School’s stormwater system will be state-of-the-art
A new elementary school under construction in Haywood County will serve as an environmental model for developers in the region.
Like a Wal-Mart, Lowe’s or any big-box development, the new Bethel Elementary School will impose a large footprint of buildings and parking lots on the land that don’t let rain water soak into the ground. But unlike most commercial developments, the elementary school won’t straight-pipe its runoff from parking lots and roofs into the closest stream.
Instead of the traditional curbs and gutters, a series of artificial wetlands and water retention areas will slow, catch and cleanse the water before it hits the creeks. Haywood Waterways Association recevied a $462,000 grant from the N.C. Clean Water Management Trust Fund to make the new Bethel Elementary School environmentally friendly.
“It will not only be trend setting in Haywood County, but it would be a site where developers can go out and see this kind of project on the ground,” said Ron Moser with Haywood Waterways Association. “It’s an ideal project to further the cause and show people on the ground what can be done.”
The old-fashioned system of straight-piping runoff from parking lots and roofs through gutters and into streams does not reduce pollution, Moser said. Gutters are magnets for everything from fast-food bags to soda bottles, which then end up in the stream. Plus the water that runs off parking lots is laden with oil, anti-freeze, transmission fluid, grease and other automotive fluids. In the summer, the runoff is hot after flowing across black asphalt — or across a hot roof — and heats up the streams, sometimes killing trout. The water running into gutters is also full of grit and fine gravel that lands in the stream and contributes to sedimentation.
By comparison, the water running off Bethel Elementary School’s parking lot and roof will seep into bioretention areas and flow along bioswails into wetlands. A bioswail is nature’s version of a gutter: a grassy trench similar to an inverted speed bump that allows water to be absorbed into the ground.
But ditching the old-fashioned curb and gutter system has been slow to catch on, Moser said.
“I think it will be exciting for the county to step forward and do a state-of-the-art environmental system that reduces the impact associated with new development,” Moser said. “If we expect commercial developers to do this sort of thing, I think as a local government and community, we ought to be willing to do it ourselves.”
During a storm, straight-piping runoff has an effect similar to that of a high-power fire hose hitting the stream bank.
“These small tributaries are faced with having to carry abnormal volumes of water and it is very destructive,” Moser said. “You get this huge flush of water and it just blows the banks out. That leads to sedimentation of the Pigeon River.”
Two small creeks on the school grounds — both trout waters — flow into the Pigeon River about a quarter-mile downstream.
“Pigeon River is where the folks in Canton get their drinking water,” Moser said.
The idea for the project at the new elementary school was developed by Moser and Bill Yarborough, a soil specialist with the N.C. Department of Agriculture who lives in the area. Moser took the idea to the school board and got what he called a “wonderful reception.”
“They were very eager to participate,” Moser said. “They wanted us to pursue the project.”
The Resource Conservation and Development Council was a partner in applying for the grant, as was Haywood Soil and Water Conservation District. The system was designed by Equinox Biological, an environmental engineering consulting firm in Asheville. The site plan for the entire school was designed by Bradshaw Engi-neering of Waynes-ville.
Haywood Water-ways will take samples of the water running off the parking lots and take samples of water flowing out of the natural areas into the stream.
“It will tell us the quality going into the wetland or bioretention area and the quality of the water coming out,” Moser said.
The monitoring will require some late-night shifts. They’ll collect runoff going into the natural system every hour for six hours following a dozen storms, and samples coming out of the natural system every six hours for 36 hours following the storm. (It takes longer for runoff to drain out than run in.)
Haywood Waterways will put up a kiosk at the site that tells about the environmentally-friendly design and create a traveling presentation.
“We want to show people what’s happening,” Moser said of the education component. “We want to show a cross section of a bioswail and wetland and say here’s what it does and how it does it.”