DUWC’S Stream and Wetland Assessment Management Park (SWAMP)

PROJECT RATIONALE

Upper Sandy Creek is a state-designated Natural Heritage Program Priority Area (NCDENR, 2001) and a headwater for the Cape Fear River watershed in the North Carolina Piedmont.

Headwater wetlands are important for improving water quality and quantity in the watershed and for reducing storm runoff. Unfortunately, most of the headwater wetlands in North Carolina’s Piedmont are presently in a disturbed state.

EPA has expressed a distinct concern about degraded water quality in the tributary watersheds that feed Jordan Lake reservoir. Stormwater from about 1,400 acres of Durham, NC, 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 region's drinking water reservoir.

New Hope Creek's poor water quality has hisrtorically been due to high nutrient concentrations (N and P), sediment load, and coliform bacteria between the confluence with Sandy Creek and its terminus in Jordan Lake, suggesting that Sandy Creek has been a significant source of impaired waters (NC DENR, 2003).

The Upper Sandy Creek floodplain (Figure 1) was impaired due to:

•Nutrient-rich stormwater runoff inputs from Duke University West Campus and adjacent suburban and urban development,

•Rapid rates of erosion within the creek system due to an incised and straightened stream profile (Figure 2) associated with high percentages of impervious surface (20.6%) in the 497 hectare watershed and rapid deliveries of drainage following storm events,

•A disconnected hydrology between the creek and the adjacent floodplain due to channel incising, and

•Elevated fecal coliforms (Figure 3) from adjoining municipal sewer lines  (See Figure 1 ) that can and do overflow during storm events.

The original three-phase restoration of the Upper Sandy Creek floodplain (Figure 4) was developed in conjunction with the Duke University Wetland Center, Duke Forest and the Dept. of Civil and Environmental Engineering. Planning began in 1998, with construction of Phase 1 beginning in late 2003.

NEXT: The Three-Phase Project

Intro

Rationale

Stream & Floodplain

Dam & Impoundment

Stormwater Treatment

Phase 4

Education

Research

REFERENCES

NCDENR/DWQ/WQS-PB. 2003. North Carolina Water Quality Assessment and Impaired Waters List (2002 Integrated 305(b) and 303(d) Report). Document Control No. 021RMT04Ff, 184 pp.

NCDENR/DWQ/WRP. 2001. Watershed Restoration Plan for the Cape Fear River Basin. 129 pp.