How can we undo a century of environmental abuse? I found one answer last week on a tour of Riverlink’s completed restoration project at the Swannanoa River at Azalea Park.
Where 10- to 20-foot walls of bare, eroding dirt once stood, gentle banks with wildlife habitat now beckon visitors to the riverside.
Like many rivers, the Swannanoa River in east Asheville has been channelized and manipulated, increasing erosion and changing the flow of the river. Abnormally high levels of sedimentation, or tiny particles of dirt, once came from old farming practices and now come from certain kinds of construction. Development also increases the speed of the water current when vegetation is removed, because plants and trees normally help soak up stormwater runoff.
The altered water flows ate away at the banks, turning them into steep cliffs. This in turn created more sedimentation, which harms water quality and wildlife.
Standing on a restored riverbank, Darrell Westmoreland of North State Environment recalled the deteriorated condition he first saw at the site.
“You could literally stand there and watch dirt fall off,” Westmoreland said.
(above) This is what the steep, eroded banks looked like before restoration.
The restoration started with an evaluation of the site and an engineering plan by Wolf Creek Engineering. Next, Westmoreland’s crew brought in some giant boulders, the root stocks of old trees, and some heavy duty earth-moving equipment.
They recontoured the banks, using the dirt they removed in some sections to shore up a fragile bank holding in some wetlands. The rocks and root stocks were carefully placed to protect the new banks and optimize the water flow. More than 6,000 plantings, from nursery plants to pruned “stakes” to carpets of grass and wildflower seeds, will grow in this spring.
Before, the banks were inaccessible and unsafe.
“A kid could come over chasing a soccer ball, not realizing there’s a 20-foot cliff,” Westmoreland said.
Now, park visitors can easily walk over from the soccer fields and sit on the rocks. Although they are not the complete solution, the open banks will also allow floodwater to spread out, helping to lessen the impact of floods downstream in the Biltmore Village.
The newly vegetated banks and stream control features also create better wildlife habitat. Still eddies give fish a place to hang out without using too much energy, and the root stocks give them a place to hide and look for bugs. That’s good news for anglers in this hatchery-supported river.
“If you’re going to fish, you want to throw it right out in front of that log,” Westmoreland said.
(above) Darrell Westmoreland of North Carolina Environmental and Hartwell Carson of Riverlink stand on a gentle slope that was once a steep, eroded bank. Below them, a root stock and tree trunk optimize stream flow and create habitat for fish and aquatic insects.
