' Q '
V s?
*L PRO"^
Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Patriot of &plutnpi(\<
Restoration Efforts Stabilize Watts Branch and Reduce Sediment Loading
Waterbody Improved
Urbanization and stream alterations, including channelization and
floodplain loss, contributed to increased volumes of stormwater
runoff in Watts Branch in the District of Columbia. The runoff severely eroded stream banks and
mobilized high levels of total suspended sediment (TSS), which prevented the stream from supporting
all of its designated uses. As a result, in 1996 the District Department of the Environment (DDOE)
added two segments of Watts Branch (totaling four miles) to the District's Clean Water Act (CWA)
section 303(d) list of impaired waters for TSS. Since then, project partners have implemented stream
restoration and upland projects that have reduced TSS loading into Watts Branch. Until additional
improvements are documented, however, the segments will remain on the impaired waters list.
Problem
Watts Branch begins in Prince George's County,
Maryland, and flows three miles northwest from the
eastern corner of the District to meet the Anacostia
River in Kenilworth Park, a National Park Service
landholding. The 3.53-square-mile Watts Branch
watershed includes 0.50 square mile of forest and
3.03 square miles of urban residential and commer-
cial land (Figure 1). Approximately 32 percent of the
watershed is covered by impervious surface. In this
heavily urbanized watershed, frequent and flashy
storms caused severe bank erosion and subsequent
mobilization of TSS in Watts Branch. Because the
stream was incised and disconnected from its
natural floodplain, high-velocity flows during rain
events caused high stress on the vertical banks and
high rates of erosion.
Both the upper and lower reaches of Watts Branch
exhibit moderate to high bank erosion. A lack of
floodplain over time led to lateral erosion of the
channelized stream, causing a higher width/depth
ratio and elevated TSS levels. Monitoring con-
ducted in 1997 indicated that the high TSS levels
caused poor habitat conditions in the creek. As a
result, DDOE added four miles of Watts Branch to
its CWA section 303(d) list in 1996 for failing to sup-
port two designated uses: (1) the protection and
propagation of fish, shellfish and wildlife and (2) the
protection of human heath related to consumption
of fish and shellfish impairment was attributed
to a number of pollutants, including TSS. DDOE
developed a total maximum daily load (TMDL) for
TSS in 2003. The TMDL required that the 68-ton
annual sediment load be reduced by 90 percent (by
61.2 tons per year).
Figure 1. Watts Branch drains a highly impervious watershed that
includes portions of Prince George's County in Maryland and
eastern Washington, D.C.
Project Highlights
Over the past several years, project partners, includ-
ing local, state and federal agencies, have collabo-
rated to increase stream channel stability and reduce
erosion caused by sediment loading. In 2010 DDOE
partnered with the U.S. Fish and Wildlife Service
(USFWS) and the U.S. Department of Agriculture's
Natural Resources Conservation Service (NRCS) to
Prince George's \
• County Wg
Washington D.C.
Washington
Watts Branch Watershed
Map by U.S. Fish and Wildlife Service, Chesapeake Bay field Office. Data Source: Washington, D.C. Government
10001 0 1000 2000 Feet
Legend
CD Watts Branch Drainage Area
CI5 County Boundary
Water
(\J Roads
Topography
Vicinity Map
Maryland

-------
Figure 2. Project partners removed
three feet of accumulated sediment
and reconnected Watts Branch with its
historical stream channel. Before the
restoration effort, Watts Branch followed
the path denoted by the yellow arrow.
Figure 3. After restoration, vegetation is
returning to the Watts Branch riparian
restoration project site shown in Figure 2.
restore a 1.7-mile seg-
ment of Watts Branch.
These partners:
•	Planted more than
10,000 trees, shrubs,
grasses and herba-
ceous plants along
the stream corridor
•	Created flood pi a i n
benches to reduce the
energy of storm fiows
that reach bankfull
stage by allowing the
flows to spread over a
larger area
•	Re-graded stream
banks and installed
more than 50 in-
stream structures
to control stream
flows and stabilize
the stream channel,
including cross vanes,
j-ho-oks and vane arms
to relieve stress on
the stream banks and
to dissipate increased
stream energy from
high stormwater flows
entering the stream
(Figures 2 and 3)
•	Created pools for fish habitat and improved fish
passage
•	Installed multiple low-impact development (LID)
practices in upland areas to treat more than four
acres of impervious surface runoff.
DDOE has leveraged funding from other agencies
to support additional projects in the Watts Branch
watershed including:
•	A Bandalong;®- litter trap to prevent floatable trash
from washing into the Anacostia River
•	A green roof and large cisterns to capture excess
stormwater runoff, to be used to flush toilets at a
local high school
•	A series of bioretention cells adjacent to Watts
Branch to capture and filter runoff from more than
1.3 acres of impervious cover
•	An upland tree planting project that added
600 canopy trees
•	A green street project that integrated LID into a
major streetscaping project.
Project partners coordinated stream restoration
work with concurrent efforts to rehabilitate sanitary
sewers, construct stormwater management facili-
ties and reduce the amount of stormwater runoff
from impervious areas. DC Water (the District's
water and sewer authority) repaired or replaced
five sewer iine stream crossings, which helped to
reduce bacteria levels in Watts Branch.
Results
The Watts Branch restoration project has improved
lateral and vertical stream stabilization and reduced
bank erosion. New flood plain benches have helped
to reduce stress on stream banks by allowing
high stormwater flows to dissipate into surround-
ing areas. Green infrastructure and LID projects
have reduced stormwater runoff, contributing to
increased channel stability. In total, these projects
have reduced TSS by approximately 46,862 pounds
per year (about one-third of the TSS reduction called
for in the 2003 TMDL); other reductions include
402 pounds per year of nitrogen and 68 pounds
per year of phosphorus. Although Watts Branch
remains listed as impaired for TSS, bacteria, organ-
ics and metals, these efforts have made progress
toward attaining water quality standards.
DDOE will monitor water quality in Watts Branch
(including assessment of pre- and post-implemen-
tation stormwater samples and macroinvertebrate
bioassessments) over the next several years to
track ongoing water quality improvements.
Partners and Funding
The Watts Branch restoration effort is the result of
a cooperative partnership between DDOE, USFWS,
NRCS, DC Water, and the District's Deputy Mayor
for Planning and Economic Development. USFWS
and Michael Baker, Inc., completed the project
designs. The project implementation costs associ -
ated with Watts Branch watershed restoration have
been covered in part by approximately $3.7 million
in funds from multiple agencies and organizations—
U.S. Environmental Protection Agency CWA section
319 project implementation funds ($910,753),
Washington, DC Capital funds ($1,855,300),
National Fish and Wildlife Foundation funds
($454,000), Chesapeake Bay Implementation funds
($140,341), and municipal separate storm sewer
system permit revenue funds ($339,605). CWA sec-
tion 319 funds have also supported wages for staff
working on Watts Branch restoration efforts.
£
<
\
^EDSrX
o
SB
%	r"
"U PROt*
UJ
©
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-13-001H
February 2013
For additional information contact:
Peter Hill, Branch Chief, Pianning and Restoration Branch
District Department of the Environment
Peter.hill@dc.gov • 202-535-2241
Josh Burch, Environmental Protection Specialist
District Department of the Environment
Josh.burch@dc.gov • 202-535-2247

-------