Water: Nonpoint Source Success Stories
Tribal Section 319 Projects: North Carolina
Streambank Restoration at Bradley & Standingdeer Campgrounds:
An Innovative Solution Solves a Common Problem
Tribal Environmental Office
P.O. Box 455
Cherokee, NC 28719
The Cherokee Indian Reservation in the southern Appalachian Mountains of western North Carolina comprises some 56,000 acres. The topography of much of the reservation land consists of very steep slopes and narrow valleys. In this area, soils are thin and generally highly erodible. Siltation is the primary cause of impairment of tribal waters. Major sources of siltation have resulted from past logging practices, gravel mining, road construction, housing construction, landfill, and other development activities. The rock/gravel mined area of Soco Creek has been designated a priority area for streambank restoration and reduction of nonpoint source pollution.
Sites on Soco Creek and the Oconaluftee River have undergone streambank restoration by stabilization techniques. Two sites where streambank restorations have been completed are Bradley Campground and Standingdeer Campground. At these sites, erosion from overland flow had resulted from land disturbance due to the high level of foot traffic by campers. A large part of the problem was campers creating footpaths and removing riparian vegetation on streambanks, leaving the banks vulnerable to erosion during storm events.
The objective of the project was to reduce erosion from overland flow and from streambank failure as the streams undercut their banks at both Bradley and Standingdeer Campgrounds. Components of the project were designed to restrict campers' access down erodible streambanks and redirect their access down nonerodible steps.
An innovative solution
To reduce erosion, native riparian trees and shrubs were planted, along with grass seeding, and coconut erosion control fabric was installed to hold the soil in place until the vegetation was established. In addition to the benefits of holding soil in place, the vegetation will eventually grow into a barrier that restricts campers' movement down the streambanks. Using a method developed by Dave Rosgen of Wildland Hydrology (Pagosa Springs, Colorado), access to the stream was provided by making a modification to rock vanes. Without compromising the hydraulic design of the rock vanes, they were extended approximately 3 feet above their normal design elevation to the top of the streambank, which is the level of the rest of the campground. The purpose of extending the vanes was to make solid rock (boulder) stair steps that serve as access points for campers to enter the stream corridor.
In this project, revegetation and rock vane construction were successfully employed for streambank restoration. Revegetation solved the erosion problem from overland storm flow, while construction of rock vanes addressed undercutting of the streambanks. The constructed vanes slow floodwater velocities near the banks and deflect high-velocity water toward the channel center to replicate conditions in healthy natural channels.