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Section 319
NONPOINI SOURCE PROGRAM SUCCESS STORY
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Community-based Erosion Control Efforts Stop Water Quality Decline
yyg	gphodv ImDroved 'n t'ie anc'	Highland Lake showed troubling
signs of declining water quality that threatened the loss of
the lake's brown trout fishery. Excessive soil erosion throughout the watershed contributed
to significant declines in water clarity and dissolved oxygen levels, prompting the Maine
Department of Environmental Protection (DEP) to add Highland Lake to Maine's 1990 Clean
Water Act (CWA) section 303(d) list of impaired waters for aquatic life support. Locally led
restoration work over the past 13 years has addressed significant erosion sites and reduced
polluted runoff. Highland Lake water clarity has gradually stabilized and now meets water
quality standards, prompting the Maine DEP to remove the lake from the CWA section
303(d) impaired waters list in 2010.
Problem
Highland Lake, a 623-acre lake in the towns of
Windham and Falmouth and near Portland, Maine,
attracts homeowners, boaters and anglers with Its
eight miles of scenic shoreland and warm and cold-
water fisheries. The lake has a watershed area of
8.4 square miles and a mean depth of 25 feet. There
are about 900 homes in the watershed, including
about 300 homes along its developed shoreline.
The lake's hand-carry public boat launch makes it an
accessible and popular destination for visitors.
Beginning in the 1980s, erosion became more
prevalent in the Highland Lake watershed due to
changes in land use, especially the conversion of
forest to developed land. These changes increased
polluted runoff and caused a gradual decline in
water quality. Stormwater runoff eroded soil from
both the newly developed and existing devel-
oped lands, and moved sediment with attached
phosphorus into the streams flowing to the lake.
Excess phosphorus "fertilized" the lake, causing
an increase in trophic state (biological productivity)
followed by reduced water clarity and dissolved
oxygen.
Maine's water quality standards require that lakes
have a stable or decreasing trophic state, subject
only to natural fluctuations. In Maine, a lake's
trophic state is based on measures of chlorophyll a,
Secchi disk transparency (clarity), concentra-
tion of dissolved oxygen and total phosphorus
concentration.
Figure 1.
Homeowners
and volunteers
planted over
1000 shrubs, trees
and groundcovers
to reduce polluted
runoff
Average annual Secchi disk transparency readings (mea-
sures of water clarity) in Highland Lake during the 1990s
were about one meter less than during the 1980s due to
increased algae and sediment. Dissolved oxygen levels
deep in the lake declined, threatening the lake's brown
trout fishery. In 1990 Maine DEP designated Highland
Lake as impaired for aquatic life support on Maine's CWA
section 303(d) list.
The total maximum daily load (TMDL) assessment
developed for Highland Lake in 2003 identified suburban
residential properties as the largest source (60 percent)
of phosphorus. Highly developed shoreland areas with
numerous homes and networks of gravei-surface roads
increased stormwater runoff and erosion. Private roads
accounted for nearly haif of the water quality impact sites
(42 percent). The TMDL estimated that the annual exter-
nal loading of phosphorus needed to be reduced by about
24 percent to attain state water quality standards.

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Project Highlights
In 1997, outreach to landowners began with a
watershed survey that documented 104 erosion
sites including private camp roads, town roads
and residential properties. The Highland Lake
Watershed Management Plan (1999) described
actions needed to restore the lake. From 1999 to
2010, best management practices (BMPs) were
installed at numerous erosion sites. Cost share
agreements with public and private landowners
resulted in BMPs being installed at priority nonpoint
source sites on 42 private and public roads to stop
excessive erosion and sediment from thousands of
feet of gravel surface roads. A residential match-
ing grant program prompted 51 landowners to
install erosion control practices including plantings,
waterbars, infiltration steps, rain gardens and riprap
(see Figure 1).
Technical staff provided assistance to landown-
ers during more than 300 site visits. The Highland
Lake Youth Conservation Corps (YCC) installed
BMPs on 176 sites in the watershed and generated
remarkable community interest in reducing polluted
runoff to the lake. Landowners learned how to care
for their lake through extensive outreach efforts,
including: camp road, septic system and raingarden
workshops; Highland Lake Association newsletters
and Web site; Cruise the Buffers boat rides, which
toured examples of good and poor lake shore buf-
fers; a Guide to Living Responsibly in the Highland
Lake Watershed; watershed boundary signs; annual
State of the Lake meetings; and a watershed forum
for the community to plan for the lake's future.
Results
After 13 years of restoration projects, including
installing erosion control practices, the amount of
sediment and phosphorus exported to Highland
Lake has declined significantly. Through 2009,
pollutant loading was reduced by an estimated
278 tons of sediment and 1,070 pounds of phospho-
rus per year. After declining significantly from 1980
to 1998, water clarity stabilized (Figure 2) as water-
shed partners implemented erosion control efforts.
The water quality data trend from 1998 through
2009 indicates a persistent stabilization of trophic
state, and now Highland Lake meets Maine's water
quality standards. As a result, Maine DEP removed
Highland Lake from its 2010 CWA section 303(d) list
of impaired waters.
Highland Mean Secchi DiskTransparencies 1974-2009
8.0 n
Q
2.0	
1.0	
0.0 J	,	,	,	,	,	,	,	
1970 1975 1980 1985 1990 1995 2000 2005 2010
Year
I Linear (Trendline (1974-1997)) Linear (Trendline (1998-2009)) I
Figure 2. Highland Lake Mean Secchi DiskTransparencies
from 1974 to 2009. Annual mean depth readings from 1974
to 1998 indicate a trend (red line) toward reduced water
clarity. Secchi readings from 1998 to 2009 indicate a trend
(green line) toward stable water clarity.
Partners and Funding
Cumberland County Soil and Water Conservation
District (CCSWCD) and the Highland Lake
Association (HLA) collaborated to raise awareness
about the impacts of polluted runoff and to help
the community implement erosion and sediment
control practices. CCSWCD prepared a water-
shed management plan and provided extensive
technical assistance, outreach services, grants
administration and projects management. HLA
advocated for the lake, persuading landowners
and neighborhoods to do erosion control work and
supporting development and funding of the YCC.
The towns of Falmouth and Windham provided
substantial YCC operational funds. Other key
partners included Maine DEP, Maine Department of
Transportation, Casco Bay Estuary Partnership and
the U.S. Environmental Protection Agency (EPA).
From 1999 to 2010, partners used approximately
$970,000 to install erosion control practices at
polluted runoff sites in the watershed. An EPA CWA
section 604(b) grant ($10,500) funded the water-
shed survey. In 1999 Maine DEP provided $206,975
in state bond funds for a priority watershed project
that fueled the start-up of work in the watershed.
From 2004 to 2010, EPA provided $339,865 in
CWA section 319 grant funds for two watershed
implementation projects (Phases 2 and 3). The
three grants attracted local matching contributions
exceeding $380,000 from landowners, the towns
of Windham and Falmouth and the HLA. Lake
Stormwater Compensation Funds through Maine
DEP also provided $36,033.
U.S. Environmental Protection Agency
/>>"	"¦£ Office of Water
<	2 Washington, DC
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1	EPA 841-F-10-001BB
PRO"*^	September 2010
For additional information contact:
Donald Kale
Maine Department of Environmental Protection
207-822-6300 • donald.kale@maine.gov
Betty Williams
Cumberland County Soil and Water Conservation
District
207-892-4700 • betty-williams@cumberlandswcd.org

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