Section 319
NONPniNT
PROGRAM SUCCESS STORY
Stream Restoration and Dam Removal Restore Waterbodies
\A/dtQrh/^H\/ Irv-imr/^waH Many years of agricultural runoff had caused nutrient and dissolved
vvaisrDOQy improvsQ . . , . .„ . ^ i i ,..,
! oxygen impairments in Manatawny Creek and an unnamed tributary
to the Manatawny. In addition, an orphaned dam on the creek had blocked migratory fish access and
triggered sediment accumulation in the stagnant waters. By 1998 Pennsylvania had included approxi-
mately 22.3 miles of Manatawny Creek and its tributary on the state's 303(d) list, citing sediment,
nutrients, low dissolved oxygen, and thermal impairments due to agriculture and hydromodification.
To address these problems, project partners stabilized stream channels, restored riparian buffers, and
removed the dam. Water quality improved as a result, allowing the state to delist both waters in 2004.
Problem
The Manatawny Creek watershed covers
91.6 square miles and includes parts of two
counties in southeastern Pennsylvania. The
creek drains into the Schuylkill River at the
town of Pottstown, approximately 40 miles
northwest of Philadelphia.
Although urbanization is taking place through-
out the watershed, much of the area remains in
agricultural use. Nonpoint source runoff from
agricultural fields and operations delivered high
nutrient and sediment loads to Manatawny
Creek and its tributaries. Algal blooms and low
dissolved oxygen levels were pervasive issues.
An orphaned dam near the mouth of the creek
compounded the upstream problems in both
Manatawny Creek and an unnamed tributary
to the Manatawny. The dam blocked migratory
fish passage and caused stagnant flows, which
allowed sediment to accumulate.
These circumstances prompted the Pennsylv-
ania Department of Environmental Protection
(PA DEP) to place approximately 20 miles
of Manatawny Creek and 2.3 miles of the
tributary on the state's 303(d) list of impaired
waters for failing to meet aquatic life uses. The
agency identified several causes of impair-
ment, including
• Low dissolved oxygen concentrations trig-
gered by nutrient-rich agricultural runoff
Restored riparian buffer along Manatawny Creek.
• Accumulated sediments from runoff and
dam-caused streamflow stagnation
• Water temperature increases produced by
stagnant waters
Project Highlights
Project partners employed several approaches
to address the water quality troubles. First,
they removed the dam in 2000, restoring the
flow of the Manatawny and the tributary. Next,
they stabilized approximately 2,000 linear
feet of stream channel to reduce erosion.
Finally, to further deal with erosion and to
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reduce nutrients entering the waterway, project
partners restored nearly 2,000 linear feet of
riparian buffers. These actions helped to reduce
annual sediment loads to Manatawny Creek by
an estimated 800 tons.
In addition to engineering approaches, project
partners used public education throughout
the project's duration. They conducted public
meetings on the dam removal project, partici-
pated in formal meetings with borough officials
and residents to discuss riparian vegetation
management, and distributed project informa-
tion through print and television media.
Results
PA DEP reassessed Manatawny Creek and its
tributaries in 2002. By that time, the state had
changed its 303(d) listing and delisting meth-
odologies. When Manatawny Creek had been
listed in the mid-1990s for not meeting aquatic
life uses, the state had based its decision on
chemical parameters like nutrients and dis-
solved oxygen. Later, as part of programmatic
changes in Pennsylvania's total maximum
daily load (TMDL) program, the state revised
its criteria to base them primarily on benthic
macroinvertebrate data.
As shown in the accompanying table, state
biologists found that Manatawny Creek's
macroinvertebrate populations consisted
largely of pollution-sensitive taxa comparable
to those found at reference locations. In addi-
tion, PA DEP showed that dissolved oxygen
consistently remained above the state stan-
dard of 5 mg/L.
On the basis of these findings, Pennsylvania
removed 20 miles of Manatawny Creek and
2.3 miles of the unnamed tributary from its
303(d) list of impaired waters. Project partners
attribute the delisting of these waterbodies
to the dam removal and stream restoration
efforts.
Partners and Funding
Using a $90,000 section 319 grant, the
Delaware Riverkeeper Network spearheaded
efforts to stabilize streambanks and restore
riparian areas. The Academy of Natural
Sciences' Patrick Center for Environmental
Research used a PA DEP Growing Greener
grant to assess the effectiveness of dam
removal as a river restoration method. The
Pennsylvania Fish and Boat Commission over-
saw the actual dam removal.
Additional partners included Greater Pottstown
Watershed Alliance; Borough of Pottstown
(Parks and Recreation); U.S. Fish and
Wildlife Service; PA DEP; U.S. Environmental
Protection Agency's Nonpoint Source Program;
Montgomery County Conservation District;
Pennsylvania Fish and Boat Commission; and
Berks County Conservancy.
Sensitivity rating
Sensitive
Facultative
Tolerant
Number of macroinvertebrate taxa
Station 1
5
9
0
Station 2
7
10
0
Station 3
7
10
0
Station 4
7
13
1
Station 5
7
9
1
Reference
Station 1
7
9
2
Reference
Station 2
5
12
2
Macroinvertebrate data for Manatawny Creek in 2002 after stream restoration and dam removal. The table
shows the number of pollution-sensitive, facultative, and pollution-tolerant taxa for five sampling stations
and two reference sites. Taxa distribution in sampling stations compared favorably with that of reference
sites. This finding, in part, led to the delisting of Manatawny Creek and an unnamed tributary.
I
55
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-06-003N
December 2006
For additional information contact:
Russell Wagner
Department of Environmental Protection,
Nonpoint Source Program
717-772-5642 • ruwagner@state.pa.us
Dave Williams
Delaware Riverkeeper Network
215-369-1188 • dave@delawareriverkeeper.org
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