Section 319
NONPOINT SOURCE PROGRAM SOCGESS STORY
istrict v C
Project Expands Wetland Functions in Tidal River
Waterbody Improved
Nearly all the historic wetlands surrounding the Anacostia
River were lost when the Washington, D.C., area was devel-
oped. Also lost were the ecosystem services that wetlands provide, including water fil-
tration and habitat. As a result, sediment and nutrients levels in the river increased. The
District of Columbia's (District's) Department of the Environment (DDOE) launched an effort
to restore some of the wetlands along the mainstream portion of the river. Restoring the
sites increased coverage of planted vegetation by more than 100 percent along the river
and improved the ability of the areas to process excess nutrients and filter sediment.
Problem
The tidal portion of the Anacostia River once
included hundreds of acres of wetlands. During
the capitol region's development, the U.S. Army
Corps of Engineers (USAGE) straightened the river
and filled in almost all the wetlands, leaving the
tidal Anacostia with little ability to process pollut-
ants flowing downstream from Maryland and the
District.
Recently DDOE and USAGE conducted a planning
study using Clean Water Act (CWA) section 319
funding and identified areas (fringe sites) in the
mainstem channel that could sustain wetlands. In
2003 the partners implemented a 17-acre wetland
restoration project called the River Fringe Wetlands.
Project Highlights
The partners identified two existing depositional
areas (Figure 1) in the river as prime spots for
raising the elevation and planting wetland plants.
They dredged sediment from approximately a mile
upstream of the sites and pumped it into two cells,
which were supported by sheet piling and coconut
coir (fiber) logs. The 1.7- to 2.3-foot target eleva-
tions were reached after two weeks of dredging
(Figure 2).
Vegetation in a similar wetland restoration proj-
ect conducted in 2000 suffered from significant
grazing damage by numerous Canada geese that
reside year-round on nearby National Park Service
land. Learning from that, the partners opted to
sufficiently raise the elevations of the River Fringe
wetland restoration project to sustain a vigorous
assemblage of wetland plants that would not
attract resident geese. In addition, the partners
Figure 1. Before
construction, the River
Fringe Wetland site was a
depositional mudflat.
added fences around the
newly planted wetlands to
deter geese from accessing
them from the ground.
The partners planted seven
species in the River Fringe
project area, the vast major-
ity of which are unpalatable
to Canada geese. One
species of interest, Zizania
aquatics (wild rice), historical-
ly dominated the wetlands.
The Anacostia Watershed
Society (AWS) reestablished
that species using a unique
method. AWS grew wild
rice and collected the seed over the course of one
growing season. It then embedded the seeds in
mud balls and invited enthusiastic school children
Figure 2. Project partners pumped
sediment into two cells to create
the River Fringe Wetland, seen
here as the slight bulge of land
extending into the river just beyond
the tennis courts.
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Figure 3. Three years after construction, the area is
densely vegetated.
to throw them into the wetland cells. The wild rice
plants, in addition to many other planted species,
have flourished over the past 7 years (Figure 3).
Results
The coverage of planted vegetation has increased
to approximately 80 percent and has remained
steady for the past 4 years (Figure 4). More than 70
species have been identified over the past 5 years
(Figure 5). Volunteer species (mostly annual spe-
cies), have been an important component of the
vegetation composition, contributing an additional
40 to 60 percent coverage. The greater than 100
percent increase indicates that numerous layers of
vegetation have created an extremely dense plant
mass. The plants absorb excess nutrients and filter
sediment from the river, thereby achieving the
project's primary goal.
Partners and Funding
The U.S. Environmental Protection Agency provided
$200,000 in CWA section 319 funding to assist
DDOE with the restoration project. DDOE con-
tributed 25 percent of the costs of the restoration
project and contributed staffing for the wetland
monitoring. The USAGE Baltimore District contrib-
uted 75 percent of the costs and handled contract
and project management duties. The $4 million total
project cost consisted of feasibility studies, design,
permitting, construction and monitoring.
Total Vegetative Cover
Compared to Cover by Planted
Species at the Anacostia River Fringe
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