Delaware Division of Fish & Wildlife

Northern Delaware Wetland Rehabilitation Program

Northern Delaware Wetlands Rehabilitation Program

The Northern Delaware Wetlands Rehabilitation Program was established by the Department of Natural Resources and Environmental Control to bring together civic and business leaders, scientists, resource managers, and property owners to develop strategies to restore nearly 10,000 acres of wetlands-31 distinct sites along the Christina and Delaware rivers in New Castle County.

wetlnd1a.jpg - 87.4 K These marshes once contained some of the state's richest waterfowl populations and served as important nursery grounds and breeding habitat for a wide variety of fish and other wildlife.

They also helped filter pollutants and sediments out of river water and provided a buffer zone during storms, protecting properties from flooding.

The marshes that are the focus of this recovery initiative have undergone a varied history of change over the years: some were drained by early Dutch and Swedish settlers, who wanted to turn marshland into farmland. other areas were drained in hopes of decreasing mosquito populations. And still other wetlands were drained to support a growing population and its attendant industrial, residential, and highway expansion.

Despite nearly three centuries of environmental abuse, however, Delaware's northern marshes can be brought back to life.
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The Northern Delaware Wetlands Rehabilitation Program seeks to achieve the following goals.

Improve Water Quality.

One key to restoring most degraded marshes is to re-establish their hydrology that is, daily tidal exchange between marsh and river. Water control structures can be installed, permitting the tides to flush nutrients and aquatic organisms into and out of the marsh as well as increase the volume of water that can be cleansed by the wetlands Another key is controlling the inputs of pollution to the marsh, conveyed during storms, through implementation of non-point source control plans.

Increase Wildlife Populations.

Constructing duck and songbird boxes, establishing preferred food and cover plants, adjusting water levels to accommodate the needs of aquatic mammals, water birds, and endangered species, and increasing the diversity of shallowwater habitats-ponds, ditches, and islands-all can help attract wildlife to once-damaged marshes.

Control Nuisance Plants.

Phragmites is a tall, tasseled plant that can overtake a wetlands forming dense stands of little value to wildlife. When interspersed among other plants and open water, however, Phragmites can provide good habitat. Thus, the goal is to control rather than eradicate this plant. The current practice is to spray Phragmites with herbicides in late summer, followed by the controlled burning of dead, standing canes during winter.

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Planning has begun for rehabilitating four northern marshes: Gambacorta and Broad Dyke marshes in New Castle, Augustine Marsh near Port Penn, and Old Wilmington Marsh.

Gambacorta Marsh.

This 41acre marsh, located within the New Castle city limits, is owned by the Trustees of New Castle Common. It is bordered on the east by a recreational trail that runs atop a dike, which isolates the marsh from the Delaware River. However, the dike does contain a water control structure. On its other three sides, the marsh is surrounded by urban and commercial development.

Part of the marsh was drained and used as landfill for industrial waste. However, the waste has been removed, and the landfill site has been capped.

Gambacorta Marsh is already on the rebound. Phragmites control efforts have cleared part of the marsh, the addition of wildlife habitat enhancement structures has attracted more waterfowl, the water control structure has been temporarily modified to allow daily tidal exchange, and a water management plan has been implemented.

Preliminary plans call for permanently modifying the existing water control structure to allow for daily tidal exchange, clearing clogged waterways to increase open water habitat, continuing Phragmites control, and enhancing the recreational and educational opportunities presented by the walkway.

Broad Dyke Marsh.

Located north of New Castle and owned by the Trustees of New Castle Common and New Castle Immanuel Episcopal Church, this 210-acre tidal freshwater marsh is bordered on three sides by housing developments and separated from the Delaware River by a dike containing a water control structure.
wetlnd8.jpg - 131.2 K This structure is designed to allow a one-way flow of water -- out of the marsh. Occasional malfunctions, however, have caused flooding of adjacent properties. In addition, the oneway exchange of water has degraded the marsh and made it a potential breeding ground for mosquitoes. Plant and animal diversity are down, and Phragmites has taken over parts of the marsh.

A recent temporary water management plan allowing tidal exchange, combined with a Phragmites control program and installation of wildlife enhancement structures, has restored much of the marsh's biodiversity. A design for a new water control structure also has been selected. it will allow managers to continue to improve tidal exchange between marsh and river, and release floodwaters rapidly during major storms.

Preliminary plans call for adding more wildlife enhancement structures and open water habitat for mosquito- eating fish, continuing Phragmites control, and building a trail, boardwalk, observation tower, and canoe launch.

Augustine Creek Marsh.

wetln8a.jpg - 41.6 K This 1,130-acre wetland south of Port Penn is bordered to the east by Route 9 and suffounded by agricultural lands. The wetland is owned by many different landowners including the State and Delaware Wildlands Inc., a private nonprofit conservation organization.

Migrating and wintering waterfowl make extensive use of the 912-acre tidal impoundment within this wetland as do migrating neotropical shorebirds. Surrounding the impoundment are forested areas that are critical habitat for many wildlife, including one of the largest heronries on the Atlantic Coast.

This wetland complex's habitat and water quality have been gradually declining because of restricted tidal flow. The marsh is evolving into a shallow, sediment-laden, open-water marsh dominated by Pbragmites. Part of this decline is due to the lack of a consistent water management plan.

Preliminary plans call for installation of an additional water control structure to permit limited tidal exchange and better water level control, implementation of an official water management plan, and Phragmites control. These rehabilitation efforts, along with the cooperation of the many landowners, have the potential to make Augustine Creek Marsh one of the premiere wetlands of the Atlantic Coast.

Old Wilmington Marsh.

This 225acre tidal freshwater marsh located just south of Wilmington near Legends Stadium and surrounded by highways and urbanization is a prime candidate for rehabilitation. Surveys are under way to assess potential contaminant levels, biological diversity, debris removal, and feasibility for outdoor education classes. A Phragmites control program will eliminate large stands of this noxious plant by helicopter herbicide application.

See the sidebar below for the remaining "top ten wetlands" targeted for immediate attention by the rehabilitation program.

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To succeed, the Northern Delaware Wetlands Rehabilitation Program needs a strong management teamcivic and business leaders, scientists, resource managers, property owners, and other private citizens. This partnership can make a vital improvement to Delaware's environment.

A grant from the National Oceanographic and Atmospheric Administration, U.S. Department of Commerce, to Delaware's Coastal Management Program will fund research and administrative costs. Other funding will come from a variety of sources including the DNREC Divisions of Fish and Wildlife and Soil and Water Conservation, enviromental fines, Superfund settlements, grants, private landowners, and private citizens through such stewardship activities as DNREC's Adopt-a-Wetland Program.

Local municipalities and industries also play a vital role in marsh restoration. For example, the Trustees of New Castle Common have committed $ 1 00,000 for a new water control structure for Broad Dyke Marsh. Ciba-Geigy has donated $310,000, and Brand Mid-Atlantic, Inc., has donated $100,000. Every contribution can help rehabilitate New Castle County's tidal freshwater marshes.

A tidal freshwater marsh is one of the most productive environments on Earth. Working together, we can help bring back to life what many thought was lost foreverDelaware's northern marshes.

The Northern Delaware Wetlands Rehabilitation Program is a collaborative partnership coordinated by the Delaware Depatiment of Natural Resources and Environmental Control's Divisions of Fish and Wildlife and Soil and Water Conservation. For more information, please contact.

Division of Fish and Wildlife
(302) 739-5295
89 Kings Highway
Dover, DE 19901
Division of Soil and Water
Conservation (302) 739-4411
89 Kings Highway
Dover, DE 19901
New Castle Conservation
District (302) 834-3560
6 People's Plaza
Newark, DE 19702

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