Section 319
NONPOINT SOURGF PROGRAM SUCCESS STORY
Restoring Stream Improves Water Quality and Fish Community Health
Waterbodv Improved During rainstorms, high volumes of rapidly moving stormwater
flow off of impervious surfaces and into Maryland's Spring
Branch, causing destructive erosion of the stream channel and contributing sediments and
nutrients to a drinking water reservoir. The Maryland Department of the Environment (MDE)
added Spring Branch to the state's Clean Water Act (CWA) section 303(d) list in 1996 for nutri-
ent and sediment impairments and expanded the listing in 2002 to include biological impair-
ments. Restoring two miles of stream has significantly reduced nutrient and sediment loads and
improved fish habitat. Water quality continues to show progress toward meeting the total maxi-
mum daily load (TMDL) limits for phosphorus and sediment in the Loch Raven Reservoir, which is
immediately downstream of the project area.
Problem
The 1,005-acre Spring Branch watershed drains
a portion of Baltimore County in the urbanized
Baltimore metropolitan region and empties into the
Loch Raven Reservoir. Spring Branch is designated
for water contact recreation use, aquatic life use
and public water supply use.
Spring Branch was once a narrow, shallow trout
stream. Fifty years of rapid urbanization created
many impervious surfaces with few stormwater
controls (Figure 1). Consequently, rainfall gener-
ates high volumes of runoff that quickly exceed the
capacity of Spring Branch. Stormwater flows have
eroded the stream channel so that it is now 30 feet
deep and 15 feet wide. Erosion has exposed sewer
pipes and created high sediment and nutrient loads
that flow into the Loch Raven Reservoir.
MDE first added Spring Branch to the CWA sec-
tion 303(d) list in 1996 for nutrient and sediment
impairments. On the basis of biological monitoring
results, MDE expanded the list of impairments to
include a biological impairment in 2002.
In 2007 the U.S. Environmental Protection Agency
approved MDE's TMDL for Loch Raven Reservoir,
which includes the Spring Branch subwatershed.
The TMDL requires that total phosphorus be reduced
by 50 percent to meet water quality standards for
dissolved oxygen and chlorophyll a (to prevent algae
blooms in the reservoir). The TMDL also requires that
suspended sediment be reduced by 25 percent to
preserve the reservoir's volume. A TMDL for biologi-
cal impairments has not yet been developed.
Spring Branch Watershed
Maryland
Figure 1. Impervious surfaces in northern
Maryland's Spring Branch watershed.
Project Highlights
In 1997 Baltimore County developed a water quality
management plan for the Loch Raven watershed.
The plan identified and evaluated nonpoint sources
of pollution and provided a watershed restora-
tion and management framework. The Baltimore
Metropolitan Council's Reservoir Technical Group
wrote a 2005 Action Strategy for the Loch Raven
Reservoir Watersheds, which called for Baltimore
County to reduce nutrient and sediment inputs to
the reservoir through a variety of best management
practices, including stream restoration. Baltimore
County chose to focus restoration efforts on Spring
Branch because of its proximity to the reservoir
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and other factors, and completed a Spring Branch
Subwatershed Small Watershed Action Plan in 2008.
The Baltimore County Department of Environmental
Protection and Resource Management (DEPRM)
conducted two phases of restoration activities on
Spring Branch—one beginning in 1997 and the
second in 2008. Both phases addressed effects of
urbanization, including the flashy (quick-to-flood)
flow regime, erosion, declining ecological func-
tion, failing infrastructure, poor water quality and
property damage.
In phase I, DEPRM created a new channel of Spring
Branch and added step pools, meander patterns
and flood plains. That and other parts of the stream
channel were stabilized using natural materials such
as boulders, tree root wads, brush mattresses and
live branch layers. In addition, DEPRM removed
1,740 feet of concrete channel (Figure 2), stabilized
or removed sanitary sewer lines, added rock-lined
step pools below storm drain pipes to dissipate
energy from the flow, and constructed a stormwater
wet pond to treat runoff from the headwaters.
Replanting 12 acres with native trees and shrubs
restored 10,000 linear feet of stream (Figure 3).
In phase II, DEPRM removed another 524 feet
of concrete channel and restored 3.23 acres of
native riparian buffer using 219 trees; 547 shrubs;
2,133 live stakes; 295 linear feet of live branch layer-
ing and 102 pounds of native riparian seed. Phase II
restored 2,814 linear feet of stream.
Figure 2. At this site (looking
toward Pot Spring Road)
before restoration efforts,
Spring Branch flowed
through a concrete channel.
The concrete step seen here
obstructed fish passage.
Results
Figure 3. After restoration,
the concrete channel seen in
Figure 2 has been removed.
Sewer lines running
along both sides of the
stream prevented partners
from restoring a natural
meandering pattern.
The phase I work reduced phosphorus loads by
27 percent, nitrogen loads by more than 30 percent
and sediment loads by 45 percent. In 2003 and
2004, monitoring at station SB-2 (downstream end
of the phase I portion of the project) showed that
few or no fish were present, and the fish index of
biotic integrity score (IBI) was classified as very poor
(score of less than 1.9). However, the fish commu-
nity responded to phase II restoration efforts. Fish
monitoring in 2009 (less than one year after phase I
was completed) showed significant increases in fish
biomass and fish IBI at stations SB-2 and SB-8 (head-
waters). Removing the concrete channel (see Figure
2) allowed the fish to swim upstream and colonize
the area. As seen in Figure 4, Fish IBI scores at both
stations improved to a classification of poor (scores
between 2.0 and 2.9).
Fish IBI (Index of Biological Integrity)
2003
2004
2008
2009
Figure 4. After phase II of the restoration
(2008), fish IBI levels increased above (SB-8)
and below (SB-2) the project area.
Although Spring Branch does not yet meet water
quality standards, reduced pollutant loads and
improving biological data indicate that progress is
being made.
Partners and Funding
Project costs included $276,473 for a new wet pond
serving 47 acres, $1.9 million for phase I work and
$1.1 million for phase II work. Most of the funding
came from Baltimore County bonds, MDE Small
Creeks and Estuaries Grant and MDE stormwater
cost share funds. A developer fee, required in lieu of
mitigation funds, helped fund plantings. CWA sec-
tion 319(h) funds contributed $240,000 for phase II
work. Baltimore City, which owns and operates the
Loch Raven Reservoir, was also a project partner.
I
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-11-001G
February 2011
For additional information contact:
Steve Stewart, Baltimore County DEPRM
Watershed Management and Monitoring
410-887-4488x240 • sstewart@baltimorecountymd.gov
Ken Shanks, Maryland Department of the Environment
410-537-4216 • kshanks@mde.state.md.us
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