PROBLEM: Wetlands are a critical part of a watershed=s ability to filter out pollutants, as well as provide wildlife and waterfowl habitat. To date more than 90 percent of the Anacostia's tidal wetlands and nearly 70 percent of its freshwater non-tidal wetlands have been destroyed or altered (Figures 34 and 35).

Figure 35. Northeast and Northwest Branches Confluence (foreground) with the Anacostia River.

It is estimated that more than 6,500 acres of tidal and non-tidal wetlands have been lost from the watershed due to historic land conversion to agriculture, urban development, and filling and dredging along the tidal river (Figure 36). Almost 50 percent of the remaining acreage is classified as open water wetlands, which generally provide very specific and often limited habitat function.

Figure 36. Changes in Wetland Acreage Over Time (modified from Warner, 1996).

STRATEGY: Permit no further net loss of wetlands in the watershed, restore the ecological integrity and function of existing degraded wetland areas, and create opportunities to establish several hundred acres of new tidal and non-tidal wetlands throughout the watershed.

PROGRESS:

Tidal Wetland Restoration
The D.C. Department of Public Works, the Environmental Protection Agency, the National Park Service and the Metropolitan Washington Council of Governments initiated efforts to restore Kenilworth Marsh, a tidal freshwater system. Their efforts were successfully merged in late 1992 with a nearby ongoing U.S. Army Corps of Engineers Anacostia River dredging project which placed 130,000 cubic yards of dredge spoil material from the river into the marsh, resulting in the creation of 32 acres of emergent marshland. This effort represents the largest tidal freshwater marsh restoration project in the nation to date (Figures 37 and 38).

Figure 37. Kenilworth Marsh Before Restoration, 1992.

Figure 38. Kenilworth Marsh after Restoration, Fall 1993.

Through the U.S. Army Corps of Engineers= Anacostia Feasibility Study (1994), designs have been undertaken to restore Kingman Lake, a similar system to the Kenilworth Marsh, located on the same river reach. Lessons learned from the Kenilworth experience will be transferred to this project (approximately 46 acres of emergent wetland are planned).

Also identified in the Corps of Engineer=s Anacostia Feasibility Study is the creation of an additional 30 acres of emergent river fringe wetlands to be located in the vicinity of nearby Kingman Lake. Though originally part of the Anacostia Feasibility Study project scope for the District of Columbia, due to funding considerations, this element will probably be phased to be a part of future initiatives.

Constructed Wetlands
Overall, approximately 138 acres of constructed wetlands have either been completed, or are currently in progress, within the Anacostia watershed.

In 1993, the Prince George=s County Department of Environmental Resources, in cooperation with the U.S. Department of Agriculture=s Beltsville Agricultural Research Center and the Washington Metropolitan Area Transit Authority, constructed 19 acres of non-tidal wetlands in Beaverdam Creek.

Prince George=s County with assistance from the Maryland Department of the Environment, recently initiated efforts to design and construct a 0.5 acre wetland marsh facility in the Fairmount Heights area of the county. The project will both help reduce pollution from stormwater before it enters the Anacostia, as well as enhance wildlife habitat.

Retrofit Pond Fringe Wetland Creation
From 1989 to 1990, the Montgomery County Department of Environmental Protection, in cooperation with the Maryland-National Capital Park and Planning Commission and the Metropolitan Washington Council of Governments, created a total of 1.1 acres of fringe wetland habitat in four stormwater management ponds. Both emergent and submerged species, such as wild rice, common three square, soft-stem bulrush, arrowhead, wild celery, etc., were successfully incorporated in the plantings.

Wetlands Regulation and Mitigation
The Maryland Department of Natural Resources asserted new authority in 1992 to further protect non-tidal wetland areas; they are also evaluating ways to transfer wetland mitigation requirements to expand watershed-wide restoration efforts.

Figure 39. Vernal Pool Water Quality Monitoring - Sligo Creek Watershed, 1994.

Amphibian Reintroduction
As part of a larger Sligo Creek restoration effort, the Montgomery County Department of Environmental Protection, Maryland Department of the Environment, Maryland-National Capital Park and Planning Commission and the Metropolitan Washington Council of Governments constructed in 1991 and 1993 both vernal pool and shallow marsh habitat areas for the re-establishment of native amphibian populations (Figure 39). By 1995, utilization of the created habitat areas by six species had been documented (i.e., spring peeper, wood frog, green frog, bull frog, American toad and spotted salamander).