The Log | School News
Nicholas School Project is Transforming Severely Degraded
Section of Durham's Sandy Creek into Wetlands
Workers are transforming a heavily
eroded, silt-clogged stretch of Durham’s Sandy Creek in Duke
Forest into an eight-acre restored wetland and flood plain
designed to help protect the Triangle’s drinking water supply
and control stormwater runoff.
The restoration, a project of the
Duke University Wetland Center, received the final permit
from the City of Durham in May and is expected to take until
the first of the year to complete. It is being funded by nearly
$1.5 million in grants and in-kind gifts.
“By restoring the natural flood
plain that used to be here before the onslaught of urban development,
we’ll recreate a healthy wetlands ecosystem that sops up pollutants
and improves wildlife habitat,” says Curtis
J. Richardson, director of the Wetland Center
and professor of resource ecology in the Nicholas School.
The project includes the re-contouring
and replanting of more than 2,000 feet of degraded stream,
and the construction of an earthen dam and four-acre stormwater
reservoir spanned by Duke Forest’s popular Al Buehler Trail
near the Washington Duke Inn and Golf Course.
The eight-acre site will serve as
an outdoor classroom and field laboratory for students and
researchers from the Nicholas School, Duke’s Pratt School
of Engineering and other area schools and universities.
Stormwater from about 1,400 acres
of Durham, including much of Duke’s campus, drains into Sandy
Creek, carrying heavy concentrations of sediment and urban
pollutants. Sandy Creek is a tributary of New Hope Creek,
which meets all state pollution standards when it enters northern
Durham County but often is in violation by the time it leaves
southern Durham County bound for Jordan Lake, part of the
Triangle’s drinking water reservoir.
A hike in June along Sandy Creek’s
path, as it flows under N.C. 751 east of its intersection
with Duke University Road, revealed a sediment-choked streambed
with crumbling banks, downed trees, and vegetation too sparse
to retain soil during heavy downpours. During big storms,
nitrogen and phosphorus levels in the water can reach three
to five times the state limits.
“It’s a mess. And we made it this
way by clearing more and more of Durham’s natural areas for
roads, parking lots and buildings,” says Richardson.
About a quarter of Durham is now
covered by impervious paving. Over the years, torrents of
storm water diverted by this paving have cut deeply into Sandy
Creek’s banks, eroding its natural bends and creating “a straight
chute for sediment and pollution,” Richardson says. “We’ve
lost the bends and contours that allowed the water to overflow
into surrounding bottomlands, where wetland plants and soils
could absorb the majority of the pollutants.”
Richardson’s team is addressing
that problem by engineering a new, more naturally meandering
streambed for Sandy Creek and filling in its old channel.
Creek banks and low-lying areas are being re-contoured and
planted as riparian and bottomland hardwood wetlands, which
researchers believe will remove up to 70 percent of the creek’s
sediment and nutrients.
The new dam and reservoir will
regulate the flow of stormwater and replace an old dam, now
in an advanced state of disrepair, farther downstream. A short
stretch of the Art Buehler Trail will be re-routed across
the dam to provide unobstructed views of the reservoir, wetland
and wildlife.
“Our goal is to recreate an ecosystem
similar to what you would have found here 75 to 100 years
ago,” Richardson explains.
Project sponsors include the Clean
Water Management Trust Fund, the North Carolina Wetland Restoration
Program, Duke Forest, the Duke University Facilities Management
Department and the Duke University Wetland Center. Check out
videos and a news release about the project at www.nicholas.duke.edu/restoration
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