1. Duke Campus
Duke’s campus surface has become more impervious as West Campus continues to be developed
One of the five core facilities operations is dedicated to stormwater management
There are many sites on campus that help Duke manage its stormwater runoff
Duke Reclamation Pond
Duke S.W.A.M.P.
Medical Center Rain Garden

2. Stormwater Management at Duke (Video)

3. Solutions: Duke Stream and Wetland Assessment Management Park (SWAMP)
Runoff from rain events on Duke University’s West Campus and parts of City of Durham was entering Jordan Lake (via a series of local streams) full of sediment, petrochemical residue, Phosphorus, Nitrogen and coliform bacteria
Jordan Lake is the major water source for the Triangle
The EPA had expressed concerns about the degraded water quality come from the tributary watersheds that feed Jordan Lake reservoir
SWAMP was built on a restored section of the Sandy Creek stream and floodplain in the Duke Forest to increase the water quality of the runoff before it left Duke’s campus headed to Jordan Lake
Rainoff from Duke campus’ impervious surfaces and athletic fields (fertilizers) are particularly full of pollutants
Learn more about Duke SWAMP
Learn more about Duke SWAMP
Source
Image Source:

4. Solutions: Duke SWAMP SWAMP annually removes: 500 tons of sediment,
64% of nitrates pollutants
28% of phosphorus pollutants
Constructed in phases
Stream and Riparian Wetland Restoration
Lake and Dam Construction
Constructed Wetland
Best Management Practices site
Google map image:
Ask Students to point out where impervious surfaces are (parking lot, buildings, atheltic fields, roads, compact grass (golf course)

5. Duke SWAMP - Stream and Riparian Wetland Restoration
The stream experienced significant erosion as a result of being in a watershed with a high percentage of impervious surfaces (20.6%)
incised and straightened stream profile associated with rapid deliveries of drainage following storm events in impervious areas
the stream was incised as much as 2.5 meters below bankfull in some places
the creek and the adjacent floodplain were seperated from channel incising
Channel before restoration

6. Duke SWAMP - Stream and Riparian Wetland Restoration
Physical changes
the new stream channel has meanders, bends and turns that slow down water flow and help to reduce erosion ƒ
Channel depth was decreased to reestablish the stream’s connection with its floodplain.promoted overbank flooding during storm events, thereby re-establishing the hydrologic link between the stream and floodplain and fostering biogeochemical transformations of stormwater. ƒ
A rock cross vane was installed just upstream of the viewing platform to stabilize the new creek channel and control water levels.
Ecological Changes
Water Quality Improvements: When the water makes longer contact with the ground and plants, many harmful pollutants (such as chemicals, fertilizers, and bacteria) are removed.
Planting of Wetland Vegetation: The removal of some invasive species and the planting of new native species that are well adapted to wet adapted to wetland conditions improves habitat and provides food and shelter for wetland animals.
Habitat Variety in Streams: Pools (deep and slow parts) and riffles (fast and shallow parts) provide more areas for water invertebrates, fish, amphibians, and reptiles to live.

7. Duke SWAMP - Stream and Riparian Wetland Restoration
Rock cross vane
Before and after pictures of the restored chanel
Rock cross vane

8. Duke SWAMP - Lake and Dam Construction
Trees were cleared and the land was sculpted to make room for the pond
A dam was built and installed with a weir
Weir - “is a barrier across the horizontal width of a river that alters the flow characteristics of water and usually results in a change in the height of the river”
SWAMP now can control water volume and depth in the pond and upstream wetland
Slower Water Flow: Water moves more slowly through the entire stream system as it backs up behind the dam, reducing the potential for stream bank erosion.
Improved Water Quality: The slower water flow provides more time for sediment and pollutants to settle out before flowing downstream to Jordan Lake
New habitat for wetland plants and animals

9. Duke SWAMP - Lake and Dam Construction
Snapping turtles, northern water snakes and northern red salamander are some all animals that can be found around the lake

10. Duke SWAMP - Constructed Wetland
Local municipal sewer lines can and do overflow during storm events
fecal coliforms escape sewage system and enter the Upper Sandy Creek and, subsequently, Jordan Lake
The recontoured channel here consists of 3 terraced stream sections connected by rock steps which is designed to
slow the stream's flow
aerate the water with oxygen
increase the quantity and frequency of stream bank overflow.
Overbank flooding during storm events is a natural process in riparian (steam-related) systems since it
further reduces the velocity of stormwater flow
encourages sediment deposition in flood blanks
The surrounding floodplain wetlands are also terraced for increased water retention time to reduce high nitrogen and phosphorus concentrations (common in campus runoff)
Nitrogen and phosphorus deposited in sediments are processed by bacteria in the soil
Or are taken up by herbaceous wetland vegetation

11. Duke SWAMP - Constructed Wetland
The location of the constructed wetland (3) is shown in relation to the dam impoundment (1) and the Sandy Creek stream and riparian wetland (2).

12. Duke SWAMP - Best Management Practices Site
BMP (Best Management Practices) site is a 0.4-acre extended detention stormwater wetland
The retention areaP is across Duke University Road from the President's House on Duke West Campus .
The stormwater BMP's catchment area is about two-thirds impervious with buildings and parking lots.
By retaining stormwater runoff for an extended period rather than letting the water flow quickly down the eroded stream channel through the watershed, the BMP promotes the retention and settling of pollutants and sediment before the water travels downstream to Jordan Lake.

13. Duke SWAMP - Best Management Practices Site

14. Solutions: Duke Reclamation Pond
The Pond functions as a 5.5 acre retention basin for campus runoff
256 acres of West Campus runoff drains into the Pond
50% of Duke’s West Campus is impervious
The pond is designed to be large enough to accommodate rainfall runoff surges
capable of holding 15.8 million gallons of water (9.1 million gallons of base water and 6.7 million gallons of surge stormwater storage.)
The pond’s aquatic plants were specifically picked to help filter pollutants in the water
Add link to SD website of this page

15. Solutions: Duke Reclamation Pond - Chiller Plant 2
Stormwater from the Pond is pumped out by the neighboring Chiller Plant #2 to be used as water in Duke’s Central Chilled Water System
This saves 100 million gallons of water annually
The 100 million gallons that are no longer purchased from The City of Durham save Duke $400,000 annually
The Pond will pay for itself by 2040

16. Solutions: Duke Reclamation Pond

17. Solutions: Duke Medical Center
Duke Medicine Circle cisterns
2 cisterns are under the open-green space meadow
Cisterns are capable of holding 100,000 gallons of runoff
Decreases storm related runoff sturge by holding water
The stored water is used for irrigation throughout the Medical Center
Any irrigation on system that uses reclaimed water will be purple!
Trent Semans Center bioretention area
Called Medical Rain Garden in earlier video from the slides
Site helps remove sediments and nutrients to decrease the amount of sediment and nutrients that will need to be removed by the Duke Pond
Water tumbles over pebbles
Helps slow the water down and increases turbidity so material will be dropped
Plants between cement ledges
Filter the deposited nutrients

18. Duke Medical Center
The Medical Center cisterns are below the oval shaped green field and the Trent bioretention area is in the not blurred circle
East Campus Williams Field also has a retention cistern underneath
Bioretention area close up