Delaware Bay and Estuary Basin

The Delaware Bay and Estuary Basin contains the  Appoquinimink River ,  Army Creek ,  Blackbird Creek ,  Broadkill River ,  C & D Canal East ,  Cedar Creek ,  Delaware Bay Drainage ,  Delaware River Drainage ,  Dragon Run Creek ,  Leipsic River ,  Little Creek ,  Mispillion River ,  Murderkill River ,  Red Lion Creek ,  Smyrna River , and  St. Jones River  watersheds.

• Size: 793.1 square miles
• 2019 U.S. Census Bureau Population: 320,467
• States: DE
• Counties: DE: New Castle, Kent and Sussex

Land Cover: The pie charts below show the percent land cover for the entire Delaware Bay and Estuary Basin and the Delaware portion of the basin respectively.

More than 90% of Delaware's Waterways are considered impaired. "Impaired waters" are severely polluted waters that do not meet water quality standards. The state's list of impaired waters, filed with the Environmental Protection Agency, includes bodies of water that suffer from 11 different impairments, the most common of which are pathogens (disease-causing bacteria and viruses) and nutrients.

Pollutants in Delaware waters are often chemicals, such as nitrogen and phosphorus from fertilizer runoff. They can come from specific "point" sources, such as sewage treatment plants, or from "nonpoint" sources, like runoff from lawns, farms, parking lots, and golf courses. Most impairments come from nonpoint sources of pollution, which are difficult to control because you can't see exactly where they originate.

The nutrients entering the Delaware Bay come from agricultural runoff, urban runoff, and municipal and industrial point source discharges. While nitrogen and phosphorus are essential for plant and animal growth, when excess amounts enter the bays, water quality can deteriorate as aquatic plant growth accelerates and the level of oxygen is reduced, leading to eutrophication.

Septic systems also contribute high amounts of nutrients to the Delaware Bay. Raw or inadequately treated sewage is a severe contributor to the declining health of the Delaware Bay. This sewage contains pathogens, which are disease-causing bacteria and viruses. The potential daily pathogen output from one person's untreated sewage can equal that of treated sewage from hundreds to even thousands of people, depending on the level of treatment.

Delaware's Department of Natural Resources and Environmental Control (DNREC), Division of Fish and Wildlife conducts on-going inventories of natural communities as well as rare and declining species, (e.g., state and globally-rare plants, birds, insects, mussels, reptiles, and amphibians). It maintains a database, both electronic and manual, of its findings throughout the state. To find out more information on the wildlife and plant communities in the Delaware Bay and Estuary Basin, visit the DNREC's  Conservation Programs page .

Because of its strategic location, the Delaware Bay and Estuary Basin's wetlands and associated uplands are extremely important to waterfowl and other wetland dependent migratory birds in the Atlantic Flyway. The wetlands across the Basin are regionally small but form a critical route for birds that migrate between and/or winter in the Delaware and Chesapeake Bays. For this reason, conservation agencies place the highest priority on the protection, restoration, and enhancement of habitats that serve as wintering areas or reduce fragmentation of prominent migratory corridors. The Delaware Bay and Estuary Basin provides unique habitat during migration for high priority species designated by the North American Waterfowl Conservation Act (NAWCA) which includes the Black Duck, Mallard, and Northern Pintail, and is a focus area for the Atlantic Coast Joint Venture.

Delaware has more than 1,600 species of native plants. More than a quarter of them are rare and can be found in more than 100 different terrestrial and wetland habitat types.

The Division of Fish and Wildlife, working with the University of Delaware's Institute for Public Administration - Water Resources Center, maintains online databases about plants and plant communities in Delaware. To find out more, visit DNREC's Conservation Programs  Plants and Plant Communities page .

The Delaware Bay and Estuary Basin is home to a variety of important forest communities. In general, the northernmost forests in the Delaware Bay and Estuary Basin are comprised of a mixture of hardwoods, primarily being dominated by oaks, beech, tulip poplar, and hickories on the drier sites. The predominate tree species in a wide variety of wetland habitats include box elder, sycamore, sweet gum, slippery elm, red maple, tulip poplar, ash, pin oak, and sometimes river birch and black willow. .

The natural resources of the Delaware Bay and Estuary Basin provide opportunities for a variety of recreational activities, such as fishing, camping, hunting, and hiking. The forests, marshes, and open waters of the Basin are popular destinations for many people, both native and visiting. Within the Basin, there are four state parks, two national wildlife refuges, approximately twelve state wildlife areas, and numerous fishing access areas that provide a variety of opportunities for recreation. Recreational fishing in the Delaware Bay and its tributaries is a popular activity. In the Delaware Estuary, some of the commonly sought-after recreational fisheries include: striped bass, bluefish, carp, catfish, drum fish, summer flounder, white perch, and yellow perch. Bluefish and summer flounder are the two most sought-after species in the Estuary. It is recommended that before fishing, individuals contact the Division of Fish and Wildlife for the most up-to-date information regarding fishing advisories for the Delaware Bay and Estuary.

Documentation

•  Whole Basin Environmental Assessment 
•  Comprehensive Conservation and Management Plan 

Partners

•  Delaware Nature Society 
•  Blackbird Creek Reserve 
•  Bombay Hook National Wildlife Refuge 
•  Delaware River Basin Commission 
•  Partnership for the Delaware Estuary 
•  Primehook National Wildlife Refuge 
•  The Nature Conservancy