Perspectives Online

Watershed Improvements

College educators use research-based knowledge to help clean up Wilmington’s Burnt Mill Creek.by Art Latham


Jason Wright (center, red shirt), Extension associate in storm-water management, and Bill Hunt (right), Extension urban storm-water specialist, meet with state water-quality officials near the headwaters of the Burnt Mill Creek.
All photos by Art Latham

Burnt Mill Creek rises from a series of scattered springs and seeps near the center of the sprawling urban area that is Wilmington.

The creek flows past neat neighborhoods with manicured lawns and parks festooned spring and summer with blooming coastal vegetation, but it also runs by the busy thoroughfares and parking lots that dot this seemingly idyllic, tourist-haunted setting.

A poster at the Wilmington Family YMCA describes the storm-water BMPs in place there.
For every foot it flows towards Smith Creek -- which runs to the Cape Fear River northwest of Wilmington’s historic waterfront -- it picks up more man- and animal-generated poisons. So many poisons, in fact, that the N.C. Department of Water Quality (DWQ), a branch of the state’s Division of Environment and Natural Resources, lists the creek as “impaired” for aquatic life, wading and recreational fishing.

The DWQ and the U.S. Environmental Protection Agency are concerned about toxins in Burnt Mill Creek from urban stormwater runoff: fecal coliform from animal wastes, mercury, phosphorus, nitrogen, copper, dioxins, turbidity, suspended solids, dissolved oxygen and aquatic weeds.

And they’re especially concerned about toxic polycyclic aromatic hydrocarbons (PAH), which can cause tumors in fish. PAH are organic compounds from coal and petroleum products such as automobile oil and exhaust particles, as well as from tire wear and asphalt roads’ leaching, says the EPA.

In 2004, DWQ identified toxic impacts from PAHs as the primary cause of biological impairment in the Burnt Mill Creek watershed, listing sedimentation and nutrient enrichment as secondary and cumulative causes.

None of this paints a rosy scenario for a growing, visitor-oriented coastal town near miles of ocean beach and river waterfront, a thriving community college and state university and a sporadic film-industry presence.

Wright (standing on wall), Hunt (front left) and Bill Lord (back to camera), Extension specialized agent in water resources, conduct a class at a rain garden installed at the Wilmington Family YMCA.
Enter some concerned citizens originally known as the New Hanover Local Watershed group, who projected watershed improvements in 2001 through the N.C. Ecosystem Enhancement Program’s (NCEEP) first local watershed planning effort. Christy Perrin, North Carolina Cooperative Extension’s Watershed Education for Communities and Officials (WECO) program director, has coordinated the group’s efforts since 2001.

Perrin and other Cooperative Extension educators and researchers from N.C. State University’s College of Agriculture and Life Sciences facilitated the planning process, subsequently landing an EPA grant administered through DWQ to restore Burnt Mill Creek’s watershed through storm-water management. The watershed organization morphed into the Burnt Mill Creek Watershed Group to focus exclusively on restoring the creek.

The group also included private and commercial property owners and other local stakeholders, as well as Extension’s team Patrick Beggs, WECO project coordinator -- like Perrin, a member of the College’s Agricultural and Resource Economics Department -- as well as others from the College’s Biological and Agricultural Engineering Department (BAE). The City of Wilmington’s Stormwater Services Department also has actively supported the group’s efforts, especially with public education underway before the group’s original involvement and through other BMPs.

“The group collaboratively decided that realistic objectives were to demonstrate that specific practices improve water quality in small subcatchments, by installing best management practices and changing the public’s behavior through education and involvement,” says Perrin, co-principal investigator on the grant and subsequent supporting grants.

Best management practices (BMPs) is engineering jargon for research-proven structures that improve water quality: bioretention areas, water harvesting systems and several other applications that control stormwater runoff. But since the land the Burnt Mill Creek watershed drains is built out, the BMPs had to be retrofits, since they could not be installed during development, Perrin notes.

In Wilmington’s “The Bottom” neighborhood, named for its low elevation, numerous rain barrels and rain gardens have been installed at private residences, along with project rain gardens at Anderson Tabernacle and at Fannie Norwood Memorial Retirement Home. Here Christy Perrin (left), Extension director of WECO; Hollis Briggs, president of the Bottom Neighborhood Empowerment Association, and Extension’s Jason Wright present a rain garden installed in Briggs’ backyard.
The team used an array of community development techniques, including public education through watershed tours. At numerous meetings with groups and individuals, team members also presented project goals, discussed common interests obtainable by partnering on retrofit projects and asked potential partners for project site ideas. Project selection criteria included choosing areas that could treat larger watershed areas, potential water quality benefits and high visibility or opportunity to set a precedent for future similar projects.

“The greatest challenge involved with constructing retrofits in a highly urbanized area was coordinating with land owners,” Perrin says. “Finding BMP retrofits that treated large drainage areas was difficult and our strategy evolved as we realized that we needed to ‘get in the door’ with landowners on smaller, but effective projects.”

Working through the community paid off in many ways. For instance, when initial field visits confirmed that a location would meet the group’s criteria, local contacts introduced the team to landowners.

“One key to success in engaging landowners has been to offer to meet on their turf, on their time,” she says.

And as landowners stepped forward to volunteer for BMP retrofits, the project’s momentum built, augmented by media coverage and word-of-mouth. The team also posted educational signs at these project sites: Mary Bridgers Park; at the installed rain gardens at Port City Java and the Wilmington Family YMCA, which also includes pervious pavement; the installed storm-water wetlands at Stonesthrow Townehomes and at a commercial site on Kerr Avenue near the creek’s headwaters; and near rain gardens and cisterns at two partnering public schools: Gregory Elementary School of Science and Math (which also got a parking lot retrofit) and Williston Middle.

The schools are in “The Bottom” neighborhood, so named for its low elevation, which now also boasts numerous rain barrels and rain gardens at private residences, as well as project rain gardens at Anderson Tabernacle and at Fannie Norwood Memorial Retirement Home. (See Summer 2009 Perspectives www.cals.ncsu.edu/agcomm/magazine/summer09/n_burnt.html)

Several of the project sites are near the area where Burnt Mill Creek first rises, so the polluted water could be cleaned as early as possible in its eventual journey to the sea. “We tried to put the BMPs as close to the creek’s headwaters as we could,” says Jason Wright, BAE Extension associate in storm-water management, who did much of the project’s on-the-ground work.

The community involvement was time-consuming, but was well worth it, he says.

For instance, the group held two community workshops near a proposed stormwater wetland in Mary Bridgers Park, where some neighboring homeowners originally resisted initial proposals, Wright says. But as the project progressed, citizens provided constructive feedback, requesting design changes and a landscape architect’s involvement. The resulting design included a pedestrian-access bridge later constructed by the Wilmington Parks and Recreation Department that met with the neighbors’ approval.

Another example: The Wilmington Family YMCA is a non-profit association with both a CEO and a board of directors who had to approve the project before they could become cooperators, which took a substantial amount of time and coordination, Wright says.

Wright and Hunt stand visit wetlands installed at Stonesthrow Townehomes in Wilmington.
“The CEO and board were aware of the environmental impact sediment loss from their gravel parking lot was having on Burnt Mill Creek, but there was a lot of skepticism about why we would want to pave a gravel lot,” says Wright. “Once we explained pervious pavement, how a rain garden works and how we would preserve as much parking as possible, they accepted it. Now every time I see the CEO, he thanks me.

“Every program we’ve done here has been like that,” he says. “It gets easier every time to convince them.”

Despite its necessarily deliberate pace, the retrofitting project not only met but exceeded its goals, Perrin says.

“Each storm-water BMP installed has been well received by the land owners,” she says. “All agreed to maintain the BMPs on their property and have BMP management guidebooks published by Wilmington’s Stormwater Services. Simultaneously, the city and NCEEP cost-shared BMP installations to restore targeted stream channels to improve aquatic habitat, and New Hanover County Cooperative Extension helped with plantings.”

In addition, NCSU monitored water-quality impacts at three BMP sites, and Dr. Mike Mallin, research professor of biology and marine biology, Center for Marine Sciences, UNC-Wilmington, monitored water quality at six creek locations.

What’s next?

“Based on recent information about high PAH levels from coal-based parking lot seals, we are investigating more thoroughly to see if commercial parking lot management practices such as using coal-based ‘sealcoat’ is a potential contributor,” Perrin says. “To that end, we received a Clean Water Management Trust Fund grant to design more projects.”

And the team recognizes that there’s more work to do.

“The creek still has problems with high fecal bacteria, algal blooms, low dissolved oxygen and high PAHs and lead in the sediments,” UNC-W’s Mallin writes in the project’s final report.

“The algal bloom problem continues due the low dissolved oxygen problem. We need to decrease nutrients to reduce algal blooms and reduce bacterial loading downstream from McCrary Pond to Wallace Park. Also, the data suggest that capturing more runoff in future BMPs will continue to reduce nutrient inputs to the creek, which will lead to multiple benefits. And we need more demonstration sites and education workshops.

“Were similar projects implemented throughout the watershed,” he says, “we would observe a measurable effect on Burnt Mill Creek.”