River, runs from the head of tide at Trenton, NJ and Morrisville, PA to Cape May, NJ and Cape Henlopen, DE. The Delaware Estuary is included in the National Estuary Program, which aims to protect estuarine systems of national importance.

Physical Characteristics of the Delaware Estuary

Estuary Terminology

Delaware Estuary References