Purpose: The waters of the Cape Fear River basin originate in Guilford County. All water users downstream of Guilford County are directly affected by stormwater that drains from the Greensboro metropolitan area. To improve the quality of waters in the South Buffalo Creek, a headwater stream in the Cape Fear Basin, the City put into place a three-tiered approach to Stormwater Control Measures (SCMs) at: (1) the source of stormwater runoff, (2) an appropriate intermediate location on the urban stream, and (3) a location near the outskirts of the urban area as the stream leaves the city. This project is complete.
This project provided the opportunity to evaluate and implement stormwater management practices and techniques unique to North Carolina’s Piedmont region. These practices and techniques have been proven successful in other areas of the United States.
The South Buffalo Creek has been rated as impaired by North Carolina Department of Environment and Natural Resources (NC DENR). All project elements were designed to complement the objectives of the Cape Fear River Basin wide Water Quality Management Plan, published by NC DENR. Drinking water supply facilities, including Jordan Lake, are affected by the quality of water in the South Buffalo Creek, a major headwater stream in the Cape Fear Watershed.
Geographical Location of Project
Location: The project is located in the headwaters of Cape Fear River Basin, in the south-central part of the city. It is on the South Buffalo Creek and its flood plain, bounded by Interstate 40 to the north, Earl Drive and Creek Ridge Road to the south, Freeman Mill Road and Rehobeth Church Road to the west. The site is one of the few undeveloped open spaces available along the highly urbanized South Buffalo Creek suitable for the development of a regional BMP that can enhance the quality of water in the stream draining the upper half the South Buffalo Creek watershed within Greensboro.
Description: The project is an in-stream pollution control facility in the Cape Fear River Watershed, designed to control the pollution in the South Buffalo Creek at a point that drains about 13 square miles in the south Greensboro area. The location of the project is about midway between the origin of the South Buffalo Creek and the point where the stream crosses the corporate boundary. At this location, the creek receives drainage from 13 square miles of urban area.
The project acquired approximately 36 acres of land, including the stream channel and the adjacent floodplain of the South Buffalo Creek, and developed an in-stream wetland pollution control facility. The pollution control facility was created by developing a riparian wetland in the bottomlands of the stream and vegetated riparian buffers along the banks of the creek.
The wetland was created by raising the stream water level (and the local ground water table), through the construction of a water level control gate structure in the creek at a location upstream of I-40 within the project site. The project created an estimated 20 acres of riparian wetlands. The wetlands, in addition to contributing to the scarce wetland resources in the Piedmont region of the state, improved the quality of the urban water runoff draining from the southwest Greensboro metropolitan area and, through it, the waters of the Cape Fear watershed. The gate structure allows the water to be partially oxygenated at the wetland location through entrainment of air as the water falls over the gate.
Wetland vegetation was selected and planted in the proposed wetland areas to supplement the reoxygenation and natural growth. The development of the wetland was monitored for seven years to ensure success.
The project included the preservation and creation of riparian buffers along both banks of the stream in the project area. The buffers included the existing wooded banks, along with the underbrush and grasses, that significantly filter pollutants from the non-point source sheet flow running off the urban land (including major roads) adjacent to the stream, as well as urban runoff carried by the stream during flood conditions.
Why did the City need this project?
- To improve South Buffalo Creek, which is listed by the state and EPA as an "impaired stream"
- To improve water quality by treating the "first flush" of rainfall runoff
- To reduce sediment, metals, and other pollutants found in urban stormwater runoff
How did the project affect me?
- No increase in flood hazards due to the project
- Enhanced habitat for fish and wildlife
- Restoration of natural stream and floodplain
- Creation of ground water wetland on the floodplain
- Grant funding from the state for 67 percent of project costs
- Improved local water quality